# -*- coding: utf-8 -*-
"""
s2gen.py
***************************************************************************
*                                                                         *
*   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.                                   *
*                                                                         *
***************************************************************************
"""
#  Need to be checked and tested

__author__ = "Thang Quach"  # type: ignore
__date__ = "2024-11-20"
__copyright__ = "(L) 2024, Thang Quach"

from qgis.core import (
    QgsApplication,
    QgsProject,
    QgsFeatureSink,
    QgsCoordinateTransform,
    QgsProcessingLayerPostProcessorInterface,
    QgsProcessingParameterExtent,
    QgsProcessingParameterNumber,
    QgsProcessingException,
    QgsProcessingParameterFeatureSink,
    QgsProcessingParameterBoolean,
    QgsProcessingAlgorithm,
    QgsFields,
    QgsField,
    QgsFeature,
    QgsGeometry,
    QgsWkbTypes,
    QgsCoordinateReferenceSystem,
    QgsVectorLayer,
    QgsPalLayerSettings,
    QgsVectorLayerSimpleLabeling,
)
from qgis.PyQt.QtGui import QIcon, QColor  # type: ignore
from qgis.PyQt.QtCore import QCoreApplication, Qt
from qgis.utils import iface
from qgis.PyQt.QtCore import QVariant  # type: ignore
import os
from ...utils.imgs import Imgs
from vgrid.utils.geometry import geodesic_dggs_metrics
from ...settings import settings
from vgrid.utils.io import validate_coordinate
from ...utils.latlon import epsg4326
from vgrid.conversion.dggs2geo import s22geo
from vgrid.dggs import s2


class S2Gen(QgsProcessingAlgorithm):
    EXTENT = "EXTENT"
    RESOLUTION = "RESOLUTION"
    SHIFT_ANTIMERIDIAN = "SHIFT_ANTIMERIDIAN"
    SPLIT_ANTIMERIDIAN = "SPLIT_ANTIMERIDIAN"
    OUTPUT = "OUTPUT"

    LOC = QgsApplication.locale()[:2]

    def translate(self, string):
        return QCoreApplication.translate("Processing", string)

    def tr(self, *string):
        # Translate to Vietnamese: arg[0] - English (translate), arg[1] - Vietnamese
        if self.LOC == "vi":
            if len(string) == 2:
                return string[1]
            else:
                return self.translate(string[0])
        else:
            return self.translate(string[0])

    def createInstance(self):
        return S2Gen()

    def name(self):
        return "s2_gen"

    def icon(self):
        return QIcon(
            os.path.join(
                os.path.dirname(os.path.dirname(__file__)),
                "../images/generator/grid_s2.svg",
            )
        )

    def displayName(self):
        return self.tr("S2", "S2")

    def group(self):
        return self.tr("Generator", "Generator")

    def groupId(self):
        return "generator"

    def tags(self):
        return self.tr("DGGS, S2, generator").split(",")

    txt_en = "S2 DGGS Generator"
    txt_vi = "S2 DGGS Generator"
    figure = "../images/tutorial/grid_s2.png"

    def shortHelpString(self):
        social_BW = Imgs().social_BW
        footer = (
            '''<div align="center">
                      <img src="'''
            + os.path.join(os.path.dirname(os.path.dirname(__file__)), self.figure)
            + """">
                    </div>
                    <div align="right">
                      <p align="right">
                      <b>"""
            + self.tr("Author: Thang Quach", "Author: Thang Quach")
            + """</b>
                      </p>"""
            + social_BW
            + """
                    </div>
                    """
        )
        return self.tr(self.txt_en, self.txt_vi) + footer

    def initAlgorithm(self, config=None):
        param = QgsProcessingParameterExtent(
            self.EXTENT, self.tr("Grid extent"), optional=True
        )
        self.addParameter(param)

