#!/usr/bin/env python3
# -*- coding: utf-8 -*-
###############################################################################
# $Id$
#
#  Project:  GDAL scripts
#  Purpose:  Perform a pansharpening operation
#  Author:   Even Rouault <even.rouault at spatialys.com>
#
###############################################################################
#  Copyright (c) 2015, Even Rouault <even.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.
###############################################################################

import os
import os.path
import sys
from numbers import Real
from typing import Optional, Sequence, Union, List

from osgeo import gdal
from osgeo_utils.auxiliary.util import GetOutputDriverFor


def Usage():
    print('Usage: gdal_pansharpen [--help-general] pan_dataset {spectral_dataset[,band=num]}+ out_dataset')
    print('                       [-of format] [-b band]* [-w weight]*')
    print('                       [-r {nearest,bilinear,cubic,cubicspline,lanczos,average}]')
    print('                       [-threads {ALL_CPUS|number}] [-bitdepth val] [-nodata val]')
    print('                       [-spat_adjust {union,intersection,none,nonewithoutwarning}]')
    print('                       [-verbose_vrt] [-co NAME=VALUE]* [-q]')
    print('')
    print('Create a dataset resulting from a pansharpening operation.')
    return -1


def main(argv=sys.argv):
    argv = gdal.GeneralCmdLineProcessor(argv)
    if argv is None:
        return -1

    pan_name = None
    spectral_names = []
    spectral_ds = []
    spectral_bands = []
    band_nums = []
    weights = []
    driver_name = None
    creation_options = []
    progress_callback = gdal.TermProgress_nocb
    resampling = None
    spat_adjust = None
    verbose_vrt = False
    num_threads = None
    bitdepth = None
    nodata_value = None

    i = 1
    argc = len(argv)
    while i < argc:
        if (argv[i] == '-of' or argv[i] == '-f') and i < len(argv) - 1:
            driver_name = argv[i + 1]
            i = i + 1
        elif argv[i] == '-r' and i < len(argv) - 1:
            resampling = argv[i + 1]
            i = i + 1
        elif argv[i] == '-spat_adjust' and i < len(argv) - 1:
            spat_adjust = argv[i + 1]
            i = i + 1
        elif argv[i] == '-b' and i < len(argv) - 1:
            band_nums.append(int(argv[i + 1]))
            i = i + 1
        elif argv[i] == '-w' and i < len(argv) - 1:
            weights.append(float(argv[i + 1]))
            i = i + 1
        elif argv[i] == '-co' and i < len(argv) - 1:
            creation_options.append(argv[i + 1])
            i = i + 1
        elif argv[i] == '-threads' and i < len(argv) - 1:
            num_threads = argv[i + 1]
            i = i + 1
        elif argv[i] == '-bitdepth' and i < len(argv) - 1:
            bitdepth = argv[i + 1]
            i = i + 1
        elif argv[i] == '-nodata' and i < len(argv) - 1:
            nodata_value = argv[i + 1]
            i = i + 1
        elif argv[i] == '-q':
            progress_callback = None
        elif argv[i] == '-verbose_vrt':
            verbose_vrt = True
        elif argv[i][0] == '-':
            sys.stderr.write('Unrecognized option : %s\n' % argv[i])
            return Usage()
        elif pan_name is None:
            pan_name = argv[i]
        else:
            spectral_names.append(argv[i])

        i = i + 1

    if pan_name is None or len(spectral_names) < 2:
        return Usage()

    dst_filename = spectral_names.pop()
    return gdal_pansharpen(argv=None,
                           pan_name=pan_name,
                           spectral_names=spectral_names, spectral_ds=spectral_ds, spectral_bands=spectral_bands,
                           band_nums=band_nums, weights=weights,
                           dst_filename=dst_filename, driver_name=driver_name, creation_options=creation_options,
                           resampling=resampling, spat_adjust=spat_adjust,
                           num_threads=num_threads, bitdepth=bitdepth, nodata_value=nodata_value,
                           verbose_vrt=verbose_vrt,
                           progress_callback=progress_callback)


def gdal_pansharpen(argv: Optional[Sequence[str]] = None,
                    pan_name: Optional[str] = None,
                    spectral_names: Optional[Sequence[str]] = None,
                    spectral_ds: Optional[List[gdal.Dataset]] = None, spectral_bands: Optional[List[gdal.Band]] = None,
                    band_nums: Optional[Sequence[int]] = None, weights: Optional[Sequence[float]] = None,
                    dst_filename: Optional[str] = None, driver_name: Optional[str] = None,
                    creation_options: Optional[Sequence[str]] = None,
                    resampling: Optional[str] = None, spat_adjust: Optional[str] = None,
                    num_threads: Optional[Union[int, str]] = None, bitdepth: Optional[Union[int, str]] = None,
                    nodata_value: Optional[Union[Real, str]] = None,
                    verbose_vrt: bool = False,
                    progress_callback: Optional = gdal.TermProgress_nocb):
    if argv:
        # this is here for backwards compatibility
        return main(argv)

    spectral_names = spectral_names or []
    spectral_ds = spectral_ds or []
    spectral_bands = spectral_bands or []
    band_nums = band_nums or []
    weights = weights or []
    creation_options = creation_options or []

    if spectral_names:
        parse_spectral_names(spectral_names=spectral_names, spectral_ds=spectral_ds, spectral_bands=spectral_bands)

