r"""
This module is designed for use in co-processing Python scripts. It provides a
class, Pipeline, which is designed to be used as the base-class for Python
pipeline. Additionally, this module has several other utility functions that are
approriate for co-processing.
"""

from paraview import simple
from vtkPVVTKExtensionsCorePython import *
import math

# -----------------------------------------------------------------------------
def IsInModulo(timestep, frequencyArray):
    """
    Return True if the given timestep is in one of the provided frequency.
    This can be interpreted as follow::

        isFM = IsInModulo(timestep, [2,3,7])

    is similar to::

        isFM = (timestep % 2 == 0) or (timestep % 3 == 0) or (timestep % 7 == 0)
    """
    for frequency in frequencyArray:
        if frequency > 0 and (timestep % frequency == 0):
            return True
    return False

class CoProcessor(object):
    """Base class for co-processing Pipelines. paraview.cpstate Module can
       be used to dump out ParaView states as co-processing pipelines. Those are
       typically subclasses of this. The subclasses must provide an
       implementation for the CreatePipeline() method."""

    def __init__(self):
        self.__PipelineCreated = False
        self.__ProducersMap = {}
        self.__WritersList = []
        self.__ViewsList = []
        self.__EnableLiveVisualization = False
        self.__LiveVisualizationFrequency = 1;
        self.__LiveVisualizationLink = None
        pass

    def SetUpdateFrequencies(self, frequencies):
        """Set the frequencies at which the pipeline needs to be updated.
           Typically, this is called by the subclass once it has determined what
           timesteps co-processing will be needed to be done.
           frequencies is a map, with key->string name of for the simulation
           input, and value is a list of frequencies.
           """
        if type(frequencies) != dict:
           raise RuntimeError,\
                 "Incorrect argument type: %s, must be a dict" % type(frequencies)
        self.__Frequencies = frequencies


    def EnableLiveVisualization(self, enable, frequency = 1):
        """Call this method to enable live-visualization. When enabled,
        DoLiveVisualization() will communicate with ParaView server if possible
        for live visualization. Frequency specifies how often the
        communication happens (default is every second)."""
        self.__EnableLiveVisualization = enable
        self.__LiveVisualizationFrequency = frequency
        if (enable):
            for currentFrequencies in self.__Frequencies.itervalues():
                if not frequency in currentFrequencies:
                    currentFrequencies.append(frequency)
                    currentFrequencies.sort()

    def CreatePipeline(self, datadescription):
        """This methods must be overridden by subclasses to create the
           visualization pipeline."""
        raise RuntimeError, "Subclasses must override this method."

    def LoadRequestedData(self, datadescription):
        """Call this method in RequestDataDescription co-processing pass to mark
           the datadescription with information about what fields and grids are
           required for this pipeline for the given timestep, if any.

           Default implementation uses the update-frequencies set using
           SetUpdateFrequencies() to determine if the current timestep needs to
           be processed and then requests all fields. Subclasses can override
           this method to provide addtional customizations."""

        timestep = datadescription.GetTimeStep()
        num_inputs = datadescription.GetNumberOfInputDescriptions()
        for cc in range(num_inputs):
            input_name = datadescription.GetInputDescriptionName(cc)

            freqs = self.__Frequencies.get(input_name, [])
            if freqs:
                if IsInModulo(timestep, freqs) :
                    datadescription.GetInputDescription(cc).AllFieldsOn()
                    datadescription.GetInputDescription(cc).GenerateMeshOn()

    def UpdateProducers(self, datadescription):
        """This method will update the producers in the pipeline. If the
           pipeline is not created, it will be created using
           self.CreatePipeline().
        """
        if not self.__PipelineCreated:
           self.CreatePipeline(datadescription)
           self.__PipelineCreated = True

        simtime = datadescription.GetTime()
        for name, producer in self.__ProducersMap.iteritems():
            producer.GetClientSideObject().SetOutput(\
                datadescription.GetInputDescriptionByName(name).GetGrid(),
                simtime)

