# -*- coding: utf-8 -*-

"""
***************************************************************************
    Grass7Algorithm.py
    ---------------------
    Date                 : February 2015
    Copyright            : (C) 2014-2015 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'February 2015'
__copyright__ = '(C) 2012-2015, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import os
import time
import uuid
import importlib

from qgis.PyQt.QtCore import QCoreApplication, QUrl
from qgis.PyQt.QtGui import QIcon

from qgis.core import QgsRasterLayer
from qgis.utils import iface

from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.ProcessingConfig import ProcessingConfig
from processing.core.ProcessingLog import ProcessingLog
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException

from processing.core.parameters import (getParameterFromString,
                                        ParameterVector,
                                        ParameterMultipleInput,
                                        ParameterExtent,
                                        ParameterNumber,
                                        ParameterSelection,
                                        ParameterRaster,
                                        ParameterTable,
                                        ParameterBoolean,
                                        ParameterString,
                                        ParameterPoint)
from processing.core.outputs import (getOutputFromString,
                                     OutputRaster,
                                     OutputVector,
                                     OutputFile,
                                     OutputHTML)

from .Grass7Utils import Grass7Utils

from processing.tools import dataobjects, system

pluginPath = os.path.normpath(os.path.join(
    os.path.split(os.path.dirname(__file__))[0], os.pardir))


class Grass7Algorithm(GeoAlgorithm):

    GRASS_OUTPUT_TYPE_PARAMETER = 'GRASS_OUTPUT_TYPE_PARAMETER'
    GRASS_MIN_AREA_PARAMETER = 'GRASS_MIN_AREA_PARAMETER'
    GRASS_SNAP_TOLERANCE_PARAMETER = 'GRASS_SNAP_TOLERANCE_PARAMETER'
    GRASS_REGION_EXTENT_PARAMETER = 'GRASS_REGION_PARAMETER'
    GRASS_REGION_CELLSIZE_PARAMETER = 'GRASS_REGION_CELLSIZE_PARAMETER'
    GRASS_REGION_ALIGN_TO_RESOLUTION = '-a_r.region'

    OUTPUT_TYPES = ['auto', 'point', 'line', 'area']

    def __init__(self, descriptionfile):
        GeoAlgorithm.__init__(self)
        self.hardcodedStrings = []
        self.descriptionFile = descriptionfile
        self.defineCharacteristicsFromFile()
        self.numExportedLayers = 0
        self._icon = None
        self.uniqueSufix = unicode(uuid.uuid4()).replace('-', '')

        # Use the ext mechanism
        name = self.commandLineName().replace('.', '_')[len('grass7:'):]
        try:
            self.module = importlib.import_module('processing.algs.grass7.ext.' + name)
        except ImportError:
            self.module = None

    def getCopy(self):
        newone = Grass7Algorithm(self.descriptionFile)
        newone.provider = self.provider
        return newone

    def getIcon(self):
        if self._icon is None:
            self._icon = QIcon(os.path.join(pluginPath, 'images', 'grass.svg'))
        return self._icon

    def help(self):
        helpPath = Grass7Utils.grassHelpPath()
        if helpPath == '':
            return False, None

        if os.path.exists(helpPath):
            return False, QUrl.fromLocalFile(os.path.join(helpPath, '{}.html'.format(self.grass7Name))).toString()
        else:
            return False, helpPath + '{}.html'.format(self.grass7Name)

    def getParameterDescriptions(self):
        descs = {}
        _, helpfile = self.help()
        try:
            infile = open(helpfile)
            lines = infile.readlines()
            for i in range(len(lines)):
                if lines[i].startswith('<DT><b>'):
                    for param in self.parameters:
                        searchLine = '<b>' + param.name + '</b>'
                        if searchLine in lines[i]:
                            i += 1
                            descs[param.name] = (lines[i])[4:-6]
                            break

