# -*- coding: utf-8 -*-
"""
s2_grid.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"
__date__ = "2024-11-20"
__copyright__ = "(L) 2024, Thang Quach"

from qgis.core import (
    QgsApplication,
    QgsProject,
    QgsFeatureSink,
    QgsProcessingLayerPostProcessorInterface,
    QgsProcessingParameterExtent,
    QgsProcessingParameterNumber,
    QgsProcessingException,
    QgsProcessingParameterFeatureSink,
    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, QSettings, Qt
from qgis.utils import iface
from qgis.PyQt.QtCore import QVariant  # type: ignore
import os
from vgrid.dggs import s2
from ...utils.imgs import Imgs
from vgrid.utils.antimeridian import fix_polygon
from shapely.geometry import Polygon, box
from vgrid.utils.geometry import geodesic_dggs_metrics
from ...settings import settings


class S2Grid(QgsProcessingAlgorithm):
    EXTENT = "EXTENT"
    RESOLUTION = "RESOLUTION"
    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 S2Grid()

    def name(self):
        return "grid_s2"

    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 "grid"

    def tags(self):
        return self.tr("DGGS, grid, 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 = 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.grid_extent = self.parameterAsExtent(parameters, self.EXTENT, context)
        if self.resolution > 8 and (
            self.grid_extent is None or self.grid_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))

        if self.grid_extent is None or self.grid_extent.isEmpty():
            extent_bbox = None
        else:
            extent_bbox = box(
                self.grid_extent.xMinimum(),
                self.grid_extent.yMinimum(),
                self.grid_extent.xMaximum(),
                self.grid_extent.yMaximum(),
            )

        region = None
        if extent_bbox:
            region = s2.LatLngRect.from_point_pair(
                s2.LatLng.from_degrees(
                    self.grid_extent.yMinimum(), self.grid_extent.xMinimum()
                ),
                s2.LatLng.from_degrees(
                    self.grid_extent.yMaximum(), self.grid_extent.xMaximum()
                ),
            )

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

        # Get covering for the specified region or all regions
        cells = (
            covering.get_covering(region)
            if region
            else covering.get_covering(s2.LatLngRect.full())
        )
        total_cells = len(cells)

        feedback.pushInfo(f"Total cells to be generated: {total_cells}.")
        # if total_cells > max_cells:
        #     feedback.reportError(f"For performance reason, it must be lesser than {max_cells}. Please input an appropriate extent or RESOLUTION")
        #     return {self.OUTPUT: dest_id}

        for idx, s2_cell_id in enumerate(cells):
            progress = int((idx / total_cells) * 100)
            feedback.setProgress(progress)

            cell = s2.Cell(s2_cell_id)
            s2_token = s2.CellId.to_token(s2_cell_id)
            vertices = []
            for i in range(4):  # S2 cells are quads
                vertex = cell.get_vertex(i)
                latlng = s2.LatLng.from_point(vertex)
                vertices.append([latlng.lng().degrees, latlng.lat().degrees])
            vertices.append(vertices[0])  # Close the ring

            cell_polygon = fix_polygon(Polygon(vertices))

            # Filter cells by extent if it exists
            if extent_bbox:
                if not cell_polygon.intersects(extent_bbox):
                    continue

            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)

            if feedback.isCanceled():
                break

        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
