# -*- coding: utf-8 -*-
"""
h3gen.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,  # type: ignore
    QgsProcessingLayerPostProcessorInterface,
    QgsProcessingParameterExtent,
    QgsProcessingParameterNumber,
    QgsProcessingException,
    QgsProcessingParameterFeatureSink,
    QgsProcessingParameterBoolean,
    QgsProcessingAlgorithm,
    QgsFields,
    QgsField,
    QgsFeature,
    QgsGeometry,
    QgsWkbTypes,
    QgsCoordinateReferenceSystem,
    QgsVectorLayer,
    QgsPalLayerSettings,
    QgsVectorLayerSimpleLabeling,
)
from qgis.PyQt.QtGui import QIcon, QColor
from qgis.PyQt.QtCore import QCoreApplication, Qt
from qgis.utils import iface
from qgis.PyQt.QtCore import QVariant
from qgis.core import QgsCoordinateTransform
import os

import h3

from ...utils.imgs import Imgs
from shapely.geometry import box
from vgrid.utils.geometry import geodesic_dggs_metrics
from ...settings import settings
from ...utils.latlon import epsg4326
from vgrid.utils.io import validate_coordinate
from vgrid.conversion.dggs2geo import h32geo
from vgrid.utils.constants import DGGS_TYPES


class H3Gen(QgsProcessingAlgorithm):
    EXTENT = "EXTENT"
    RESOLUTION = "RESOLUTION"
    SPLIT_ANTIMERIDIAN = "SPLIT_ANTIMERIDIAN"
    SHIFT_ANTIMERIDIAN = "SHIFT_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 H3Gen()

    def name(self):
        return "h3_gen"

    def icon(self):
        return QIcon(
            os.path.join(
                os.path.dirname(os.path.dirname(__file__)),
                "../images/generator/grid_h3.svg",
            )
        )

    def displayName(self):
        return self.tr("H3", "H3")

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

    def groupId(self):
        return "generator"

    def tags(self):
        return self.tr("DGGS, grid, H3, generator").split(",")

    txt_en = "H3 DGGS Generator"
    txt_vi = "H3 DGGS Generator"
    figure = "../images/tutorial/grid_h3.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("Canvas extent"), optional=True
        )
        self.addParameter(param)

        min_res = DGGS_TYPES['h3']["min_res"]
        max_res = DGGS_TYPES['h3']["max_res"]

        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 Atimeridian"),
            defaultValue=True,
        )
        self.addParameter(param)

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

        param = QgsProcessingParameterFeatureSink(self.OUTPUT, "H3")
        self.addParameter(param)

    def prepareAlgorithm(self, parameters, context, feedback):
        self.resolution = self.parameterAsInt(parameters, self.RESOLUTION, context)
        self.canvas_extent = self.parameterAsExtent(parameters, self.EXTENT, context)
        self.split_antimeridian = self.parameterAsBoolean(
            parameters, self.SPLIT_ANTIMERIDIAN, context
        )
        self.shift_antimeridian = self.parameterAsBoolean(
            parameters, self.SHIFT_ANTIMERIDIAN, context
        )
        if self.resolution > 4 and (
            self.canvas_extent is None or self.canvas_extent.isEmpty()
        ):
            feedback.reportError(
                "For performance reason, when resolution is greater than 4, the canvas extent must be set."
            )
            return False

        return True

    def outputFields(self):
        output_fields = QgsFields()
        output_fields.append(QgsField("h3", 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()
        # Output layer initialization
        (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():
            extent_bbox = None
        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()
                    )
                    transformed_extent = trans_to_4326.transform(self.canvas_extent)
                    min_lon, min_lat, max_lon, max_lat = (
                        transformed_extent.xMinimum(),
                        transformed_extent.yMinimum(),
                        transformed_extent.xMaximum(),
                        transformed_extent.yMaximum(),
                    )
            except Exception:
                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
            )
            extent_bbox = box(min_lon, min_lat, max_lon, max_lat)

        if extent_bbox:
            feedback.pushInfo(f"Generating cells within extent: {extent_bbox}.")
            bbox_cells = h3.geo_to_cells(extent_bbox, self.resolution)
            total_cells = len(bbox_cells)

            feedback.pushInfo(f"Total cells to be generated: {total_cells}.")
            for idx, bbox_cell in enumerate(bbox_cells):
                if feedback.isCanceled():
                    break
                progress = int((idx / total_cells) * 100)
                feedback.setProgress(progress)
                # Apply antimeridian fix if requested
                if self.shift_antimeridian:
                    cell_polygon = h32geo(bbox_cell, fix_antimeridian='shift_west')
                elif self.split_antimeridian:
                    cell_polygon = h32geo(bbox_cell, fix_antimeridian='split')
                else:
                    cell_polygon = h32geo(bbox_cell)
                cell_geometry = QgsGeometry.fromWkt(cell_polygon.wkt)
                # if not cell_geometry.intersects(QgsGeometry.fromRect(self.canvas_extent)):
                #     continue
                h3_feature = QgsFeature()
                h3_feature.setGeometry(cell_geometry)

                num_edges = 6
                if h3.is_pentagon(bbox_cell):
                    num_edges = 5
                center_lat, center_lon, avg_edge_len, cell_area, cell_perimeter = (
                    geodesic_dggs_metrics(cell_polygon, num_edges)
                )
                h3_feature.setAttributes(
                    [
                        bbox_cell,
                        self.resolution,
                        center_lat,
                        center_lon,
                        avg_edge_len,
                        cell_area,
                        cell_perimeter,
                    ]
                )
                sink.addFeature(h3_feature, QgsFeatureSink.FastInsert)

        else:
            base_cells = h3.get_res0_cells()
            total_base_cells = len(base_cells)
            total_cells = h3.get_num_cells(self.resolution)
            feedback.pushInfo(f"Total cells to be generated: {total_cells}.")
            for idx, cell in enumerate(base_cells):
                progress = int((idx / total_base_cells) * 100)
                feedback.setProgress(progress)

                child_cells = h3.cell_to_children(cell, self.resolution)
                # Progress bar for child cells
                for child_cell in child_cells:
                    if feedback.isCanceled():
                        break
                    # Apply antimeridian fix if requested
                    if self.shift_antimeridian:
                        cell_polygon = h32geo(child_cell, fix_antimeridian='shift_west')
                    elif self.split_antimeridian:
                        cell_polygon = h32geo(child_cell, fix_antimeridian='split')
                    else:
                        cell_polygon = h32geo(child_cell)
                    cell_geometry = QgsGeometry.fromWkt(cell_polygon.wkt)
                    h3_feature = QgsFeature()
                    h3_feature.setGeometry(cell_geometry)

                    num_edges = 6
                    if h3.is_pentagon(child_cell):
                        num_edges = 5

                    center_lat, center_lon, avg_edge_len, cell_area, cell_perimeter = (
                        geodesic_dggs_metrics(cell_polygon, num_edges)
                    )
                    h3_feature.setAttributes(
                        [
                            child_cell,
                            self.resolution,
                            center_lat,
                            center_lon,
                            avg_edge_len,
                            cell_area,
                            cell_perimeter,
                        ]
                    )
                    sink.addFeature(h3_feature, QgsFeatureSink.FastInsert)

        feedback.pushInfo("H3 DGGS generation completed.")

        if context.willLoadLayerOnCompletion(dest_id):
            lineColor = settings.h3Color
            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 = "h3"
            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