    if pan_name is None or not spectral_bands:
        return 1

    pan_ds = gdal.Open(pan_name)
    if pan_ds is None:
        return 1

    if driver_name is None:
        driver_name = GetOutputDriverFor(dst_filename)

    if not band_nums:
        band_nums = [j + 1 for j in range(len(spectral_bands))]
    else:
        for band in band_nums:
            if band < 0 or band > len(spectral_bands):
                print('Invalid band number in -b: %d' % band)
                return 1

    if weights and len(weights) != len(spectral_bands):
        print('There must be as many -w values specified as input spectral bands')
        return 1

    vrt_xml = """<VRTDataset subClass="VRTPansharpenedDataset">\n"""
    if band_nums != [j + 1 for j in range(len(spectral_bands))]:
        for i, band in enumerate(band_nums):
            sband = spectral_bands[band - 1]
            datatype = gdal.GetDataTypeName(sband.DataType)
            colorname = gdal.GetColorInterpretationName(sband.GetColorInterpretation())
            vrt_xml += """  <VRTRasterBand dataType="%s" band="%d" subClass="VRTPansharpenedRasterBand">
      <ColorInterp>%s</ColorInterp>
  </VRTRasterBand>\n""" % (datatype, i + 1, colorname)

    vrt_xml += """  <PansharpeningOptions>\n"""

    if weights:
        vrt_xml += """      <AlgorithmOptions>\n"""
        vrt_xml += """        <Weights>"""
        for i, weight in enumerate(weights):
            if i > 0:
                vrt_xml += ","
            vrt_xml += "%.16g" % weight
        vrt_xml += "</Weights>\n"
        vrt_xml += """      </AlgorithmOptions>\n"""

    if resampling is not None:
        vrt_xml += f'      <Resampling>{resampling}</Resampling>\n'

    if num_threads is not None:
        vrt_xml += f'      <NumThreads>{num_threads}</NumThreads>\n'

    if bitdepth is not None:
        vrt_xml += f'      <BitDepth>{bitdepth}</BitDepth>\n'

    if nodata_value is not None:
        vrt_xml += f'      <NoData>{nodata_value}</NoData>\n'

    if spat_adjust is not None:
        vrt_xml += f'      <SpatialExtentAdjustment>{spat_adjust}</SpatialExtentAdjustment>\n'

    pan_relative = '0'
    if driver_name.upper() == 'VRT':
        if not os.path.isabs(pan_name):
            pan_relative = '1'
            pan_name = os.path.relpath(pan_name, os.path.dirname(dst_filename))

    vrt_xml += """    <PanchroBand>
      <SourceFilename relativeToVRT="%s">%s</SourceFilename>
      <SourceBand>1</SourceBand>
    </PanchroBand>\n""" % (pan_relative, pan_name)

    for i, sband in enumerate(spectral_bands):
        dstband = ''
        for j, band in enumerate(band_nums):
            if i + 1 == band:
                dstband = ' dstBand="%d"' % (j + 1)
                break

        ms_relative = '0'
        ms_name = spectral_ds[i].GetDescription()
        if driver_name.upper() == 'VRT':
            if not os.path.isabs(ms_name):
                ms_relative = '1'
                ms_name = os.path.relpath(ms_name, os.path.dirname(dst_filename))

        vrt_xml += """    <SpectralBand%s>
      <SourceFilename relativeToVRT="%s">%s</SourceFilename>
      <SourceBand>%d</SourceBand>
    </SpectralBand>\n""" % (dstband, ms_relative, ms_name, sband.GetBand())

    vrt_xml += """  </PansharpeningOptions>\n"""
    vrt_xml += """</VRTDataset>\n"""

    if driver_name.upper() == 'VRT':
        f = gdal.VSIFOpenL(dst_filename, 'wb')
        if f is None:
            print('Cannot create %s' % dst_filename)
            return 1
        gdal.VSIFWriteL(vrt_xml, 1, len(vrt_xml), f)
        gdal.VSIFCloseL(f)
        if verbose_vrt:
            vrt_ds = gdal.Open(dst_filename, gdal.GA_Update)
            vrt_ds.SetMetadata(vrt_ds.GetMetadata())
        else:
            vrt_ds = gdal.Open(dst_filename)
        if vrt_ds is None:
            return 1

        return 0

    vrt_ds = gdal.Open(vrt_xml)
    out_ds = gdal.GetDriverByName(driver_name).CreateCopy(dst_filename, vrt_ds, 0, creation_options,
                                                          callback=progress_callback)
    if out_ds is None:
        return 1
    return 0


def parse_spectral_names(spectral_names: Sequence[str],
                         spectral_ds: List[gdal.Dataset],
                         spectral_bands: List[gdal.Band]):
    for spectral_arg in spectral_names:
        # add selected bands
        pos = spectral_arg.find(',band=')
        if pos > 0:
            spectral_name = spectral_arg[0:pos]
            ds = gdal.Open(spectral_name)
            if ds is None:
                return 1
            band_num = int(spectral_arg[pos + len(',band='):])
            band = ds.GetRasterBand(band_num)
            spectral_ds.append(ds)
            spectral_bands.append(band)
        else:
            # add all bands
            spectral_name = spectral_arg
            ds = gdal.Open(spectral_name)
            if ds is None:
                return 1
            for j in range(ds.RasterCount):
                spectral_ds.append(ds)
                spectral_bands.append(ds.GetRasterBand(j + 1))


if __name__ == '__main__':
    sys.exit(main(sys.argv))