            infile.close()
        except Exception:
            pass
        return descs

    def defineCharacteristicsFromFile(self):
        lines = open(self.descriptionFile)
        line = lines.readline().strip('\n').strip()
        self.grass7Name = line
        line = lines.readline().strip('\n').strip()
        self.name = line
        self.i18n_name = QCoreApplication.translate("GrassAlgorithm", line)
        if " - " not in self.name:
            self.name = self.grass7Name + " - " + self.name
            self.i18n_name = self.grass7Name + " - " + self.i18n_name
        line = lines.readline().strip('\n').strip()
        self.group = line
        self.i18n_group = QCoreApplication.translate("GrassAlgorithm", line)
        hasRasterOutput = False
        hasVectorInput = False
        vectorOutputs = 0
        line = lines.readline().strip('\n').strip()
        while line != '':
            try:
                line = line.strip('\n').strip()
                if line.startswith('Hardcoded'):
                    self.hardcodedStrings.append(line[len('Hardcoded|'):])
                elif line.startswith('Parameter'):
                    parameter = getParameterFromString(line)
                    self.addParameter(parameter)
                    if isinstance(parameter, ParameterVector):
                        hasVectorInput = True
                    if isinstance(parameter, ParameterMultipleInput) \
                       and parameter.datatype < 3:
                        hasVectorInput = True
                elif line.startswith('*Parameter'):
                    param = getParameterFromString(line[1:])
                    param.isAdvanced = True
                    self.addParameter(param)
                else:
                    output = getOutputFromString(line)
                    self.addOutput(output)
                    if isinstance(output, OutputRaster):
                        hasRasterOutput = True
                    elif isinstance(output, OutputVector):
                        vectorOutputs += 1
                    if isinstance(output, OutputHTML):
                        self.addOutput(OutputFile("rawoutput", output.description +
                                                  " (raw output)", "txt"))
                line = lines.readline().strip('\n').strip()
            except Exception as e:
                ProcessingLog.addToLog(
                    ProcessingLog.LOG_ERROR,
                    self.tr('Could not open GRASS GIS 7 algorithm: %s\n%s' % (self.descriptionFile, line)))
                raise e
        lines.close()

        self.addParameter(ParameterExtent(
            self.GRASS_REGION_EXTENT_PARAMETER,
            self.tr('GRASS GIS 7 region extent'))
        )
        if hasRasterOutput:
            self.addParameter(ParameterNumber(
                self.GRASS_REGION_CELLSIZE_PARAMETER,
                self.tr('GRASS GIS 7 region cellsize (leave 0 for default)'),
                0, None, 0.0))
        if hasVectorInput:
            param = ParameterNumber(self.GRASS_SNAP_TOLERANCE_PARAMETER,
                                    'v.in.ogr snap tolerance (-1 = no snap)',
                                    - 1, None, -1.0)
            param.isAdvanced = True
            self.addParameter(param)
            param = ParameterNumber(self.GRASS_MIN_AREA_PARAMETER,
                                    'v.in.ogr min area', 0, None, 0.0001)
            param.isAdvanced = True
            self.addParameter(param)
        if vectorOutputs == 1:
            param = ParameterSelection(self.GRASS_OUTPUT_TYPE_PARAMETER,
                                       'v.out.ogr output type',
                                       self.OUTPUT_TYPES)
            param.isAdvanced = True
            self.addParameter(param)

    def getDefaultCellsize(self):
        cellsize = 0
        for param in self.parameters:
            if param.value:
                if isinstance(param, ParameterRaster):
                    if isinstance(param.value, QgsRasterLayer):
                        layer = param.value
                    else:
                        layer = dataobjects.getObjectFromUri(param.value)
                    cellsize = max(cellsize, (layer.extent().xMaximum()
                                              - layer.extent().xMinimum())
                                   / layer.width())
                elif isinstance(param, ParameterMultipleInput):

                    layers = param.value.split(';')
                    for layername in layers:
                        layer = dataobjects.getObjectFromUri(layername)
                        if isinstance(layer, QgsRasterLayer):
                            cellsize = max(cellsize, (
                                layer.extent().xMaximum()
                                - layer.extent().xMinimum())
                                / layer.width()
                            )

        if cellsize == 0:
            cellsize = 100
        return cellsize

    def processAlgorithm(self, progress):
        if system.isWindows():
            path = Grass7Utils.grassPath()
            if path == '':
                raise GeoAlgorithmExecutionException(
                    self.tr('GRASS GIS 7 folder is not configured. Please '
                            'configure it before running GRASS GIS 7 algorithms.'))

