# -*- coding: utf-8 -*-

"""
***************************************************************************
    SinglePartsToMultiparts.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf 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.                                   *
*                                                                         *
***************************************************************************
"""
from builtins import str

__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import os

from qgis.PyQt.QtGui import QIcon

from qgis.core import QgsFeature, QgsGeometry, QgsWkbTypes, QgsProcessingUtils

from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputVector

pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]


class SinglePartsToMultiparts(GeoAlgorithm):

    INPUT = 'INPUT'
    FIELD = 'FIELD'
    OUTPUT = 'OUTPUT'

    def icon(self):
        return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'single_to_multi.png'))

    def group(self):
        return self.tr('Vector geometry tools')

    def name(self):
        return 'singlepartstomultipart'

    def displayName(self):
        return self.tr('Singleparts to multipart')

    def defineCharacteristics(self):
        self.addParameter(ParameterVector(self.INPUT, self.tr('Input layer')))
        self.addParameter(ParameterTableField(self.FIELD,
                                              self.tr('Unique ID field'), self.INPUT))

        self.addOutput(OutputVector(self.OUTPUT, self.tr('Multipart')))

    def processAlgorithm(self, context, feedback):
        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT), context)
        fieldName = self.getParameterValue(self.FIELD)

        geomType = QgsWkbTypes.multiType(layer.wkbType())

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.fields(), geomType, layer.crs(),
                                                                     context)

        outFeat = QgsFeature()
        inGeom = QgsGeometry()

        index = layer.fields().lookupField(fieldName)

        collection_geom = {}
        collection_attrs = {}

        features = QgsProcessingUtils.getFeatures(layer, context)
        total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
        for current, feature in enumerate(features):
            atMap = feature.attributes()
            idVar = atMap[index]
            key = str(idVar).strip()
            if key not in collection_geom:
                collection_geom[key] = []
                collection_attrs[key] = atMap

            inGeom = feature.geometry()
            collection_geom[key].append(inGeom)

            feedback.setProgress(int(current * total))

        for key, geoms in collection_geom.items():
            outFeat.setAttributes(collection_attrs[key])
            outFeat.setGeometry(QgsGeometry.collectGeometry(geoms))
            writer.addFeature(outFeat)

        del writer