"""
***************************************************************************
    ImportIntoSpatialite.py
    ---------------------
    Date                 : October 2016
    Copyright            : (C) 2016 by Mathieu Pellerin
    Email                : nirvn dot asia at gmail 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__ = "Mathieu Pellerin"
__date__ = "October 2016"
__copyright__ = "(C) 2012, Mathieu Pellerin"

from qgis.core import (
    QgsDataSourceUri,
    QgsFeatureSink,
    QgsProcessingAlgorithm,
    QgsVectorLayerExporter,
    QgsProcessing,
    QgsProcessingException,
    QgsProcessingParameterFeatureSource,
    QgsProcessingParameterVectorLayer,
    QgsProcessingParameterField,
    QgsProcessingParameterString,
    QgsProcessingParameterBoolean,
    QgsWkbTypes,
    QgsProviderRegistry,
    QgsProviderConnectionException,
    QgsAbstractDatabaseProviderConnection,
)

from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm


class ImportIntoSpatialite(QgisAlgorithm):
    DATABASE = "DATABASE"
    TABLENAME = "TABLENAME"
    INPUT = "INPUT"
    OVERWRITE = "OVERWRITE"
    CREATEINDEX = "CREATEINDEX"
    GEOMETRY_COLUMN = "GEOMETRY_COLUMN"
    LOWERCASE_NAMES = "LOWERCASE_NAMES"
    DROP_STRING_LENGTH = "DROP_STRING_LENGTH"
    FORCE_SINGLEPART = "FORCE_SINGLEPART"
    PRIMARY_KEY = "PRIMARY_KEY"
    ENCODING = "ENCODING"

    def group(self):
        return self.tr("Database")

    def groupId(self):
        return "database"

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

    def initAlgorithm(self, config=None):
        self.addParameter(
            QgsProcessingParameterFeatureSource(
                self.INPUT,
                self.tr("Layer to import"),
                types=[QgsProcessing.SourceType.TypeVector],
            )
        )
        self.addParameter(
            QgsProcessingParameterVectorLayer(
                self.DATABASE, self.tr("File database"), optional=False
            )
        )
        self.addParameter(
            QgsProcessingParameterString(
                self.TABLENAME,
                self.tr("Table to import to (leave blank to use layer name)"),
                optional=True,
            )
        )
        self.addParameter(
            QgsProcessingParameterField(
                self.PRIMARY_KEY,
                self.tr("Primary key field"),
                None,
                self.INPUT,
                QgsProcessingParameterField.DataType.Any,
                False,
                True,
            )
        )
        self.addParameter(
            QgsProcessingParameterString(
                self.GEOMETRY_COLUMN, self.tr("Geometry column"), "geom"
            )
        )
        self.addParameter(
            QgsProcessingParameterString(
                self.ENCODING, self.tr("Encoding"), "UTF-8", optional=True
            )
        )
        self.addParameter(
            QgsProcessingParameterBoolean(self.OVERWRITE, self.tr("Overwrite"), True)
        )
        self.addParameter(
            QgsProcessingParameterBoolean(
                self.CREATEINDEX, self.tr("Create spatial index"), True
            )
        )
        self.addParameter(
            QgsProcessingParameterBoolean(
                self.LOWERCASE_NAMES, self.tr("Convert field names to lowercase"), True
            )
        )
        self.addParameter(
            QgsProcessingParameterBoolean(
                self.DROP_STRING_LENGTH,
                self.tr("Drop length constraints on character fields"),
                False,
            )
        )
        self.addParameter(
            QgsProcessingParameterBoolean(
                self.FORCE_SINGLEPART,
                self.tr("Create single-part geometries instead of multi-part"),
                False,
            )
        )

    def flags(self):
        return super().flags() | QgsProcessingAlgorithm.Flag.FlagNoThreading

    def name(self):
        return "importintospatialite"

    def displayName(self):
        return self.tr("Export to SpatiaLite")

    def shortDescription(self):
        return self.tr("Exports a vector layer to a SpatiaLite database")

    def tags(self):
        return self.tr("import,table,layer,into,copy").split(",")

    def processAlgorithm(self, parameters, context, feedback):
        database = self.parameterAsVectorLayer(parameters, self.DATABASE, context)