        # Create brand new commands lists
        self.commands = []
        self.outputCommands = []
        self.exportedLayers = {}

        # If GRASS session has been created outside of this algorithm then
        # get the list of layers loaded in GRASS otherwise start a new
        # session
        existingSession = Grass7Utils.sessionRunning
        if existingSession:
            self.exportedLayers = Grass7Utils.getSessionLayers()
        else:
            Grass7Utils.startGrass7Session()

        # Handle ext functions for inputs/command/outputs
        if self.module:
            if hasattr(self.module, 'processInputs'):
                func = getattr(self.module, 'processInputs')
                func(self)
            else:
                self.processInputs()

            if hasattr(self.module, 'processCommand'):
                func = getattr(self.module, 'processCommand')
                func(self)
            else:
                self.processCommand()

            if hasattr(self.module, 'processOutputs'):
                func = getattr(self.module, 'processOutputs')
                func(self)
            else:
                self.processOutputs()
        else:
            self.processInputs()
            self.processCommand()
            self.processOutputs()

        # Run GRASS
        loglines = []
        loglines.append(self.tr('GRASS GIS 7 execution commands'))
        for line in self.commands:
            progress.setCommand(line)
            loglines.append(line)
        if ProcessingConfig.getSetting(Grass7Utils.GRASS_LOG_COMMANDS):
            ProcessingLog.addToLog(ProcessingLog.LOG_INFO, loglines)

        Grass7Utils.executeGrass7(self.commands, progress, self.outputCommands)

        for out in self.outputs:
            if isinstance(out, OutputHTML):
                with open(self.getOutputFromName("rawoutput").value) as f:
                    rawOutput = "".join(f.readlines())
                with open(out.value, "w") as f:
                    f.write("<pre>%s</pre>" % rawOutput)

        # If the session has been created outside of this algorithm, add
        # the new GRASS GIS 7 layers to it otherwise finish the session
        if existingSession:
            Grass7Utils.addSessionLayers(self.exportedLayers)
        else:
            Grass7Utils.endGrass7Session()

    def processInputs(self):
        """Prepare the GRASS import commands"""
        for param in self.parameters:
            if isinstance(param, ParameterRaster):
                if param.value is None:
                    continue
                value = param.value

                # Check if the layer hasn't already been exported in, for
                # example, previous GRASS calls in this session
                if value in self.exportedLayers.keys():
                    continue
                else:
                    self.setSessionProjectionFromLayer(value, self.commands)
                    self.commands.append(self.exportRasterLayer(value))
            if isinstance(param, ParameterVector):
                if param.value is None:
                    continue
                value = param.value
                if value in self.exportedLayers.keys():
                    continue
                else:
                    self.setSessionProjectionFromLayer(value, self.commands)
                    self.commands.append(self.exportVectorLayer(value))
            if isinstance(param, ParameterTable):
                pass
            if isinstance(param, ParameterMultipleInput):
                if param.value is None:
                    continue
                layers = param.value.split(';')
                if layers is None or len(layers) == 0:
                    continue
                if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                    for layer in layers:
                        if layer in self.exportedLayers.keys():
                            continue
                        else:
                            self.setSessionProjectionFromLayer(layer, self.commands)
                            self.commands.append(self.exportRasterLayer(layer))
                elif param.datatype in [ParameterMultipleInput.TYPE_VECTOR_ANY,
                                        ParameterMultipleInput.TYPE_VECTOR_LINE,
                                        ParameterMultipleInput.TYPE_VECTOR_POLYGON,
                                        ParameterMultipleInput.TYPE_VECTOR_POINT]:
                    for layer in layers:
                        if layer in self.exportedLayers.keys():
                            continue
                        else:
                            self.setSessionProjectionFromLayer(layer, self.commands)
                            self.commands.append(self.exportVectorLayer(layer))

        self.setSessionProjectionFromProject(self.commands)

        region = \
            unicode(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
        regionCoords = region.split(',')
        command = 'g.region'
        command += ' n=' + unicode(regionCoords[3])
        command += ' s=' + unicode(regionCoords[2])
        command += ' e=' + unicode(regionCoords[1])
        command += ' w=' + unicode(regionCoords[0])
        cellsize = self.getParameterValue(self.GRASS_REGION_CELLSIZE_PARAMETER)
        if cellsize:
            command += ' res=' + unicode(cellsize)
        else:
            command += ' res=' + unicode(self.getDefaultCellsize())
        alignToResolution = \
            self.getParameterValue(self.GRASS_REGION_ALIGN_TO_RESOLUTION)
        if alignToResolution:
            command += ' -a'
        self.commands.append(command)

    def processCommand(self):
        """Prepare the GRASS algorithm command"""
        command = self.grass7Name
        command += ' ' + ' '.join(self.hardcodedStrings)

