"""
***************************************************************************
    CheckValidity.py
    ---------------------
    Date                 : May 2015
    Copyright            : (C) 2015 by Arnaud Morvan
    Email                : arnaud dot morvan at camptocamp 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__ = "Arnaud Morvan"
__date__ = "May 2015"
__copyright__ = "(C) 2015, Arnaud Morvan"

import os

from qgis.PyQt.QtGui import QIcon
from qgis.PyQt.QtCore import QMetaType

from qgis.core import (
    Qgis,
    QgsApplication,
    QgsSettings,
    QgsGeometry,
    QgsFeature,
    QgsField,
    QgsFeatureRequest,
    QgsFeatureSink,
    QgsWkbTypes,
    QgsFields,
    QgsProcessing,
    QgsProcessingException,
    QgsProcessingFeatureSource,
    QgsProcessingParameterFeatureSource,
    QgsProcessingParameterEnum,
    QgsProcessingParameterFeatureSink,
    QgsProcessingOutputNumber,
    QgsProcessingParameterBoolean,
)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm

settings_method_key = "/digitizing/validate-geometries"
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]


class CheckValidity(QgisAlgorithm):
    INPUT_LAYER = "INPUT_LAYER"
    METHOD = "METHOD"
    VALID_OUTPUT = "VALID_OUTPUT"
    VALID_COUNT = "VALID_COUNT"
    INVALID_OUTPUT = "INVALID_OUTPUT"
    INVALID_COUNT = "INVALID_COUNT"
    ERROR_OUTPUT = "ERROR_OUTPUT"
    ERROR_COUNT = "ERROR_COUNT"
    IGNORE_RING_SELF_INTERSECTION = "IGNORE_RING_SELF_INTERSECTION"

    def icon(self):
        return QgsApplication.getThemeIcon("/algorithms/mAlgorithmCheckGeometry.svg")

    def svgIconPath(self):
        return QgsApplication.iconPath("/algorithms/mAlgorithmCheckGeometry.svg")

    def group(self):
        return self.tr("Vector geometry")

    def groupId(self):
        return "vectorgeometry"

    def tags(self):
        return self.tr("valid,invalid,detect,error").split(",")

    def __init__(self):
        super().__init__()

    def initAlgorithm(self, config=None):
        self.methods = [
            self.tr("The one selected in digitizing settings"),
            "QGIS",
            "GEOS",
        ]

        self.addParameter(
            QgsProcessingParameterFeatureSource(
                self.INPUT_LAYER, self.tr("Input layer")
            )
        )
        self.addParameter(
            QgsProcessingParameterEnum(
                self.METHOD, self.tr("Method"), self.methods, defaultValue=2
            )
        )
        self.parameterDefinition(self.METHOD).setMetadata(
            {"widget_wrapper": {"useCheckBoxes": True, "columns": 3}}
        )

        self.addParameter(
            QgsProcessingParameterBoolean(
                self.IGNORE_RING_SELF_INTERSECTION,
                self.tr("Ignore ring self intersections"),
                defaultValue=False,
            )
        )

        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.VALID_OUTPUT,
                self.tr("Valid output"),
                QgsProcessing.SourceType.TypeVectorAnyGeometry,
                None,
                True,
            )
        )
        self.addOutput(
            QgsProcessingOutputNumber(
                self.VALID_COUNT, self.tr("Count of valid features")
            )
        )

        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.INVALID_OUTPUT,
                self.tr("Invalid output"),
                QgsProcessing.SourceType.TypeVectorAnyGeometry,
                None,
                True,
            )
        )
        self.addOutput(
            QgsProcessingOutputNumber(
                self.INVALID_COUNT, self.tr("Count of invalid features")
            )
        )

        self.addParameter(
            QgsProcessingParameterFeatureSink(
                self.ERROR_OUTPUT,
                self.tr("Error output"),
                QgsProcessing.SourceType.TypeVectorAnyGeometry,
                None,
                True,
            )
        )
        self.addOutput(
            QgsProcessingOutputNumber(self.ERROR_COUNT, self.tr("Count of errors"))
        )

    def name(self):
        return "checkvalidity"

    def displayName(self):
        return self.tr("Check validity")

