#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# ******************************************************************************
#  $Id$
#
# Project:  Google Summer of Code 2007, 2008 (http://code.google.com/soc/)
# Support:  BRGM (http://www.brgm.fr)
# Purpose:  Convert a raster into TMS (Tile Map Service) tiles in a directory.
#           - generate Google Earth metadata (KML SuperOverlay)
#           - generate simple HTML viewer based on Google Maps and OpenLayers
#           - support of global tiles (Spherical Mercator) for compatibility
#               with interactive web maps a la Google Maps
# Author:   Klokan Petr Pridal, klokan at klokan dot cz
#
###############################################################################
# Copyright (c) 2008, Klokan Petr Pridal
# Copyright (c) 2010-2013, Even Rouault <even dot rouault at spatialys.com>
# Copyright (c) 2021, Idan Miara <idan@miara.com>
#
#  Permission is hereby granted, free of charge, to any person obtaining a
#  copy of this software and associated documentation files (the "Software"),
#  to deal in the Software without restriction, including without limitation
#  the rights to use, copy, modify, merge, publish, distribute, sublicense,
#  and/or sell copies of the Software, and to permit persons to whom the
#  Software is furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included
#  in all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
#  OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
#  THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
#  FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
#  DEALINGS IN THE SOFTWARE.
# ******************************************************************************

from __future__ import print_function, division

import contextlib
import glob
import json
import math
import optparse
import os
import shutil
import stat
import sys
import tempfile
import threading
from functools import partial
from typing import List, NoReturn, Tuple, Optional, Any
from uuid import uuid4
from xml.etree import ElementTree

from osgeo import gdal
from osgeo import osr

Options = Any

try:
    from PIL import Image
    import numpy
    import osgeo.gdal_array as gdalarray
    numpy_available = True
except ImportError:
    # 'antialias' resampling is not available
    numpy_available = False

__version__ = "$Id$"

resampling_list = (
    'average', 'near', 'bilinear', 'cubic', 'cubicspline', 'lanczos',
    'antialias', 'mode', 'max', 'min', 'med', 'q1', 'q3')
webviewer_list = ('all', 'google', 'openlayers', 'leaflet', 'mapml', 'none')


def makedirs(path):
    """ Wrapper for os.makedirs() that can work with /vsi files too """
    if path.startswith('/vsi'):
        if gdal.MkdirRecursive(path, 0o755) != 0:
            raise Exception(f'Cannot create {path}')
    else:
        os.makedirs(path, exist_ok=True)


def isfile(path):
    """ Wrapper for os.path.isfile() that can work with /vsi files too """
    if path.startswith('/vsi'):
        stat_res = gdal.VSIStatL(path)
        if stat is None:
            return False
        return stat.S_ISREG(stat_res.mode)
    else:
        return os.path.isfile(path)


class VSIFile:
    """ Expose a simplistic file-like API for a /vsi file """
    def __init__(self, filename, f):
        self.filename = filename
        self.f = f

    def write(self, content):
        if gdal.VSIFWriteL(content, 1, len(content), self.f) != len(content):
            raise Exception('Error while writing into %s' % self.filename)


@contextlib.contextmanager
def my_open(filename, mode):
    """ Wrapper for open() built-in method that can work with /vsi files too """
    if filename.startswith('/vsi'):
        f = gdal.VSIFOpenL(filename, mode)
        if f is None:
            raise Exception(f'Cannot open {filename} in {mode}')
        try:
            yield VSIFile(filename, f)
        finally:
            if gdal.VSIFCloseL(f) != 0:
                raise Exception(f'Cannot close {filename}')
    else:
        yield open(filename, mode)


class UnsupportedTileMatrixSet(Exception):
    pass

class TileMatrixSet(object):
    def __init__(self) -> None:
        self.identifier = None
        self.srs = None
        self.topleft_x = None
        self.topleft_y = None
        self.matrix_width = None        # at zoom 0
        self.matrix_height = None       # at zoom 0
        self.tile_size = None
        self.resolution = None          # at zoom 0
        self.level_count = None

    def GeorefCoordToTileCoord(self, x, y, z, overriden_tile_size):
        res = self.resolution * self.tile_size / overriden_tile_size / (2**z)
        tx = int((x - self.topleft_x) / (res * overriden_tile_size))
        # In default mode, we use a bottom-y origin
        ty = int((y - (self.topleft_y - self.matrix_height * self.tile_size * self.resolution)) / (res * overriden_tile_size))
        return tx, ty

    def ZoomForPixelSize(self, pixelSize, overriden_tile_size):
        "Maximal scaledown zoom of the pyramid closest to the pixelSize."

        for i in range(self.level_count):
            res = self.resolution * self.tile_size / overriden_tile_size / (2**i)
            if pixelSize > res:
                return max(0, i - 1)    # We don't want to scale up
        return self.level_count - 1

    def PixelsToMeters(self, px, py, zoom, overriden_tile_size):
        "Converts pixel coordinates in given zoom level of pyramid to EPSG:3857"

        res = self.resolution * self.tile_size / overriden_tile_size / (2**zoom)
        mx = px * res + self.topleft_x
        my = py * res + (self.topleft_y - self.matrix_height * self.tile_size * self.resolution)
        return mx, my

    def TileBounds(self, tx, ty, zoom, overriden_tile_size):
        "Returns bounds of the given tile in georef coordinates"

        minx, miny = self.PixelsToMeters(tx * overriden_tile_size, ty * overriden_tile_size, zoom, overriden_tile_size)
        maxx, maxy = self.PixelsToMeters((tx + 1) * overriden_tile_size, (ty + 1) * overriden_tile_size, zoom, overriden_tile_size)
        return (minx, miny, maxx, maxy)

    @staticmethod
    def parse(j: dict) -> 'TileMatrixSet':
        assert 'identifier' in j
        assert 'supportedCRS' in j
        assert 'tileMatrix' in j
        assert isinstance(j['tileMatrix'], list)
        srs = osr.SpatialReference()
        assert srs.SetFromUserInput(str(j['supportedCRS'])) == 0
        swapaxis = srs.EPSGTreatsAsLatLong() or srs.EPSGTreatsAsNorthingEasting()
        metersPerUnit = 1.0
        if srs.IsProjected():
            metersPerUnit = srs.GetLinearUnits()
        elif srs.IsGeographic():
            metersPerUnit = srs.GetSemiMajor() * math.pi / 180
        tms = TileMatrixSet()
        tms.srs = srs
        tms.identifier = str(j['identifier'])
        for i, tileMatrix in enumerate(j['tileMatrix']):
            assert 'topLeftCorner' in tileMatrix
            assert isinstance(tileMatrix['topLeftCorner'], list)
            topLeftCorner = tileMatrix['topLeftCorner']
            assert len(topLeftCorner) == 2
            assert 'scaleDenominator' in tileMatrix
            assert 'tileWidth' in tileMatrix
            assert 'tileHeight' in tileMatrix

            topleft_x = topLeftCorner[0]
            topleft_y = topLeftCorner[1]
            tileWidth = tileMatrix['tileWidth']
            tileHeight = tileMatrix['tileHeight']
            if tileWidth != tileHeight:
                raise UnsupportedTileMatrixSet('Only square tiles supported')
            # Convention in OGC TileMatrixSet definition. See gcore/tilematrixset.cpp
            resolution = tileMatrix['scaleDenominator'] * 0.28e-3 / metersPerUnit
            if swapaxis:
                topleft_x, topleft_y = topleft_y, topleft_x
            if i == 0:
                tms.topleft_x = topleft_x
                tms.topleft_y = topleft_y
                tms.resolution = resolution
                tms.tile_size = tileWidth

                assert 'matrixWidth' in tileMatrix
                assert 'matrixHeight' in tileMatrix
                tms.matrix_width = tileMatrix['matrixWidth']
                tms.matrix_height = tileMatrix['matrixHeight']
            else:
                if topleft_x != tms.topleft_x or topleft_y != tms.topleft_y:
                    raise UnsupportedTileMatrixSet('All levels should have same origin')
                if abs(tms.resolution / (1 << i) - resolution) > 1e-8 * resolution:
                    raise UnsupportedTileMatrixSet('Only resolutions varying as power-of-two supported')
                if tileWidth != tms.tile_size:
                    raise UnsupportedTileMatrixSet('All levels should have same tile size')
        tms.level_count = len(j['tileMatrix'])
        return tms

tmsMap = {}

profile_list = ['mercator', 'geodetic', 'raster']

# Read additional tile matrix sets from GDAL data directory
filename = gdal.FindFile('gdal', 'tms_MapML_APSTILE.json')
if filename:
    dirname = os.path.dirname(filename)
    for tmsfilename in glob.glob(os.path.join(dirname, "tms_*.json")):
        data = open(tmsfilename, 'rb').read()
        try:
            j = json.loads(data.decode('utf-8'))
        except:
            j = None
        if j is None:
            print('Cannot parse ' + tmsfilename)
            continue
        try:
            tms = TileMatrixSet.parse(j)
        except UnsupportedTileMatrixSet:
            continue
        except:
            print('Cannot parse ' + tmsfilename)
            continue
        tmsMap[tms.identifier] = tms
        profile_list.append(tms.identifier)

threadLocal = threading.local()

# =============================================================================
# =============================================================================
# =============================================================================

__doc__globalmaptiles = """
globalmaptiles.py

Global Map Tiles as defined in Tile Map Service (TMS) Profiles
==============================================================

Functions necessary for generation of global tiles used on the web.
It contains classes implementing coordinate conversions for:

  - GlobalMercator (based on EPSG:3857)
       for Google Maps, Yahoo Maps, Bing Maps compatible tiles
  - GlobalGeodetic (based on EPSG:4326)
       for OpenLayers Base Map and Google Earth compatible tiles

More info at:

http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification
http://wiki.osgeo.org/wiki/WMS_Tiling_Client_Recommendation
http://msdn.microsoft.com/en-us/library/bb259689.aspx
http://code.google.com/apis/maps/documentation/overlays.html#Google_Maps_Coordinates

Created by Klokan Petr Pridal on 2008-07-03.
Google Summer of Code 2008, project GDAL2Tiles for OSGEO.

In case you use this class in your product, translate it to another language
or find it useful for your project please let me know.
My email: klokan at klokan dot cz.
I would like to know where it was used.

Class is available under the open-source GDAL license (www.gdal.org).
"""

MAXZOOMLEVEL = 32


class GlobalMercator(object):
    r"""
    TMS Global Mercator Profile
    ---------------------------

    Functions necessary for generation of tiles in Spherical Mercator projection,
    EPSG:3857.

    Such tiles are compatible with Google Maps, Bing Maps, Yahoo Maps,
    UK Ordnance Survey OpenSpace API, ...
    and you can overlay them on top of base maps of those web mapping applications.

    Pixel and tile coordinates are in TMS notation (origin [0,0] in bottom-left).

    What coordinate conversions do we need for TMS Global Mercator tiles::

         LatLon      <->       Meters      <->     Pixels    <->       Tile

     WGS84 coordinates   Spherical Mercator  Pixels in pyramid  Tiles in pyramid
         lat/lon            XY in meters     XY pixels Z zoom      XYZ from TMS
        EPSG:4326           EPSG:387
         .----.              ---------               --                TMS
        /      \     <->     |       |     <->     /----/    <->      Google
        \      /             |       |           /--------/          QuadTree
         -----               ---------         /------------/
       KML, public         WebMapService         Web Clients      TileMapService

    What is the coordinate extent of Earth in EPSG:3857?

      [-20037508.342789244, -20037508.342789244, 20037508.342789244, 20037508.342789244]
      Constant 20037508.342789244 comes from the circumference of the Earth in meters,
      which is 40 thousand kilometers, the coordinate origin is in the middle of extent.
      In fact you can calculate the constant as: 2 * math.pi * 6378137 / 2.0
      $ echo 180 85 | gdaltransform -s_srs EPSG:4326 -t_srs EPSG:3857
      Polar areas with abs(latitude) bigger then 85.05112878 are clipped off.

    What are zoom level constants (pixels/meter) for pyramid with EPSG:3857?

      whole region is on top of pyramid (zoom=0) covered by 256x256 pixels tile,
      every lower zoom level resolution is always divided by two
      initialResolution = 20037508.342789244 * 2 / 256 = 156543.03392804062

    What is the difference between TMS and Google Maps/QuadTree tile name convention?

      The tile raster itself is the same (equal extent, projection, pixel size),
      there is just different identification of the same raster tile.
      Tiles in TMS are counted from [0,0] in the bottom-left corner, id is XYZ.
      Google placed the origin [0,0] to the top-left corner, reference is XYZ.
      Microsoft is referencing tiles by a QuadTree name, defined on the website:
      http://msdn2.microsoft.com/en-us/library/bb259689.aspx

    The lat/lon coordinates are using WGS84 datum, yes?

      Yes, all lat/lon we are mentioning should use WGS84 Geodetic Datum.
      Well, the web clients like Google Maps are projecting those coordinates by
      Spherical Mercator, so in fact lat/lon coordinates on sphere are treated as if
      the were on the WGS84 ellipsoid.

      From MSDN documentation:
      To simplify the calculations, we use the spherical form of projection, not
      the ellipsoidal form. Since the projection is used only for map display,
      and not for displaying numeric coordinates, we don't need the extra precision
      of an ellipsoidal projection. The spherical projection causes approximately
      0.33 percent scale distortion in the Y direction, which is not visually
      noticeable.

    How do I create a raster in EPSG:3857 and convert coordinates with PROJ.4?

      You can use standard GIS tools like gdalwarp, cs2cs or gdaltransform.
      All of the tools supports -t_srs 'epsg:3857'.

      For other GIS programs check the exact definition of the projection:
      More info at http://spatialreference.org/ref/user/google-projection/
      The same projection is designated as EPSG:3857. WKT definition is in the
      official EPSG database.

      Proj4 Text:
        +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0
        +k=1.0 +units=m +nadgrids=@null +no_defs

      Human readable WKT format of EPSG:3857:
         PROJCS["Google Maps Global Mercator",
             GEOGCS["WGS 84",
                 DATUM["WGS_1984",
                     SPHEROID["WGS 84",6378137,298.257223563,
                         AUTHORITY["EPSG","7030"]],
                     AUTHORITY["EPSG","6326"]],
                 PRIMEM["Greenwich",0],
                 UNIT["degree",0.0174532925199433],
                 AUTHORITY["EPSG","4326"]],
             PROJECTION["Mercator_1SP"],
             PARAMETER["central_meridian",0],
             PARAMETER["scale_factor",1],
             PARAMETER["false_easting",0],
             PARAMETER["false_northing",0],
             UNIT["metre",1,
                 AUTHORITY["EPSG","9001"]]]
    """

    def __init__(self, tile_size: int = 256) -> None:
        "Initialize the TMS Global Mercator pyramid"
        self.tile_size = tile_size
        self.initialResolution = 2 * math.pi * 6378137 / self.tile_size
        # 156543.03392804062 for tile_size 256 pixels
        self.originShift = 2 * math.pi * 6378137 / 2.0
        # 20037508.342789244

    def LatLonToMeters(self, lat, lon):
        "Converts given lat/lon in WGS84 Datum to XY in Spherical Mercator EPSG:3857"

        mx = lon * self.originShift / 180.0
        my = math.log(math.tan((90 + lat) * math.pi / 360.0)) / (math.pi / 180.0)

        my = my * self.originShift / 180.0
        return mx, my

    def MetersToLatLon(self, mx, my):
        "Converts XY point from Spherical Mercator EPSG:3857 to lat/lon in WGS84 Datum"

        lon = (mx / self.originShift) * 180.0
        lat = (my / self.originShift) * 180.0

        lat = 180 / math.pi * (2 * math.atan(math.exp(lat * math.pi / 180.0)) - math.pi / 2.0)
        return lat, lon

    def PixelsToMeters(self, px, py, zoom):
        "Converts pixel coordinates in given zoom level of pyramid to EPSG:3857"

        res = self.Resolution(zoom)
        mx = px * res - self.originShift
        my = py * res - self.originShift
        return mx, my

    def MetersToPixels(self, mx, my, zoom):
        "Converts EPSG:3857 to pyramid pixel coordinates in given zoom level"

        res = self.Resolution(zoom)
        px = (mx + self.originShift) / res
        py = (my + self.originShift) / res
        return px, py

    def PixelsToTile(self, px, py):
        "Returns a tile covering region in given pixel coordinates"

        tx = int(math.ceil(px / float(self.tile_size)) - 1)
        ty = int(math.ceil(py / float(self.tile_size)) - 1)
        return tx, ty

    def PixelsToRaster(self, px, py, zoom):
        "Move the origin of pixel coordinates to top-left corner"

        mapSize = self.tile_size << zoom
        return px, mapSize - py

    def MetersToTile(self, mx, my, zoom):
        "Returns tile for given mercator coordinates"

        px, py = self.MetersToPixels(mx, my, zoom)
        return self.PixelsToTile(px, py)

    def TileBounds(self, tx, ty, zoom):
        "Returns bounds of the given tile in EPSG:3857 coordinates"

        minx, miny = self.PixelsToMeters(tx * self.tile_size, ty * self.tile_size, zoom)
        maxx, maxy = self.PixelsToMeters((tx + 1) * self.tile_size, (ty + 1) * self.tile_size, zoom)
        return (minx, miny, maxx, maxy)

    def TileLatLonBounds(self, tx, ty, zoom):
        "Returns bounds of the given tile in latitude/longitude using WGS84 datum"

        bounds = self.TileBounds(tx, ty, zoom)
        minLat, minLon = self.MetersToLatLon(bounds[0], bounds[1])
        maxLat, maxLon = self.MetersToLatLon(bounds[2], bounds[3])

        return (minLat, minLon, maxLat, maxLon)

    def Resolution(self, zoom):
        "Resolution (meters/pixel) for given zoom level (measured at Equator)"

        # return (2 * math.pi * 6378137) / (self.tile_size * 2**zoom)
        return self.initialResolution / (2**zoom)

    def ZoomForPixelSize(self, pixelSize):
        "Maximal scaledown zoom of the pyramid closest to the pixelSize."

        for i in range(MAXZOOMLEVEL):
            if pixelSize > self.Resolution(i):
                return max(0, i - 1)    # We don't want to scale up
        return MAXZOOMLEVEL - 1

    def GoogleTile(self, tx, ty, zoom):
        "Converts TMS tile coordinates to Google Tile coordinates"

        # coordinate origin is moved from bottom-left to top-left corner of the extent
        return tx, (2**zoom - 1) - ty

    def QuadTree(self, tx, ty, zoom):
        "Converts TMS tile coordinates to Microsoft QuadTree"

        quadKey = ""
        ty = (2**zoom - 1) - ty
        for i in range(zoom, 0, -1):
            digit = 0
            mask = 1 << (i - 1)
            if (tx & mask) != 0:
                digit += 1
            if (ty & mask) != 0:
                digit += 2
            quadKey += str(digit)

        return quadKey


class GlobalGeodetic(object):
    r"""
    TMS Global Geodetic Profile
    ---------------------------

    Functions necessary for generation of global tiles in Plate Carre projection,
    EPSG:4326, "unprojected profile".

