# -*- coding: utf-8 -*-
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from qgis.core import *
from qgis.gui import *
from osgeo import ogr

from ui_widgetRasterize import Ui_GdalToolsWidget as Ui_Widget
from widgetPluginBase import GdalToolsBasePluginWidget as BasePluginWidget
import GdalTools_utils as Utils

class GdalToolsDialog(QWidget, Ui_Widget, BasePluginWidget):

  def __init__(self, iface):
      QWidget.__init__(self)
      self.iface = iface

      self.setupUi(self)
      BasePluginWidget.__init__(self, self.iface, "gdal_rasterize")

      self.outSelector.setType( self.outSelector.FILE )

      # set the default QSpinBoxes and QProgressBar value
      self.widthSpin.setValue(3000)
      self.heightSpin.setValue(3000)

      self.lastEncoding = Utils.getLastUsedEncoding()

      self.setParamsStatus(
        [
          (self.inSelector, SIGNAL("filenameChanged()")),
          (self.outSelector, SIGNAL("filenameChanged()")),
          (self.attributeComboBox, SIGNAL("currentIndexChanged(int)")),
          ( [self.widthSpin, self.heightSpin], SIGNAL( "valueChanged(int)" ), self.resizeGroupBox, "1.8.0" ),
        ]
      )

      self.connect(self.inSelector, SIGNAL("selectClicked()"), self.fillInputFileEdit)
      self.connect(self.outSelector, SIGNAL("selectClicked()"), self.fillOutputFileEdit)
      self.connect(self.inSelector, SIGNAL("layerChanged()"), self.fillFieldsCombo)

  def onLayersChanged(self):
      self.inSelector.setLayers( Utils.LayerRegistry.instance().getVectorLayers() )

  def fillFieldsCombo(self):
      if self.inSelector.layer() == None:
        return
      self.lastEncoding = self.inSelector.layer().dataProvider().encoding()
      self.loadFields( self.getInputFileName() )

  def fillInputFileEdit(self):
      lastUsedFilter = Utils.FileFilter.lastUsedVectorFilter()
      inputFile, encoding = Utils.FileDialog.getOpenFileName(self, self.tr( "Select the input file for Rasterize" ), Utils.FileFilter.allVectorsFilter(), lastUsedFilter, True)
      if inputFile.isEmpty():
        return
      Utils.FileFilter.setLastUsedVectorFilter(lastUsedFilter)

      self.inSelector.setFilename(inputFile)
      self.lastEncoding = encoding

      self.loadFields( inputFile )

  def fillOutputFileEdit(self):
      lastUsedFilter = Utils.FileFilter.lastUsedRasterFilter()

      # rasterize supports output file creation for GDAL 1.8
      gdalVersion = Utils.GdalConfig.version()
      if gdalVersion >= "1.8.0":
        fileDialogFunc = Utils.FileDialog.getSaveFileName
      else:
        fileDialogFunc = Utils.FileDialog.getOpenFileName

      outputFile = fileDialogFunc(self, self.tr( "Select the raster file to save the results to" ), Utils.FileFilter.allRastersFilter(), lastUsedFilter)
      if outputFile.isEmpty():
        return
      Utils.FileFilter.setLastUsedRasterFilter(lastUsedFilter)

      self.outSelector.setFilename(outputFile)

      # required either -ts or -tr to create the output file 
      if gdalVersion >= "1.8.0":
        if not QFileInfo(outputFile).exists():
          QMessageBox.information( self, self.tr( "Output size required" ), self.tr( "The output file doesn't exist. You must set up the output size to create it." ) )
          self.resizeGroupBox.setChecked(True)

  def getArguments(self):
      arguments = QStringList()
      if self.attributeComboBox.currentIndex() >= 0:
        arguments << "-a"
        arguments << self.attributeComboBox.currentText()
      if self.resizeGroupBox.isChecked():
        arguments << "-ts"
        arguments << str( self.widthSpin.value() )
        arguments << str( self.heightSpin.value() )
      inputFn = self.getInputFileName()
      if not inputFn.isEmpty():
        arguments << "-l" 
        arguments << QFileInfo( inputFn ).baseName()
      arguments << inputFn
      arguments << self.getOutputFileName()
      return arguments

  def getInputFileName(self):
      return self.inSelector.filename()

  def getOutputFileName(self):
      return self.outSelector.filename()

  def addLayerIntoCanvas(self, fileInfo):
      self.iface.addRasterLayer(fileInfo.filePath())

  def loadFields(self, vectorFile):
      self.attributeComboBox.clear()

      if vectorFile.isEmpty():
        return

      try:
        (fields, names) = Utils.getVectorFields(vectorFile)
      except Utils.UnsupportedOGRFormat, e:
        QErrorMessage(self).showMessage( e.args[0] )
        self.inSelector.setLayer( None )
        return

      ncodec = QTextCodec.codecForName(self.lastEncoding)
      for name in names:
        self.attributeComboBox.addItem( ncodec.toUnicode(name) )