"""
***************************************************************************
    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"
    CREATION_OPTIONS = "CREATION_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,
            )
        )

        # backwards compatibility parameter
        # TODO QGIS 4: remove parameter and related logic
        options_param = QgsProcessingParameterString(
            self.OPTIONS,
            self.tr("Additional creation options"),
            defaultValue="",
            optional=True,
        )
        options_param.setFlags(
            options_param.flags() | QgsProcessingParameterDefinition.Flag.Hidden
        )
        options_param.setMetadata({"widget_wrapper": {"widget_type": "rasteroptions"}})
        self.addParameter(options_param)

        creation_options_param = QgsProcessingParameterString(
            self.CREATION_OPTIONS,
            self.tr("Additional creation options"),
            defaultValue="",
            optional=True,
        )
        creation_options_param.setFlags(
            creation_options_param.flags()
            | QgsProcessingParameterDefinition.Flag.FlagAdvanced
        )
        creation_options_param.setMetadata(
            {"widget_wrapper": {"widget_type": "rasteroptions"}}
        )
        self.addParameter(creation_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.CREATION_OPTIONS, context)
        # handle backwards compatibility parameter OPTIONS
        if self.OPTIONS in parameters and parameters[self.OPTIONS] not in (None, ""):
            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)]