    Such tiles are compatible with Google Earth (as any other EPSG:4326 rasters)
    and you can overlay the tiles on top of OpenLayers base map.

    Pixel and tile coordinates are in TMS notation (origin [0,0] in bottom-left).

    What coordinate conversions do we need for TMS Global Geodetic tiles?

      Global Geodetic tiles are using geodetic coordinates (latitude,longitude)
      directly as planar coordinates XY (it is also called Unprojected or Plate
      Carre). We need only scaling to pixel pyramid and cutting to tiles.
      Pyramid has on top level two tiles, so it is not square but rectangle.
      Area [-180,-90,180,90] is scaled to 512x256 pixels.
      TMS has coordinate origin (for pixels and tiles) in bottom-left corner.
      Rasters are in EPSG:4326 and therefore are compatible with Google Earth.

         LatLon      <->      Pixels      <->     Tiles

     WGS84 coordinates   Pixels in pyramid  Tiles in pyramid
         lat/lon         XY pixels Z zoom      XYZ from TMS
        EPSG:4326
         .----.                ----
        /      \     <->    /--------/    <->      TMS
        \      /         /--------------/
         -----        /--------------------/
       WMS, KML    Web Clients, Google Earth  TileMapService
    """

    def __init__(self, tmscompatible: Optional[bool], tile_size: int = 256) -> None:
        self.tile_size = tile_size
        if tmscompatible:
            # Defaults the resolution factor to 0.703125 (2 tiles @ level 0)
            # Adhers to OSGeo TMS spec
            # http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification#global-geodetic
            self.resFact = 180.0 / self.tile_size
        else:
            # Defaults the resolution factor to 1.40625 (1 tile @ level 0)
            # Adheres OpenLayers, MapProxy, etc default resolution for WMTS
            self.resFact = 360.0 / self.tile_size

    def LonLatToPixels(self, lon, lat, zoom):
        "Converts lon/lat to pixel coordinates in given zoom of the EPSG:4326 pyramid"

        res = self.resFact / 2**zoom
        px = (180 + lon) / res
        py = (90 + lat) / res
        return px, py

    def PixelsToTile(self, px, py):
        "Returns coordinates of the tile covering region in pixel coordinates"

        tx = int(math.ceil(px / float(self.tile_size)) - 1)
        ty = int(math.ceil(py / float(self.tile_size)) - 1)
        return tx, ty

    def LonLatToTile(self, lon, lat, zoom):
        "Returns the tile for zoom which covers given lon/lat coordinates"

        px, py = self.LonLatToPixels(lon, lat, zoom)
        return self.PixelsToTile(px, py)

    def Resolution(self, zoom):
        "Resolution (arc/pixel) for given zoom level (measured at Equator)"

        return self.resFact / 2**zoom

    def ZoomForPixelSize(self, pixelSize):
        "Maximal scaledown zoom of the pyramid closest to the pixelSize."

        for i in range(MAXZOOMLEVEL):
            if pixelSize > self.Resolution(i):
                return max(0, i - 1)    # We don't want to scale up
        return MAXZOOMLEVEL - 1

    def TileBounds(self, tx, ty, zoom):
        "Returns bounds of the given tile"
        res = self.resFact / 2**zoom
        return (
            tx * self.tile_size * res - 180,
            ty * self.tile_size * res - 90,
            (tx + 1) * self.tile_size * res - 180,
            (ty + 1) * self.tile_size * res - 90
        )

    def TileLatLonBounds(self, tx, ty, zoom):
        "Returns bounds of the given tile in the SWNE form"
        b = self.TileBounds(tx, ty, zoom)
        return (b[1], b[0], b[3], b[2])


class Zoomify(object):
    """
    Tiles compatible with the Zoomify viewer
    ----------------------------------------
    """

    def __init__(self, width, height, tile_size=256, tileformat='jpg'):
        """Initialization of the Zoomify tile tree"""

        self.tile_size = tile_size
        self.tileformat = tileformat
        imagesize = (width, height)
        tiles = (math.ceil(width / tile_size), math.ceil(height / tile_size))

        # Size (in tiles) for each tier of pyramid.
        self.tierSizeInTiles = []
        self.tierSizeInTiles.append(tiles)

        # Image size in pixels for each pyramid tierself
        self.tierImageSize = []
        self.tierImageSize.append(imagesize)

        while (imagesize[0] > tile_size or imagesize[1] > tile_size):
            imagesize = (math.floor(imagesize[0] / 2), math.floor(imagesize[1] / 2))
            tiles = (math.ceil(imagesize[0] / tile_size), math.ceil(imagesize[1] / tile_size))
            self.tierSizeInTiles.append(tiles)
            self.tierImageSize.append(imagesize)

        self.tierSizeInTiles.reverse()
        self.tierImageSize.reverse()

        # Depth of the Zoomify pyramid, number of tiers (zoom levels)
        self.numberOfTiers = len(self.tierSizeInTiles)

        # Number of tiles up to the given tier of pyramid.
        self.tileCountUpToTier = []
        self.tileCountUpToTier[0] = 0
        for i in range(1, self.numberOfTiers + 1):
            self.tileCountUpToTier.append(
                self.tierSizeInTiles[i - 1][0] * self.tierSizeInTiles[i - 1][1] +
                self.tileCountUpToTier[i - 1]
            )

    def tilefilename(self, x, y, z):
        """Returns filename for tile with given coordinates"""

        tileIndex = x + y * self.tierSizeInTiles[z][0] + self.tileCountUpToTier[z]
        return os.path.join("TileGroup%.0f" % math.floor(tileIndex / 256),
                            "%s-%s-%s.%s" % (z, x, y, self.tileformat))


class GDALError(Exception):
    pass


def exit_with_error(message: str, details: str = "") -> NoReturn:
    # Message printing and exit code kept from the way it worked using the OptionParser (in case
    # someone parses the error output)
    sys.stderr.write("Usage: gdal2tiles.py [options] input_file [output]\n\n")
    sys.stderr.write("gdal2tiles.py: error: %s\n" % message)
    if details:
        sys.stderr.write("\n\n%s\n" % details)

    sys.exit(2)


def set_cache_max(cache_in_bytes: int) -> None:
    # We set the maximum using `SetCacheMax` and `GDAL_CACHEMAX` to support both fork and spawn as multiprocessing start methods.
    # https://github.com/OSGeo/gdal/pull/2112
    os.environ['GDAL_CACHEMAX'] = '%d' % int(cache_in_bytes / 1024 / 1024)
    gdal.SetCacheMax(cache_in_bytes)


def generate_kml(tx, ty, tz, tileext, tile_size, tileswne, options, children=None, **args):
    """
    Template for the KML. Returns filled string.
    """
    if not children:
        children = []

    args['tx'], args['ty'], args['tz'] = tx, ty, tz
    args['tileformat'] = tileext
    if 'tile_size' not in args:
        args['tile_size'] = tile_size

    if 'minlodpixels' not in args:
        args['minlodpixels'] = int(args['tile_size'] / 2)
    if 'maxlodpixels' not in args:
        args['maxlodpixels'] = int(args['tile_size'] * 8)
    if children == []:
        args['maxlodpixels'] = -1

    if tx is None:
        tilekml = False
        args['xml_escaped_title'] = gdal.EscapeString(options.title, gdal.CPLES_XML)
    else:
        tilekml = True
        args['realtiley'] = GDAL2Tiles.getYTile(ty, tz, options)
        args['xml_escaped_title'] = "%d/%d/%d.kml" % (tz, tx, args['realtiley'])
        args['south'], args['west'], args['north'], args['east'] = tileswne(tx, ty, tz)

    if tx == 0:
        args['drawOrder'] = 2 * tz + 1
    elif tx is not None:
        args['drawOrder'] = 2 * tz
    else:
        args['drawOrder'] = 0

    url = options.url
    if not url:
        if tilekml:
            url = "../../"
        else:
            url = ""

    s = """<?xml version="1.0" encoding="utf-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Document>
    <name>%(xml_escaped_title)s</name>
    <description></description>
    <Style>
      <ListStyle id="hideChildren">
        <listItemType>checkHideChildren</listItemType>
      </ListStyle>
    </Style>""" % args
    if tilekml:
        s += """
    <Region>
      <LatLonAltBox>
        <north>%(north).14f</north>
        <south>%(south).14f</south>
        <east>%(east).14f</east>
        <west>%(west).14f</west>
      </LatLonAltBox>
      <Lod>
        <minLodPixels>%(minlodpixels)d</minLodPixels>
        <maxLodPixels>%(maxlodpixels)d</maxLodPixels>
      </Lod>
    </Region>
    <GroundOverlay>
      <drawOrder>%(drawOrder)d</drawOrder>
      <Icon>
        <href>%(realtiley)d.%(tileformat)s</href>
      </Icon>
      <LatLonBox>
        <north>%(north).14f</north>
        <south>%(south).14f</south>
        <east>%(east).14f</east>
        <west>%(west).14f</west>
      </LatLonBox>
    </GroundOverlay>
""" % args

    for cx, cy, cz in children:
        csouth, cwest, cnorth, ceast = tileswne(cx, cy, cz)
        ytile = GDAL2Tiles.getYTile(cy, cz, options)
        s += """
    <NetworkLink>
      <name>%d/%d/%d.%s</name>
      <Region>
        <LatLonAltBox>
          <north>%.14f</north>
          <south>%.14f</south>
          <east>%.14f</east>
          <west>%.14f</west>
        </LatLonAltBox>
        <Lod>
          <minLodPixels>%d</minLodPixels>
          <maxLodPixels>-1</maxLodPixels>
        </Lod>
      </Region>
      <Link>
        <href>%s%d/%d/%d.kml</href>
        <viewRefreshMode>onRegion</viewRefreshMode>
        <viewFormat/>
      </Link>
    </NetworkLink>
        """ % (cz, cx, ytile, args['tileformat'], cnorth, csouth, ceast, cwest,
               args['minlodpixels'], url, cz, cx, ytile)

    s += """      </Document>
</kml>
    """
    return s


def scale_query_to_tile(dsquery, dstile, tiledriver, options, tilefilename=''):
    """Scales down query dataset to the tile dataset"""

    querysize = dsquery.RasterXSize
    tile_size = dstile.RasterXSize
    tilebands = dstile.RasterCount

    if options.resampling == 'average':

        # Function: gdal.RegenerateOverview()
        for i in range(1, tilebands + 1):
            # Black border around NODATA
            res = gdal.RegenerateOverview(dsquery.GetRasterBand(i), dstile.GetRasterBand(i),
                                          'average')
            if res != 0:
                exit_with_error("RegenerateOverview() failed on %s, error %d" % (
                    tilefilename, res))

    elif options.resampling == 'antialias' and numpy_available:

        if tilefilename.startswith('/vsi'):
            raise Exception('Outputing to /vsi file systems with antialias mode is not supported')

        # Scaling by PIL (Python Imaging Library) - improved Lanczos
        array = numpy.zeros((querysize, querysize, tilebands), numpy.uint8)
        for i in range(tilebands):
            array[:, :, i] = gdalarray.BandReadAsArray(dsquery.GetRasterBand(i + 1),
                                                       0, 0, querysize, querysize)
        im = Image.fromarray(array, 'RGBA')     # Always four bands
        im1 = im.resize((tile_size, tile_size), Image.ANTIALIAS)
        if os.path.exists(tilefilename):
            im0 = Image.open(tilefilename)
            im1 = Image.composite(im1, im0, im1)
        im1.save(tilefilename, tiledriver)

    else:

        if options.resampling == 'near':
            gdal_resampling = gdal.GRA_NearestNeighbour

        elif options.resampling == 'bilinear':
            gdal_resampling = gdal.GRA_Bilinear

        elif options.resampling == 'cubic':
            gdal_resampling = gdal.GRA_Cubic

        elif options.resampling == 'cubicspline':
            gdal_resampling = gdal.GRA_CubicSpline

        elif options.resampling == 'lanczos':
            gdal_resampling = gdal.GRA_Lanczos

        elif options.resampling == 'mode':
            gdal_resampling = gdal.GRA_Mode

        elif options.resampling == 'max':
            gdal_resampling = gdal.GRA_Max

        elif options.resampling == 'min':
            gdal_resampling = gdal.GRA_Min

        elif options.resampling == 'med':
            gdal_resampling = gdal.GRA_Med

        elif options.resampling == 'q1':
            gdal_resampling = gdal.GRA_Q1

        elif options.resampling == 'q3':
            gdal_resampling = gdal.GRA_Q3

        # Other algorithms are implemented by gdal.ReprojectImage().
        dsquery.SetGeoTransform((0.0, tile_size / float(querysize), 0.0, 0.0, 0.0,
                                 tile_size / float(querysize)))
        dstile.SetGeoTransform((0.0, 1.0, 0.0, 0.0, 0.0, 1.0))

        res = gdal.ReprojectImage(dsquery, dstile, None, None, gdal_resampling)
        if res != 0:
            exit_with_error("ReprojectImage() failed on %s, error %d" % (tilefilename, res))


def setup_no_data_values(input_dataset: gdal.Dataset, options: Options) -> List[float]:
    """
    Extract the NODATA values from the dataset or use the passed arguments as override if any
    """
    in_nodata = []
    if options.srcnodata:
        nds = list(map(float, options.srcnodata.split(',')))
        if len(nds) < input_dataset.RasterCount:
            in_nodata = (nds * input_dataset.RasterCount)[:input_dataset.RasterCount]
        else:
            in_nodata = nds
    else:
        for i in range(1, input_dataset.RasterCount + 1):
            band = input_dataset.GetRasterBand(i)
            raster_no_data = band.GetNoDataValue()
            if raster_no_data is not None:
                # Ignore nodata values that are not in the range of the band data type (see https://github.com/OSGeo/gdal/pull/2299)
                if band.DataType == gdal.GDT_Byte and (raster_no_data != int(raster_no_data) or raster_no_data < 0 or raster_no_data > 255):
                    # We should possibly do similar check for other data types
                    in_nodata = []
                    break
                in_nodata.append(raster_no_data)

    if options.verbose:
        print("NODATA: %s" % in_nodata)

    return in_nodata


def setup_input_srs(input_dataset: gdal.Dataset, options: Options) -> Tuple[Optional[osr.SpatialReference], Optional[str]]:
    """
    Determines and returns the Input Spatial Reference System (SRS) as an osr object and as a
    WKT representation

    Uses in priority the one passed in the command line arguments. If None, tries to extract them
    from the input dataset
    """

    input_srs = None
    input_srs_wkt = None

    if options.s_srs:
        input_srs = osr.SpatialReference()
        input_srs.SetFromUserInput(options.s_srs)
        input_srs_wkt = input_srs.ExportToWkt()
    else:
        input_srs_wkt = input_dataset.GetProjection()
        if not input_srs_wkt and input_dataset.GetGCPCount() != 0:
            input_srs_wkt = input_dataset.GetGCPProjection()
        if input_srs_wkt:
            input_srs = osr.SpatialReference()
            input_srs.ImportFromWkt(input_srs_wkt)

    if input_srs is not None:
        input_srs.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)

    return input_srs, input_srs_wkt


def setup_output_srs(input_srs: Optional[osr.SpatialReference], options: Options) -> Optional[osr.SpatialReference]:
    """
    Setup the desired SRS (based on options)
    """
    output_srs = osr.SpatialReference()

    if options.profile == 'mercator':
        output_srs.ImportFromEPSG(3857)
    elif options.profile == 'geodetic':
        output_srs.ImportFromEPSG(4326)
    elif options.profile == 'raster':
        output_srs = input_srs
    else:
        output_srs = tmsMap[options.profile].srs.Clone()

    if output_srs:
        output_srs.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)

    return output_srs


def has_georeference(dataset: gdal.Dataset) -> bool:
    return (dataset.GetGeoTransform() != (0.0, 1.0, 0.0, 0.0, 0.0, 1.0) or
            dataset.GetGCPCount() != 0)


def reproject_dataset(from_dataset: gdal.Dataset, from_srs: Optional[osr.SpatialReference], to_srs: Optional[osr.SpatialReference], options: Optional[Options] = None) -> gdal.Dataset:
    """
    Returns the input dataset in the expected "destination" SRS.
    If the dataset is already in the correct SRS, returns it unmodified
    """
    if not from_srs or not to_srs:
        raise GDALError("from and to SRS must be defined to reproject the dataset")

    if (from_srs.ExportToProj4() != to_srs.ExportToProj4()) or (from_dataset.GetGCPCount() != 0):

        if from_srs.IsGeographic() and to_srs.GetAuthorityName(None) == 'EPSG' and to_srs.GetAuthorityCode(None) == '3857':
            from_gt = from_dataset.GetGeoTransform(can_return_null=True)
            if from_gt and from_gt[2] == 0 and from_gt[4] == 0 and from_gt[5] < 0:
                maxlat = from_gt[3]
                minlat = from_gt[3] + from_dataset.RasterYSize * from_gt[5]
                MAX_LAT = 85.0511287798066
                adjustBounds = False
                if maxlat > MAX_LAT:
                    maxlat = MAX_LAT
                    adjustBounds = True
                if minlat < -MAX_LAT:
                    minlat = -MAX_LAT
                    adjustBounds = True
                if adjustBounds:
                    ct = osr.CoordinateTransformation(from_srs, to_srs)
                    west, south = ct.TransformPoint(from_gt[0], minlat)[:2]
                    east, north = ct.TransformPoint(from_gt[0] + from_dataset.RasterXSize * from_gt[1], maxlat)[:2]
                    return gdal.Warp("", from_dataset, format='VRT', outputBounds = [west, south, east, north], dstSRS = 'EPSG:3857')

        to_dataset = gdal.AutoCreateWarpedVRT(from_dataset,
                                              from_srs.ExportToWkt(), to_srs.ExportToWkt())

        if options and options.verbose:
            print("Warping of the raster by AutoCreateWarpedVRT (result saved into 'tiles.vrt')")
            to_dataset.GetDriver().CreateCopy("tiles.vrt", to_dataset)

        return to_dataset
    else:
        return from_dataset


def add_gdal_warp_options_to_string(vrt_string, warp_options):
    if not warp_options:
        return vrt_string

    vrt_root = ElementTree.fromstring(vrt_string)
    options = vrt_root.find("GDALWarpOptions")

    if options is None:
        return vrt_string

    for key, value in warp_options.items():
        tb = ElementTree.TreeBuilder()
        tb.start("Option", {"name": key})
        tb.data(value)
        tb.end("Option")
        elem = tb.close()
        options.insert(0, elem)

    return ElementTree.tostring(vrt_root).decode()


def update_no_data_values(warped_vrt_dataset: gdal.Dataset, nodata_values: List[float], options: Optional[Options] = None) -> gdal.Dataset:
    """
    Takes an array of NODATA values and forces them on the WarpedVRT file dataset passed
    """
    # TODO: gbataille - Seems that I forgot tests there
    assert nodata_values != []

    vrt_string = warped_vrt_dataset.GetMetadata("xml:VRT")[0]

    vrt_string = add_gdal_warp_options_to_string(
        vrt_string, {"INIT_DEST": "NO_DATA", "UNIFIED_SRC_NODATA": "YES"})