        # Add algorithm command
        for param in self.parameters:
            if param.value is None or param.value == '':
                continue
            if param.name in [self.GRASS_REGION_CELLSIZE_PARAMETER, self.GRASS_REGION_EXTENT_PARAMETER, self.GRASS_MIN_AREA_PARAMETER, self.GRASS_SNAP_TOLERANCE_PARAMETER, self.GRASS_OUTPUT_TYPE_PARAMETER, self.GRASS_REGION_ALIGN_TO_RESOLUTION]:
                continue
            if isinstance(param, (ParameterRaster, ParameterVector)):
                value = param.value
                if value in self.exportedLayers.keys():
                    command += ' ' + param.name + '="' \
                        + self.exportedLayers[value] + '"'
                else:
                    command += ' ' + param.name + '="' + value + '"'
            elif isinstance(param, ParameterMultipleInput):
                s = param.value
                for layer in self.exportedLayers.keys():
                    s = s.replace(layer, self.exportedLayers[layer])
                s = s.replace(';', ',')
                command += ' ' + param.name + '="' + s + '"'
            elif isinstance(param, ParameterBoolean):
                if param.value:
                    command += ' ' + param.name
            elif isinstance(param, ParameterSelection):
                idx = int(param.value)
                command += ' ' + param.name + '=' + unicode(param.options[idx])
            elif isinstance(param, ParameterString):
                command += ' ' + param.name + '="' + unicode(param.value) + '"'
            elif isinstance(param, ParameterPoint):
                command += ' ' + param.name + '=' + unicode(param.value)
            else:
                command += ' ' + param.name + '="' + unicode(param.value) + '"'

        for out in self.outputs:
            if isinstance(out, OutputFile):
                command += ' > ' + out.value
            elif not isinstance(out, OutputHTML):
                # We add an output name to make sure it is unique if the session
                # uses this algorithm several times.
                uniqueOutputName = out.name + self.uniqueSufix
                command += ' ' + out.name + '=' + uniqueOutputName

                # Add output file to exported layers, to indicate that
                # they are present in GRASS
                self.exportedLayers[out.value] = uniqueOutputName

        command += ' --overwrite'
        self.commands.append(command)

    def processOutputs(self):
        """Prepare the GRASS v.out.ogr commands"""
        for out in self.outputs:
            if isinstance(out, OutputRaster):
                filename = out.value

                # Raster layer output: adjust region to layer before
                # exporting
                self.commands.append('g.region raster=' + out.name + self.uniqueSufix)
                self.outputCommands.append('g.region raster=' + out.name
                                           + self.uniqueSufix)

                if self.grass7Name == 'r.statistics':
                    # r.statistics saves its results in a non-qgis compatible
                    # way. Post-process them with r.mapcalc.
                    calcExpression = 'correctedoutput' + self.uniqueSufix
                    calcExpression += '=@' + out.name + self.uniqueSufix
                    command = 'r.mapcalc expression="' + calcExpression + '"'
                    self.commands.append(command)
                    self.outputCommands.append(command)

                    command = 'r.out.gdal --overwrite -c createopt="TFW=YES,COMPRESS=LZW"'
                    command += ' input='
                    command += 'correctedoutput' + self.uniqueSufix
                    command += ' output="' + filename + '"'
                else:
                    command = 'r.out.gdal --overwrite -c createopt="TFW=YES,COMPRESS=LZW"'
                    command += ' input='

                if self.grass7Name == 'r.horizon':
                    command += out.name + self.uniqueSufix + '_0'
                elif self.grass7Name == 'r.statistics':
                    self.commands.append(command)
                    self.outputCommands.append(command)
                else:
                    command += out.name + self.uniqueSufix
                    command += ' output="' + filename + '"'
                    self.commands.append(command)
                    self.outputCommands.append(command)

