# -*- 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.                                   *
*                                                                         *
***************************************************************************
"""

__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 PyQt4.QtCore import *
from qgis.core import *
from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from sextante.core.QGisLayers import QGisLayers
from sextante.algs.ftools import FToolsUtils as utils
from sextante.parameters.ParameterVector import ParameterVector
from sextante.parameters.ParameterTableField import ParameterTableField

from sextante.outputs.OutputVector import OutputVector

class SinglePartsToMultiparts(GeoAlgorithm):

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

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

    def defineCharacteristics(self):
        self.name = "Singleparts to multipart"
        self.group = "Vector geometry tools"

        self.addParameter(ParameterVector(self.INPUT, "Input layer"))
        self.addParameter(ParameterTableField(self.FIELD, "Unique ID field", self.INPUT))

        self.addOutput(OutputVector(self.OUTPUT, "Output layer"))

    def processAlgorithm(self, progress):
        layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT))
        output = self.getOutputValue(self.OUTPUT)
        fieldName = self.getParameterValue(self.FIELD)

        geomType = self.singleToMultiGeom(layer.dataProvider().geometryType())

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.pendingFields().toList(),
                     geomType, layer.crs())

        inFeat = QgsFeature()
        outFeat = QgsFeature()
        inGeom = QgsGeometry()
        outGeom = QgsGeometry()

        index = layer.fieldNameIndex(fieldName)
        unique = utils.getUniqueValues(layer, index)

        current = 0
        features = QGisLayers.features(layer)
        total = 100.0 / float(len(features) * len(unique))

        if not len(unique) == layer.featureCount():
            for i in unique:
                multi_feature= []
                first = True
                features = QGisLayers.features(layer)
                for inFeat in features:
                    atMap = inFeat.attributes()
                    idVar = atMap[index]
                    if unicode(idVar).strip() == unicode(i).strip():
                        if first:
                            attrs = atMap
                            first = False
                        inGeom = QgsGeometry(inFeat.geometry())
                        vType = inGeom.type()
                        feature_list = self.extractAsMulti(inGeom)
                        multi_feature.extend(feature_list)

                    current += 1
                    progress.setPercentage(int(current * total))

                outFeat.setAttributes(attrs)
                outGeom = QgsGeometry(self.convertGeometry(multi_feature, vType))
                outFeat.setGeometry(outGeom)
                writer.addFeature(outFeat)

            del writer
        else:
            raise GeoAlgorithmExecutionException("Invalid unique ID field")

    def singleToMultiGeom(self, wkbType):
      try:
          if wkbType in (QGis.WKBPoint, QGis.WKBMultiPoint,
                          QGis.WKBPoint25D, QGis.WKBMultiPoint25D):
              return QGis.WKBMultiPoint
          elif wkbType in (QGis.WKBLineString, QGis.WKBMultiLineString,
                            QGis.WKBMultiLineString25D, QGis.WKBLineString25D):
              return QGis.WKBMultiLineString
          elif wkbType in (QGis.WKBPolygon, QGis.WKBMultiPolygon,
                            QGis.WKBMultiPolygon25D, QGis.WKBPolygon25D):
              return QGis.WKBMultiPolygon
          else:
              return QGis.WKBUnknown
      except Exception, err:
          print unicode(err)

    def extractAsMulti(self, geom):
      if geom.type() == QGis.Point:
          if geom.isMultipart():
              return geom.asMultiPoint()
          else:
              return [geom.asPoint()]
      elif geom.type() == QGis.Line:
          if geom.isMultipart():
              return geom.asMultiPolyline()
          else:
              return [geom.asPolyline()]
      else:
          if geom.isMultipart():
              return geom.asMultiPolygon()
          else:
              return [geom.asPolygon()]

    def convertGeometry(self, geom_list, vType):
      if vType == QGis.Point:
          return QgsGeometry().fromMultiPoint(geom_list)
      elif vType == QGis.Line:
          return QgsGeometry().fromMultiPolyline(geom_list)
      else:
          return QgsGeometry().fromMultiPolygon(geom_list)