        databaseuri = database.dataProvider().dataSourceUri()
        uri = QgsDataSourceUri(databaseuri)
        if uri.database() == "":
            if "|layername" in databaseuri:
                databaseuri = databaseuri[: databaseuri.find("|layername")]
            elif "|layerid" in databaseuri:
                databaseuri = databaseuri[: databaseuri.find("|layerid")]
            uri = QgsDataSourceUri("dbname='%s'" % (databaseuri))

        try:
            md = QgsProviderRegistry.instance().providerMetadata("spatialite")
            conn = md.createConnection(uri.uri(), {})
        except QgsProviderConnectionException:
            raise QgsProcessingException(
                self.tr("Could not connect to {}").format(uri.uri())
            )

        overwrite = self.parameterAsBoolean(parameters, self.OVERWRITE, context)
        createIndex = self.parameterAsBoolean(parameters, self.CREATEINDEX, context)
        convertLowerCase = self.parameterAsBoolean(
            parameters, self.LOWERCASE_NAMES, context
        )
        dropStringLength = self.parameterAsBoolean(
            parameters, self.DROP_STRING_LENGTH, context
        )
        forceSinglePart = self.parameterAsBoolean(
            parameters, self.FORCE_SINGLEPART, context
        )
        primaryKeyField = (
            self.parameterAsString(parameters, self.PRIMARY_KEY, context) or "id"
        )
        encoding = self.parameterAsString(parameters, self.ENCODING, context)

        source = self.parameterAsSource(parameters, self.INPUT, context)
        if source is None:
            raise QgsProcessingException(
                self.invalidSourceError(parameters, self.INPUT)
            )

        table = self.parameterAsString(parameters, self.TABLENAME, context)
        if table:
            table.strip()
        if not table or table == "":
            table = source.sourceName()
            table = table.replace(".", "_")
        table = table.replace(" ", "").lower()
        providerName = "spatialite"

        geomColumn = self.parameterAsString(parameters, self.GEOMETRY_COLUMN, context)
        if not geomColumn:
            geomColumn = "geom"

        options = {}
        if overwrite:
            options["overwrite"] = True
        if convertLowerCase:
            options["lowercaseFieldNames"] = True
            geomColumn = geomColumn.lower()
        if dropStringLength:
            options["dropStringConstraints"] = True
        if forceSinglePart:
            options["forceSinglePartGeometryType"] = True

        # Clear geometry column for non-geometry tables
        if source.wkbType() == QgsWkbTypes.Type.NoGeometry:
            geomColumn = None

        uri.setDataSource("", table, geomColumn, "", primaryKeyField)

        if encoding:
            options["fileEncoding"] = encoding

        exporter = QgsVectorLayerExporter(
            uri.uri(),
            providerName,
            source.fields(),
            source.wkbType(),
            source.sourceCrs(),
            overwrite,
            options,
        )

        if exporter.errorCode() != QgsVectorLayerExporter.ExportError.NoError:
            raise QgsProcessingException(
                self.tr("Error importing to Spatialite\n{0}").format(
                    exporter.errorMessage()
                )
            )

        features = source.getFeatures()
        total = 100.0 / source.featureCount() if source.featureCount() else 0
        for current, f in enumerate(features):
            if feedback.isCanceled():
                break

            if not exporter.addFeature(f, QgsFeatureSink.Flag.FastInsert):
                feedback.reportError(exporter.errorMessage())

            feedback.setProgress(int(current * total))

        exporter.flushBuffer()
        if exporter.errorCode() != QgsVectorLayerExporter.ExportError.NoError:
            raise QgsProcessingException(
                self.tr("Error importing to Spatialite\n{0}").format(
                    exporter.errorMessage()
                )
            )

        if geomColumn and createIndex:
            try:
                options = QgsAbstractDatabaseProviderConnection.SpatialIndexOptions()
                options.geometryColumnName = geomColumn
                conn.createSpatialIndex("", table, options)
            except QgsProviderConnectionException as e:
                raise QgsProcessingException(
                    self.tr("Error creating spatial index:\n{0}").format(e)
                )

        return {}