# TODO: gbataille - check the need for this replacement. Seems to work without
#         # replace BandMapping tag for NODATA bands....
#         for i in range(len(nodata_values)):
#             s = s.replace(
#                 '<BandMapping src="%i" dst="%i"/>' % ((i+1), (i+1)),
#                 """
# <BandMapping src="%i" dst="%i">
# <SrcNoDataReal>%i</SrcNoDataReal>
# <SrcNoDataImag>0</SrcNoDataImag>
# <DstNoDataReal>%i</DstNoDataReal>
# <DstNoDataImag>0</DstNoDataImag>
# </BandMapping>
#                 """ % ((i+1), (i+1), nodata_values[i], nodata_values[i]))

    corrected_dataset = gdal.Open(vrt_string)

    # set NODATA_VALUE metadata
    corrected_dataset.SetMetadataItem(
        'NODATA_VALUES', ' '.join([str(i) for i in nodata_values]))

    if options and options.verbose:
        print("Modified warping result saved into 'tiles1.vrt'")

        with open("tiles1.vrt", "w") as f:
            f.write(corrected_dataset.GetMetadata("xml:VRT")[0])

    return corrected_dataset


def add_alpha_band_to_string_vrt(vrt_string: str) -> str:
    # TODO: gbataille - Old code speak of this being equivalent to gdalwarp -dstalpha
    # To be checked

    vrt_root = ElementTree.fromstring(vrt_string)

    index = 0
    nb_bands = 0
    for subelem in list(vrt_root):
        if subelem.tag == "VRTRasterBand":
            nb_bands += 1
            color_node = subelem.find("./ColorInterp")
            if color_node is not None and color_node.text == "Alpha":
                raise Exception("Alpha band already present")
        else:
            if nb_bands:
                # This means that we are one element after the Band definitions
                break

        index += 1

    tb = ElementTree.TreeBuilder()
    tb.start("VRTRasterBand",
             {'dataType': "Byte", "band": str(nb_bands + 1), "subClass": "VRTWarpedRasterBand"})
    tb.start("ColorInterp", {})
    tb.data("Alpha")
    tb.end("ColorInterp")
    tb.end("VRTRasterBand")
    elem = tb.close()

    vrt_root.insert(index, elem)

    warp_options = vrt_root.find(".//GDALWarpOptions")
    tb = ElementTree.TreeBuilder()
    tb.start("DstAlphaBand", {})
    tb.data(str(nb_bands + 1))
    tb.end("DstAlphaBand")
    elem = tb.close()
    warp_options.append(elem)

    # TODO: gbataille - this is a GDALWarpOptions. Why put it in a specific place?
    tb = ElementTree.TreeBuilder()
    tb.start("Option", {"name": "INIT_DEST"})
    tb.data("0")
    tb.end("Option")
    elem = tb.close()
    warp_options.append(elem)

    return ElementTree.tostring(vrt_root).decode()


def update_alpha_value_for_non_alpha_inputs(warped_vrt_dataset: gdal.Dataset, options: Optional[Options] = None) -> gdal.Dataset:
    """
    Handles dataset with 1 or 3 bands, i.e. without alpha channel, in the case the nodata value has
    not been forced by options
    """
    if warped_vrt_dataset.RasterCount in [1, 3]:

        vrt_string = warped_vrt_dataset.GetMetadata("xml:VRT")[0]

        vrt_string = add_alpha_band_to_string_vrt(vrt_string)

        warped_vrt_dataset = gdal.Open(vrt_string)

        if options and options.verbose:
            print("Modified -dstalpha warping result saved into 'tiles1.vrt'")

            with open("tiles1.vrt", "w") as f:
                f.write(warped_vrt_dataset.GetMetadata("xml:VRT")[0])

    return warped_vrt_dataset


def nb_data_bands(dataset: gdal.Dataset) -> int:
    """
    Return the number of data (non-alpha) bands of a gdal dataset
    """
    alphaband = dataset.GetRasterBand(1).GetMaskBand()
    if ((alphaband.GetMaskFlags() & gdal.GMF_ALPHA) or
            dataset.RasterCount == 4 or
            dataset.RasterCount == 2):
        return dataset.RasterCount - 1
    return dataset.RasterCount

def create_base_tile(tile_job_info: 'TileJobInfo', tile_detail: 'TileDetail') -> None:

    dataBandsCount = tile_job_info.nb_data_bands
    output = tile_job_info.output_file_path
    tileext = tile_job_info.tile_extension
    tile_size = tile_job_info.tile_size
    options = tile_job_info.options

    tilebands = dataBandsCount + 1

    cached_ds = getattr(threadLocal, 'cached_ds', None)
    if cached_ds and cached_ds.GetDescription() == tile_job_info.src_file:
        ds = cached_ds
    else:
        ds = gdal.Open(tile_job_info.src_file, gdal.GA_ReadOnly)
        threadLocal.cached_ds = ds

    mem_drv = gdal.GetDriverByName('MEM')
    out_drv = gdal.GetDriverByName(tile_job_info.tile_driver)
    alphaband = ds.GetRasterBand(1).GetMaskBand()

    tx = tile_detail.tx
    ty = tile_detail.ty
    tz = tile_detail.tz
    rx = tile_detail.rx
    ry = tile_detail.ry
    rxsize = tile_detail.rxsize
    rysize = tile_detail.rysize
    wx = tile_detail.wx
    wy = tile_detail.wy
    wxsize = tile_detail.wxsize
    wysize = tile_detail.wysize
    querysize = tile_detail.querysize

    # Tile dataset in memory
    tilefilename = os.path.join(
        output, str(tz), str(tx), "%s.%s" % (ty, tileext))
    dstile = mem_drv.Create('', tile_size, tile_size, tilebands)

    data = alpha = None

    if options.verbose:
        print("\tReadRaster Extent: ",
              (rx, ry, rxsize, rysize), (wx, wy, wxsize, wysize))

    # Query is in 'nearest neighbour' but can be bigger in then the tile_size
    # We scale down the query to the tile_size by supplied algorithm.

    if rxsize != 0 and rysize != 0 and wxsize != 0 and wysize != 0:
        alpha = alphaband.ReadRaster(rx, ry, rxsize, rysize, wxsize, wysize)

        # Detect totally transparent tile and skip its creation
        if tile_job_info.exclude_transparent and len(alpha) == alpha.count('\x00'.encode('ascii')):
            return

        data = ds.ReadRaster(rx, ry, rxsize, rysize, wxsize, wysize,
                             band_list=list(range(1, dataBandsCount + 1)))

    # The tile in memory is a transparent file by default. Write pixel values into it if
    # any
    if data:
        if tile_size == querysize:
            # Use the ReadRaster result directly in tiles ('nearest neighbour' query)
            dstile.WriteRaster(wx, wy, wxsize, wysize, data,
                               band_list=list(range(1, dataBandsCount + 1)))
            dstile.WriteRaster(wx, wy, wxsize, wysize, alpha, band_list=[tilebands])

            # Note: For source drivers based on WaveLet compression (JPEG2000, ECW,
            # MrSID) the ReadRaster function returns high-quality raster (not ugly
            # nearest neighbour)
            # TODO: Use directly 'near' for WaveLet files
        else:
            # Big ReadRaster query in memory scaled to the tile_size - all but 'near'
            # algo
            dsquery = mem_drv.Create('', querysize, querysize, tilebands)
            # TODO: fill the null value in case a tile without alpha is produced (now
            # only png tiles are supported)
            dsquery.WriteRaster(wx, wy, wxsize, wysize, data,
                                band_list=list(range(1, dataBandsCount + 1)))
            dsquery.WriteRaster(wx, wy, wxsize, wysize, alpha, band_list=[tilebands])

            scale_query_to_tile(dsquery, dstile, tile_job_info.tile_driver, options,
                                tilefilename=tilefilename)
            del dsquery

    del data

    if options.resampling != 'antialias':
        # Write a copy of tile to png/jpg
        out_drv.CreateCopy(tilefilename, dstile, strict=0)

    del dstile

    # Create a KML file for this tile.
    if tile_job_info.kml:
        swne = get_tile_swne(tile_job_info, options)
        if swne is not None:
            kmlfilename = os.path.join(output, str(tz), str(tx), '%d.kml' % GDAL2Tiles.getYTile(ty, tz, options))
            if not options.resume or not isfile(kmlfilename):
                with my_open(kmlfilename, 'wb') as f:
                    f.write(generate_kml(
                        tx, ty, tz, tile_job_info.tile_extension, tile_job_info.tile_size,
                        swne, tile_job_info.options
                    ).encode('utf-8'))

def create_overview_tile(base_tz: int, base_tiles: List[Tuple[int, int]], output_folder: str, tile_job_info: 'TileJobInfo', options: Options):
    """ Generating an overview tile from no more than 4 underlying tiles(base tiles) """

    mem_driver = gdal.GetDriverByName('MEM')
    tile_driver = tile_job_info.tile_driver
    out_driver = gdal.GetDriverByName(tile_driver)

    tilebands = tile_job_info.nb_data_bands + 1

    dsquery = mem_driver.Create('', 2 * tile_job_info.tile_size,
                                2 * tile_job_info.tile_size, tilebands)
    # TODO: fill the null value
    dstile = mem_driver.Create('', tile_job_info.tile_size, tile_job_info.tile_size,
                               tilebands)

    usable_base_tiles = []

    for base_tile in base_tiles:
        base_tx = base_tile[0]
        base_ty = base_tile[1]
        base_ty_real = GDAL2Tiles.getYTile(base_ty, base_tz, options)

        base_tile_path = os.path.join(output_folder, str(base_tz), str(base_tx),
                                      "%s.%s" % (base_ty_real, tile_job_info.tile_extension))
        if not isfile(base_tile_path):
            continue

        dsquerytile = gdal.Open(base_tile_path, gdal.GA_ReadOnly)

        if base_tx % 2 == 0:
            tileposx = 0
        else:
            tileposx = tile_job_info.tile_size

        if options.xyz and options.profile == 'raster':
            if base_ty % 2 == 0:
                tileposy = 0
            else:
                tileposy = tile_job_info.tile_size
        else:
            if base_ty % 2 == 0:
                tileposy = tile_job_info.tile_size
            else:
                tileposy = 0

        dsquery.WriteRaster(
            tileposx, tileposy, tile_job_info.tile_size,
            tile_job_info.tile_size,
            dsquerytile.ReadRaster(0, 0,
                                   tile_job_info.tile_size,
                                   tile_job_info.tile_size),
            band_list=list(range(1, tilebands + 1)))

        usable_base_tiles.append(base_tile)

    overview_tz = base_tz - 1
    overview_tx = base_tiles[0][0] >> 1
    overview_ty = base_tiles[0][1] >> 1
    overview_ty_real = GDAL2Tiles.getYTile(overview_ty, overview_tz, options)

    tilefilename = os.path.join(output_folder, str(overview_tz), str(overview_tx),
                                "%s.%s" % (overview_ty_real, tile_job_info.tile_extension))
    if options.verbose:
        print(tilefilename)
    if options.resume and isfile(tilefilename):
        if options.verbose:
            print("Tile generation skipped because of --resume")
        return

    if usable_base_tiles:
        scale_query_to_tile(dsquery, dstile, tile_driver, options,
                            tilefilename=tilefilename)
        # Write a copy of tile to png/jpg
        if options.resampling != 'antialias':
            # Write a copy of tile to png/jpg
            out_driver.CreateCopy(tilefilename, dstile, strict=0)
            # Remove useless side car file
            aux_xml = tilefilename + '.aux.xml'
            if gdal.VSIStatL(aux_xml) is not None:
                gdal.Unlink(aux_xml)

        if options.verbose:
            print("\tbuild from zoom", base_tz, " tiles:", *base_tiles)

        # Create a KML file for this tile.
        if tile_job_info.kml:
            swne = get_tile_swne(tile_job_info, options)
            if swne is not None:
                with my_open(os.path.join(
                    output_folder,
                    '%d/%d/%d.kml' % (overview_tz, overview_tx, overview_ty_real)
                ), 'wb') as f:
                    f.write(generate_kml(
                        overview_tx, overview_ty, overview_tz, tile_job_info.tile_extension, tile_job_info.tile_size,
                        swne, options, [(t[0], t[1], base_tz) for t in base_tiles]
                    ).encode('utf-8'))


def group_overview_base_tiles(base_tz: int, output_folder: str, tile_job_info: 'TileJobInfo') -> List[List[Tuple[int, int]]]:
    """ Group base tiles that belong to the same overview tile """

    overview_to_bases = {}
    tminx, tminy, tmaxx, tmaxy = tile_job_info.tminmax[base_tz]
    for ty in range(tmaxy, tminy - 1, -1):
        overview_ty = ty >> 1
        for tx in range(tminx, tmaxx + 1):
            overview_tx = tx >> 1
            base_tile = (tx, ty)
            overview_tile = (overview_tx, overview_ty)

            if overview_tile not in overview_to_bases:
                overview_to_bases[overview_tile] = []

            overview_to_bases[overview_tile].append(base_tile)

    # Create directories for the tiles
    overview_tz = base_tz - 1
    for tx in range(tminx, tmaxx + 1):
        overview_tx = tx >> 1
        tiledirname = os.path.join(output_folder, str(overview_tz), str(overview_tx))
        makedirs(tiledirname)

    return list(overview_to_bases.values())


def count_overview_tiles(tile_job_info: 'TileJobInfo') -> int:
    tile_number = 0
    for tz in range(tile_job_info.tmaxz - 1, tile_job_info.tminz - 1, -1):
        tminx, tminy, tmaxx, tmaxy = tile_job_info.tminmax[tz]
        tile_number += (1 + abs(tmaxx - tminx)) * (1 + abs(tmaxy - tminy))

    return tile_number


def optparse_init() -> optparse.OptionParser:
    """Prepare the option parser for input (argv)"""

    usage = "Usage: %prog [options] input_file [output]"
    p = optparse.OptionParser(usage, version="%prog " + __version__)
    p.add_option("-p", "--profile", dest='profile',
                 type='choice', choices=profile_list,
                 help=("Tile cutting profile (%s) - default 'mercator' "
                       "(Google Maps compatible)" % ",".join(profile_list)))
    p.add_option("-r", "--resampling", dest="resampling",
                 type='choice', choices=resampling_list,
                 help="Resampling method (%s) - default 'average'" % ",".join(resampling_list))
    p.add_option('-s', '--s_srs', dest="s_srs", metavar="SRS",
                 help="The spatial reference system used for the source input data")
    p.add_option('-z', '--zoom', dest="zoom",
                 help="Zoom levels to render (format:'2-5', '10-' or '10').")
    p.add_option('-e', '--resume', dest="resume", action="store_true",
                 help="Resume mode. Generate only missing files.")
    p.add_option('-a', '--srcnodata', dest="srcnodata", metavar="NODATA",
                 help="Value in the input dataset considered as transparent")
    p.add_option('-d', '--tmscompatible', dest="tmscompatible", action="store_true",
                 help=("When using the geodetic profile, specifies the base resolution "
                       "as 0.703125 or 2 tiles at zoom level 0."))
    p.add_option('--xyz',
                 action='store_true', dest='xyz',
                 help="Use XYZ tile numbering (OSM Slippy Map tiles) instead of TMS")
    p.add_option("-v", "--verbose",
                 action="store_true", dest="verbose",
                 help="Print status messages to stdout")
    p.add_option("-x", "--exclude",
                 action="store_true", dest="exclude_transparent",
                 help="Exclude transparent tiles from result tileset")
    p.add_option("-q", "--quiet",
                 action="store_true", dest="quiet",
                 help="Disable messages and status to stdout")
    p.add_option("--processes",
                 dest="nb_processes",
                 type='int',
                 help="Number of processes to use for tiling")
    p.add_option("--mpi",
                 action="store_true", dest="mpi",
                 help="Assume launched by mpiexec and ignore --processes. "
                      "User should set GDAL_CACHEMAX to size per process.")
    p.add_option("--tilesize", dest="tilesize",  metavar="PIXELS", default=256,
                 type='int',
                 help="Width and height in pixel of a tile")

    # KML options
    g = optparse.OptionGroup(p, "KML (Google Earth) options",
                    "Options for generated Google Earth SuperOverlay metadata")
    g.add_option("-k", "--force-kml", dest='kml', action="store_true",
                 help=("Generate KML for Google Earth - default for 'geodetic' profile and "
                       "'raster' in EPSG:4326. For a dataset with different projection use "
                       "with caution!"))
    g.add_option("-n", "--no-kml", dest='kml', action="store_false",
                 help="Avoid automatic generation of KML files for EPSG:4326")
    g.add_option("-u", "--url", dest='url',
                 help="URL address where the generated tiles are going to be published")
    p.add_option_group(g)

    # HTML options
    g = optparse.OptionGroup(p, "Web viewer options",
                    "Options for generated HTML viewers a la Google Maps")
    g.add_option("-w", "--webviewer", dest='webviewer', type='choice', choices=webviewer_list,
                 help="Web viewer to generate (%s) - default 'all'" % ",".join(webviewer_list))
    g.add_option("-t", "--title", dest='title',
                 help="Title of the map")
    g.add_option("-c", "--copyright", dest='copyright',
                 help="Copyright for the map")
    g.add_option("-g", "--googlekey", dest='googlekey',
                 help="Google Maps API key from http://code.google.com/apis/maps/signup.html")
    g.add_option("-b", "--bingkey", dest='bingkey',
                 help="Bing Maps API key from https://www.bingmapsportal.com/")
    p.add_option_group(g)

