"""
***************************************************************************
    viewshed.py
    ---------------------
    Date                 : October 2019
    Copyright            : (C) 2019 by Alexander Bruy
    Email                : alexander dot bruy 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__ = 'Alexander Bruy'
__date__ = 'October 2019'
__copyright__ = '(C) 2019, Alexander Bruy'

import os

from qgis.core import (QgsRasterFileWriter,
                       QgsProcessingException,
                       QgsProcessingParameterDefinition,
                       QgsProcessingParameterRasterLayer,
                       QgsProcessingParameterBand,
                       QgsProcessingParameterPoint,
                       QgsProcessingParameterNumber,
                       QgsProcessingParameterDistance,
                       QgsProcessingParameterString,
                       QgsProcessingParameterRasterDestination)
from processing.algs.gdal.GdalAlgorithm import GdalAlgorithm
from processing.algs.gdal.GdalUtils import GdalUtils

pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]


class viewshed(GdalAlgorithm):
    INPUT = 'INPUT'
    BAND = 'BAND'
    OBSERVER = 'OBSERVER'
    OBSERVER_HEIGHT = 'OBSERVER_HEIGHT'
    TARGET_HEIGHT = 'TARGET_HEIGHT'
    MAX_DISTANCE = 'MAX_DISTANCE'
    OPTIONS = 'OPTIONS'
    EXTRA = 'EXTRA'
    OUTPUT = 'OUTPUT'

    def __init__(self):
        super().__init__()

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT,
                                                            self.tr('Input layer')))
        self.addParameter(QgsProcessingParameterBand(self.BAND,
                                                     self.tr('Band number'),
                                                     1,
                                                     parentLayerParameterName=self.INPUT))
        self.addParameter(QgsProcessingParameterPoint(self.OBSERVER,
                                                      self.tr('Observer location')))
        self.addParameter(QgsProcessingParameterNumber(self.OBSERVER_HEIGHT,
                                                       self.tr('Observer height, DEM units'),
                                                       type=QgsProcessingParameterNumber.Type.Double,
                                                       minValue=0.0,
                                                       defaultValue=1.0))
        self.addParameter(QgsProcessingParameterNumber(self.TARGET_HEIGHT,
                                                       self.tr('Target height, DEM units'),
                                                       type=QgsProcessingParameterNumber.Type.Double,
                                                       minValue=0.0,
                                                       defaultValue=1.0))
        self.addParameter(QgsProcessingParameterDistance(self.MAX_DISTANCE,
                                                         self.tr('Maximum distance from observer to compute visibility'),
                                                         parentParameterName=self.INPUT,
                                                         minValue=0.0,
                                                         defaultValue=100.0))

        options_param = QgsProcessingParameterString(self.OPTIONS,
                                                     self.tr('Additional creation options'),
                                                     defaultValue='',
                                                     optional=True)
        options_param.setFlags(options_param.flags() | QgsProcessingParameterDefinition.Flag.FlagAdvanced)
        options_param.setMetadata({'widget_wrapper': {'widget_type': 'rasteroptions'}})
        self.addParameter(options_param)

        extra_param = QgsProcessingParameterString(self.EXTRA,
                                                   self.tr('Additional command-line parameters'),
                                                   defaultValue=None,
                                                   optional=True)
        extra_param.setFlags(extra_param.flags() | QgsProcessingParameterDefinition.Flag.FlagAdvanced)
        self.addParameter(extra_param)

        self.addParameter(QgsProcessingParameterRasterDestination(self.OUTPUT,
                                                                  self.tr('Output')))

    def name(self):
        return 'viewshed'

    def displayName(self):
        return self.tr('Viewshed')

    def group(self):
        return self.tr('Raster miscellaneous')

    def groupId(self):
        return 'rastermiscellaneous'

    def commandName(self):
        return 'gdal_viewshed'

    def getConsoleCommands(self, parameters, context, feedback, executing=True):
        dem = self.parameterAsRasterLayer(parameters, self.INPUT, context)
        if dem is None:
            raise QgsProcessingException(self.invalidRasterError(parameters, self.INPUT))
        dem_input_details = GdalUtils.gdal_connection_details_from_layer(
            dem)

        out = self.parameterAsOutputLayer(parameters, self.OUTPUT, context)
        self.setOutputValue(self.OUTPUT, out)

        observer = self.parameterAsPoint(parameters, self.OBSERVER, context, dem.crs())

        arguments = [
            '-b',
            f'{self.parameterAsInt(parameters, self.BAND, context)}',
            '-ox',
            f'{observer.x()}',
            '-oy',
            f'{observer.y()}',
            '-oz',
            f'{self.parameterAsDouble(parameters, self.OBSERVER_HEIGHT, context)}',
            '-tz',
            f'{self.parameterAsDouble(parameters, self.TARGET_HEIGHT, context)}',
            '-md',
            f'{self.parameterAsDouble(parameters, self.MAX_DISTANCE, context)}',

            '-f',
            QgsRasterFileWriter.driverForExtension(os.path.splitext(out)[1])
        ]

        options = self.parameterAsString(parameters, self.OPTIONS, context)
        if options:
            arguments.extend(GdalUtils.parseCreationOptions(options))

        if self.EXTRA in parameters and parameters[self.EXTRA] not in (None, ''):
            extra = self.parameterAsString(parameters, self.EXTRA, context)
            arguments.append(extra)

        arguments.append(dem_input_details.connection_string)
        arguments.append(out)

        if dem_input_details.credential_options:
            arguments.extend(dem_input_details.credential_options_as_arguments())

        return [self.commandName(), GdalUtils.escapeAndJoin(arguments)]