import os
from qgis.core import *
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from sextante.core.GeoAlgorithm import GeoAlgorithm
from sextante.parameters.ParameterTable import ParameterTable
from sextante.outputs.OutputTable import OutputTable
from sextante.parameters.ParameterMultipleInput import ParameterMultipleInput
from sextante.parameters.ParameterRaster import ParameterRaster
from sextante.outputs.OutputRaster import OutputRaster
from sextante.parameters.ParameterVector import ParameterVector
from sextante.parameters.ParameterBoolean import ParameterBoolean
from sextante.core.SextanteUtils import SextanteUtils
from sextante.outputs.OutputVector import OutputVector
from sextante.saga.SagaUtils import SagaUtils
from sextante.saga.SagaGroupNameDecorator import SagaGroupNameDecorator
from sextante.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from sextante.core.SextanteLog import SextanteLog
from sextante.parameters.ParameterFactory import ParameterFactory
from sextante.outputs.OutputFactory import OutputFactory
from sextante.core.SextanteConfig import SextanteConfig
from sextante.core.QGisLayers import QGisLayers
from sextante.parameters.ParameterNumber import ParameterNumber
from sextante.parameters.ParameterSelection import ParameterSelection
from sextante.core.LayerExporter import LayerExporter
import subprocess
from sextante.parameters.ParameterExtent import ParameterExtent
from PyQt4 import QtGui
from sextante.parameters.ParameterFixedTable import ParameterFixedTable

class SagaAlgorithm(GeoAlgorithm):

    OUTPUT_EXTENT = "OUTPUT_EXTENT"

    def __init__(self, descriptionfile):
        self.resample = True #True if it should resample
                             #in case several non-matching raster layers are used as input
        GeoAlgorithm.__init__(self)
        self.descriptionFile = descriptionfile
        self.defineCharacteristicsFromFile()
        if self.resample:
            #reconsider resampling policy now that we know the input parameters
            self.resample = self.setResamplingPolicy()

    def getCopy(self):
        newone = SagaAlgorithm(self.descriptionFile)
        newone.provider = self.provider
        return newone


    def setResamplingPolicy(self):
        count = 0
        for param in self.parameters:
            if isinstance(param, ParameterRaster):
                count += 1
            if isinstance(param, ParameterMultipleInput):
                if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                    return True

        return count > 1

    def getIcon(self):
        return  QIcon(os.path.dirname(__file__) + "/../images/saga.png")

    def defineCharacteristicsFromFile(self):
        lines = open(self.descriptionFile)
        line = lines.readline().strip("\n").strip()
        self.name = line
        line = lines.readline().strip("\n").strip()
        self.undecoratedGroup = line
        self.group = SagaGroupNameDecorator.getDecoratedName(self.undecoratedGroup)
        while line != "":
            line = line.strip("\n").strip()
            if line.startswith("Parameter"):
                self.addParameter(ParameterFactory.getFromString(line))
            elif line.startswith("DontResample"):
                self.resample = False
            elif line.startswith("Extent"): #An extent parameter that wraps 4 SAGA numerical parameters
                self.extentParamNames = line[6:].strip().split(" ")
                self.addParameter(ParameterExtent(self.OUTPUT_EXTENT, "Output extent", "0,1,0,1"))
            else:
                self.addOutput(OutputFactory.getFromString(line))
            line = lines.readline().strip("\n").strip()
        lines.close()


    def calculateResamplingExtent(self):
        '''this method calculates the resampling extent, but it might set self.resample
        to false if, with the current layers, there is no need to resample'''
        auto = SextanteConfig.getSetting(SagaUtils.SAGA_AUTO_RESAMPLING)
        if auto:
            first = True;
            self.inputExtentsCount = 0
            for param in self.parameters:
                if param.value:
                    if isinstance(param, ParameterRaster):
                        if isinstance(param.value, QgsRasterLayer):
                            layer = param.value
                        else:
                            layer = QGisLayers.getObjectFromUri(param.value)
                        self.addToResamplingExtent(layer, first)
                        first = False
                    if isinstance(param, ParameterMultipleInput):
                        if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                            layers = param.value.split(";")
                            for layername in layers:
                                layer = QGisLayers.getObjectFromUri(layername)
                                self.addToResamplingExtent(layer, first)
                                first = False
            if self.inputExtentsCount < 2:
                self.resample = False
        else:
            self.xmin = SextanteConfig.getSetting(SagaUtils.SAGA_RESAMPLING_REGION_XMIN)
            self.xmax = SextanteConfig.getSetting(SagaUtils.SAGA_RESAMPLING_REGION_XMAX)
            self.ymin = SextanteConfig.getSetting(SagaUtils.SAGA_RESAMPLING_REGION_YMIN)
            self.ymax = SextanteConfig.getSetting(SagaUtils.SAGA_RESAMPLING_REGION_YMAX)
            self.cellsize = SextanteConfig.getSetting(SagaUtils.SAGA_RESAMPLING_REGION_CELLSIZE)