    def processAlgorithm(self, parameters, context, feedback):
        ignore_ring_self_intersection = self.parameterAsBoolean(
            parameters, self.IGNORE_RING_SELF_INTERSECTION, context
        )
        method_param = self.parameterAsEnum(parameters, self.METHOD, context)
        if method_param == 0:
            settings = QgsSettings()
            method = int(settings.value(settings_method_key, 0)) - 1
            method = max(method, 0)
        else:
            method = method_param - 1

        return self.doCheck(
            method, parameters, context, feedback, ignore_ring_self_intersection
        )

    def doCheck(
        self, method, parameters, context, feedback, ignore_ring_self_intersection
    ):
        flags = (
            QgsGeometry.ValidityFlag.FlagAllowSelfTouchingHoles
            if ignore_ring_self_intersection
            else QgsGeometry.ValidityFlags()
        )
        source = self.parameterAsSource(parameters, self.INPUT_LAYER, context)
        if source is None:
            raise QgsProcessingException(
                self.invalidSourceError(parameters, self.INPUT_LAYER)
            )

        (valid_output_sink, valid_output_dest_id) = self.parameterAsSink(
            parameters,
            self.VALID_OUTPUT,
            context,
            source.fields(),
            source.wkbType(),
            source.sourceCrs(),
        )
        valid_count = 0

        invalid_fields = source.fields()
        invalid_fields.append(
            QgsField("_errors", QMetaType.Type.QString, "string", 255)
        )
        (invalid_output_sink, invalid_output_dest_id) = self.parameterAsSink(
            parameters,
            self.INVALID_OUTPUT,
            context,
            invalid_fields,
            source.wkbType(),
            source.sourceCrs(),
        )
        invalid_count = 0

        error_fields = QgsFields()
        error_fields.append(QgsField("message", QMetaType.Type.QString, "string", 255))
        (error_output_sink, error_output_dest_id) = self.parameterAsSink(
            parameters,
            self.ERROR_OUTPUT,
            context,
            error_fields,
            QgsWkbTypes.Type.Point,
            source.sourceCrs(),
        )
        error_count = 0

        features = source.getFeatures(
            QgsFeatureRequest(),
            QgsProcessingFeatureSource.Flag.FlagSkipGeometryValidityChecks,
        )
        total = 100.0 / source.featureCount() if source.featureCount() else 0
        for current, inFeat in enumerate(features):
            if feedback.isCanceled():
                break
            geom = inFeat.geometry()
            attrs = inFeat.attributes()

            valid = True
            if not geom.isNull() and not geom.isEmpty():
                errors = list(
                    geom.validateGeometry(Qgis.GeometryValidationEngine(method), flags)
                )
                if errors:
                    valid = False
                    reasons = []
                    for error in errors:
                        errFeat = QgsFeature()
                        error_geom = QgsGeometry.fromPointXY(error.where())
                        errFeat.setGeometry(error_geom)
                        errFeat.setAttributes([error.what()])
                        if error_output_sink:
                            error_output_sink.addFeature(
                                errFeat, QgsFeatureSink.Flag.FastInsert
                            )
                        error_count += 1

                        reasons.append(error.what())

                    reason = "\n".join(reasons)
                    if len(reason) > 255:
                        reason = reason[:252] + "…"
                    attrs.append(reason)

            outFeat = QgsFeature()
            outFeat.setGeometry(geom)
            outFeat.setAttributes(attrs)

            if valid:
                if valid_output_sink:
                    valid_output_sink.addFeature(
                        outFeat, QgsFeatureSink.Flag.FastInsert
                    )
                valid_count += 1

            else:
                if invalid_output_sink:
                    invalid_output_sink.addFeature(
                        outFeat, QgsFeatureSink.Flag.FastInsert
                    )
                invalid_count += 1

            feedback.setProgress(int(current * total))

        results = {
            self.VALID_COUNT: valid_count,
            self.INVALID_COUNT: invalid_count,
            self.ERROR_COUNT: error_count,
        }
        if valid_output_sink:
            valid_output_sink.finalize()
            results[self.VALID_OUTPUT] = valid_output_dest_id
        if invalid_output_sink:
            invalid_output_sink.finalize()
            results[self.INVALID_OUTPUT] = invalid_output_dest_id
        if error_output_sink:
            error_output_sink.finalize()
            results[self.ERROR_OUTPUT] = error_output_dest_id
        return results