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

"""
***************************************************************************
    Clip.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 qgis.core import QGis, QgsFeature, QgsGeometry, QgsFeatureRequest, QgsWKBTypes
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.ProcessingLog import ProcessingLog
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects, vector


class Clip(GeoAlgorithm):

    INPUT = 'INPUT'
    OVERLAY = 'OVERLAY'
    OUTPUT = 'OUTPUT'

    def defineCharacteristics(self):
        self.name, self.i18n_name = self.trAlgorithm('Clip')
        self.group, self.i18n_group = self.trAlgorithm('Vector overlay tools')
        self.addParameter(ParameterVector(Clip.INPUT,
                                          self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_ANY]))
        self.addParameter(ParameterVector(Clip.OVERLAY,
                                          self.tr('Clip layer'), [ParameterVector.VECTOR_TYPE_POLYGON]))
        self.addOutput(OutputVector(Clip.OUTPUT, self.tr('Clipped')))

    def processAlgorithm(self, progress):
        layerA = dataobjects.getObjectFromUri(
            self.getParameterValue(Clip.INPUT))
        layerB = dataobjects.getObjectFromUri(
            self.getParameterValue(Clip.OVERLAY))

        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
            layerA.pendingFields(),
            layerA.dataProvider().geometryType(),
            layerA.dataProvider().crs())

        inFeatA = QgsFeature()
        inFeatB = QgsFeature()
        outFeat = QgsFeature()

        index = vector.spatialindex(layerB)

        selectionA = vector.features(layerA)

        current = 0
        total = 100.0 / float(len(selectionA))

        for inFeatA in selectionA:
            geom = QgsGeometry(inFeatA.geometry())
            attrs = inFeatA.attributes()
            intersects = index.intersects(geom.boundingBox())
            first = True
            found = False
            if len(intersects) > 0:
                for i in intersects:
                    layerB.getFeatures(
                        QgsFeatureRequest().setFilterFid(i)).nextFeature(
                            inFeatB)
                    tmpGeom = QgsGeometry(inFeatB.geometry())
                    if tmpGeom.intersects(geom):
                        found = True
                        if first:
                            outFeat.setGeometry(QgsGeometry(tmpGeom))
                            first = False
                        else:
                            try:
                                cur_geom = QgsGeometry(outFeat.geometry())
                                new_geom = QgsGeometry(
                                    cur_geom.combine(tmpGeom))
                                outFeat.setGeometry(QgsGeometry(new_geom))
                            except:
                                ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
                                                       self.tr('GEOS geoprocessing error: One or '
                                                               'more input features have invalid '
                                                               'geometry.'))
                                break
                if found:
                    try:
                        cur_geom = QgsGeometry(outFeat.geometry())
                        new_geom = QgsGeometry(geom.intersection(cur_geom))
                        if new_geom.wkbType() == QGis.WKBUnknown or QgsWKBTypes.flatType(new_geom.geometry().wkbType()) == QgsWKBTypes.GeometryCollection:
                            int_com = QgsGeometry(geom.combine(cur_geom))
                            int_sym = QgsGeometry(geom.symDifference(cur_geom))
                            new_geom = QgsGeometry(int_com.difference(int_sym))
                        try:
                            outFeat.setGeometry(new_geom)
                            outFeat.setAttributes(attrs)
                            writer.addFeature(outFeat)
                        except:
                            ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
                                                   self.tr('Feature geometry error: One or more '
                                                           'output features ignored due to '
                                                           'invalid geometry.'))
                            continue
                    except:
                        ProcessingLog.addToLog(ProcessingLog.LOG_ERROR,
                                               self.tr('GEOS geoprocessing error: One or more '
                                                       'input features have invalid geometry.'))
                        continue

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

        del writer