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

"""
***************************************************************************
    PointsAlongGeometry.py
    ---------------------
    Date                 : August 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__ = 'August 2016'
__copyright__ = '(C) 2016, Nyall Dawson'

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

__revision__ = '$Format:%H$'

import os
import math

from qgis.PyQt.QtCore import QVariant
from qgis.PyQt.QtGui import QIcon

from qgis.core import (QgsFeature,
                       QgsFeatureSink,
                       QgsWkbTypes,
                       QgsField,
                       QgsProcessing,
                       QgsProcessingUtils,
                       QgsProcessingParameterNumber,
                       QgsProcessingParameterFeatureSource,
                       QgsProcessingParameterFeatureSink)

from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm

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


class PointsAlongGeometry(QgisAlgorithm):

    INPUT = 'INPUT'
    OUTPUT = 'OUTPUT'
    DISTANCE = 'DISTANCE'
    START_OFFSET = 'START_OFFSET'
    END_OFFSET = 'END_OFFSET'

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

    def tags(self):
        return self.tr('create,interpolate,points,lines').split(',')

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

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

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT,
                                                              self.tr('Input layer'), [QgsProcessing.TypeVectorPolygon, QgsProcessing.TypeVectorLine]))
        self.addParameter(QgsProcessingParameterNumber(self.DISTANCE,
                                                       self.tr('Distance'), minValue=0.0, defaultValue=1.0))
        self.addParameter(QgsProcessingParameterNumber(self.START_OFFSET,
                                                       self.tr('Start offset'), minValue=0.0, defaultValue=0.0))
        self.addParameter(QgsProcessingParameterNumber(self.END_OFFSET,
                                                       self.tr('End offset'), minValue=0.0, defaultValue=0.0))

        self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr('Points'), QgsProcessing.TypeVectorPoint))

    def name(self):
        return 'pointsalonglines'

    def displayName(self):
        return self.tr('Points along lines')

    def processAlgorithm(self, parameters, context, feedback):
        source = self.parameterAsSource(parameters, self.INPUT, context)
        distance = self.parameterAsDouble(parameters, self.DISTANCE, context)
        start_offset = self.parameterAsDouble(parameters, self.START_OFFSET, context)
        end_offset = self.parameterAsDouble(parameters, self.END_OFFSET, context)

        fields = source.fields()
        fields.append(QgsField('distance', QVariant.Double))
        fields.append(QgsField('angle', QVariant.Double))

        (sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
                                               fields, QgsWkbTypes.Point, 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

            input_geometry = input_feature.geometry()
            if not input_geometry:
                sink.addFeature(input_feature, QgsFeatureSink.FastInsert)
            else:
                if input_geometry.type == QgsWkbTypes.PolygonGeometry:
                    length = input_geometry.geometry().perimeter()
                else:
                    length = input_geometry.length() - end_offset
                current_distance = start_offset

                while current_distance <= length:
                    point = input_geometry.interpolate(current_distance)
                    angle = math.degrees(input_geometry.interpolateAngle(current_distance))

                    output_feature = QgsFeature()
                    output_feature.setGeometry(point)
                    attrs = input_feature.attributes()
                    attrs.append(current_distance)
                    attrs.append(angle)
                    output_feature.setAttributes(attrs)
                    sink.addFeature(output_feature, QgsFeatureSink.FastInsert)

                    current_distance += distance

            feedback.setProgress(int(current * total))

        return {self.OUTPUT: dest_id}