    def WriteData(self, datadescription):
        """This method will update all writes present in the pipeline, as
           needed, to generate the output data files, respecting the
           write-frequencies set on the writers."""
        timestep = datadescription.GetTimeStep()
        for writer in self.__WritersList:
            if (timestep % writer.cpFrequency) == 0 or \
                    datadescription.GetForceOutput() == True:
                writer.FileName = writer.cpFileName.replace("%t", str(timestep))
                writer.UpdatePipeline(datadescription.GetTime())

    def WriteImages(self, datadescription, rescale_lookuptable=False):
        """This method will update all views, if present and write output
            images, as needed."""
        timestep = datadescription.GetTimeStep()

        for view in self.__ViewsList:
            if timestep % view.cpFrequency == 0 or \
                                            datadescription.GetForceOutput() == True:
                fname = view.cpFileName
                fname = fname.replace("%t", str(timestep))
                if view.cpFitToScreen != 0:
                    if view.IsA("vtkSMRenderViewProxy") == True:
                        view.ResetCamera()
                    elif view.IsA("vtkSMContextViewProxy") == True:
                        view.ResetDisplay()
                    else:
                        print ' do not know what to do with a ', view.GetClassName()
                view.ViewTime = datadescription.GetTime()
                if rescale_lookuptable:
                    self.RescaleDataRange(view, datadescription.GetTime())
                simple.WriteImage(fname, view, Magnification=view.cpMagnification)

    def DoLiveVisualization(self, datadescription, hostname, port):
        """This method execute the code-stub needed to communicate with ParaView
           for live-visualization. Call this method only if you want to support
           live-visualization with your co-processing module."""

        if (not self.__EnableLiveVisualization or
            (datadescription.GetTimeStep() %
             self.__LiveVisualizationFrequency) != 0):
            return

        # make sure the live insitu is initialized
        if not self.__LiveVisualizationLink:
           # Create the vtkLiveInsituLink i.e.  the "link" to the visualization processes.
           from paraview import servermanager
           self.__LiveVisualizationLink = servermanager.vtkLiveInsituLink()

           # Tell vtkLiveInsituLink what host/port must it connect to for the visualization
           # process.
           self.__LiveVisualizationLink.SetHostname(hostname)
           self.__LiveVisualizationLink.SetInsituPort(int(port))

           # Initialize the "link"
           self.__LiveVisualizationLink.SimulationInitialize(servermanager.ActiveConnection.Session.GetSessionProxyManager())

        time = datadescription.GetTime()

        # For every new timestep, update the simulation state before proceeding.
        self.__LiveVisualizationLink.SimulationUpdate(time)

        # sources need to be updated by insitu code. vtkLiveInsituLink never updates
        # the pipeline, it simply uses the data available at the end of the pipeline,
        # if any.
        from paraview import simple
        for source in simple.GetSources().values():
           source.UpdatePipeline(time)

        # push extracts to the visualization process.
        self.__LiveVisualizationLink.SimulationPostProcess(time)

    def CreateProducer(self, datadescription, inputname):
        """Creates a producer proxy for the grid. This method is generally used in
         CreatePipeline() call to create producers."""
        # Check that the producer name for the input given is valid for the
        # current setup.
        if not datadescription.GetInputDescriptionByName(inputname):
            raise RuntimeError, "Simulation input name '%s' does not exist" % inputname

        grid = datadescription.GetInputDescriptionByName(inputname).GetGrid()

        producer = simple.PVTrivialProducer()
        # we purposefully don't set the time for the PVTrivialProducer here.
        # when we update the pipeline we will do it then.
        producer.GetClientSideObject().SetOutput(grid)

        if grid.IsA("vtkImageData") == True or \
                grid.IsA("vtkStructuredGrid") == True or \
                grid.IsA("vtkRectilinearGrid") == True:
            extent = datadescription.GetInputDescriptionByName(inputname).GetWholeExtent()
            producer.WholeExtent= [ extent[0], extent[1], extent[2], extent[3], extent[4], extent[5] ]