    # MapML options
    g = optparse.OptionGroup(p, "MapML options",
                    "Options for generated MapML file")
    g.add_option("--mapml-template", dest='mapml_template', action="store_true",
                 help=("Filename of a template mapml file where variables will "
                       "be substituted. If not specified, the generic "
                       "template_tiles.mapml file from GDAL data resources "
                       "will be used"))
    p.add_option_group(g)


    p.set_defaults(verbose=False, profile="mercator", kml=None, url='',
                   webviewer='all', copyright='', resampling='average', resume=False,
                   googlekey='INSERT_YOUR_KEY_HERE', bingkey='INSERT_YOUR_KEY_HERE',
                   processes=1)

    return p


def process_args(argv: List[str]) -> Tuple[str, str, Options]:
    parser = optparse_init()
    options, args = parser.parse_args(args=argv)

    # Args should be either an input file OR an input file and an output folder
    if not args:
        exit_with_error("You need to specify at least an input file as argument to the script")
    if len(args) > 2:
        exit_with_error("Processing of several input files is not supported.",
                        "Please first use a tool like gdal_vrtmerge.py or gdal_merge.py on the "
                        "files: gdal_vrtmerge.py -o merged.vrt %s" % " ".join(args))

    input_file = args[0]
    if not isfile(input_file):
        exit_with_error("The provided input file %s does not exist or is not a file" % input_file)

    if len(args) == 2:
        output_folder = args[1]
    else:
        # Directory with input filename without extension in actual directory
        output_folder = os.path.splitext(os.path.basename(input_file))[0]

    if options.webviewer == 'mapml':
        options.xyz = True
        if options.profile == 'geodetic':
            options.tmscompatible = True

    options = options_post_processing(options, input_file, output_folder)

    return input_file, output_folder, options


def options_post_processing(options: Options, input_file: str, output_folder: str) -> Options:
    if not options.title:
        options.title = os.path.basename(input_file)

    # User specified zoom levels
    tminz = None
    tmaxz = None
    if hasattr(options, 'zoom') and options.zoom and isinstance(options.zoom, str):
        minmax = options.zoom.split('-', 1)
        zoom_min = minmax[0]
        tminz = int(zoom_min)

        if len(minmax) == 2:
            # Min-max zoom value
            zoom_max = minmax[1]
            if zoom_max:
                # User-specified (non-automatically calculated)
                tmaxz = int(zoom_max)
                if tmaxz < tminz:
                    raise Exception('max zoom (%d) less than min zoom (%d)' %
                                    (tmaxz, tminz))
        else:
            # Single zoom value (min = max)
            tmaxz = tminz
    options.zoom = [tminz, tmaxz]

    if options.url and not options.url.endswith('/'):
        options.url += '/'
    if options.url:
        out_path = output_folder
        if out_path.endswith("/"):
            out_path = out_path[:-1]
        options.url += os.path.basename(out_path) + '/'

    # Supported options
    if options.resampling == 'antialias' and not numpy_available:
        exit_with_error("'antialias' resampling algorithm is not available.",
                        "Install PIL (Python Imaging Library) and numpy.")

    try:
        os.path.basename(input_file).encode('ascii')
    except UnicodeEncodeError:
        full_ascii = False
    else:
        full_ascii = True

    # LC_CTYPE check
    if not full_ascii and 'UTF-8' not in os.environ.get("LC_CTYPE", ""):
        if not options.quiet:
            print("\nWARNING: "
                  "You are running gdal2tiles.py with a LC_CTYPE environment variable that is "
                  "not UTF-8 compatible, and your input file contains non-ascii characters. "
                  "The generated sample googlemaps, openlayers or "
                  "leaflet files might contain some invalid characters as a result\n")

    # Output the results
    if options.verbose:
        print("Options:", options)
        print("Input:", input_file)
        print("Output:", output_folder)
        print("Cache: %s MB" % (gdal.GetCacheMax() / 1024 / 1024))
        print('')

    return options


class TileDetail(object):
    tx = 0
    ty = 0
    tz = 0
    rx = 0
    ry = 0
    rxsize = 0
    rysize = 0
    wx = 0
    wy = 0
    wxsize = 0
    wysize = 0
    querysize = 0

    def __init__(self, **kwargs):
        for key in kwargs:
            if hasattr(self, key):
                setattr(self, key, kwargs[key])

    def __unicode__(self):
        return "TileDetail %s\n%s\n%s\n" % (self.tx, self.ty, self.tz)

    def __str__(self):
        return "TileDetail %s\n%s\n%s\n" % (self.tx, self.ty, self.tz)

    def __repr__(self):
        return "TileDetail %s\n%s\n%s\n" % (self.tx, self.ty, self.tz)


class TileJobInfo(object):
    """
    Plain object to hold tile job configuration for a dataset
    """
    src_file = ""
    nb_data_bands = 0
    output_file_path = ""
    tile_extension = ""
    tile_size = 0
    tile_driver = None
    kml = False
    tminmax = []
    tminz = 0
    tmaxz = 0
    in_srs_wkt = 0
    out_geo_trans = []
    ominy = 0
    is_epsg_4326 = False
    options = None
    exclude_transparent = False

    def __init__(self, **kwargs):
        for key in kwargs:
            if hasattr(self, key):
                setattr(self, key, kwargs[key])

    def __unicode__(self):
        return "TileJobInfo %s\n" % (self.src_file)

    def __str__(self):
        return "TileJobInfo %s\n" % (self.src_file)

    def __repr__(self):
        return "TileJobInfo %s\n" % (self.src_file)


class Gdal2TilesError(Exception):
    pass


class GDAL2Tiles(object):

    def __init__(self, input_file: str, output_folder: str, options: Options) -> None:
        """Constructor function - initialization"""
        self.out_drv = None
        self.mem_drv = None
        self.warped_input_dataset = None
        self.out_srs = None
        self.nativezoom = None
        self.tminmax = None
        self.tsize = None
        self.mercator = None
        self.geodetic = None
        self.dataBandsCount = None
        self.out_gt = None
        self.tileswne = None
        self.swne = None
        self.ominx = None
        self.omaxx = None
        self.omaxy = None
        self.ominy = None

        self.input_file = None
        self.output_folder = None

        self.isepsg4326 = None
        self.in_srs = None
        self.in_srs_wkt = None

        # Tile format
        self.tile_size = 256
        if options.tilesize:
            self.tile_size = options.tilesize
        self.tiledriver = 'PNG'
        self.tileext = 'png'
        if options.mpi:
            makedirs(output_folder)
            self.tmp_dir = tempfile.mkdtemp(dir=output_folder)
        else:
            self.tmp_dir = tempfile.mkdtemp()
        self.tmp_vrt_filename = os.path.join(self.tmp_dir, str(uuid4()) + '.vrt')

        # Should we read bigger window of the input raster and scale it down?
        # Note: Modified later by open_input()
        # Not for 'near' resampling
        # Not for Wavelet based drivers (JPEG2000, ECW, MrSID)
        # Not for 'raster' profile
        self.scaledquery = True
        # How big should be query window be for scaling down
        # Later on reset according the chosen resampling algorithm
        self.querysize = 4 * self.tile_size

        # Should we use Read on the input file for generating overview tiles?
        # Note: Modified later by open_input()
        # Otherwise the overview tiles are generated from existing underlying tiles
        self.overviewquery = False

        self.input_file = input_file
        self.output_folder = output_folder
        self.options = options

        if self.options.resampling == 'near':
            self.querysize = self.tile_size

        elif self.options.resampling == 'bilinear':
            self.querysize = self.tile_size * 2

        self.tminz, self.tmaxz = self.options.zoom

        # KML generation
        self.kml = self.options.kml

    # -------------------------------------------------------------------------
    def open_input(self) -> None:
        """Initialization of the input raster, reprojection if necessary"""
        gdal.AllRegister()

        self.out_drv = gdal.GetDriverByName(self.tiledriver)
        self.mem_drv = gdal.GetDriverByName('MEM')

        if not self.out_drv:
            raise Exception("The '%s' driver was not found, is it available in this GDAL build?" %
                            self.tiledriver)
        if not self.mem_drv:
            raise Exception("The 'MEM' driver was not found, is it available in this GDAL build?")

        # Open the input file

        if self.input_file:
            input_dataset: gdal.Dataset = gdal.Open(self.input_file, gdal.GA_ReadOnly)
        else:
            raise Exception("No input file was specified")

        if self.options.verbose:
            print("Input file:",
                  "( %sP x %sL - %s bands)" % (input_dataset.RasterXSize,
                                               input_dataset.RasterYSize,
                                               input_dataset.RasterCount))

        if not input_dataset:
            # Note: GDAL prints the ERROR message too
            exit_with_error("It is not possible to open the input file '%s'." % self.input_file)

        # Read metadata from the input file
        if input_dataset.RasterCount == 0:
            exit_with_error("Input file '%s' has no raster band" % self.input_file)

        if input_dataset.GetRasterBand(1).GetRasterColorTable():
            exit_with_error(
                "Please convert this file to RGB/RGBA and run gdal2tiles on the result.",
                "From paletted file you can create RGBA file (temp.vrt) by:\n"
                "gdal_translate -of vrt -expand rgba %s temp.vrt\n"
                "then run:\n"
                "gdal2tiles temp.vrt" % self.input_file
            )

        if input_dataset.GetRasterBand(1).DataType != gdal.GDT_Byte:
            exit_with_error(
                "Please convert this file to 8-bit and run gdal2tiles on the result.",
                "To scale pixel values you can use:\n"
                "gdal_translate -of VRT -ot Byte -scale %s temp.vrt\n"
                "then run:\n"
                "gdal2tiles temp.vrt" % self.input_file
            )

        in_nodata = setup_no_data_values(input_dataset, self.options)

        if self.options.verbose:
            print("Preprocessed file:",
                  "( %sP x %sL - %s bands)" % (input_dataset.RasterXSize,
                                               input_dataset.RasterYSize,
                                               input_dataset.RasterCount))

        self.in_srs, self.in_srs_wkt = setup_input_srs(input_dataset, self.options)

        self.out_srs = setup_output_srs(self.in_srs, self.options)

        # If input and output reference systems are different, we reproject the input dataset into
        # the output reference system for easier manipulation

        self.warped_input_dataset = None

        if self.options.profile != 'raster':

            if not self.in_srs:
                exit_with_error(
                    "Input file has unknown SRS.",
                    "Use --s_srs EPSG:xyz (or similar) to provide source reference system.")

            if not has_georeference(input_dataset):
                exit_with_error(
                    "There is no georeference - neither affine transformation (worldfile) "
                    "nor GCPs. You can generate only 'raster' profile tiles.",
                    "Either gdal2tiles with parameter -p 'raster' or use another GIS "
                    "software for georeference e.g. gdal_transform -gcp / -a_ullr / -a_srs"
                )

            if ((self.in_srs.ExportToProj4() != self.out_srs.ExportToProj4()) or
                    (input_dataset.GetGCPCount() != 0)):
                self.warped_input_dataset = reproject_dataset(
                    input_dataset, self.in_srs, self.out_srs)

                if in_nodata:
                    self.warped_input_dataset = update_no_data_values(
                        self.warped_input_dataset, in_nodata, options=self.options)
                else:
                    self.warped_input_dataset = update_alpha_value_for_non_alpha_inputs(
                        self.warped_input_dataset, options=self.options)

            if self.warped_input_dataset and self.options.verbose:
                print("Projected file:", "tiles.vrt", "( %sP x %sL - %s bands)" % (
                    self.warped_input_dataset.RasterXSize,
                    self.warped_input_dataset.RasterYSize,
                    self.warped_input_dataset.RasterCount))

        if not self.warped_input_dataset:
            self.warped_input_dataset = input_dataset

        gdal.GetDriverByName('VRT').CreateCopy(self.tmp_vrt_filename,
                                               self.warped_input_dataset)

        self.dataBandsCount = nb_data_bands(self.warped_input_dataset)

        # KML test
        self.isepsg4326 = False
        srs4326 = osr.SpatialReference()
        srs4326.ImportFromEPSG(4326)
        srs4326.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)
        if self.out_srs and srs4326.ExportToProj4() == self.out_srs.ExportToProj4():
            self.isepsg4326 = True
            if self.kml is None:
                self.kml = True
            if self.kml and self.options.verbose:
                print("KML autotest OK!")

        if self.kml is None:
            self.kml = False

        # Read the georeference
        self.out_gt = self.warped_input_dataset.GetGeoTransform()

        # Test the size of the pixel

        # Report error in case rotation/skew is in geotransform (possible only in 'raster' profile)
        if (self.out_gt[2], self.out_gt[4]) != (0, 0):
            exit_with_error("Georeference of the raster contains rotation or skew. "
                            "Such raster is not supported. Please use gdalwarp first.")

        # Here we expect: pixel is square, no rotation on the raster

        # Output Bounds - coordinates in the output SRS
        self.ominx = self.out_gt[0]
        self.omaxx = self.out_gt[0] + self.warped_input_dataset.RasterXSize * self.out_gt[1]
        self.omaxy = self.out_gt[3]
        self.ominy = self.out_gt[3] - self.warped_input_dataset.RasterYSize * self.out_gt[1]
        # Note: maybe round(x, 14) to avoid the gdal_translate behavior, when 0 becomes -1e-15

        if self.options.verbose:
            print("Bounds (output srs):", round(self.ominx, 13), self.ominy, self.omaxx, self.omaxy)

        # Calculating ranges for tiles in different zoom levels
        if self.options.profile == 'mercator':

            self.mercator = GlobalMercator(tile_size=self.tile_size)

            # Function which generates SWNE in LatLong for given tile
            self.tileswne = self.mercator.TileLatLonBounds

            # Generate table with min max tile coordinates for all zoomlevels
            self.tminmax = list(range(0, MAXZOOMLEVEL))
            for tz in range(0, MAXZOOMLEVEL):
                tminx, tminy = self.mercator.MetersToTile(self.ominx, self.ominy, tz)
                tmaxx, tmaxy = self.mercator.MetersToTile(self.omaxx, self.omaxy, tz)
                # crop tiles extending world limits (+-180,+-90)
                tminx, tminy = max(0, tminx), max(0, tminy)
                tmaxx, tmaxy = min(2**tz - 1, tmaxx), min(2**tz - 1, tmaxy)
                self.tminmax[tz] = (tminx, tminy, tmaxx, tmaxy)

            # TODO: Maps crossing 180E (Alaska?)

            # Get the minimal zoom level (map covers area equivalent to one tile)
            if self.tminz is None:
                self.tminz = self.mercator.ZoomForPixelSize(
                    self.out_gt[1] *
                    max(self.warped_input_dataset.RasterXSize,
                        self.warped_input_dataset.RasterYSize) /
                    float(self.tile_size))

            # Get the maximal zoom level
            # (closest possible zoom level up on the resolution of raster)
            if self.tmaxz is None:
                self.tmaxz = self.mercator.ZoomForPixelSize(self.out_gt[1])
                self.tmaxz = max(self.tminz, self.tmaxz)

            self.tminz = min(self.tminz, self.tmaxz)

            if self.options.verbose:
                print("Bounds (latlong):",
                      self.mercator.MetersToLatLon(self.ominx, self.ominy),
                      self.mercator.MetersToLatLon(self.omaxx, self.omaxy))
                print('MinZoomLevel:', self.tminz)
                print("MaxZoomLevel:",
                      self.tmaxz,
                      "(",
                      self.mercator.Resolution(self.tmaxz),
                      ")")

        elif self.options.profile == 'geodetic':

            self.geodetic = GlobalGeodetic(self.options.tmscompatible, tile_size=self.tile_size)

            # Function which generates SWNE in LatLong for given tile
            self.tileswne = self.geodetic.TileLatLonBounds

            # Generate table with min max tile coordinates for all zoomlevels
            self.tminmax = list(range(0, MAXZOOMLEVEL))
            for tz in range(0, MAXZOOMLEVEL):
                tminx, tminy = self.geodetic.LonLatToTile(self.ominx, self.ominy, tz)
                tmaxx, tmaxy = self.geodetic.LonLatToTile(self.omaxx, self.omaxy, tz)
                # crop tiles extending world limits (+-180,+-90)
                tminx, tminy = max(0, tminx), max(0, tminy)
                tmaxx, tmaxy = min(2**(tz + 1) - 1, tmaxx), min(2**tz - 1, tmaxy)
                self.tminmax[tz] = (tminx, tminy, tmaxx, tmaxy)

            # TODO: Maps crossing 180E (Alaska?)

            # Get the maximal zoom level
            # (closest possible zoom level up on the resolution of raster)
            if self.tminz is None:
                self.tminz = self.geodetic.ZoomForPixelSize(
                    self.out_gt[1] *
                    max(self.warped_input_dataset.RasterXSize,
                        self.warped_input_dataset.RasterYSize) /
                    float(self.tile_size))

            # Get the maximal zoom level
            # (closest possible zoom level up on the resolution of raster)
            if self.tmaxz is None:
                self.tmaxz = self.geodetic.ZoomForPixelSize(self.out_gt[1])
                self.tmaxz = max(self.tminz, self.tmaxz)

            self.tminz = min(self.tminz, self.tmaxz)

            if self.options.verbose:
                print("Bounds (latlong):", self.ominx, self.ominy, self.omaxx, self.omaxy)

        elif self.options.profile == 'raster':

            def log2(x):
                return math.log10(x) / math.log10(2)

            self.nativezoom = max(0, int(
                max(math.ceil(log2(self.warped_input_dataset.RasterXSize / float(self.tile_size))),
                    math.ceil(log2(self.warped_input_dataset.RasterYSize / float(self.tile_size))))))

            if self.options.verbose:
                print("Native zoom of the raster:", self.nativezoom)

            # Get the minimal zoom level (whole raster in one tile)
            if self.tminz is None:
                self.tminz = 0

            # Get the maximal zoom level (native resolution of the raster)
            if self.tmaxz is None:
                self.tmaxz = self.nativezoom
                self.tmaxz = max(self.tminz, self.tmaxz)
            elif self.tmaxz > self.nativezoom:
                # If the user requests at a higher precision than the native
                # one, generate an oversample temporary VRT file, and tile from
                # it
                oversample_factor = 1 << (self.tmaxz - self.nativezoom)
                if self.options.resampling in ("average", "antialias"):
                    resampleAlg = "average"
                elif self.options.resampling in (
                    "near",
                    "bilinear",
                    "cubic",
                    "cubicspline",
                    "lanczos",
                    "mode",
                ):
                    resampleAlg = self.options.resampling
                else:
                    resampleAlg = "bilinear"  # fallback
                gdal.Translate(
                    self.tmp_vrt_filename,
                    input_dataset,
                    width=self.warped_input_dataset.RasterXSize * oversample_factor,
                    height=self.warped_input_dataset.RasterYSize * oversample_factor,
                    resampleAlg=resampleAlg,
                )
                self.warped_input_dataset = gdal.Open(self.tmp_vrt_filename)
                self.out_gt = self.warped_input_dataset.GetGeoTransform()
                self.nativezoom = self.tmaxz

