# -*- coding: utf-8 -*-
"""
qtmgen.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.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = "Thang Quach"
__date__ = "2024-11-20"
__copyright__ = "(L) 2024, Thang Quach"

from qgis.core import (
    QgsApplication,
    QgsProject,
    QgsFeatureSink,
    QgsCoordinateTransform,
    QgsProcessingLayerPostProcessorInterface,
    QgsProcessingParameterExtent,
    QgsProcessingParameterNumber,
    QgsProcessingException,
    QgsProcessingParameterFeatureSink,
    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
import os
from vgrid.dggs import qtm
from vgrid.dggs.qtm import QTM_INITIAL_FACETS
from vgrid.utils.geometry import geodesic_dggs_metrics
from shapely.geometry import box
from ...utils.help_footer import social_links_footer
from ...settings import settings
from vgrid.utils.io import validate_coordinate
from ...utils.latlon import epsg4326


class QTMGen(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 QTMGen()

    def name(self):
        return "qtm_gen"

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

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

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

    def groupId(self):
        return "generator"

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

    txt_en = "QTM DGGS Generator"
    txt_vi = "QTM DGGS Generator"
    figure = "../images/tutorial/grid_qtm.png"

    def shortHelpString(self):
        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_links_footer()
            + """
                    </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("QTM")
        param = QgsProcessingParameterNumber(
            self.RESOLUTION,
            self.tr(f"Resolution [{min_res}..{max_res}]"),
            QgsProcessingParameterNumber.Integer,
            defaultValue=2,
            minValue=min_res,
            maxValue=max_res,
            optional=False,
        )
        self.addParameter(param)

        param = QgsProcessingParameterFeatureSink(self.OUTPUT, "QTM")
        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)
        if self.resolution > 9 and (
            self.canvas_extent is None or self.canvas_extent.isEmpty()
        ):
            feedback.reportError(
                "For performance reason, when resolution is greater than 9, the canvas extent must be set."
            )
            return False

        return True

    def outputFields(self):
        output_fields = QgsFields()
        # Append DGGS fields
        output_fields.append(QgsField("qtm", 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_lon, min_lat, max_lon, max_lat = validate_coordinate(
                min_lon, min_lat, max_lon, max_lat
            )
            extent_bbox = box(min_lon, min_lat, max_lon, max_lat)

        QTMID = {}
        levelFacets = {}
        if extent_bbox:
            for lvl in range(self.resolution):
                levelFacets[lvl] = []
                QTMID[lvl] = []

                if lvl == 0:
                    for i, facet in enumerate(QTM_INITIAL_FACETS):
                        QTMID[0].append(str(i + 1))
                        facet_geom = qtm.constructGeometry(facet)
                        levelFacets[0].append(facet)
                        if facet_geom.intersects(extent_bbox) and self.resolution == 1:
                            cell_geometry = QgsGeometry.fromWkt(facet_geom.wkt)
                            qtm_feature = QgsFeature()
                            qtm_feature.setGeometry(cell_geometry)
                            qtm_id = QTMID[0][i]
                            num_edges = 3
                            (
                                center_lat,
                                center_lon,
                                avg_edge_len,
                                cell_area,
                                cell_perimeter,
                            ) = geodesic_dggs_metrics(facet_geom, num_edges)
                            qtm_feature.setAttributes(
                                [
                                    qtm_id,
                                    self.resolution,
                                    center_lat,
                                    center_lon,
                                    avg_edge_len,
                                    cell_area,
                                    cell_perimeter,
                                ]
                            )
                            sink.addFeature(qtm_feature, QgsFeatureSink.FastInsert)
                        if feedback.isCanceled():
                            break
                else:
                    for i, pf in enumerate(levelFacets[lvl - 1]):
                        subdivided_facets = qtm.divideFacet(pf)
                        for j, subfacet in enumerate(subdivided_facets):
                            subfacet_geom = qtm.constructGeometry(subfacet)
                            if subfacet_geom.intersects(
                                extent_bbox
                            ):  # Only keep intersecting facets
                                cell_geometry = QgsGeometry.fromWkt(subfacet_geom.wkt)
                                new_id = QTMID[lvl - 1][i] + str(j)
                                QTMID[lvl].append(new_id)
                                levelFacets[lvl].append(subfacet)
                                if (
                                    lvl == self.resolution - 1
                                ):  # Only store final resolution
                                    qtm_feature = QgsFeature()
                                    qtm_feature.setGeometry(cell_geometry)
                                    qtm_id = new_id
                                    num_edges = 3
                                    (
                                        center_lat,
                                        center_lon,
                                        avg_edge_len,
                                        cell_area,
                                        cell_perimeter,
                                    ) = geodesic_dggs_metrics(subfacet_geom, num_edges)
                                    qtm_feature.setAttributes(
                                        [
                                            qtm_id,
                                            self.resolution,
                                            center_lat,
                                            center_lon,
                                            avg_edge_len,
                                            cell_area,
                                            cell_perimeter,
                                        ]
                                    )
                                    sink.addFeature(
                                        qtm_feature, QgsFeatureSink.FastInsert
                                    )
                            if feedback.isCanceled():
                                break

