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

"""
***************************************************************************
    JoinAttributes.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 PyQt4.QtGui import *
from qgis.core import *
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterTable
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector


class JoinAttributes(GeoAlgorithm):

    OUTPUT_LAYER = 'OUTPUT_LAYER'
    INPUT_LAYER = 'INPUT_LAYER'
    INPUT_LAYER_2 = 'INPUT_LAYER_2'
    TABLE_FIELD = 'TABLE_FIELD'
    TABLE_FIELD_2 = 'TABLE_FIELD_2'

    def defineCharacteristics(self):
        self.name = 'Join attributes table'
        self.group = 'Vector general tools'
        self.addParameter(ParameterVector(self.INPUT_LAYER, 'Input layer',
                          [ParameterVector.VECTOR_TYPE_ANY], False))
        self.addParameter(ParameterTable(self.INPUT_LAYER_2, 'Input layer 2',
                          False))
        self.addParameter(ParameterTableField(self.TABLE_FIELD, 'Table field',
                          self.INPUT_LAYER))
        self.addParameter(ParameterTableField(self.TABLE_FIELD_2,
                          'Table field 2', self.INPUT_LAYER_2))
        self.addOutput(OutputVector(self.OUTPUT_LAYER, 'Output layer'))

    def processAlgorithm(self, progress):
        input = self.getParameterValue(self.INPUT_LAYER)
        input2 = self.getParameterValue(self.INPUT_LAYER_2)
        output = self.getOutputFromName(self.OUTPUT_LAYER)
        field = self.getParameterValue(self.TABLE_FIELD)
        field2 = self.getParameterValue(self.TABLE_FIELD_2)

        # Layer 1
        layer = dataobjects.getObjectFromUri(input)
        provider = layer.dataProvider()
        joinField1Index = layer.fieldNameIndex(field)

        # Layer 2
        layer2 = dataobjects.getObjectFromUri(input2)
        provider2 = layer2.dataProvider()

        joinField2Index = layer2.fieldNameIndex(field2)

        # Output
        outFields = vector.combineVectorFields(layer,layer2)

        writer = output.getVectorWriter(outFields, provider.geometryType(),
                layer.crs())

        inFeat = QgsFeature()
        inFeat2 = QgsFeature()
        outFeat = QgsFeature()

        # Cache attributes of Layer 2
        cache = {}
        features2 = vector.features(layer2)
        for inFeat2 in features2:
            attrs2 = inFeat2.attributes()
            joinValue2 = unicode(attrs2[joinField2Index])
            # Put the attributes into the dict if the join key is not contained in the keys of the dict.
            # Note: This behavior is same as previous behavior of this function,
            # but different from the attribute cache function of QGIS core.
            if not joinValue2 in cache:
                cache[joinValue2] = attrs2

        # Create output vector layer with additional attribute
        features = vector.features(layer)
        for inFeat in features:
            outFeat.setGeometry(inFeat.geometry())
            attrs = inFeat.attributes()
            joinValue1 = unicode(attrs[joinField1Index])
            attrs.extend(cache.get(joinValue1, []))
            outFeat.setAttributes(attrs)
            writer.addFeature(outFeat)
        del writer
