"""
***************************************************************************
    v_net_distance.py
    ---------------------
    Date                 : December 2015
    Copyright            : (C) 2015 by Médéric Ribreux
    Email                : medspx at medspx dot fr
***************************************************************************
*                                                                         *
*   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__ = 'Médéric Ribreux'
__date__ = 'December 2015'
__copyright__ = '(C) 2015, Médéric Ribreux'

import os
from .v_net import variableOutput
from processing.tools.system import getTempFilename
from qgis.core import QgsProcessingParameterString


def processCommand(alg, parameters, context, feedback):
    """ Handle data preparation for v.net.distance:
    * Integrate point layers into network vector map.
    * Make v.net.distance use those layers.
    * Delete the threshold parameter.
    * If where statement, connect to the db
    """
    # Grab the point layer and delete this parameter
    lineLayer = alg.exportedLayers['input']
    fromLayer = alg.exportedLayers['flayer']
    toLayer = alg.exportedLayers['tlayer']
    intLayer = 'bufnet' + os.path.basename(getTempFilename(context=context))
    netLayer = 'net' + os.path.basename(getTempFilename(context=context))
    threshold = alg.parameterAsDouble(parameters, 'threshold', context)

    # Create the v.net connect command for from_layer integration
    command = 'v.net -s input={} points={} output={} operation=connect threshold={} arc_layer=1 node_layer=2'.format(
        lineLayer, fromLayer, intLayer, threshold)
    alg.commands.append(command)

    # Do it again with to_layer
    command = 'v.net -s input={} points={} output={} operation=connect threshold={} arc_layer=1 node_layer=3'.format(
        intLayer, toLayer, netLayer, threshold)
    alg.commands.append(command)

    # Connect the point layer database to the layer 2 of the network
    command = 'v.db.connect -o map={} table={} layer=2'.format(netLayer, fromLayer)
    alg.commands.append(command)

    command = 'v.db.connect -o map={} table={} layer=3'.format(netLayer, toLayer)
    alg.commands.append(command)

    # remove undesired parameters
    alg.removeParameter('flayer')
    alg.removeParameter('tlayer')
    alg.removeParameter('threshold')
    alg.exportedLayers['input'] = netLayer

    # Add the two new parameters
    fLayer = QgsProcessingParameterString('from_layer', None, 2, False, False)
    alg.addParameter(fLayer)
    tLayer = QgsProcessingParameterString('to_layer', None, 3, False, False)
    alg.addParameter(tLayer)
    alg.processCommand(parameters, context, feedback)


def processOutputs(alg, parameters, context, feedback):
    outputParameter = {'output': ['output', 'line', 1, True]}
    variableOutput(alg, outputParameter, parameters, context)
