# -*- 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.                                   *
*                                                                         *
***************************************************************************
"""
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException

__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__ = '$Format:%H$'

from processing.core.GeoAlgorithm import GeoAlgorithm
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from processing.algs.ftools import FToolsUtils as utils
from processing.parameters.ParameterVector import ParameterVector
from processing.core.QGisLayers import QGisLayers
from processing.outputs.OutputVector import OutputVector
from processing.parameters.ParameterBoolean import ParameterBoolean
from processing.parameters.ParameterTableField import ParameterTableField
from processing.core.ProcessingLog import ProcessingLog

class Dissolve(GeoAlgorithm):

    INPUT = "INPUT"
    OUTPUT = "OUTPUT"
    FIELD = "FIELD"
    DISSOLVE_ALL = "DISSOLVE_ALL"

    #===========================================================================
    # def getIcon(self):
    #    return QtGui.QIcon(os.path.dirname(__file__) + "/icons/dissolve.png")
    #===========================================================================

    def processAlgorithm(self, progress):
        useField = not self.getParameterValue(Dissolve.DISSOLVE_ALL)
        fieldname = self.getParameterValue(Dissolve.FIELD)
        vlayerA = QGisLayers.getObjectFromUri(self.getParameterValue(Dissolve.INPUT))
        field = vlayerA.fieldNameIndex(fieldname)
        vproviderA = vlayerA.dataProvider()
        fields = vproviderA.fields()
        writer = self.getOutputFromName(Dissolve.OUTPUT).getVectorWriter(fields, vproviderA.geometryType(), vproviderA.crs() )
        outFeat = QgsFeature()
        nElement = 0
        nFeat = vproviderA.featureCount()
        if not useField:
            first = True
            features = QGisLayers.features(vlayerA)
            for inFeat in features:
                nElement += 1
                progress.setPercentage(int(nElement/nFeat * 100))
                if first:
                    attrs = inFeat.attributes()
                    tmpInGeom = QgsGeometry( inFeat.geometry() )
                    outFeat.setGeometry( tmpInGeom )
                    first = False
                else:
                    tmpInGeom = QgsGeometry( inFeat.geometry() )
                    tmpOutGeom = QgsGeometry( outFeat.geometry() )
                    try:
                        tmpOutGeom = QgsGeometry( tmpOutGeom.combine( tmpInGeom ) )
                        outFeat.setGeometry( tmpOutGeom )
                    except:
                        raise GeoAlgorithmExecutionException("Geometry exception while dissolving")
                    outFeat.setAttributes( attrs )
                    writer.addFeature( outFeat )
        else:
            unique = utils.getUniqueValues( vlayerA, int( field ) )
            nFeat = nFeat * len( unique )
            for item in unique:
                first = True
                add = True
                features = QGisLayers.features(vlayerA)
                for inFeat in features:
                    nElement += 1
                    progress.setPercentage(int(nElement/nFeat * 100))
                    atMap = inFeat.attributes()
                    tempItem = atMap[ field ]
                    if unicode(tempItem).strip() == unicode(item).strip():
                        if first:
                            QgsGeometry( inFeat.geometry() )
                            tmpInGeom = QgsGeometry( inFeat.geometry() )
                            outFeat.setGeometry( tmpInGeom )
                            first = False
                            attrs = inFeat.attributes()
                        else:
                            tmpInGeom = QgsGeometry( inFeat.geometry() )
                            tmpOutGeom = QgsGeometry( outFeat.geometry() )
                            try:
                                tmpOutGeom = QgsGeometry( tmpOutGeom.combine( tmpInGeom ) )
                                outFeat.setGeometry( tmpOutGeom )
                            except:
                                raise GeoAlgorithmExecutionException("Geometry exception while dissolving")
                if add:
                    outFeat.setAttributes( attrs )
                    writer.addFeature( outFeat )
        del writer

    def defineCharacteristics(self):
        self.name = "Dissolve"
        self.group = "Vector geometry tools"
        self.addParameter(ParameterVector(Dissolve.INPUT, "Input layer", [ParameterVector.VECTOR_TYPE_POLYGON]))
        self.addParameter(ParameterBoolean(Dissolve.DISSOLVE_ALL, "Dissolve all (do not use field)", True))
        self.addParameter(ParameterTableField(Dissolve.FIELD, "Unique ID field",Dissolve.INPUT, optional=True ))
        self.addOutput(OutputVector(Dissolve.OUTPUT, "Dissolved"))