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

"""
***************************************************************************
    AlgorithmExecutor.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__ = '$Format:%H$'

from PyQt4.QtGui import *
from PyQt4.QtCore import *
from qgis.core import *
from processing.core.ProcessingLog import ProcessingLog
from processing.core.GeoAlgorithmExecutionException import \
        GeoAlgorithmExecutionException
from processing.gui.Postprocessing import handleAlgorithmResults
from processing.tools import dataobjects
from processing.tools.system import *
from processing.tools import vector
from processing.gui.SilentProgress import SilentProgress


def runalg(alg, progress=None):
    """Executes a given algorithm, showing its progress in the
    progress object passed along.

    Return true if everything went OK, false if the algorithm
    could not be completed.
    """
    if progress is None:
        progress = SilentProgress()
    try:
        alg.execute(progress)
        return True
    except GeoAlgorithmExecutionException, e:
        ProcessingLog.addToLog(sys.exc_info()[0], ProcessingLog.LOG_ERROR)
        progress.error(e.msg)
        return False

def runalgIterating(alg, paramToIter, progress):
    # Generate all single-feature layers
    settings = QSettings()
    systemEncoding = settings.value('/UI/encoding', 'System')
    layerfile = alg.getParameterValue(paramToIter)
    layer = dataobjects.getObjectFromUri(layerfile, False)
    feat = QgsFeature()
    filelist = []
    outputs = {}
    provider = layer.dataProvider()
    features = vector.features(layer)
    for feat in features:
        output = getTempFilename('shp')
        filelist.append(output)
        writer = QgsVectorFileWriter(output, systemEncoding,
                provider.fields(), provider.geometryType(), layer.crs())
        writer.addFeature(feat)
        del writer

    # store output values to use them later as basenames for all outputs
    for out in alg.outputs:
        outputs[out.name] = out.value

    # now run all the algorithms
    for i,f in enumerate(filelist):
        alg.setParameterValue(paramToIter, f)
        for out in alg.outputs:
            filename = outputs[out.name]
            if filename:
                filename = filename[:filename.rfind('.')] + '_' + str(i) \
                    + filename[filename.rfind('.'):]
            out.value = filename
        progress.setText(tr('Executing iteration %s/%s...' % (str(i), str(len(filelist)))))
        progress.setPercentage(i * 100 / len(filelist))
        if runalg(alg):
            handleAlgorithmResults(alg, None, False)
        else:
            return False

    return True

def tr(string, context=''):
    if context == '':
        context = 'AlgorithmExecutor'
    return QCoreApplication.translate(context, string)