    def addToResamplingExtent(self, layer, first):
        if first:
            self.inputExtentsCount = 1
            self.xmin = layer.extent().xMinimum()
            self.xmax = layer.extent().xMaximum()
            self.ymin = layer.extent().yMinimum()
            self.ymax = layer.extent().yMaximum()
            self.cellsize = (layer.extent().xMaximum() - layer.extent().xMinimum())/layer.width()
        else:
            cellsize = (layer.extent().xMaximum() - layer.extent().xMinimum())/layer.width()
            if self.xmin != layer.extent().xMinimum() \
                    or self.xmax != layer.extent().xMaximum() \
                    or self.ymin != layer.extent().yMinimum() \
                    or self.ymax != layer.extent().yMaximum() \
                    or self.cellsize != cellsize:
                self.xmin = min(self.xmin, layer.extent().xMinimum())
                self.xmax = max(self.xmax, layer.extent().xMaximum())
                self.ymin = min(self.ymin, layer.extent().yMinimum())
                self.ymax = max(self.ymax, layer.extent().yMaximum())
                self.cellsize = max(self.cellsize, cellsize)
                self.inputExtentsCount += 1


    def processAlgorithm(self, progress):
        if SextanteUtils.isWindows():
            path = SagaUtils.sagaPath()
            if path == "":
                raise GeoAlgorithmExecutionException("SAGA folder is not configured.\nPlease configure it before running SAGA algorithms.")
        #useSelection = SextanteConfig.getSetting(SagaUtils.SAGA_USE_SELECTED)
        commands = list()
        self.exportedLayers = {}

        #1: Export rasters to sgrd and vectors to shp
        #   Tables must be in dbf format. We check that.
        if self.resample:
            self.calculateResamplingExtent()
        for param in self.parameters:
            if isinstance(param, ParameterRaster):
                if param.value == None:
                    continue
                value = param.value
                if not value.endswith("sgrd"):
                    commands.append(self.exportRasterLayer(value))
                if self.resample:
                    commands.append(self.resampleRasterLayer(value));
            if isinstance(param, ParameterVector):
                if param.value == None:
                    continue
                layer = QGisLayers.getObjectFromUri(param.value, False)
                if layer:
                    filename = LayerExporter.exportVectorLayer(layer)
                    self.exportedLayers[param.value]=filename
                elif not param.value.endswith("shp"):
                        raise GeoAlgorithmExecutionException("Unsupported file format")
            if isinstance(param, ParameterTable):
                if param.value == None:
                    continue
                value = param.value
                if not value.endswith("dbf"):
                    raise GeoAlgorithmExecutionException("Unsupported file format")
            if isinstance(param, ParameterMultipleInput):
                if param.value == None:
                    continue
                layers = param.value.split(";")
                if layers == None or len(layers) == 0:
                    continue
                if param.datatype == ParameterMultipleInput.TYPE_RASTER:
                    for layerfile in layers:
                        if not layerfile.endswith("sgrd"):
                            commands.append(self.exportRasterLayer(layerfile))
                        if self.resample:
                            commands.append(self.resampleRasterLayer(layerfile));
                elif param.datatype == ParameterMultipleInput.TYPE_VECTOR_ANY:
                    for layerfile in layers:
                        layer = QGisLayers.getObjectFromUri(layerfile, False)
                        if layer:
                            filename = LayerExporter.exportVectorLayer(layer)
                            self.exportedLayers[layerfile]=filename
                        elif (not value.endswith("shp")):
                            raise GeoAlgorithmExecutionException("Unsupported file format")

        #2: set parameters and outputs
        if SextanteUtils.isWindows():
            command = self.undecoratedGroup  + " \"" + self.name + "\""
        else:
            command = "lib" + self.undecoratedGroup  + " \"" + self.name + "\""

        for param in self.parameters:
            if param.value is None:
                continue
            if isinstance(param, (ParameterRaster, ParameterVector)):
                value = param.value
                if value in self.exportedLayers.keys():
                    command+=(" -" + param.name + " \"" + self.exportedLayers[value] + "\"")
                else:
                    command+=(" -" + param.name + " " + value)
            elif isinstance(param, ParameterMultipleInput):
                s = param.value
                for layer in self.exportedLayers.keys():
                    s = s.replace(layer, self.exportedLayers[layer])
                command+=(" -" + param.name + " \"" + s + "\"");
            elif isinstance(param, ParameterBoolean):
                if param.value:
                    command+=(" -" + param.name);
            elif isinstance(param, ParameterFixedTable):
                tempTableFile  = SextanteUtils.getTempFilename("txt")
                f = open(tempTableFile, "w")
                f.write('\t'.join([col for col in param.cols]) + "\n")
                values = param.value.split(",")
                for i in range(0, len(values), 3):
                    s = values[i] + "\t" + values[i+1] + "\t" + values[i+2] + "\n"
                    f.write(s)
                f.close()
                command+=( " -" + param.name + " " + tempTableFile)
            elif isinstance(param, ParameterExtent):
                values = param.value.split(",")
                for i in range(4):
                    command+=(" -" + self.extentParamNames[i] + " " + str(values[i]));
            elif isinstance(param, (ParameterNumber, ParameterSelection)):
                command+=(" -" + param.name + " " + str(param.value));
            else:
                command+=(" -" + param.name + " \"" + str(param.value) + "\"");