            # Generate table with min max tile coordinates for all zoomlevels
            self.tminmax = list(range(0, self.tmaxz + 1))
            self.tsize = list(range(0, self.tmaxz + 1))
            for tz in range(0, self.tmaxz + 1):
                tsize = 2.0**(self.nativezoom - tz) * self.tile_size
                tminx, tminy = 0, 0
                tmaxx = int(math.ceil(self.warped_input_dataset.RasterXSize / tsize)) - 1
                tmaxy = int(math.ceil(self.warped_input_dataset.RasterYSize / tsize)) - 1
                self.tsize[tz] = math.ceil(tsize)
                self.tminmax[tz] = (tminx, tminy, tmaxx, tmaxy)

            # Function which generates SWNE in LatLong for given tile
            if self.kml and self.in_srs_wkt:
                ct = osr.CoordinateTransformation(self.in_srs, srs4326)

                def rastertileswne(x, y, z):
                    pixelsizex = (2**(self.tmaxz - z) * self.out_gt[1])       # X-pixel size in level
                    west = self.out_gt[0] + x * self.tile_size * pixelsizex
                    east = west + self.tile_size * pixelsizex
                    if self.options.xyz:
                        north = self.omaxy - y * self.tile_size * pixelsizex
                        south = north - self.tile_size * pixelsizex
                    else:
                        south = self.ominy + y * self.tile_size * pixelsizex
                        north = south + self.tile_size * pixelsizex
                    if not self.isepsg4326:
                        # Transformation to EPSG:4326 (WGS84 datum)
                        west, south = ct.TransformPoint(west, south)[:2]
                        east, north = ct.TransformPoint(east, north)[:2]
                    return south, west, north, east

                self.tileswne = rastertileswne
            else:
                self.tileswne = lambda x, y, z: (0, 0, 0, 0)   # noqa

        else:

            tms = tmsMap[self.options.profile]

            # Function which generates SWNE in LatLong for given tile
            self.tileswne = None # not implemented

            # Generate table with min max tile coordinates for all zoomlevels
            self.tminmax = list(range(0, tms.level_count+1))
            for tz in range(0, tms.level_count+1):
                tminx, tminy = tms.GeorefCoordToTileCoord(self.ominx, self.ominy, tz, self.tile_size)
                tmaxx, tmaxy = tms.GeorefCoordToTileCoord(self.omaxx, self.omaxy, tz, self.tile_size)
                tminx, tminy = max(0, tminx), max(0, tminy)
                tmaxx, tmaxy = min(tms.matrix_width * 2**tz - 1, tmaxx), min(tms.matrix_height * 2**tz - 1, tmaxy)
                self.tminmax[tz] = (tminx, tminy, tmaxx, tmaxy)

            # Get the minimal zoom level (map covers area equivalent to one tile)
            if self.tminz is None:
                self.tminz = tms.ZoomForPixelSize(
                    self.out_gt[1] *
                    max(self.warped_input_dataset.RasterXSize,
                        self.warped_input_dataset.RasterYSize) /
                    float(self.tile_size), self.tile_size)

            # Get the maximal zoom level
            # (closest possible zoom level up on the resolution of raster)
            if self.tmaxz is None:
                self.tmaxz = tms.ZoomForPixelSize(self.out_gt[1], self.tile_size)
                self.tmaxz = max(self.tminz, self.tmaxz)

            self.tminz = min(self.tminz, self.tmaxz)

            if self.options.verbose:
                print("Bounds (georef):", self.ominx, self.ominy, self.omaxx, self.omaxy)
                print('MinZoomLevel:', self.tminz)
                print("MaxZoomLevel:", self.tmaxz)


    def generate_metadata(self) -> None:
        """
        Generation of main metadata files and HTML viewers (metadata related to particular
        tiles are generated during the tile processing).
        """

        makedirs(self.output_folder)

        if self.options.profile == 'mercator':

            south, west = self.mercator.MetersToLatLon(self.ominx, self.ominy)
            north, east = self.mercator.MetersToLatLon(self.omaxx, self.omaxy)
            south, west = max(-85.05112878, south), max(-180.0, west)
            north, east = min(85.05112878, north), min(180.0, east)
            self.swne = (south, west, north, east)

            # Generate googlemaps.html
            if self.options.webviewer in ('all', 'google') and self.options.profile == 'mercator':
                if (not self.options.resume or not
                        isfile(os.path.join(self.output_folder, 'googlemaps.html'))):
                    with my_open(os.path.join(self.output_folder, 'googlemaps.html'), 'wb') as f:
                        f.write(self.generate_googlemaps().encode('utf-8'))

            # Generate leaflet.html
            if self.options.webviewer in ('all', 'leaflet'):
                if (not self.options.resume or not
                        isfile(os.path.join(self.output_folder, 'leaflet.html'))):
                    with my_open(os.path.join(self.output_folder, 'leaflet.html'), 'wb') as f:
                        f.write(self.generate_leaflet().encode('utf-8'))

        elif self.options.profile == 'geodetic':

            west, south = self.ominx, self.ominy
            east, north = self.omaxx, self.omaxy
            south, west = max(-90.0, south), max(-180.0, west)
            north, east = min(90.0, north), min(180.0, east)
            self.swne = (south, west, north, east)

        elif self.options.profile == 'raster':

            west, south = self.ominx, self.ominy
            east, north = self.omaxx, self.omaxy

            self.swne = (south, west, north, east)

        else:
            self.swne = None

        # Generate openlayers.html
        if self.options.webviewer in ('all', 'openlayers'):
            if (not self.options.resume or not
                    isfile(os.path.join(self.output_folder, 'openlayers.html'))):
                with my_open(os.path.join(self.output_folder, 'openlayers.html'), 'wb') as f:
                    f.write(self.generate_openlayers().encode('utf-8'))

        # Generate tilemapresource.xml.
        if not self.options.xyz and self.swne is not None and (not self.options.resume or not isfile(os.path.join(self.output_folder, 'tilemapresource.xml'))):
            with my_open(os.path.join(self.output_folder, 'tilemapresource.xml'), 'wb') as f:
                f.write(self.generate_tilemapresource().encode('utf-8'))

        # Generate mapml file
        if self.options.webviewer in ('all', 'mapml') and \
           self.options.xyz and \
           self.options.profile != 'raster' and \
           (self.options.profile != 'geodetic' or self.options.tmscompatible) and \
           (not self.options.resume or not isfile(os.path.join(self.output_folder, 'mapml.mapml'))):
            with my_open(os.path.join(self.output_folder, 'mapml.mapml'), 'wb') as f:
                f.write(self.generate_mapml().encode('utf-8'))


        if self.kml and self.tileswne is not None:
            # TODO: Maybe problem for not automatically generated tminz
            # The root KML should contain links to all tiles in the tminz level
            children = []
            xmin, ymin, xmax, ymax = self.tminmax[self.tminz]
            for x in range(xmin, xmax + 1):
                for y in range(ymin, ymax + 1):
                    children.append([x, y, self.tminz])
            # Generate Root KML
            if self.kml:
                if (not self.options.resume or not
                        isfile(os.path.join(self.output_folder, 'doc.kml'))):
                    with my_open(os.path.join(self.output_folder, 'doc.kml'), 'wb') as f:
                        f.write(generate_kml(
                            None, None, None, self.tileext, self.tile_size, self.tileswne,
                            self.options, children
                        ).encode('utf-8'))

    def generate_base_tiles(self) -> Tuple[TileJobInfo, List[TileDetail]]:
        """
        Generation of the base tiles (the lowest in the pyramid) directly from the input raster
        """

        if not self.options.quiet:
            print("Generating Base Tiles:")

        if self.options.verbose:
            print('')
            print("Tiles generated from the max zoom level:")
            print("----------------------------------------")
            print('')

        # Set the bounds
        tminx, tminy, tmaxx, tmaxy = self.tminmax[self.tmaxz]

        ds = self.warped_input_dataset
        tilebands = self.dataBandsCount + 1
        querysize = self.querysize

        if self.options.verbose:
            print("dataBandsCount: ", self.dataBandsCount)
            print("tilebands: ", tilebands)

        tcount = (1 + abs(tmaxx - tminx)) * (1 + abs(tmaxy - tminy))
        ti = 0

        tile_details = []

        tz = self.tmaxz

        # Create directories for the tiles
        for tx in range(tminx, tmaxx + 1):
            tiledirname = os.path.join(self.output_folder, str(tz), str(tx))
            makedirs(tiledirname)

        for ty in range(tmaxy, tminy - 1, -1):
            for tx in range(tminx, tmaxx + 1):

                ti += 1
                ytile = GDAL2Tiles.getYTile(ty, tz, self.options)
                tilefilename = os.path.join(
                    self.output_folder, str(tz), str(tx), "%s.%s" % (ytile, self.tileext))
                if self.options.verbose:
                    print(ti, '/', tcount, tilefilename)

                if self.options.resume and isfile(tilefilename):
                    if self.options.verbose:
                        print("Tile generation skipped because of --resume")
                    continue

                if self.options.profile == 'mercator':
                    # Tile bounds in EPSG:3857
                    b = self.mercator.TileBounds(tx, ty, tz)
                elif self.options.profile == 'geodetic':
                    b = self.geodetic.TileBounds(tx, ty, tz)
                elif self.options.profile != 'raster':
                    b = tmsMap[self.options.profile].TileBounds(tx, ty, tz, self.tile_size)

                # Don't scale up by nearest neighbour, better change the querysize
                # to the native resolution (and return smaller query tile) for scaling

                if self.options.profile != 'raster':
                    rb, wb = self.geo_query(ds, b[0], b[3], b[2], b[1])

                    # Pixel size in the raster covering query geo extent
                    nativesize = wb[0] + wb[2]
                    if self.options.verbose:
                        print("\tNative Extent (querysize", nativesize, "): ", rb, wb)

                    # Tile bounds in raster coordinates for ReadRaster query
                    rb, wb = self.geo_query(ds, b[0], b[3], b[2], b[1], querysize=querysize)

                    rx, ry, rxsize, rysize = rb
                    wx, wy, wxsize, wysize = wb

                else:     # 'raster' profile:

                    tsize = int(self.tsize[tz])   # tile_size in raster coordinates for actual zoom
                    xsize = self.warped_input_dataset.RasterXSize     # size of the raster in pixels
                    ysize = self.warped_input_dataset.RasterYSize
                    querysize = self.tile_size

                    rx = tx * tsize
                    rxsize = 0
                    if tx == tmaxx:
                        rxsize = xsize % tsize
                    if rxsize == 0:
                        rxsize = tsize

                    ry = ty * tsize
                    rysize = 0
                    if ty == tmaxy:
                        rysize = ysize % tsize
                    if rysize == 0:
                        rysize = tsize

                    wx, wy = 0, 0
                    wxsize = int(rxsize / float(tsize) * self.tile_size)
                    wysize = int(rysize / float(tsize) * self.tile_size)

                    if not self.options.xyz:
                        ry = ysize - (ty * tsize) - rysize
                        if wysize != self.tile_size:
                            wy = self.tile_size - wysize

                # Read the source raster if anything is going inside the tile as per the computed
                # geo_query
                tile_details.append(
                    TileDetail(
                        tx=tx, ty=ytile, tz=tz, rx=rx, ry=ry, rxsize=rxsize, rysize=rysize, wx=wx,
                        wy=wy, wxsize=wxsize, wysize=wysize, querysize=querysize,
                    )
                )

        conf = TileJobInfo(
            src_file=self.tmp_vrt_filename,
            nb_data_bands=self.dataBandsCount,
            output_file_path=self.output_folder,
            tile_extension=self.tileext,
            tile_driver=self.tiledriver,
            tile_size=self.tile_size,
            kml=self.kml,
            tminmax=self.tminmax,
            tminz=self.tminz,
            tmaxz=self.tmaxz,
            in_srs_wkt=self.in_srs_wkt,
            out_geo_trans=self.out_gt,
            ominy=self.ominy,
            is_epsg_4326=self.isepsg4326,
            options=self.options,
            exclude_transparent=self.options.exclude_transparent,
        )

        return conf, tile_details

    def geo_query(self, ds, ulx, uly, lrx, lry, querysize=0):
        """
        For given dataset and query in cartographic coordinates returns parameters for ReadRaster()
        in raster coordinates and x/y shifts (for border tiles). If the querysize is not given, the
        extent is returned in the native resolution of dataset ds.

        raises Gdal2TilesError if the dataset does not contain anything inside this geo_query
        """
        geotran = ds.GetGeoTransform()
        rx = int((ulx - geotran[0]) / geotran[1] + 0.001)
        ry = int((uly - geotran[3]) / geotran[5] + 0.001)
        rxsize = max(1, int((lrx - ulx) / geotran[1] + 0.5))
        rysize = max(1, int((lry - uly) / geotran[5] + 0.5))

        if not querysize:
            wxsize, wysize = rxsize, rysize
        else:
            wxsize, wysize = querysize, querysize

        # Coordinates should not go out of the bounds of the raster
        wx = 0
        if rx < 0:
            rxshift = abs(rx)
            wx = int(wxsize * (float(rxshift) / rxsize))
            wxsize = wxsize - wx
            rxsize = rxsize - int(rxsize * (float(rxshift) / rxsize))
            rx = 0
        if rx + rxsize > ds.RasterXSize:
            wxsize = int(wxsize * (float(ds.RasterXSize - rx) / rxsize))
            rxsize = ds.RasterXSize - rx

        wy = 0
        if ry < 0:
            ryshift = abs(ry)
            wy = int(wysize * (float(ryshift) / rysize))
            wysize = wysize - wy
            rysize = rysize - int(rysize * (float(ryshift) / rysize))
            ry = 0
        if ry + rysize > ds.RasterYSize:
            wysize = int(wysize * (float(ds.RasterYSize - ry) / rysize))
            rysize = ds.RasterYSize - ry

        return (rx, ry, rxsize, rysize), (wx, wy, wxsize, wysize)

    def generate_tilemapresource(self) -> str:
        """
        Template for tilemapresource.xml. Returns filled string. Expected variables:
          title, north, south, east, west, isepsg4326, projection, publishurl,
          zoompixels, tile_size, tileformat, profile
        """

        args = {}
        args['xml_escaped_title'] = gdal.EscapeString(self.options.title, gdal.CPLES_XML)
        args['south'], args['west'], args['north'], args['east'] = self.swne
        args['tile_size'] = self.tile_size
        args['tileformat'] = self.tileext
        args['publishurl'] = self.options.url
        args['profile'] = self.options.profile

        if self.options.profile == 'mercator':
            args['srs'] = "EPSG:3857"
        elif self.options.profile == 'geodetic':
            args['srs'] = "EPSG:4326"
        elif self.options.s_srs:
            args['srs'] = self.options.s_srs
        elif self.out_srs:
            args['srs'] = self.out_srs.ExportToWkt()
        else:
            args['srs'] = ""

        s = """<?xml version="1.0" encoding="utf-8"?>
    <TileMap version="1.0.0" tilemapservice="http://tms.osgeo.org/1.0.0">
      <Title>%(xml_escaped_title)s</Title>
      <Abstract></Abstract>
      <SRS>%(srs)s</SRS>
      <BoundingBox minx="%(west).14f" miny="%(south).14f" maxx="%(east).14f" maxy="%(north).14f"/>
      <Origin x="%(west).14f" y="%(south).14f"/>
      <TileFormat width="%(tile_size)d" height="%(tile_size)d" mime-type="image/%(tileformat)s" extension="%(tileformat)s"/>
      <TileSets profile="%(profile)s">
""" % args    # noqa
        for z in range(self.tminz, self.tmaxz + 1):
            if self.options.profile == 'raster':
                s += """        <TileSet href="%s%d" units-per-pixel="%.14f" order="%d"/>\n""" % (
                    args['publishurl'], z, (2**(self.nativezoom - z) * self.out_gt[1]), z)
            elif self.options.profile == 'mercator':
                s += """        <TileSet href="%s%d" units-per-pixel="%.14f" order="%d"/>\n""" % (
                    args['publishurl'], z, 156543.0339 / 2**z, z)
            elif self.options.profile == 'geodetic':
                s += """        <TileSet href="%s%d" units-per-pixel="%.14f" order="%d"/>\n""" % (
                    args['publishurl'], z, 0.703125 / 2**z, z)
        s += """      </TileSets>
    </TileMap>
    """
        return s


    def generate_googlemaps(self) -> str:
        """
        Template for googlemaps.html implementing Overlay of tiles for 'mercator' profile.
        It returns filled string. Expected variables:
        title, googlemapskey, north, south, east, west, minzoom, maxzoom, tile_size, tileformat,
        publishurl
        """
        args = {}
        args["xml_escaped_title"] = gdal.EscapeString(
            self.options.title, gdal.CPLES_XML
        )
        args["googlemapsurl"] = "https://maps.googleapis.com/maps/api/js"
        if self.options.googlekey != "INSERT_YOUR_KEY_HERE":
            args["googlemapsurl"] += "?key=" + self.options.googlekey
            args["googlemapsurl_hint"] = ""
        else:
            args[
                "googlemapsurl_hint"
            ] = "<!-- Replace URL below with https://maps.googleapis.com/maps/api/js?key=INSERT_YOUR_KEY_HERE -->"
        args["south"], args["west"], args["north"], args["east"] = self.swne
        args["minzoom"] = self.tminz
        args["maxzoom"] = self.tmaxz
        args["tile_size"] = self.tile_size
        args["tileformat"] = self.tileext
        args["publishurl"] = self.options.url
        args["copyright"] = self.options.copyright

        # Logic below inspired from https://www.gavinharriss.com/code/opacity-control
        # which borrowed on gdal2tiles itself to migrate from Google Maps V2 to V3

        args[
            "custom_tile_overlay_js"
        ] = """
// Beginning of https://github.com/gavinharriss/google-maps-v3-opacity-control/blob/master/CustomTileOverlay.js
// with CustomTileOverlay.prototype.getTileUrl() method customized for gdal2tiles needs.