        # Save the producer for easy access in UpdateProducers() call.
        self.__ProducersMap[inputname] = producer
        producer.UpdatePipeline()
        return producer

    def CreateWriter(self, proxy_ctor, filename, freq):
        """Creates a writer proxy. This method is generally used in
           CreatePipeline() to create writers. All writes created as such will
           write the output files appropriately in WriteData() is called."""
        writer = proxy_ctor()
        writer.FileName = filename
        writer.add_attribute("cpFrequency", freq)
        writer.add_attribute("cpFileName", filename)
        self.__WritersList.append(writer)
        return writer

    def CreateView(self, proxy_ctor, filename, freq, fittoscreen, magnification, width, height):
        """Create a CoProcessing view for image capture with extra meta-data
           such as magnification, size and frequency."""
        view = proxy_ctor()
        view.add_attribute("cpFileName", filename)
        view.add_attribute("cpFrequency", freq)
        view.add_attribute("cpFileName", filename)
        view.add_attribute("cpFitToScreen", fittoscreen)
        view.add_attribute("cpMagnification", magnification)
        view.ViewSize = [ width, height ]
        self.__ViewsList.append(view)
        return view

    def RescaleDataRange(self, view, time):
        """DataRange can change across time, sometime we want to rescale the
           color map to match to the closer actual data range."""
        reps = view.Representations
        for rep in reps:
            if not hasattr(rep, 'Visibility') or \
                not rep.Visibility or \
                not hasattr(rep, 'MapScalars') or \
                not rep.MapScalars or \
                not rep.LookupTable:
                # rep is either not visibile or not mapping scalars using a LUT.
                continue;

            input = rep.Input
            input.UpdatePipeline(time) #make sure range is up-to-date
            lut = rep.LookupTable
            if rep.ColorAttributeType == 'POINT_DATA':
                datainformation = input.GetPointDataInformation()
            elif rep.ColorAttributeType == 'CELL_DATA':
                datainformation = input.GetCellDataInformation()
            else:
                print 'something strange with color attribute type', rep.ColorAttributeType

            if datainformation.GetArray(rep.ColorArrayName) == None:
                # there is no array on this process. it's possible
                # that this process has no points or cells
                continue

            if lut.VectorMode != 'Magnitude' or \
               datainformation.GetArray(rep.ColorArrayName).GetNumberOfComponents() == 1:
                datarange = datainformation.GetArray(rep.ColorArrayName).GetRange(lut.VectorComponent)
            else:
                # -1 corresponds to the magnitude.
                datarange = datainformation.GetArray(rep.ColorArrayName).GetRange(-1)

            import vtkParallelCorePython
            import paraview.vtk as vtk
            import paraview.servermanager
            pm = paraview.servermanager.vtkProcessModule.GetProcessModule()
            globalController = pm.GetGlobalController()
            localarray = vtk.vtkDoubleArray()
            localarray.SetNumberOfTuples(2)
            localarray.SetValue(0, -datarange[0]) # negate so that MPI_MAX gets min instead of doing a MPI_MIN and MPI_MAX
            localarray.SetValue(1, datarange[1])
            globalarray = vtk.vtkDoubleArray()
            globalarray.SetNumberOfTuples(2)
            globalController.AllReduce(localarray, globalarray, 0)
            globaldatarange = [-globalarray.GetValue(0), globalarray.GetValue(1)]
            rgbpoints = lut.RGBPoints.GetData()
            numpts = len(rgbpoints)/4
            if globaldatarange[0] != rgbpoints[0] or globaldatarange[1] != rgbpoints[(numpts-1)*4]:
                # rescale all of the points
                oldrange = rgbpoints[(numpts-1)*4] - rgbpoints[0]
                newrange = globaldatarange[1] - globaldatarange[0]
                # only readjust if the new range isn't zero.
                if newrange != 0:
                   newrgbpoints = list(rgbpoints)
                   # if the old range isn't 0 then we use that ranges distribution
                   if oldrange != 0:
                      for v in range(numpts-1):
                         newrgbpoints[v*4] = globaldatarange[0]+(rgbpoints[v*4] - rgbpoints[0])*newrange/oldrange

                      # avoid numerical round-off, at least with the last point
                      newrgbpoints[(numpts-1)*4] = globaldatarange[1]
                   else: # the old range is 0 so the best we can do is to space the new points evenly
                      for v in range(numpts+1):
                         newrgbpoints[v*4] = globaldatarange[0]+v*newrange/(1.0*numpts)

                   lut.RGBPoints.SetData(newrgbpoints)
