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

"""
***************************************************************************
    Dissolve.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.                                   *
*                                                                         *
***************************************************************************
"""

__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 collections import defaultdict

from qgis.PyQt.QtGui import QIcon

from qgis.core import QgsFeature, QgsGeometry

from processing.core.ProcessingLog import ProcessingLog
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterBoolean
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputVector
from processing.tools import vector, dataobjects

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


class Dissolve(GeoAlgorithm):

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

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

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

    def name(self):
        return 'Dissolve'

    def displayName(self):
        return self.tr('Dissolve')

    def defineCharacteristics(self):
        self.addParameter(ParameterVector(Dissolve.INPUT,
                                          self.tr('Input layer'),
                                          [dataobjects.TYPE_VECTOR_POLYGON, dataobjects.TYPE_VECTOR_LINE]))
        self.addParameter(ParameterBoolean(Dissolve.DISSOLVE_ALL,
                                           self.tr('Dissolve all (do not use fields)'), True))
        self.addParameter(ParameterTableField(Dissolve.FIELD,
                                              self.tr('Unique ID fields'), Dissolve.INPUT, optional=True, multiple=True))
        self.addOutput(OutputVector(Dissolve.OUTPUT, self.tr('Dissolved')))

    def processAlgorithm(self, feedback):
        useField = not self.getParameterValue(Dissolve.DISSOLVE_ALL)
        field_names = self.getParameterValue(Dissolve.FIELD)
        vlayerA = dataobjects.getObjectFromUri(
            self.getParameterValue(Dissolve.INPUT))

        writer = self.getOutputFromName(
            Dissolve.OUTPUT).getVectorWriter(
                vlayerA.fields().toList(),
                vlayerA.wkbType(),
                vlayerA.crs())

        outFeat = QgsFeature()
        features = vector.features(vlayerA)
        total = 100.0 / len(features)

        if not useField:
            first = True
            # we dissolve geometries in blocks using unaryUnion
            geom_queue = []
            for current, inFeat in enumerate(features):
                feedback.setProgress(int(current * total))
                if first:
                    outFeat.setAttributes(inFeat.attributes())
                    first = False

                tmpInGeom = inFeat.geometry()
                if tmpInGeom.isNull() or tmpInGeom.isEmpty():
                    continue

                errors = tmpInGeom.validateGeometry()
                if len(errors) != 0:
                    for error in errors:
                        ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
                                               self.tr('ValidateGeometry()'
                                                       'error: One or more '
                                                       'input features have '
                                                       'invalid geometry: ') +
                                               error.what())
                    continue

                geom_queue.append(tmpInGeom)

                if len(geom_queue) > 10000:
                    # queue too long, combine it
                    try:
                        temp_output_geometry = QgsGeometry.unaryUnion(geom_queue)
                        geom_queue = [temp_output_geometry]
                    except:
                        raise GeoAlgorithmExecutionException(
                            self.tr('Geometry exception while dissolving'))

            try:
                outFeat.setGeometry(QgsGeometry.unaryUnion(geom_queue))
            except:
                raise GeoAlgorithmExecutionException(
                    self.tr('Geometry exception while dissolving'))

            writer.addFeature(outFeat)
        else:
            field_indexes = [vlayerA.fields().lookupField(f) for f in field_names.split(';')]

            attribute_dict = {}
            geometry_dict = defaultdict(lambda: [])

            for inFeat in features:
                attrs = inFeat.attributes()

                index_attrs = tuple([attrs[i] for i in field_indexes])

                tmpInGeom = QgsGeometry(inFeat.geometry())
                if tmpInGeom and tmpInGeom.isEmpty():
                    continue
                errors = tmpInGeom.validateGeometry()
                if len(errors) != 0:
                    for error in errors:
                        ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
                                               self.tr('ValidateGeometry() '
                                                       'error: One or more input'
                                                       'features have invalid '
                                                       'geometry: ') +
                                               error.what())

                if index_attrs not in attribute_dict:
                    # keep attributes of first feature
                    attribute_dict[index_attrs] = attrs

                geometry_dict[index_attrs].append(tmpInGeom)

            nFeat = len(attribute_dict)

            nElement = 0
            for key, value in list(geometry_dict.items()):
                outFeat = QgsFeature()
                nElement += 1
                feedback.setProgress(int(nElement * 100 / nFeat))
                try:
                    tmpOutGeom = QgsGeometry.unaryUnion(value)
                except:
                    raise GeoAlgorithmExecutionException(
                        self.tr('Geometry exception while dissolving'))
                outFeat.setGeometry(tmpOutGeom)
                outFeat.setAttributes(attribute_dict[key])
                writer.addFeature(outFeat)

        del writer