/*******************************************************************************
Copyright (c) 2010-2012. Gavin Harriss
Site: http://www.gavinharriss.com/
Originally developed for: http://www.topomap.co.nz/
Licences: Creative Commons Attribution 3.0 New Zealand License
http://creativecommons.org/licenses/by/3.0/nz/
******************************************************************************/

CustomTileOverlay = function (map, opacity) {
    this.tileSize = new google.maps.Size(256, 256); // Change to tile size being used

    this.map = map;
    this.opacity = opacity;
    this.tiles = [];

    this.visible = false;
    this.initialized = false;

    this.self = this;
}

CustomTileOverlay.prototype = new google.maps.OverlayView();

CustomTileOverlay.prototype.getTile = function (p, z, ownerDocument) {
    // If tile already exists then use it
    for (var n = 0; n < this.tiles.length; n++) {
        if (this.tiles[n].id == 't_' + p.x + '_' + p.y + '_' + z) {
            return this.tiles[n];
        }
    }

    // If tile doesn't exist then create it
    var tile = ownerDocument.createElement('div');
    var tp = this.getTileUrlCoord(p, z);
    tile.id = 't_' + tp.x + '_' + tp.y + '_' + z
    tile.style.width = this.tileSize.width + 'px';
    tile.style.height = this.tileSize.height + 'px';
    tile.style.backgroundImage = 'url(' + this.getTileUrl(tp, z) + ')';
    tile.style.backgroundRepeat = 'no-repeat';

    if (!this.visible) {
        tile.style.display = 'none';
    }

    this.tiles.push(tile)

    this.setObjectOpacity(tile);

    return tile;
}

// Save memory / speed up the display by deleting tiles out of view
// Essential for use on iOS devices such as iPhone and iPod!
CustomTileOverlay.prototype.deleteHiddenTiles = function (zoom) {
    var bounds = this.map.getBounds();
    var tileNE = this.getTileUrlCoordFromLatLng(bounds.getNorthEast(), zoom);
    var tileSW = this.getTileUrlCoordFromLatLng(bounds.getSouthWest(), zoom);

    var minX = tileSW.x - 1;
    var maxX = tileNE.x + 1;
    var minY = tileSW.y - 1;
    var maxY = tileNE.y + 1;

    var tilesToKeep = [];
    var tilesLength = this.tiles.length;
    for (var i = 0; i < tilesLength; i++) {
        var idParts = this.tiles[i].id.split("_");
        var tileX = Number(idParts[1]);
        var tileY = Number(idParts[2]);
        var tileZ = Number(idParts[3]);
        if ((
                (minX < maxX && (tileX >= minX && tileX <= maxX))
                || (minX > maxX && ((tileX >= minX && tileX <= (Math.pow(2, zoom) - 1)) || (tileX >= 0 && tileX <= maxX))) // Lapped the earth!
            )
            && (tileY >= minY && tileY <= maxY)
            && tileZ == zoom) {
            tilesToKeep.push(this.tiles[i]);
        }
        else {
            delete this.tiles[i];
        }
    }

    this.tiles = tilesToKeep;
};

CustomTileOverlay.prototype.pointToTile = function (point, z) {
    var projection = this.map.getProjection();
    var worldCoordinate = projection.fromLatLngToPoint(point);
    var pixelCoordinate = new google.maps.Point(worldCoordinate.x * Math.pow(2, z), worldCoordinate.y * Math.pow(2, z));
    var tileCoordinate = new google.maps.Point(Math.floor(pixelCoordinate.x / this.tileSize.width), Math.floor(pixelCoordinate.y / this.tileSize.height));
    return tileCoordinate;
}

CustomTileOverlay.prototype.getTileUrlCoordFromLatLng = function (latlng, zoom) {
    return this.getTileUrlCoord(this.pointToTile(latlng, zoom), zoom)
}

CustomTileOverlay.prototype.getTileUrlCoord = function (coord, zoom) {
    var tileRange = 1 << zoom;
    var y = tileRange - coord.y - 1;
    var x = coord.x;
    if (x < 0 || x >= tileRange) {
        x = (x % tileRange + tileRange) % tileRange;
    }
    return new google.maps.Point(x, y);
}

// Modified for gdal2tiles needs
CustomTileOverlay.prototype.getTileUrl = function (tile, zoom) {

      if ((zoom < mapMinZoom) || (zoom > mapMaxZoom)) {
          return "https://gdal.org/resources/gdal2tiles/none.png";
      }
      var ymax = 1 << zoom;
      var y = ymax - tile.y -1;
      var tileBounds = new google.maps.LatLngBounds(
          fromMercatorPixelToLatLng( new google.maps.Point( (tile.x)*256, (y+1)*256 ) , zoom ),
          fromMercatorPixelToLatLng( new google.maps.Point( (tile.x+1)*256, (y)*256 ) , zoom )
      );
      if (mapBounds.intersects(tileBounds)) {
          return zoom+"/"+tile.x+"/"+tile.y+".png";
      } else {
          return "https://gdal.org/resources/gdal2tiles/none.png";
      }

}

CustomTileOverlay.prototype.initialize = function () {
    if (this.initialized) {
        return;
    }
    var self = this.self;
    this.map.overlayMapTypes.insertAt(0, self);
    this.initialized = true;
}

CustomTileOverlay.prototype.hide = function () {
    this.visible = false;

    var tileCount = this.tiles.length;
    for (var n = 0; n < tileCount; n++) {
        this.tiles[n].style.display = 'none';
    }
}

CustomTileOverlay.prototype.show = function () {
    this.initialize();
    this.visible = true;
    var tileCount = this.tiles.length;
    for (var n = 0; n < tileCount; n++) {
        this.tiles[n].style.display = '';
    }
}

CustomTileOverlay.prototype.releaseTile = function (tile) {
    tile = null;
}

CustomTileOverlay.prototype.setOpacity = function (op) {
    this.opacity = op;

    var tileCount = this.tiles.length;
    for (var n = 0; n < tileCount; n++) {
        this.setObjectOpacity(this.tiles[n]);
    }
}

CustomTileOverlay.prototype.setObjectOpacity = function (obj) {
    if (this.opacity > 0) {
        if (typeof (obj.style.filter) == 'string') { obj.style.filter = 'alpha(opacity:' + this.opacity + ')'; }
        if (typeof (obj.style.KHTMLOpacity) == 'string') { obj.style.KHTMLOpacity = this.opacity / 100; }
        if (typeof (obj.style.MozOpacity) == 'string') { obj.style.MozOpacity = this.opacity / 100; }
        if (typeof (obj.style.opacity) == 'string') { obj.style.opacity = this.opacity / 100; }
    }
}

// End of https://github.com/gavinharriss/google-maps-v3-opacity-control/blob/master/CustomTileOverlay.js
"""

        args[
            "ext_draggable_object_js"
        ] = """
// Beginning of https://github.com/gavinharriss/google-maps-v3-opacity-control/blob/master/ExtDraggableObject.js

/**
 * @name ExtDraggableObject
 * @version 1.0
 * @author Gabriel Schneider
 * @copyright (c) 2009 Gabriel Schneider
 * @fileoverview This sets up a given DOM element to be draggable
 *     around the page.
 */

/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Sets up a DOM element to be draggable. The options available
 *     within {@link ExtDraggableObjectOptions} are: top, left, container,
 *     draggingCursor, draggableCursor, intervalX, intervalY,
 *     toleranceX, toleranceY, restrictX, and restrictY.
 * @param {HTMLElement} src The element to make draggable
 * @param {ExtDraggableObjectOptions} [opts] options
 * @constructor
 */
function ExtDraggableObject(src, opt_drag) {
  var me = this;
  var event_ = (window["GEvent"]||google.maps.Event||google.maps.event);
  var opt_drag_=opt_drag||{};
  var draggingCursor_ = opt_drag_.draggingCursor||"default";
  var draggableCursor_ = opt_drag_.draggableCursor||"default";
  var moving_ = false, preventDefault_;
  var currentX_, currentY_, formerY_, formerX_, formerMouseX_, formerMouseY_;
  var top_, left_;
  var mouseDownEvent_, mouseUpEvent_, mouseMoveEvent_;
  var originalX_, originalY_;
  var halfIntervalX_ = Math.round(opt_drag_.intervalX/2);
  var halfIntervalY_ = Math.round(opt_drag_.intervalY/2);
  var target_ = src.setCapture?src:document;

  if (typeof opt_drag_.intervalX !== "number") {
    opt_drag_.intervalX = 1;
  }
  if (typeof opt_drag_.intervalY !== "number") {
    opt_drag_.intervalY = 1;
  }
  if (typeof opt_drag_.toleranceX !== "number") {
    opt_drag_.toleranceX = Infinity;
  }
  if (typeof opt_drag_.toleranceY !== "number") {
    opt_drag_.toleranceY = Infinity;
  }

  mouseDownEvent_ = event_.addDomListener(src, "mousedown", mouseDown_);
  mouseUpEvent_ = event_.addDomListener(target_, "mouseup", mouseUp_);

  setCursor_(false);
  if (opt_drag_.container) {

  }
  src.style.position = "absolute";
  opt_drag_.left = opt_drag_.left||src.offsetLeft;
  opt_drag_.top = opt_drag_.top||src.offsetTop;
  opt_drag_.interval = opt_drag_.interval||1;
  moveTo_(opt_drag_.left, opt_drag_.top, false);

  /**
   * Set the cursor for {@link src} based on whether or not
   *     the element is currently being dragged.
   * @param {Boolean} a Is the element being dragged?
   * @private
   */
  function setCursor_(a) {
    if(a) {
      src.style.cursor = draggingCursor_;
    } else {
      src.style.cursor = draggableCursor_;
    }
  }

  /**
   * Moves the element {@link src} to the given
   *     location.
   * @param {Number} x The left position to move to.
   * @param {Number} y The top position to move to.
   * @param {Boolean} prevent Prevent moving?
   * @private
   */
  function moveTo_(x, y, prevent) {
    var roundedIntervalX_, roundedIntervalY_;
    left_ = Math.round(x);
    top_ = Math.round(y);
    if (opt_drag_.intervalX>1) {
      roundedIntervalX_ = Math.round(left_%opt_drag_.intervalX);
      left_ = (roundedIntervalX_<halfIntervalX_)?(left_-roundedIntervalX_):(left_+(opt_drag_.intervalX-roundedIntervalX_));
    }
    if (opt_drag_.intervalY>1) {
      roundedIntervalY_ = Math.round(top_%opt_drag_.intervalY);
      top_ = (roundedIntervalY_<halfIntervalY_)?(top_-roundedIntervalY_):(top_+(opt_drag_.intervalY-roundedIntervalY_));
    }
    if (opt_drag_.container&&opt_drag_.container.offsetWidth) {
      left_ = Math.max(0,Math.min(left_,opt_drag_.container.offsetWidth-src.offsetWidth));
      top_ = Math.max(0,Math.min(top_,opt_drag_.container.offsetHeight-src.offsetHeight));
    }
    if (typeof currentX_ === "number") {
      if (((left_-currentX_)>opt_drag_.toleranceX||(currentX_-(left_+src.offsetWidth))>opt_drag_.toleranceX)||((top_-currentY_)>opt_drag_.toleranceY||(currentY_-(top_+src.offsetHeight))>opt_drag_.toleranceY)) {
        left_ = originalX_;
        top_ = originalY_;
      }
    }
    if(!opt_drag_.restrictX&&!prevent) {
      src.style.left = left_ + "px";
    }
    if(!opt_drag_.restrictY&&!prevent) {
      src.style.top = top_ + "px";
    }
  }

  /**
   * Handles the mousemove event.
   * @param {event} ev The event data sent by the browser.
   * @private
   */
  function mouseMove_(ev) {
    var e=ev||event;
    currentX_ = formerX_+((e.pageX||(e.clientX+document.body.scrollLeft+document.documentElement.scrollLeft))-formerMouseX_);
    currentY_ = formerY_+((e.pageY||(e.clientY+document.body.scrollTop+document.documentElement.scrollTop))-formerMouseY_);
    formerX_ = currentX_;
    formerY_ = currentY_;
    formerMouseX_ = e.pageX||(e.clientX+document.body.scrollLeft+document.documentElement.scrollLeft);
    formerMouseY_ = e.pageY||(e.clientY+document.body.scrollTop+document.documentElement.scrollTop);
    if (moving_) {
      moveTo_(currentX_,currentY_, preventDefault_);
      event_.trigger(me, "drag", {mouseX: formerMouseX_, mouseY: formerMouseY_, startLeft: originalX_, startTop: originalY_, event:e});
    }
  }

  /**
   * Handles the mousedown event.
   * @param {event} ev The event data sent by the browser.
   * @private
   */
  function mouseDown_(ev) {
    var e=ev||event;
    setCursor_(true);
    event_.trigger(me, "mousedown", e);
    if (src.style.position !== "absolute") {
      src.style.position = "absolute";
      return;
    }
    formerMouseX_ = e.pageX||(e.clientX+document.body.scrollLeft+document.documentElement.scrollLeft);
    formerMouseY_ = e.pageY||(e.clientY+document.body.scrollTop+document.documentElement.scrollTop);
    originalX_ = src.offsetLeft;
    originalY_ = src.offsetTop;
    formerX_ = originalX_;
    formerY_ = originalY_;
    mouseMoveEvent_ = event_.addDomListener(target_, "mousemove", mouseMove_);
    if (src.setCapture) {
      src.setCapture();
    }
    if (e.preventDefault) {
      e.preventDefault();
      e.stopPropagation();
    } else {
      e.cancelBubble=true;
      e.returnValue=false;
    }
    moving_ = true;
    event_.trigger(me, "dragstart", {mouseX: formerMouseX_, mouseY: formerMouseY_, startLeft: originalX_, startTop: originalY_, event:e});
  }

  /**
   * Handles the mouseup event.
   * @param {event} ev The event data sent by the browser.
   * @private
   */
  function mouseUp_(ev) {
    var e=ev||event;
    if (moving_) {
      setCursor_(false);
      event_.removeListener(mouseMoveEvent_);
      if (src.releaseCapture) {
        src.releaseCapture();
      }
      moving_ = false;
      event_.trigger(me, "dragend", {mouseX: formerMouseX_, mouseY: formerMouseY_, startLeft: originalX_, startTop: originalY_, event:e});
    }
    currentX_ = currentY_ = null;
    event_.trigger(me, "mouseup", e);
  }

  /**
   * Move the element {@link src} to the given location.
   * @param {Point} point An object with an x and y property
   *     that represents the location to move to.
   */
  me.moveTo = function(point) {
    moveTo_(point.x, point.y, false);
  };

  /**
   * Move the element {@link src} by the given amount.
   * @param {Size} size An object with an x and y property
   *     that represents distance to move the element.
   */
  me.moveBy = function(size) {
    moveTo_(src.offsetLeft + size.width, src.offsetHeight + size.height, false);
  }

  /**
   * Sets the cursor for the dragging state.
   * @param {String} cursor The name of the cursor to use.
   */
  me.setDraggingCursor = function(cursor) {
    draggingCursor_ = cursor;
    setCursor_(moving_);
  };

  /**
   * Sets the cursor for the draggable state.
   * @param {String} cursor The name of the cursor to use.
   */
  me.setDraggableCursor = function(cursor) {
    draggableCursor_ = cursor;
    setCursor_(moving_);
  };

  /**
   * Returns the current left location.
   * @return {Number}
   */
  me.left = function() {
    return left_;
  };

  /**
   * Returns the current top location.
   * @return {Number}
   */
  me.top = function() {
    return top_;
  };

  /**
   * Returns the number of intervals the element has moved
   *     along the X axis. Useful for scrollbar type
   *     applications.
   * @return {Number}
   */
  me.valueX = function() {
    var i = opt_drag_.intervalX||1;
    return Math.round(left_ / i);
  };

  /**
   * Returns the number of intervals the element has moved
   *     along the Y axis. Useful for scrollbar type
   *     applications.
   * @return {Number}
   */
  me.valueY = function() {
    var i = opt_drag_.intervalY||1;
    return Math.round(top_ / i);
  };

  /**
   * Sets the left position of the draggable object based on
   *     intervalX.
   * @param {Number} value The location to move to.
   */
  me.setValueX = function(value) {
    moveTo_(value * opt_drag_.intervalX, top_, false);
  };

  /**
   * Sets the top position of the draggable object based on
   *     intervalY.
   * @param {Number} value The location to move to.
   */
  me.setValueY = function(value) {
    moveTo_(left_, value * opt_drag_.intervalY, false);
  };

  /**
   * Prevents the default movement behavior of the object.
   *     The object can still be moved by other methods.
   */
  me.preventDefaultMovement = function(prevent) {
    preventDefault_ = prevent;
  };
}
  /**
   * @name ExtDraggableObjectOptions
   * @class This class represents the optional parameter passed into constructor of
   * <code>ExtDraggableObject</code>.
   * @property {Number} [top] Top pixel
   * @property {Number} [left] Left pixel
   * @property {HTMLElement} [container] HTMLElement as container.
   * @property {String} [draggingCursor] Dragging Cursor
   * @property {String} [draggableCursor] Draggable Cursor
   * @property {Number} [intervalX] Interval in X direction
   * @property {Number} [intervalY] Interval in Y direction
   * @property {Number} [toleranceX] Tolerance X in pixel
   * @property {Number} [toleranceY] Tolerance Y in pixel
   * @property {Boolean} [restrictX] Whether to restrict move in X direction
   * @property {Boolean} [restrictY] Whether to restrict move in Y direction
   */

 // End of https://github.com/gavinharriss/google-maps-v3-opacity-control/blob/master/ExtDraggableObject.js
"""

        s = (
            r"""<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
            <html xmlns="http://www.w3.org/1999/xhtml" xmlns:v="urn:schemas-microsoft-com:vml">
              <head>
                <title>%(xml_escaped_title)s</title>
                <meta http-equiv="content-type" content="text/html; charset=utf-8"/>
                <meta http-equiv='imagetoolbar' content='no'/>
                <style type="text/css"> v\:* {behavior:url(#default#VML);}
                    html, body { overflow: hidden; padding: 0; height: 100%%; width: 100%%; font-family: 'Lucida Grande',Geneva,Arial,Verdana,sans-serif; }
                    body { margin: 10px; background: #fff; }
                    h1 { margin: 0; padding: 6px; border:0; font-size: 20pt; }
                    #header { height: 43px; padding: 0; background-color: #eee; border: 1px solid #888; }
              #subheader { height: 12px; text-align: right; font-size: 10px; color: #555;}
              #map { height: 95%%; border: 1px solid #888; }
          </style>
          %(googlemapsurl_hint)s
          <script src='%(googlemapsurl)s'></script>
          <script>
          //<![CDATA[