        for out in self.outputs:
            if isinstance(out, OutputRaster):
                filename = out.value
                if not filename.endswith(".tif"):
                    filename += ".tif"
                    out.value = filename
                filename = SextanteUtils.tempFolder() + os.sep + os.path.basename(filename) + ".sgrd"
                command+=(" -" + out.name + " \"" + filename + "\"");
            if isinstance(out, OutputVector):
                filename = out.value
                if not filename.endswith(".shp"):
                    filename += ".shp"
                    out.value = filename
                command+=(" -" + out.name + " \"" + filename + "\"");
            if isinstance(out, OutputTable):
                filename = out.value
                if not filename.endswith(".dbf"):
                    filename += ".dbf"
                    out.value = filename
                command+=(" -" + out.name + " \"" + filename + "\"");

        commands.append(command)

        #3:Export resulting raster layers
        for out in self.outputs:
            if isinstance(out, OutputRaster):
                filename = out.value
                filename2 = SextanteUtils.tempFolder() + os.sep + os.path.basename(filename) + ".sgrd"
                if SextanteUtils.isWindows():
                    commands.append("io_gdal 1 -GRIDS \"" + filename2 + "\" -FORMAT 1 -TYPE 0 -FILE \"" + filename + "\"");
                else:
                    commands.append("libio_gdal 1 -GRIDS \"" + filename2 + "\" -FORMAT 1 -TYPE 0 -FILE \"" + filename + "\"");

        #4 Run SAGA
        SagaUtils.createSagaBatchJobFileFromSagaCommands(commands)
        loglines = []
        loglines.append("SAGA execution commands")
        for line in commands:
            loglines.append(line)
        SextanteLog.addToLog(SextanteLog.LOG_INFO, loglines)
        SagaUtils.executeSaga(progress);


    def resampleRasterLayer(self,layer):
        '''this is supposed to be run after having exported all raster layers'''
        if layer in self.exportedLayers.keys():
            inputFilename = self.exportedLayers[layer]
        else:
            inputFilename = layer
        destFilename = SextanteUtils.getTempFilename("sgrd")
        self.exportedLayers[layer]= destFilename
        if SextanteUtils.isWindows():
            s = "grid_tools \"Resampling\" -INPUT \"" + inputFilename + "\" -TARGET 0 -SCALE_UP_METHOD 4 -SCALE_DOWN_METHOD 4 -USER_XMIN " +\
                str(self.xmin) + " -USER_XMAX " + str(self.xmax) + " -USER_YMIN " + str(self.ymin) + " -USER_YMAX "  + str(self.ymax) +\
                " -USER_SIZE " + str(self.cellsize) + " -USER_GRID \"" + destFilename + "\""
        else:
            s = "libgrid_tools \"Resampling\" -INPUT \"" + inputFilename + "\" -TARGET 0 -SCALE_UP_METHOD 4 -SCALE_DOWN_METHOD 4 -USER_XMIN " +\
                str(self.xmin) + " -USER_XMAX " + str(self.xmax) + " -USER_YMIN " + str(self.ymin) + " -USER_YMAX "  + str(self.ymax) +\
                " -USER_SIZE " + str(self.cellsize) + " -USER_GRID \"" + destFilename + "\""
        return s


    def exportRasterLayer(self, layer):
        destFilename = SextanteUtils.getTempFilename("sgrd")
        self.exportedLayers[layer]= destFilename
        if SextanteUtils.isWindows():
            return "io_gdal 0 -GRIDS \"" + destFilename + "\" -FILES \"" + layer+"\""
        else:
            return "libio_gdal 0 -GRIDS \"" + destFilename + "\" -FILES \"" + layer + "\""


    def checkBeforeOpeningParametersDialog(self):
        if SextanteUtils.isWindows():
            path = SagaUtils.sagaPath()
            if path == "":
                return "SAGA folder is not configured.\nPlease configure it before running SAGA algorithms."
        else:
            SAGA_INSTALLED = "SAGA_INSTALLED"
            settings = QSettings()
            if settings.contains(SAGA_INSTALLED):
                return
            command = ["saga_cmd"]
            proc = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE, stdin=subprocess.PIPE,stderr=subprocess.STDOUT, universal_newlines=True).stdout
            for line in iter(proc.readline, ""):
                if "________" in line:
                    settings.setValue(SAGA_INSTALLED, True)
                    return
            return "It seems that SAGA is not correctly installed in your system.\nPlease install it before running SAGA algorithms."

    def helpFile(self):
        return  os.path.join(os.path.dirname(__file__), "help", self.name.replace(" ", "") + ".html")