        min_res, max_res, _ = settings.getResolution("S2")
        param = QgsProcessingParameterNumber(
            self.RESOLUTION,
            self.tr(f"Resolution [{min_res}..{max_res}]"),
            QgsProcessingParameterNumber.Integer,
            defaultValue=1,
            minValue=min_res,
            maxValue=max_res,
            optional=False,
        )
        self.addParameter(param)

        param = QgsProcessingParameterBoolean(
            self.SHIFT_ANTIMERIDIAN,
            self.tr("Shift at Antimeridian"),
            defaultValue=True,
        )
        self.addParameter(param)

        param = QgsProcessingParameterBoolean(
            self.SPLIT_ANTIMERIDIAN,
            self.tr("Split at Antimeridian"),
            defaultValue=False,
        )
        self.addParameter(param)

        param = QgsProcessingParameterFeatureSink(self.OUTPUT, "S2")
        self.addParameter(param)

    def prepareAlgorithm(self, parameters, context, feedback):
        self.resolution = self.parameterAsInt(parameters, self.RESOLUTION, context)
        # Get the extent parameter
        self.canvas_extent = self.parameterAsExtent(parameters, self.EXTENT, context)
        self.shift_antimeridian = self.parameterAsBoolean(
            parameters, self.SHIFT_ANTIMERIDIAN, context
        )
        self.split_antimeridian = self.parameterAsBoolean(
            parameters, self.SPLIT_ANTIMERIDIAN, context
        )
        if self.resolution > 8 and (
            self.canvas_extent is None or self.canvas_extent.isEmpty()
        ):
            feedback.reportError(
                "For performance reason, when resolution is greater than 8, the grid extent must be set."
            )
            return False

        return True

    def outputFields(self):
        output_fields = QgsFields()
        output_fields.append(QgsField("s2", QVariant.String))
        output_fields.append(QgsField("resolution", QVariant.Int))
        output_fields.append(QgsField("center_lat", QVariant.Double))
        output_fields.append(QgsField("center_lon", QVariant.Double))
        output_fields.append(QgsField("avg_edge_len", QVariant.Double))
        output_fields.append(QgsField("cell_area", QVariant.Double))
        output_fields.append(QgsField("cell_perimeter", QVariant.Double))
        return output_fields

    def processAlgorithm(self, parameters, context, feedback):
        fields = self.outputFields()
        (sink, dest_id) = self.parameterAsSink(
            parameters,
            self.OUTPUT,
            context,
            fields,
            QgsWkbTypes.Polygon,
            QgsCoordinateReferenceSystem("EPSG:4326"),
        )

        if not sink:
            raise QgsProcessingException(self.invalidSinkError(parameters, self.OUTPUT))

        canvas_crs = QgsProject.instance().crs()
        if self.canvas_extent is None or self.canvas_extent.isEmpty():
            min_lon, min_lat, max_lon, max_lat = -180, -90, 180, 90
        else:
            try:
                min_lon, min_lat, max_lon, max_lat = (
                    self.canvas_extent.xMinimum(),
                    self.canvas_extent.yMinimum(),
                    self.canvas_extent.xMaximum(),
                    self.canvas_extent.yMaximum(),
                )
                # Transform extent to EPSG:4326 if needed
                if epsg4326 != canvas_crs:
                    trans_to_4326 = QgsCoordinateTransform(
                        canvas_crs, epsg4326, QgsProject.instance()
                    )
                    self.canvas_extent = trans_to_4326.transform(self.canvas_extent)
                    min_lon, min_lat, max_lon, max_lat = (
                        self.canvas_extent.xMinimum(),
                        self.canvas_extent.yMinimum(),
                        self.canvas_extent.xMaximum(),
                        self.canvas_extent.yMaximum(),
                    )
            except Exception:
                # min_lon, min_lat, max_lon, max_lat = -180.0, -85.05112878, 180.0, 85.05112878
                min_lon, min_lat, max_lon, max_lat = -180, -90, 180, 90

            min_lat, min_lon, max_lat, max_lon = validate_coordinate(
                min_lat, min_lon, max_lat, max_lon
            )

        region = s2.LatLngRect(
            s2.LatLng.from_degrees(min_lat, min_lon),
            s2.LatLng.from_degrees(max_lat, max_lon),
        )

        coverer = s2.RegionCoverer()
        coverer.min_level = self.resolution
        coverer.max_level = self.resolution
        # coverer.max_cells = 10_000

        cells = coverer.get_covering(region)
        total_cells = len(cells)

        feedback.pushInfo(f"Total cells to be generated: {total_cells}.")