                /*
                 * Constants for given map
                 * TODO: read it from tilemapresource.xml
                 */

                var mapBounds = new google.maps.LatLngBounds(
                    new google.maps.LatLng(%(south)s, %(west)s),
                    new google.maps.LatLng(%(north)s, %(east)s));
                var mapMinZoom = %(minzoom)s;
                var mapMaxZoom = %(maxzoom)s;


                var initialOpacity = 0.75 * 100;
                var map;

                /*
                 * Full-screen Window Resize
                 */

                function getWindowHeight() {
                    if (self.innerHeight) return self.innerHeight;
                    if (document.documentElement && document.documentElement.clientHeight)
                        return document.documentElement.clientHeight;
                    if (document.body) return document.body.clientHeight;
                    return 0;
                }

                function getWindowWidth() {
                    if (self.innerWidth) return self.innerWidth;
                    if (document.documentElement && document.documentElement.clientWidth)
                        return document.documentElement.clientWidth;
                    if (document.body) return document.body.clientWidth;
                    return 0;
                }

                function resize() {
                    var map = document.getElementById("map");
                    var header = document.getElementById("header");
                    var subheader = document.getElementById("subheader");
                    map.style.height = (getWindowHeight()-80) + "px";
                    map.style.width = (getWindowWidth()-20) + "px";
                    header.style.width = (getWindowWidth()-20) + "px";
                    subheader.style.width = (getWindowWidth()-20) + "px";
                    // map.checkResize();
                }


                // getZoomByBounds(): adapted from https://stackoverflow.com/a/9982152
                /**
                * Returns the zoom level at which the given rectangular region fits in the map view.
                * The zoom level is computed for the currently selected map type.
                * @param {google.maps.Map} map
                * @param {google.maps.LatLngBounds} bounds
                * @return {Number} zoom level
                **/
                function getZoomByBounds(  map, bounds ){
                  var MAX_ZOOM = 21 ;
                  var MIN_ZOOM =  0 ;

                  var ne= map.getProjection().fromLatLngToPoint( bounds.getNorthEast() );
                  var sw= map.getProjection().fromLatLngToPoint( bounds.getSouthWest() );

                  var worldCoordWidth = Math.abs(ne.x-sw.x);
                  var worldCoordHeight = Math.abs(ne.y-sw.y);
                  //Fit padding in pixels
                  var FIT_PAD = 40;
                  for( var zoom = MAX_ZOOM; zoom >= MIN_ZOOM; --zoom ){
                      if( worldCoordWidth*(1<<zoom)+2*FIT_PAD < map.getDiv().offsetWidth &&
                          worldCoordHeight*(1<<zoom)+2*FIT_PAD < map.getDiv().offsetHeight )
                      {
                          if( zoom > mapMaxZoom )
                              zoom = mapMaxZoom;
                          return zoom;
                      }
                  }
                  return 0;
                }

                function fromMercatorPixelToLatLng(pixel, zoom)
                {
                    var CST = 6378137 * Math.PI;
                    var res = 2 * CST / 256 / Math.pow(2, zoom);
                    var X = -CST + pixel.x * res;
                    var Y = CST - pixel.y * res;
                    var lon = X / CST * 180;
                    var lat = Math.atan(Math.sinh(Y / CST * Math.PI)) / Math.PI * 180;
                    return new google.maps.LatLng(lat, lon);
                }


                var OPACITY_MAX_PIXELS = 57; // Width of opacity control image

                function createOpacityControl(map, opacity) {
                    var sliderImageUrl = "https://gdal.org/resources/gdal2tiles/opacity-slider.png";

                    // Create main div to hold the control.
                    var opacityDiv = document.createElement('DIV');
                    var opacityDivMargin = 5;
                    opacityDiv.setAttribute("style", "margin:" + opacityDivMargin + "px;overflow-x:hidden;overflow-y:hidden;background:url(" + sliderImageUrl + ") no-repeat;width:71px;height:21px;cursor:pointer;");

                    // Create knob
                    var opacityKnobDiv = document.createElement('DIV');
                    opacityKnobDiv.setAttribute("style", "padding:0;margin:0;overflow-x:hidden;overflow-y:hidden;background:url(" + sliderImageUrl + ") no-repeat -71px 0;width:14px;height:21px;");
                    opacityDiv.appendChild(opacityKnobDiv);

                    var opacityCtrlKnob = new ExtDraggableObject(opacityKnobDiv, {
                        restrictY: true,
                        container: opacityDiv
                    });

                    google.maps.event.addListener(opacityCtrlKnob, "dragend", function () {
                        setOpacity(opacityCtrlKnob.valueX());
                    });

                    google.maps.event.addDomListener(opacityDiv, "click", function (e) {
                        var left = this.getBoundingClientRect().left;
                        var x = e.pageX - left - opacityDivMargin;
                        opacityCtrlKnob.setValueX(x);
                        setOpacity(x);
                    });

                    map.controls[google.maps.ControlPosition.TOP_RIGHT].push(opacityDiv);

                    // Set initial value
                    var initialValue = OPACITY_MAX_PIXELS / (100 / opacity);
                    opacityCtrlKnob.setValueX(initialValue);
                    setOpacity(initialValue);
                }

                function setOpacity(pixelX) {
                    // Range = 0 to OPACITY_MAX_PIXELS
                    var value = (100 / OPACITY_MAX_PIXELS) * pixelX;
                    if (value < 0) value = 0;
                    if (value == 0) {
                        if (overlay.visible == true) {
                            overlay.hide();
                        }
                    }
                    else {
                        overlay.setOpacity(value);
                        if (overlay.visible == false) {
                            overlay.show();
                        }
                    }
                }

                function createCopyrightControl(map, copyright) {
                    const label = document.createElement("label");
                    label.style.backgroundColor = "#ffffff";
                    label.textContent = copyright;

                    const div = document.createElement("div");
                    div.appendChild(label);

                    map.controls[google.maps.ControlPosition.BOTTOM_RIGHT].push(div);
                }

                %(ext_draggable_object_js)s

                /*
                 * Main load function:
                 */

                function load() {

                    var options = {
                      center: mapBounds.getCenter(),
                      zoom: mapMaxZoom,
                      mapTypeId: google.maps.MapTypeId.HYBRID,

                      // Add map type control
                      mapTypeControl: true,
                      mapTypeControlOptions: {
                          style: google.maps.MapTypeControlStyle.HORIZONTAL_BAR,
                          position: google.maps.ControlPosition.TOP_LEFT
                      },

                      // Add scale
                      scaleControl: true,
                      scaleControlOptions: {
                          position: google.maps.ControlPosition.BOTTOM_RIGHT
                      }
                    };

                    map = new google.maps.Map( document.getElementById("map"), options);
                    google.maps.event.addListenerOnce(map, "projection_changed", function() {
                       map.setZoom(getZoomByBounds( map, mapBounds ));
                    });

                    %(custom_tile_overlay_js)s

                    overlay = new CustomTileOverlay(map, initialOpacity);
                    overlay.show();

                    google.maps.event.addListener(map, 'tilesloaded', function () {
                        overlay.deleteHiddenTiles(map.getZoom());
                    });

                    // Add opacity control and set initial value
                    createOpacityControl(map, initialOpacity);

                    var copyright = "%(copyright)s";
                    if( copyright != "" ) {
                        createCopyrightControl(map, copyright);
                    }

                    resize();
                }

                onresize=function(){ resize(); };

                //]]>
                </script>
              </head>
              <body onload="load()">
                  <div id="header"><h1>%(xml_escaped_title)s</h1></div>
                  <div id="subheader">Generated by <a href="https://gdal.org/programs/gdal2tiles.html">GDAL2Tiles</a>, Copyright &copy; 2008 <a href="http://www.klokan.cz/">Klokan Petr Pridal</a>,  <a href="https://gdal.org">GDAL</a> &amp; <a href="http://www.osgeo.org/">OSGeo</a> <a href="http://code.google.com/soc/">GSoC</a>
            <!-- PLEASE, LET THIS NOTE ABOUT AUTHOR AND PROJECT SOMEWHERE ON YOUR WEBSITE, OR AT LEAST IN THE COMMENT IN HTML. THANK YOU -->
                  </div>
                   <div id="map"></div>
              </body>
            </html>
        """
            % args
        )  # noqa

        # TODO? when there is self.kml, before the transition to GoogleMapsV3 API,
        # we used to offer a way to display the KML file in Google Earth
        # cf https://github.com/OSGeo/gdal/blob/32f32a69bbf5c408c6c8ac2cc6f1d915a7a1c576/swig/python/gdal-utils/osgeo_utils/gdal2tiles.py#L3203 to #L3243

        return s

    def generate_leaflet(self) -> str:
        """
        Template for leaflet.html implementing overlay of tiles for 'mercator' profile.
        It returns filled string. Expected variables:
        title, north, south, east, west, minzoom, maxzoom, tile_size, tileformat, publishurl
        """

        args = {}
        args['double_quote_escaped_title'] = self.options.title.replace('"', '\\"')
        args['xml_escaped_title'] = gdal.EscapeString(self.options.title, gdal.CPLES_XML)
        args['south'], args['west'], args['north'], args['east'] = self.swne
        args['centerlon'] = (args['north'] + args['south']) / 2.
        args['centerlat'] = (args['west'] + args['east']) / 2.
        args['minzoom'] = self.tminz
        args['maxzoom'] = self.tmaxz
        args['beginzoom'] = self.tmaxz
        args['tile_size'] = self.tile_size  # not used
        args['tileformat'] = self.tileext
        args['publishurl'] = self.options.url  # not used
        args['copyright'] = self.options.copyright.replace('"', '\\"')

        if self.options.xyz:
            args['tms'] = 0
        else:
            args['tms'] = 1

        s = """<!DOCTYPE html>
        <html lang="en">
          <head>
            <meta charset="utf-8">
            <meta name='viewport' content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no' />
            <title>%(xml_escaped_title)s</title>

            <!-- Leaflet -->
            <link rel="stylesheet" href="https://unpkg.com/leaflet@0.7.5/dist/leaflet.css" />
            <script src="https://unpkg.com/leaflet@0.7.5/dist/leaflet.js"></script>

            <style>
                body { margin:0; padding:0; }
                body, table, tr, td, th, div, h1, h2, input { font-family: "Calibri", "Trebuchet MS", "Ubuntu", Serif; font-size: 11pt; }
                #map { position:absolute; top:0; bottom:0; width:100%%; } /* full size */
                .ctl {
                    padding: 2px 10px 2px 10px;
                    background: white;
                    background: rgba(255,255,255,0.9);
                    box-shadow: 0 0 15px rgba(0,0,0,0.2);
                    border-radius: 5px;
                    text-align: right;
                }
                .title {
                    font-size: 18pt;
                    font-weight: bold;
                }
                .src {
                    font-size: 10pt;
                }

            </style>

        </head>
        <body>

        <div id="map"></div>

        <script>
        /* **** Leaflet **** */

        // Base layers
        //  .. OpenStreetMap
        var osm = L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors', minZoom: %(minzoom)s, maxZoom: %(maxzoom)s});

        //  .. CartoDB Positron
        var cartodb = L.tileLayer('http://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png', {attribution: '&copy; <a href="http://www.openstreetmap.org/copyright">OpenStreetMap</a> contributors, &copy; <a href="http://cartodb.com/attributions">CartoDB</a>', minZoom: %(minzoom)s, maxZoom: %(maxzoom)s});

        //  .. OSM Toner
        var toner = L.tileLayer('http://{s}.tile.stamen.com/toner/{z}/{x}/{y}.png', {attribution: 'Map tiles by <a href="http://stamen.com">Stamen Design</a>, under <a href="http://creativecommons.org/licenses/by/3.0">CC BY 3.0</a>. Data by <a href="http://openstreetmap.org">OpenStreetMap</a>, under <a href="http://www.openstreetmap.org/copyright">ODbL</a>.', minZoom: %(minzoom)s, maxZoom: %(maxzoom)s});

        //  .. White background
        var white = L.tileLayer("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAQAAAAEAAQMAAABmvDolAAAAA1BMVEX///+nxBvIAAAAH0lEQVQYGe3BAQ0AAADCIPunfg43YAAAAAAAAAAA5wIhAAAB9aK9BAAAAABJRU5ErkJggg==", {minZoom: %(minzoom)s, maxZoom: %(maxzoom)s});

        // Overlay layers (TMS)
        var lyr = L.tileLayer('./{z}/{x}/{y}.%(tileformat)s', {tms: %(tms)s, opacity: 0.7, attribution: "%(copyright)s", minZoom: %(minzoom)s, maxZoom: %(maxzoom)s});

        // Map
        var map = L.map('map', {
            center: [%(centerlon)s, %(centerlat)s],
            zoom: %(beginzoom)s,
            minZoom: %(minzoom)s,
            maxZoom: %(maxzoom)s,
            layers: [osm]
        });

        var basemaps = {"OpenStreetMap": osm, "CartoDB Positron": cartodb, "Stamen Toner": toner, "Without background": white}
        var overlaymaps = {"Layer": lyr}

        // Title
        var title = L.control();
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl title');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = "%(double_quote_escaped_title)s";
        };
        title.addTo(map);

        // Note
        var src = 'Generated by <a href="https://gdal.org/programs/gdal2tiles.html">GDAL2Tiles</a>, Copyright &copy; 2008 <a href="http://www.klokan.cz/">Klokan Petr Pridal</a>,  <a href="https://gdal.org">GDAL</a> &amp; <a href="http://www.osgeo.org/">OSGeo</a> <a href="http://code.google.com/soc/">GSoC</a>';
        var title = L.control({position: 'bottomleft'});
        title.onAdd = function(map) {
            this._div = L.DomUtil.create('div', 'ctl src');
            this.update();
            return this._div;
        };
        title.update = function(props) {
            this._div.innerHTML = src;
        };
        title.addTo(map);


        // Add base layers
        L.control.layers(basemaps, overlaymaps, {collapsed: false}).addTo(map);

        // Fit to overlay bounds (SW and NE points with (lat, lon))
        map.fitBounds([[%(south)s, %(east)s], [%(north)s, %(west)s]]);

        </script>

        </body>
        </html>

        """ % args    # noqa

        return s

    def generate_openlayers(self) -> str:
        """
        Template for openlayers.html, with the tiles as overlays, and base layers.

        It returns filled string.
        """

        args = {}
        args['xml_escaped_title'] = gdal.EscapeString(self.options.title, gdal.CPLES_XML)
        args['bingkey'] = self.options.bingkey
        args['minzoom'] = self.tminz
        args['maxzoom'] = self.tmaxz
        args['tile_size'] = self.tile_size
        args['tileformat'] = self.tileext
        args['publishurl'] = self.options.url
        args['copyright'] = self.options.copyright
        if self.options.xyz:
            args['sign_y'] = ''
        else:
            args['sign_y'] = '-'

        args['ominx'] = self.ominx
        args['ominy'] = self.ominy
        args['omaxx'] = self.omaxx
        args['omaxy'] = self.omaxy
        args['center_x'] = (self.ominx + self.omaxx) / 2
        args['center_y'] = (self.ominy + self.omaxy) / 2

        s = r"""<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <title>%(xml_escaped_title)s</title>
    <meta http-equiv='imagetoolbar' content='no'/>
    <style type="text/css"> v\:* {behavior:url(#default#VML);}
        html, body { overflow: hidden; padding: 0; height: 100%%; width: 100%%; font-family: 'Lucida Grande',Geneva,Arial,Verdana,sans-serif; }
        body { margin: 10px; background: #fff; }
        h1 { margin: 0; padding: 6px; border:0; font-size: 20pt; }
        #header { height: 43px; padding: 0; background-color: #eee; border: 1px solid #888; }
        #subheader { height: 12px; text-align: right; font-size: 10px; color: #555;}
        #map { height: 90%%; border: 1px solid #888; }
    </style>
    <link rel="stylesheet" href="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@main/dist/en/v7.0.0/legacy/ol.css" type="text/css">
    <script src="https://cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@main/dist/en/v7.0.0/legacy/ol.js"></script>
    <script src="https://unpkg.com/ol-layerswitcher@3.5.0"></script>
    <link rel="stylesheet" href="https://unpkg.com/ol-layerswitcher@3.5.0/src/ol-layerswitcher.css" />
</head>
<body>
    <div id="header"><h1>%(xml_escaped_title)s</h1></div>
    <div id="subheader">Generated by <a href="https://gdal.org/programs/gdal2tiles.html">GDAL2Tiles</a>&nbsp;&nbsp;&nbsp;&nbsp;</div>
    <div id="map" class="map"></div>
    <div id="mouse-position"></div>
    <script type="text/javascript">
        var mousePositionControl = new ol.control.MousePosition({
            className: 'custom-mouse-position',
            target: document.getElementById('mouse-position'),
            undefinedHTML: '&nbsp;'
        });
        var map = new ol.Map({
            controls: ol.control.defaults.defaults().extend([mousePositionControl]),
            target: 'map',
""" % args

        if self.options.profile == 'mercator' or self.options.profile == 'geodetic':
            s += """
            layers: [
                new ol.layer.Group({
                        title: 'Base maps',
                        layers: [
                            new ol.layer.Tile({
                                title: 'OpenStreetMap',
                                type: 'base',
                                visible: true,
                                source: new ol.source.OSM()
                            }),
                            new ol.layer.Tile({
                                title: 'Bing Roads',
                                type: 'base',
                                visible: false,
                                source: new ol.source.BingMaps({
                                    key: "%(bingkey)s",
                                    imagerySet: 'Road'
                                })
                            }),
                            new ol.layer.Tile({
                                title: 'Bing Aerial',
                                type: 'base',
                                visible: false,
                                source: new ol.source.BingMaps({
                                    key: "%(bingkey)s",
                                    imagerySet: 'Aerial'
                                })
                            }),
                            new ol.layer.Tile({
                                title: 'Bing Hybrid',
                                type: 'base',
                                visible: false,
                                source: new ol.source.BingMaps({
                                    key: "%(bingkey)s",
                                    imagerySet: 'AerialWithLabels'
                                })
                            }),
                        ]
                }),""" % args    # noqa

        if self.options.profile == 'mercator':
            s += """
                new ol.layer.Group({
                    title: 'Overlay',
                    layers: [
                        new ol.layer.Tile({
                            title: 'Overlay',
                            // opacity: 0.7,
                            extent: [%(ominx)f, %(ominy)f,%(omaxx)f, %(omaxy)f],
                            source: new ol.source.XYZ({
                                attributions: '%(copyright)s',
                                minZoom: %(minzoom)d,
                                maxZoom: %(maxzoom)d,
                                url: './{z}/{x}/{%(sign_y)sy}.%(tileformat)s',
                                tileSize: [%(tile_size)d, %(tile_size)d]
                            })
                        }),
                    ]
                }),""" % args    # noqa

