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

"""
***************************************************************************
    SplitRGBBands.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf 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__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

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

__revision__ = '2f64a3c4e74022c5555ee19862f034ffacc2b5fe'

import os
from qgis.core import (QgsProcessingParameterRasterLayer,
                       QgsProcessingParameterRasterDestination)
from processing.tools.system import getTempFilename
from . import SagaUtils
from .SagaAlgorithmBase import SagaAlgorithmBase

pluginPath = os.path.normpath(os.path.join(
    os.path.split(os.path.dirname(__file__))[0], os.pardir))


class SplitRGBBands(SagaAlgorithmBase):

    INPUT = 'INPUT'
    R = 'R'
    G = 'G'
    B = 'B'

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

    def initAlgorithm(self, config=None):
        self.addParameter(QgsProcessingParameterRasterLayer(self.INPUT, self.tr('Input layer')))

        self.addParameter(QgsProcessingParameterRasterDestination(self.R, self.tr('Output R band layer')))
        self.addParameter(QgsProcessingParameterRasterDestination(self.G, self.tr('Output G band layer')))
        self.addParameter(QgsProcessingParameterRasterDestination(self.B, self.tr('Output B band layer')))

    def name(self):
        return 'splitrgbbands'

    def displayName(self):
        return self.tr('Split RGB bands')

    def group(self):
        return self.tr('Image tools')

    def processAlgorithm(self, parameters, context, feedback):
        # TODO: check correct num of bands
        inLayer = self.parameterAsRasterLayer(parameters, self.INPUT, context)
        input = inLayer.source()
        temp = getTempFilename(None).replace('.', '')
        basename = os.path.basename(temp)
        validChars = \
            'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
        safeBasename = ''.join(c for c in basename if c in validChars)
        temp = os.path.join(os.path.dirname(temp), safeBasename)

        r = self.parameterAsOutputLayer(parameters, self.R, context)
        g = self.parameterAsOutputLayer(parameters, self.G, context)
        b = self.parameterAsOutputLayer(parameters, self.B, context)

        commands = []
        version = SagaUtils.getInstalledVersion(True)
        trailing = ""
        lib = ""
        commands.append('%sio_gdal 0 -GRIDS "%s" -FILES "%s"' % (lib, temp, input)
                        )
        commands.append('%sio_gdal 1 -GRIDS "%s_%s1.sgrd" -FORMAT 1 -TYPE 0 -FILE "%s"' % (lib, temp, trailing, r)
                        )
        commands.append('%sio_gdal 1 -GRIDS "%s_%s2.sgrd" -FORMAT 1 -TYPE 0 -FILE "%s"' % (lib, temp, trailing, g)
                        )
        commands.append('%sio_gdal 1 -GRIDS "%s_%s3.sgrd" -FORMAT 1 -TYPE 0 -FILE "%s"' % (lib, temp, trailing, b)
                        )

        SagaUtils.createSagaBatchJobFileFromSagaCommands(commands)
        SagaUtils.executeSaga(feedback)

        return {self.R: r, self.G: g, self.B: b}