        for idx, s2_cell_id in enumerate(cells):
            if feedback.isCanceled():
                break

            progress = int((idx / total_cells) * 100)
            feedback.setProgress(progress)

            s2_token = s2.CellId.to_token(s2_cell_id)
            # Apply antimeridian fix if requested
            if self.shift_antimeridian:
                cell_polygon = s22geo(s2_token, fix_antimeridian='shift_east')
            elif self.split_antimeridian:
                cell_polygon = s22geo(s2_token, fix_antimeridian='split')
            else:
                cell_polygon = s22geo(s2_token)

            cell_geometry = QgsGeometry.fromWkt(cell_polygon.wkt)
            s2_feature = QgsFeature()
            s2_feature.setGeometry(cell_geometry)

            num_edges = 4
            center_lat, center_lon, avg_edge_len, cell_area, cell_perimeter = (
                geodesic_dggs_metrics(cell_polygon, num_edges)
            )
            s2_feature.setAttributes(
                [
                    s2_token,
                    self.resolution,
                    center_lat,
                    center_lon,
                    avg_edge_len,
                    cell_area,
                    cell_perimeter,
                ]
            )
            sink.addFeature(s2_feature, QgsFeatureSink.FastInsert)

        feedback.pushInfo("S2 DGGS generation completed.")
        if context.willLoadLayerOnCompletion(dest_id):
            # lineColor = QColor('#FF0000')
            lineColor = settings.s2Color
            fontColor = QColor("#000000")
            context.layerToLoadOnCompletionDetails(dest_id).setPostProcessor(
                StylePostProcessor.create(lineColor, fontColor)
            )

        return {self.OUTPUT: dest_id}


class StylePostProcessor(QgsProcessingLayerPostProcessorInterface):
    instance = None
    line_color = None
    font_color = None

    def __init__(self, line_color, font_color):
        self.line_color = line_color
        self.font_color = font_color
        super().__init__()

    def postProcessLayer(self, layer, context, feedback):
        if not isinstance(layer, QgsVectorLayer):
            return
        sym = layer.renderer().symbol().symbolLayer(0)
        sym.setBrushStyle(Qt.BrushStyle.NoBrush)
        sym.setStrokeColor(self.line_color)
        if settings.gridLabel:
            label = QgsPalLayerSettings()
            label.fieldName = "s2"
            format = label.format()
            format.setColor(self.font_color)
            format.setSize(8)
            label.setFormat(format)
            labeling = QgsVectorLayerSimpleLabeling(label)
            layer.setLabeling(labeling)
            layer.setLabelsEnabled(True)

        iface.layerTreeView().refreshLayerSymbology(layer.id())
        root = QgsProject.instance().layerTreeRoot()
        layer_node = root.findLayer(layer.id())
        if layer_node:
            layer_node.setCustomProperty("showFeatureCount", True)

        # iface.mapCanvas().setExtent(layer.extent())
        iface.mapCanvas().refresh()

    # Hack to work around sip bug!
    @staticmethod
    def create(line_color, font_color) -> "StylePostProcessor":
        """
        Returns a new instance of the post processor, keeping a reference to the sip
        wrapper so that sip doesn't get confused with the Python subclass and call
        the base wrapper implementation instead... ahhh sip, you wonderful piece of sip
        """
        StylePostProcessor.instance = StylePostProcessor(line_color, font_color)
        return StylePostProcessor.instance
