"""
***************************************************************************
    r_drain.py
    ----------
    Date                 : February 2016
    Copyright            : (C) 2016 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__ = "February 2016"
__copyright__ = "(C) 2016, Médéric Ribreux"


def checkParameterValuesBeforeExecuting(alg, parameters, context):
    """Verify if we have the right parameters"""
    # start_coordinates and start_points are mutually exclusives
    if alg.parameterAsString(
        parameters, "start_coordinates", context
    ) and alg.parameterAsVectorLayer(parameters, "start_points", context):
        return False, alg.tr(
            "You need to set either start coordinates OR a start points vector layer!"
        )

    # You need to set at least one parameter
    if not alg.parameterAsString(
        parameters, "start_coordinates", context
    ) and not alg.parameterAsVectorLayer(parameters, "start_points", context):
        return False, alg.tr(
            "You need to set either start coordinates OR a start points vector layer!"
        )

    paramscore = [
        f for f in ["-c", "-a", "-n"] if alg.parameterAsBoolean(parameters, f, context)
    ]
    if len(paramscore) > 1:
        return False, alg.tr("-c, -a, -n parameters are mutually exclusive!")
    return True, None