        elif self.options.profile == 'geodetic':

            if self.options.tmscompatible:
                base_res = 180. / self.tile_size
            else:
                base_res = 360. / self.tile_size
            resolutions = [ base_res / 2**i for i in range(self.tmaxz+1) ]
            args['resolutions'] = '[' + ','.join('%.18g' % res for res in resolutions) + ']'

            if self.options.xyz:
                if self.options.tmscompatible:
                    args['origin'] = '[-180,90]'
                else:
                    args['origin'] = '[-180,270]'
                args['y_formula'] = 'tileCoord[2]'
            else:
                args['origin'] = '[-180,-90]'
                args['y_formula'] = '- 1 - tileCoord[2]'

            s += """
                new ol.layer.Group({
                    title: 'Overlay',
                    layers: [
                        new ol.layer.Tile({
                            title: 'Overlay',
                            // opacity: 0.7,
                            extent: [%(ominx)f, %(ominy)f,%(omaxx)f, %(omaxy)f],
                            source: new ol.source.TileImage({
                                attributions: '%(copyright)s',
                                projection: 'EPSG:4326',
                                minZoom: %(minzoom)d,
                                maxZoom: %(maxzoom)d,
                                tileGrid: new ol.tilegrid.TileGrid({
                                    extent: [-180,-90,180,90],
                                    origin: %(origin)s,
                                    resolutions: %(resolutions)s,
                                    tileSize: [%(tile_size)d, %(tile_size)d]
                                }),
                                tileUrlFunction: function(tileCoord) {
                                    return ('./{z}/{x}/{y}.%(tileformat)s'
                                        .replace('{z}', String(tileCoord[0]))
                                        .replace('{x}', String(tileCoord[1]))
                                        .replace('{y}', String(%(y_formula)s)));
                                },
                            })
                        }),
                    ]
                }),""" % args    # noqa

        elif self.options.profile == 'raster':

            base_res =  2**(self.nativezoom) * self.out_gt[1]
            resolutions = [ base_res / 2**i for i in range(self.tmaxz+1) ]
            args['maxres'] = resolutions[self.tminz]
            args['resolutions'] = '[' + ','.join('%.18g' % res for res in resolutions) + ']'
            args['tilegrid_extent'] = '[%.18g,%.18g,%.18g,%.18g]' % (self.ominx, self.ominy, self.omaxx, self.omaxy)

            if self.options.xyz:
                args['origin'] = '[%.18g,%.18g]' % (self.ominx, self.omaxy)
                args['y_formula'] = 'tileCoord[2]'
            else:
                args['origin'] = '[%.18g,%.18g]' % (self.ominx, self.ominy)
                args['y_formula'] = '- 1 - tileCoord[2]'

            s += """
            layers: [
                new ol.layer.Group({
                    title: 'Overlay',
                    layers: [
                        new ol.layer.Tile({
                            title: 'Overlay',
                            // opacity: 0.7,
                            source: new ol.source.TileImage({
                                attributions: '%(copyright)s',
                                tileGrid: new ol.tilegrid.TileGrid({
                                    extent: %(tilegrid_extent)s,
                                    origin: %(origin)s,
                                    resolutions: %(resolutions)s,
                                    tileSize: [%(tile_size)d, %(tile_size)d]
                                }),
                                tileUrlFunction: function(tileCoord) {
                                    return ('./{z}/{x}/{y}.%(tileformat)s'
                                        .replace('{z}', String(tileCoord[0]))
                                        .replace('{x}', String(tileCoord[1]))
                                        .replace('{y}', String(%(y_formula)s)));
                                },
                            })
                        }),
                    ]
                }),""" % args    # noqa

        else:

            tms = tmsMap[self.options.profile]
            base_res = tms.resolution
            resolutions = [ base_res / 2**i for i in range(self.tmaxz+1) ]
            args['maxres'] = resolutions[self.tminz]
            args['resolutions'] = '[' + ','.join('%.18g' % res for res in resolutions) + ']'
            args['matrixsizes'] = '[' + ','.join('[%d,%d]' % (tms.matrix_width << i, tms.matrix_height << i) for i in range(len(resolutions))) + ']'

            if self.options.xyz:
                args['origin'] = '[%.18g,%.18g]' % (tms.topleft_x, tms.topleft_y)
                args['y_formula'] = 'tileCoord[2]'
            else:
                args['origin'] = '[%.18g,%.18g]' % (tms.topleft_x, tms.topleft_y - tms.resolution * tms.tile_size)
                args['y_formula'] = '- 1 - tileCoord[2]'

            args['tilegrid_extent'] = '[%.18g,%.18g,%.18g,%.18g]' % ( \
                tms.topleft_x,
                tms.topleft_y - tms.matrix_height * tms.resolution * tms.tile_size,
                tms.topleft_x + tms.matrix_width * tms.resolution * tms.tile_size,
                tms.topleft_y)

            s += """
            layers: [
                new ol.layer.Group({
                    title: 'Overlay',
                    layers: [
                        new ol.layer.Tile({
                            title: 'Overlay',
                            // opacity: 0.7,
                            extent: [%(ominx)f, %(ominy)f,%(omaxx)f, %(omaxy)f],
                            source: new ol.source.TileImage({
                                attributions: '%(copyright)s',
                                minZoom: %(minzoom)d,
                                maxZoom: %(maxzoom)d,
                                tileGrid: new ol.tilegrid.TileGrid({
                                    extent: %(tilegrid_extent)s,
                                    origin: %(origin)s,
                                    resolutions: %(resolutions)s,
                                    sizes: %(matrixsizes)s,
                                    tileSize: [%(tile_size)d, %(tile_size)d]
                                }),
                                tileUrlFunction: function(tileCoord) {
                                    return ('./{z}/{x}/{y}.%(tileformat)s'
                                        .replace('{z}', String(tileCoord[0]))
                                        .replace('{x}', String(tileCoord[1]))
                                        .replace('{y}', String(%(y_formula)s)));
                                },
                            })
                        }),
                    ]
                }),""" % args    # noqa

        s += """
            ],
            view: new ol.View({
                center: [%(center_x)f, %(center_y)f],""" % args  # noqa

        if self.options.profile in ('mercator', 'geodetic'):
            args['view_zoom'] = args['minzoom']
            if self.options.profile == 'geodetic' and self.options.tmscompatible:
                args['view_zoom'] += 1
            s += """
                zoom: %(view_zoom)d,""" % args  # noqa
        else:
            s += """
                resolution: %(maxres)f,""" % args  # noqa

        if self.options.profile == 'geodetic':
            s += """
                projection: 'EPSG:4326',"""
        elif self.options.profile != 'mercator':
            if self.in_srs and self.in_srs.IsProjected() and self.in_srs.GetAuthorityName(None) == 'EPSG':
                s += """
                projection: new ol.proj.Projection({code: 'EPSG:%s', units:'m'}),""" % self.in_srs.GetAuthorityCode(None)

        s += """
            })
        });"""
        if self.options.profile in ('mercator', 'geodetic'):
            s += """
        map.addControl(new ol.control.LayerSwitcher());"""
        s += """
    </script>
</body>
</html>"""

        return s

    def generate_mapml(self) -> str:

        if self.options.mapml_template:
            template = self.options.mapml_template
        else:
            template = gdal.FindFile('gdal', 'template_tiles.mapml')
        s = open(template, 'rb').read().decode('utf-8')

        if self.options.profile == 'mercator':
            tiling_scheme = 'OSMTILE'
        elif self.options.profile == 'geodetic':
            tiling_scheme = 'WGS84'
        else:
            tiling_scheme = self.options.profile

        s = s.replace('${TILING_SCHEME}', tiling_scheme)
        s = s.replace('${URL}', self.options.url if self.options.url else "./")
        tminx, tminy, tmaxx, tmaxy = self.tminmax[self.tmaxz]
        s = s.replace('${MINTILEX}', str(tminx))
        s = s.replace('${MINTILEY}', str(GDAL2Tiles.getYTile(tmaxy, self.tmaxz, self.options)))
        s = s.replace('${MAXTILEX}', str(tmaxx))
        s = s.replace('${MAXTILEY}', str(GDAL2Tiles.getYTile(tminy, self.tmaxz, self.options)))
        s = s.replace('${CURZOOM}', str(self.tmaxz))
        s = s.replace('${MINZOOM}', str(self.tminz))
        s = s.replace('${MAXZOOM}', str(self.tmaxz))
        s = s.replace('${TILEEXT}', str(self.tileext))

        return s

    @staticmethod
    def getYTile(ty, tz, options):
        """
        Calculates the y-tile number based on whether XYZ or TMS (default) system is used
        :param ty: The y-tile number
        :param tz: The z-tile number
        :return: The transformed y-tile number
        """
        if options.xyz and options.profile != 'raster':
            if options.profile in ('mercator', 'geodetic'):
                return (2**tz - 1) - ty  # Convert from TMS to XYZ numbering system

            tms = tmsMap[options.profile]
            return (tms.matrix_height * 2**tz - 1) - ty  # Convert from TMS to XYZ numbering system

        return ty


def worker_tile_details(input_file: str, output_folder: str, options: Options) -> Tuple[TileJobInfo, List[TileDetail]]:
    gdal2tiles = GDAL2Tiles(input_file, output_folder, options)
    gdal2tiles.open_input()
    gdal2tiles.generate_metadata()
    tile_job_info, tile_details = gdal2tiles.generate_base_tiles()
    return tile_job_info, tile_details

class ProgressBar(object):

    def __init__(self, total_items: int) -> None:
        self.total_items = total_items
        self.nb_items_done = 0
        self.current_progress = 0
        self.STEP = 2.5

    def start(self) -> None:
        sys.stdout.write("0")

    def log_progress(self, nb_items: int = 1) -> None:
        self.nb_items_done += nb_items
        progress = float(self.nb_items_done) / self.total_items * 100
        if progress >= self.current_progress + self.STEP:
            done = False
            while not done:
                if self.current_progress + self.STEP <= progress:
                    self.current_progress += self.STEP
                    if self.current_progress % 10 == 0:
                        sys.stdout.write(str(int(self.current_progress)))
                        if self.current_progress == 100:
                            sys.stdout.write("\n")
                    else:
                        sys.stdout.write(".")
                else:
                    done = True
        sys.stdout.flush()


def get_tile_swne(tile_job_info, options):
    if options.profile == 'mercator':
        mercator = GlobalMercator()
        tile_swne = mercator.TileLatLonBounds
    elif options.profile == 'geodetic':
        geodetic = GlobalGeodetic(options.tmscompatible)
        tile_swne = geodetic.TileLatLonBounds
    elif options.profile == 'raster':
        srs4326 = osr.SpatialReference()
        srs4326.ImportFromEPSG(4326)
        srs4326.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)
        if tile_job_info.kml and tile_job_info.in_srs_wkt:
            in_srs = osr.SpatialReference()
            in_srs.SetAxisMappingStrategy(osr.OAMS_TRADITIONAL_GIS_ORDER)
            in_srs.ImportFromWkt(tile_job_info.in_srs_wkt)
            ct = osr.CoordinateTransformation(in_srs, srs4326)

            def rastertileswne(x, y, z):
                pixelsizex = (2 ** (tile_job_info.tmaxz - z) * tile_job_info.out_geo_trans[1])
                west = tile_job_info.out_geo_trans[0] + x * tile_job_info.tile_size * pixelsizex
                east = west + tile_job_info.tile_size * pixelsizex
                if options.xyz:
                    north = tile_job_info.out_geo_trans[3] - y * tile_job_info.tile_size * pixelsizex
                    south = north - tile_job_info.tile_size * pixelsizex
                else:
                    south = tile_job_info.ominy + y * tile_job_info.tile_size * pixelsizex
                    north = south + tile_job_info.tile_size * pixelsizex
                if not tile_job_info.is_epsg_4326:
                    # Transformation to EPSG:4326 (WGS84 datum)
                    west, south = ct.TransformPoint(west, south)[:2]
                    east, north = ct.TransformPoint(east, north)[:2]
                return south, west, north, east

            tile_swne = rastertileswne
        else:
            tile_swne = lambda x, y, z: (0, 0, 0, 0)   # noqa
    else:
        tile_swne = None

    return tile_swne


def single_threaded_tiling(input_file: str, output_folder: str, options: Options) -> None:
    """
    Keep a single threaded version that stays clear of multiprocessing, for platforms that would not
    support it
    """
    if options.verbose:
        print("Begin tiles details calc")
    conf, tile_details = worker_tile_details(input_file, output_folder, options)

    if options.verbose:
        print("Tiles details calc complete.")

    if not options.verbose and not options.quiet:
        base_progress_bar = ProgressBar(len(tile_details))
        base_progress_bar.start()

    for tile_detail in tile_details:
        create_base_tile(conf, tile_detail)

        if not options.verbose and not options.quiet:
            base_progress_bar.log_progress()

    if getattr(threadLocal, 'cached_ds', None):
        del threadLocal.cached_ds

    if not options.quiet:
        count = count_overview_tiles(conf)
        if count:
            print("Generating Overview Tiles:")

            if not options.verbose:
                overview_progress_bar = ProgressBar(count)
                overview_progress_bar.start()

    for base_tz in range(conf.tmaxz, conf.tminz, -1):
        base_tile_groups = group_overview_base_tiles(base_tz, output_folder, conf)
        for base_tiles in base_tile_groups:
            create_overview_tile(base_tz, base_tiles, output_folder, conf, options)
            if not options.verbose and not options.quiet:
                overview_progress_bar.log_progress()


    shutil.rmtree(os.path.dirname(conf.src_file))


def multi_threaded_tiling(input_file: str, output_folder: str, options: Options, pool) -> None:
    nb_processes = options.nb_processes or 1

    if options.verbose:
        print("Begin tiles details calc")

    conf, tile_details = worker_tile_details(input_file, output_folder, options)

    if options.verbose:
        print("Tiles details calc complete.")

    if not options.verbose and not options.quiet:
        base_progress_bar = ProgressBar(len(tile_details))
        base_progress_bar.start()

    # TODO: gbataille - check the confs for which each element is an array... one useless level?
    # TODO: gbataille - assign an ID to each job for print in verbose mode "ReadRaster Extent ..."
    chunksize = max(1, min(128, len(tile_details) // nb_processes))
    for _ in pool.imap_unordered(partial(create_base_tile, conf), tile_details, chunksize=chunksize):
        if not options.verbose and not options.quiet:
            base_progress_bar.log_progress()

    if not options.quiet:
        count = count_overview_tiles(conf)
        if count:
            print("Generating Overview Tiles:")

            if not options.verbose:
                overview_progress_bar = ProgressBar(count)
                overview_progress_bar.start()

    for base_tz in range(conf.tmaxz, conf.tminz, -1):
        base_tile_groups = group_overview_base_tiles(base_tz, output_folder, conf)
        chunksize = max(1, min(128, len(base_tile_groups) // nb_processes))
        for _ in pool.imap_unordered(partial(create_overview_tile, base_tz, output_folder=output_folder,
                                             tile_job_info=conf, options=options), base_tile_groups, chunksize=chunksize):
            if not options.verbose and not options.quiet:
                overview_progress_bar.log_progress()


    shutil.rmtree(os.path.dirname(conf.src_file))


class UseExceptions(object):
    def __enter__(self):
        self.old_used_exceptions = gdal.GetUseExceptions()
        if not self.old_used_exceptions:
            gdal.UseExceptions()
    def __exit__(self, type, value, tb):
        if not self.old_used_exceptions:
            gdal.DontUseExceptions()


class DividedCache(object):
    def __init__(self, nb_processes):
        self.nb_processes = nb_processes
    def __enter__(self):
        self.gdal_cache_max = gdal.GetCacheMax()
        # Make sure that all processes do not consume more than `gdal.GetCacheMax()`
        gdal_cache_max_per_process = max(1024 * 1024,
            math.floor(self.gdal_cache_max / self.nb_processes))
        set_cache_max(gdal_cache_max_per_process)
    def __exit__(self, type, value, tb):
        # Set the maximum cache back to the original value
        set_cache_max(self.gdal_cache_max)


def main(argv: List[str] = sys.argv) -> int:
    # TODO: gbataille - use mkdtemp to work in a temp directory
    # TODO: gbataille - debug intermediate tiles.vrt not produced anymore?
    # TODO: gbataille - Refactor generate overview tiles to not depend on self variables

    # For multiprocessing, we need to propagate the configuration options to
    # the environment, so that forked processes can inherit them.
    for i in range(len(argv)):
        if argv[i] == '--config' and i + 2 < len(argv):
            os.environ[argv[i+1]] = argv[i+2]

    if '--mpi' in argv:
        from mpi4py import MPI
        from mpi4py.futures import MPICommExecutor
        with UseExceptions(), MPICommExecutor(MPI.COMM_WORLD, root=0) as pool:
            if pool is None:
                return 0
            # add interface of multiprocessing.Pool to MPICommExecutor
            pool.imap_unordered = partial(pool.map, unordered=True)
            return submain(argv, pool, MPI.COMM_WORLD.Get_size())
    else:
        return submain(argv)


def submain(argv: List[str], pool=None, pool_size=0) -> int:

    argv = gdal.GeneralCmdLineProcessor(argv)
    if argv is None:
        return 0
    input_file, output_folder, options = process_args(argv[1:])
    if pool_size:
        options.nb_processes = pool_size
    nb_processes = options.nb_processes or 1

    with UseExceptions():
        if pool is not None:  # MPI
            multi_threaded_tiling(input_file, output_folder, options, pool)
        elif nb_processes == 1:
            single_threaded_tiling(input_file, output_folder, options)
        else:
            # Trick inspired from https://stackoverflow.com/questions/45720153/python-multiprocessing-error-attributeerror-module-main-has-no-attribute
            # and https://bugs.python.org/issue42949
            import __main__
            if not hasattr(__main__, '__spec__'):
                __main__.__spec__ = None
            from multiprocessing import Pool
            with DividedCache(nb_processes), Pool(processes=nb_processes) as pool:
                multi_threaded_tiling(input_file, output_folder, options, pool)

    return 0


# vim: set tabstop=4 shiftwidth=4 expandtab:

# Running main() must be protected that way due to use of multiprocessing on Windows:
# https://docs.python.org/3/library/multiprocessing.html#the-spawn-and-forkserver-start-methods
if __name__ == '__main__':
    sys.exit(main(sys.argv))
