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

"""
***************************************************************************
    PointsToPaths.py
    ---------------------
    Date                 : April 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.                                   *
*                                                                         *
***************************************************************************
"""

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

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

__revision__ = '$Format:%H$'

from datetime import datetime
from datetime import timedelta

from PyQt4.QtCore import *

from qgis.core import *

from processing import interface
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.ProcessingLog import ProcessingLog
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterTableField import ParameterTableField
from processing.parameters.ParameterString import ParameterString
#from processing.parameters.ParameterNumber import ParameterNumber
from processing.outputs.OutputVector import OutputVector
from processing.tools import dataobjects, vector

class PointsToPaths(GeoAlgorithm):

    VECTOR = 'VECTOR'
    GROUP_FIELD = 'GROUP_FIELD'
    ORDER_FIELD = 'ORDER_FIELD'
    DATE_FORMAT = 'DATE_FORMAT'
    #GAP_PERIOD = 'GAP_PERIOD'
    OUTPUT = 'OUTPUT'

    def defineCharacteristics(self):
        self.name = 'Points to path'
        self.group = 'Vector creation tools'
        self.addParameter(ParameterVector(self.VECTOR,
            'Input point layer', [ParameterVector.VECTOR_TYPE_POINT]))
        self.addParameter(
            ParameterTableField(self.GROUP_FIELD, 'Group field', self.VECTOR))
        self.addParameter(
            ParameterTableField(self.ORDER_FIELD, 'Order field', self.VECTOR))
        self.addParameter(ParameterString(self.DATE_FORMAT,
            'Date format (if order field is DateTime)', '', optional=True))
        #self.addParameter(ParameterNumber(
        #    self.GAP_PERIOD,
        #    'Gap period (if order field is DateTime)', 0, 60, 0))
        self.addOutput(OutputVector(self.OUTPUT, 'Paths'))

    def processAlgorithm(self, progress):
        layer = dataobjects.getObjectFromUri(
            self.getParameterValue(self.VECTOR))
        groupField = self.getParameterValue(self.GROUP_FIELD)
        orderField = self.getParameterValue(self.ORDER_FIELD)
        dateFormat = unicode(self.getParameterValue(self.DATE_FORMAT))
        #gap = int(self.getParameterValue(self.GAP_PERIOD))

        fields = QgsFields()
        fields.append(QgsField('group', QVariant.String, '', 254, 0))
        fields.append(QgsField('begin', QVariant.String, '', 254, 0))
        fields.append(QgsField('end', QVariant.String, '', 254, 0))
        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(
            fields, QGis.WKBLineString, layer.dataProvider().crs())

        points = dict()
        features = vector.features(layer)
        total = 100.0 / len(features)
        for count, f in enumerate(features):
            point = f.geometry().asPoint()
            group = f[groupField]
            order = f[orderField]
            if dateFormat != '':
                order = datetime.strptime(unicode(order), dateFormat)
            if group in points:
                points[group].append((order, point))
            else:
                points[group] = [(order, point)]

            progress.setPercentage(int(count * total))

        progress.setPercentage(0)

        count = 0
        total = 100.0 / len(points)
        for k, v in points.iteritems():
            v.sort()
            f = QgsFeature()
            f.initAttributes(len(fields))
            f.setFields(fields)
            f['group'] = k
            f['begin'] = v[0][0]
            f['end'] = v[-1][0]
            line = []
            for node in v:
                line.append(node[1])
            f.setGeometry(QgsGeometry.fromPolyline(line))
            writer.addFeature(f)
            count += 1
            progress.setPercentage(int(count * total))

        del writer