            if isinstance(out, OutputVector):
                filename = out.value
                typeidx = self.getParameterValue(self.GRASS_OUTPUT_TYPE_PARAMETER)
                outtype = ('auto' if typeidx
                           is None else self.OUTPUT_TYPES[typeidx])
                if self.grass7Name == 'r.flow':
                    command = 'v.out.ogr type=line layer=0 -s -e input=' + out.name + self.uniqueSufix
                elif self.grass7Name == 'v.voronoi':
                    if '-l' in self.commands[-1]:
                        command = 'v.out.ogr type=line layer=0 -s -e input=' + out.name + self.uniqueSufix
                    else:
                        command = 'v.out.ogr -s -e input=' + out.name + self.uniqueSufix
                        command += ' type=' + outtype
                elif self.grass7Name == 'v.sample':
                    command = 'v.out.ogr type=point -s -e input=' + out.name + self.uniqueSufix
                else:
                    command = 'v.out.ogr -s -e input=' + out.name + self.uniqueSufix
                    command += ' type=' + outtype
                command += ' output="' + os.path.dirname(out.value) + '"'
                command += ' format=ESRI_Shapefile'
                command += ' output_layer=' + os.path.basename(out.value)[:-4]
                command += ' --overwrite'
                self.commands.append(command)
                self.outputCommands.append(command)

    def exportVectorLayer(self, orgFilename):

        # TODO: improve this. We are now exporting if it is not a shapefile,
        # but the functionality of v.in.ogr could be used for this.
        # We also export if there is a selection
        if not os.path.exists(orgFilename) or not orgFilename.endswith('shp'):
            layer = dataobjects.getObjectFromUri(orgFilename, False)
            if layer:
                filename = dataobjects.exportVectorLayer(layer)
        else:
            layer = dataobjects.getObjectFromUri(orgFilename, False)
            if layer:
                useSelection = \
                    ProcessingConfig.getSetting(ProcessingConfig.USE_SELECTED)
                if useSelection and layer.selectedFeatureCount() != 0:
                    filename = dataobjects.exportVectorLayer(layer)
                else:
                    filename = orgFilename
            else:
                filename = orgFilename
        destFilename = self.getTempFilename()
        self.exportedLayers[orgFilename] = destFilename
        command = 'v.in.ogr'
        min_area = self.getParameterValue(self.GRASS_MIN_AREA_PARAMETER)
        command += ' min_area=' + unicode(min_area)
        snap = self.getParameterValue(self.GRASS_SNAP_TOLERANCE_PARAMETER)
        command += ' snap=' + unicode(snap)
        command += ' input="' + os.path.dirname(filename) + '"'
        command += ' layer=' + os.path.basename(filename)[:-4]
        command += ' output=' + destFilename
        command += ' --overwrite -o'
        return command

    def setSessionProjectionFromProject(self, commands):
        if not Grass7Utils.projectionSet and iface:
            proj4 = iface.mapCanvas().mapSettings().destinationCrs().toProj4()
            command = 'g.proj'
            command += ' -c'
            command += ' proj4="' + proj4 + '"'
            self.commands.append(command)
            Grass7Utils.projectionSet = True

    def setSessionProjectionFromLayer(self, layer, commands):
        if not Grass7Utils.projectionSet:
            qGisLayer = dataobjects.getObjectFromUri(layer)
            if qGisLayer:
                proj4 = unicode(qGisLayer.crs().toProj4())
                command = 'g.proj'
                command += ' -c'
                command += ' proj4="' + proj4 + '"'
                self.commands.append(command)
                Grass7Utils.projectionSet = True

    def exportRasterLayer(self, layer):
        destFilename = self.getTempFilename()
        self.exportedLayers[layer] = destFilename
        command = 'r.external'
        command += ' input="' + layer + '"'
        command += ' band=1'
        command += ' output=' + destFilename
        command += ' --overwrite -o'
        return command

    def getTempFilename(self):
        filename = 'tmp' + unicode(time.time()).replace('.', '') \
            + unicode(system.getNumExportedLayers())
        return filename

    def commandLineName(self):
        return 'grass7:' + self.name[:self.name.find(' ')]

    def checkBeforeOpeningParametersDialog(self):
        return Grass7Utils.checkGrass7IsInstalled()

    def checkParameterValuesBeforeExecuting(self):
        if self.module:
            if hasattr(self.module, 'checkParameterValuesBeforeExecuting'):
                func = getattr(self.module, 'checkParameterValuesBeforeExecuting')
                return func(self)
        return
