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

"""
***************************************************************************
    Boundary.py
    --------------
    Date                 : July 2016
    Copyright            : (C) 2016 by Nyall Dawson
    Email                : nyall dot dawson 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__ = 'Nyall Dawson'
__date__ = 'July 2016'
__copyright__ = '(C) 2016, Nyall Dawson'

# This will get replaced with a git SHA1 when you do a git archive323

__revision__ = '$Format:%H$'

import os

from qgis.core import (QgsGeometry,
                       QgsWkbTypes,
                       QgsFeatureSink,
                       QgsProcessing,
                       QgsProcessingParameterFeatureSource,
                       QgsProcessingParameterFeatureSink)

from qgis.PyQt.QtGui import QIcon

from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm

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


class Boundary(QgisAlgorithm):

    INPUT_LAYER = 'INPUT_LAYER'
    OUTPUT_LAYER = 'OUTPUT_LAYER'

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

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT_LAYER, self.tr('Input layer'), [QgsProcessing.TypeVectorLine, QgsProcessing.TypeVectorPolygon]))
        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT_LAYER, self.tr('Boundary')))

    def icon(self):
        return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'convex_hull.png'))

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

    def name(self):
        return 'boundary'

    def displayName(self):
        return self.tr('Boundary')

    def processAlgorithm(self, parameters, context, feedback):
        source = self.parameterAsSource(parameters, self.INPUT_LAYER, context)

        input_wkb = source.wkbType()
        if QgsWkbTypes.geometryType(input_wkb) == QgsWkbTypes.LineGeometry:
            output_wkb = QgsWkbTypes.MultiPoint
        elif QgsWkbTypes.geometryType(input_wkb) == QgsWkbTypes.PolygonGeometry:
            output_wkb = QgsWkbTypes.MultiLineString
        if QgsWkbTypes.hasZ(input_wkb):
            output_wkb = QgsWkbTypes.addZ(output_wkb)
        if QgsWkbTypes.hasM(input_wkb):
            output_wkb = QgsWkbTypes.addM(output_wkb)

        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT_LAYER, context,
                                               source.fields(), output_wkb, source.sourceCrs())

        features = source.getFeatures()
        total = 100.0 / source.featureCount() if source.featureCount() else 0

        for current, input_feature in enumerate(features):
            if feedback.isCanceled():
                break
            output_feature = input_feature
            input_geometry = input_feature.geometry()
            if input_geometry:
                output_geometry = QgsGeometry(input_geometry.geometry().boundary())
                if not output_geometry:
                    feedback.reportError(self.tr('No boundary for feature {} (possibly a closed linestring?)').format(input_feature.id()))
                    output_feature.clearGeometry()
                else:
                    output_feature.setGeometry(output_geometry)

            sink.addFeature(output_feature, QgsFeatureSink.FastInsert)
            feedback.setProgress(int(current * total))

        return {self.OUTPUT_LAYER: dest_id}