        else:  # global scale
            total_cells = 8 * 4 ** (self.resolution - 1)
            feedback.pushInfo(f"Total cells to be generated: {total_cells}.")
            processed_cells = 0  # Counter for progress tracking
            for lvl in range(self.resolution):
                levelFacets[lvl] = []
                QTMID[lvl] = []

                if lvl == 0:
                    for i, facet in enumerate(QTM_INITIAL_FACETS):
                        facet_geom = qtm.constructGeometry(facet)
                        QTMID[0].append(str(i + 1))
                        levelFacets[0].append(facet)
                        if self.resolution == 1:
                            qtm_id = QTMID[0][i]
                            num_edges = 3
                            (
                                center_lat,
                                center_lon,
                                avg_edge_len,
                                cell_area,
                                cell_perimeter,
                            ) = geodesic_dggs_metrics(facet_geom, num_edges)
                            cell_geometry = QgsGeometry.fromWkt(facet_geom.wkt)
                            qtm_feature = QgsFeature()
                            qtm_feature.setGeometry(cell_geometry)
                            qtm_feature.setAttributes(
                                [
                                    qtm_id,
                                    self.resolution,
                                    center_lat,
                                    center_lon,
                                    avg_edge_len,
                                    cell_area,
                                    cell_perimeter,
                                ]
                            )
                            sink.addFeature(qtm_feature, QgsFeatureSink.FastInsert)
                            # Update progress
                            processed_cells += 1
                            feedback.setProgress(
                                int(100 * processed_cells / total_cells)
                            )
                            if feedback.isCanceled():
                                break
                else:
                    for i, pf in enumerate(levelFacets[lvl - 1]):
                        subdivided_facets = qtm.divideFacet(pf)
                        for j, subfacet in enumerate(subdivided_facets):
                            new_id = QTMID[lvl - 1][i] + str(j)
                            QTMID[lvl].append(new_id)
                            levelFacets[lvl].append(subfacet)
                            if lvl == self.resolution - 1:
                                subfacet_geom = qtm.constructGeometry(subfacet)
                                qtm_id = new_id
                                num_edges = 3
                                (
                                    center_lat,
                                    center_lon,
                                    avg_edge_len,
                                    cell_area,
                                    cell_perimeter,
                                ) = geodesic_dggs_metrics(subfacet_geom, num_edges)

                                cell_geometry = QgsGeometry.fromWkt(subfacet_geom.wkt)
                                qtm_feature = QgsFeature()
                                qtm_feature.setGeometry(cell_geometry)
                                qtm_feature.setAttributes(
                                    [
                                        qtm_id,
                                        self.resolution,
                                        center_lat,
                                        center_lon,
                                        avg_edge_len,
                                        cell_area,
                                        cell_perimeter,
                                    ]
                                )
                                sink.addFeature(qtm_feature, QgsFeatureSink.FastInsert)
                                # Update progress
                                processed_cells += 1
                                feedback.setProgress(
                                    int(100 * processed_cells / total_cells)
                                )

                            if feedback.isCanceled():
                                break

        feedback.pushInfo("QTM DGGS generation completed.")
        if context.willLoadLayerOnCompletion(dest_id):
            lineColor = settings.qtmColor
            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 = "qtm"
            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
