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

"""
***************************************************************************
    UnthreadedAlgorithmExecutor.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.SilentProgress import SilentProgress
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


class UnthreadedAlgorithmExecutor:

    @staticmethod
    def runalg(alg, progress):
        """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.
        """

        try:
            alg.execute(progress)
            return True
        except GeoAlgorithmExecutionException, e:
            ProcessingLog.addToLog(sys.exc_info()[0], ProcessingLog.LOG_ERROR)
            progress.error(e.msg)
            return False
        except Exception:
            msg = 'Uncaught error executing ' + str(alg.name) \
                + '\nSee log for more information'
            ProcessingLog.addToLog(sys.exc_info()[0], ProcessingLog.LOG_ERROR)
            progress.error(msg)
            return False

    @staticmethod
    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('Executing iteration ' + str(i) + '/'
                             + str(len(filelist)) + '...')
            progress.setPercentage(i * 100 / len(filelist))
            if UnthreadedAlgorithmExecutor.runalg(alg, SilentProgress()):
                handleAlgorithmResults(alg, SilentProgress(), False)                 
            else:
                return False

        return True