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

"""
***************************************************************************
    VectorSplit.py
    ---------------------
    Date                 : September 2014
    Copyright            : (C) 2014 by Alexander Bruy
    Email                : alexander dot bruy 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 builtins import str

__author__ = 'Alexander Bruy'
__date__ = 'September 2014'
__copyright__ = '(C) 2014, Alexander Bruy'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import os

from qgis.PyQt.QtGui import QIcon
from qgis.core import (QgsProcessingUtils,
                       QgsFeatureSink,
                       QgsProcessingParameterFeatureSource,
                       QgsProcessingParameterField,
                       QgsProcessingParameterFolderOutput,
                       QgsProcessingOutputFolder,
                       QgsExpression,
                       QgsFeatureRequest)

from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputDirectory
from processing.tools import vector
from processing.tools.system import mkdir

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


class VectorSplit(QgisAlgorithm):

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

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

    def __init__(self):
        super().__init__()

        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
                                                              self.tr('Input layer')))

        self.addParameter(QgsProcessingParameterField(self.FIELD,
                                                      self.tr('Unique ID field'), None, self.INPUT))

        self.addParameter(QgsProcessingParameterFolderOutput(self.OUTPUT,
                                                             self.tr('Output directory')))

        self.addOutput(QgsProcessingOutputFolder(self.OUTPUT, self.tr('Output directory')))

    def name(self):
        return 'splitvectorlayer'

    def displayName(self):
        return self.tr('Split vector layer')

    def processAlgorithm(self, parameters, context, feedback):
        source = self.parameterAsSource(parameters, self.INPUT, context)
        fieldName = self.parameterAsString(parameters, self.FIELD, context)
        directory = self.parameterAsString(parameters, self.OUTPUT, context)

        mkdir(directory)

        fieldIndex = source.fields().lookupField(fieldName)
        uniqueValues = source.uniqueValues(fieldIndex)
        baseName = os.path.join(directory, '{0}'.format(fieldName))

        fields = source.fields()
        crs = source.sourceCrs()
        geomType = source.wkbType()

        total = 100.0 / len(uniqueValues) if uniqueValues else 1

        for current, i in enumerate(uniqueValues):
            if feedback.isCanceled():
                break
            fName = u'{0}_{1}.shp'.format(baseName, str(i).strip())
            feedback.pushInfo(self.tr('Creating layer: {}').format(fName))

            sink, dest = QgsProcessingUtils.createFeatureSink(fName, context, fields, geomType, crs)

            filter = '{} = {}'.format(QgsExpression.quotedColumnRef(fieldName), QgsExpression.quotedValue(i))
            req = QgsFeatureRequest().setFilterExpression(filter)

            count = 0
            for f in source.getFeatures(req):
                if feedback.isCanceled():
                    break
                sink.addFeature(f, QgsFeatureSink.FastInsert)
                count += 1
            feedback.pushInfo(self.tr('Added {} features to layer').format(count))
            del sink

            feedback.setProgress(int(current * total))

        return {self.OUTPUT: directory}