r"""
    This module is a ParaViewWeb server application.
    The following command line illustrate how to use it::

        $ pvpython .../pv_web_data_prober.py --data-dir /.../path-to-your-data-directory

    Any ParaViewWeb executable script come with a set of standard arguments that
    can be overriden if need be::

        --port 8080
             Port number on which the HTTP server will listen to.

        --content /path-to-web-content/
             Directory that you want to server as static web content.
             By default, this variable is empty which mean that we rely on another server
             to deliver the static content and the current process only focus on the
             WebSocket connectivity of clients.

        --authKey vtkweb-secret
             Secret key that should be provided by the client to allow it to make any
             WebSocket communication. The client will assume if none is given that the
             server expect "vtkweb-secret" as secret key.

"""

# Application to probe datasets.

import sys
import os
import os.path

# import paraview modules.
from paraview import simple, servermanager, vtk
from paraview.web import wamp      as pv_wamp
from paraview.web import protocols as pv_protocols

from vtk.web import server
from vtkWebCorePython import *

# import annotations
from autobahn.wamp import exportRpc

from twisted.python import log
import logging

try:
    import argparse
except ImportError:
    # since  Python 2.6 and earlier don't have argparse, we simply provide
    # the source for the same as _argparse and we use it instead.
    import _argparse as argparse

# =============================================================================
# Create custom Data Prober class to handle clients requests
# =============================================================================

class _DataProber(pv_wamp.PVServerProtocol):
    """
    DataProber extends paraview.web.PVServerProtocol to add API for loading
    datasets add probing them.
    """

    DataPath = "."
    PipelineObjects = []
    Database = ""
    Widget = None
    View = None
    authKey = "vtkweb-secret"

    def initialize(self):
        global directoryToList
        self.registerVtkWebProtocol(pv_protocols.ParaViewWebMouseHandler())
        self.registerVtkWebProtocol(pv_protocols.ParaViewWebViewPort())
        self.registerVtkWebProtocol(pv_protocols.ParaViewWebViewPortImageDelivery())
        self.registerVtkWebProtocol(pv_protocols.ParaViewWebViewPortGeometryDelivery())

        # Update authentication key to use
        self.updateSecret(_DataProber.authKey)

    @classmethod
    def setupApplication(cls):
        """Setups the default application state."""
        # read data directory.

        root = { "name": "ROOT", "dirs" : [], "files" : []}
        directory_map = {}
        directory_map[_DataProber.DataPath] = root
        for path, dirs, files in os.walk(_DataProber.DataPath):
            element = directory_map[path]

            for name in dirs:
                item = { "name": name, "dirs" : [], "files" : []}
                item["name"] = name
                directory_map[os.path.join(path, name)] = item
                element["dirs"].append(item)
            element["files"] = []
            for name in files:
                relpath = os.path.relpath(os.path.join(path, name),
                    _DataProber.DataPath)
                item = { "name" : name, "itemValue" : relpath}
                element["files"].append(item)
        cls.Database = root
        cls.View = simple.CreateRenderView()
        simple.Render()

        # setup animation scene
        scene = simple.GetAnimationScene()
        simple.GetTimeTrack()
        scene.PlayMode = "Snap To TimeSteps"

    @classmethod
    def endInteractionCallback(cls, factory):
        def callback(caller, event):
            caller.GetProperty("Point1WorldPosition").Copy(
                caller.GetProperty("Point1WorldPositionInfo"))
            caller.GetProperty("Point2WorldPosition").Copy(
                caller.GetProperty("Point2WorldPositionInfo"))
            factory.dispatch("http://vtk.org/event#probeDataChanged", True)
        return callback

    def update3DWidget(self):
        cls = self.__class__
        if not cls.Widget:
            widget = simple.servermanager.rendering.LineWidgetRepresentation()
            widget.Point1WorldPosition = [-1, -1, -1]
            widget.Point2WorldPosition = [1, 1, 1]
            cls.View.Representations.append(widget)
            widget.Enabled = 1
            cls.Widget = widget
            widget.SMProxy.AddObserver(vtk.vtkCommand.EndInteractionEvent,
                cls.endInteractionCallback(self.factory))

        if cls.PipelineObjects:
            # compute bounds for all pipeline objects.
            total_bounds = [ vtk.VTK_DOUBLE_MAX, vtk.VTK_DOUBLE_MIN,
                             vtk.VTK_DOUBLE_MAX, vtk.VTK_DOUBLE_MIN,
                             vtk.VTK_DOUBLE_MAX, vtk.VTK_DOUBLE_MIN]
            for item in cls.PipelineObjects:
                reader = item["Reader"]
                probe = item["Probe"]
                bounds = reader.GetDataInformation().GetBounds()
                if vtk.vtkMath.AreBoundsInitialized(bounds):
                    if total_bounds[0] > bounds[0]:
                        total_bounds[0] = bounds[0]
                    if total_bounds[1] < bounds[1]:
                        total_bounds[1] = bounds[1]
                    if total_bounds[2] > bounds[2]:
                        total_bounds[2] = bounds[2]
                    if total_bounds[3] < bounds[3]:
                        total_bounds[3] = bounds[3]
                    if total_bounds[4] > bounds[4]:
                        total_bounds[4] = bounds[4]
                    if total_bounds[5] < bounds[5]:
                        total_bounds[5] = bounds[5]
            if total_bounds[0] <= total_bounds[1]:
                cls.Widget.Point1WorldPosition = [bounds[0], bounds[2], bounds[4]]
                cls.Widget.Point2WorldPosition = [bounds[1], bounds[3], bounds[5]]
        minpos = cls.Widget.Point1WorldPosition
        maxpos = cls.Widget.Point2WorldPosition
        return (minpos[0], maxpos[0], minpos[1], maxpos[1], minpos[2], maxpos[2])

    @classmethod
    def toHTML(cls, element):
        if element.has_key("itemValue"):
            return '<li itemValue="%s">%s</li>' % (element["itemValue"],
                element["name"])

        if element["name"] != "ROOT":
            text = "<li>"
            text += element["name"]
            text += "<ul>"
        else:
            text = ""

        for item in element["dirs"]:
            text += cls.toHTML(item)
        for item in element["files"]:
            text += cls.toHTML(item)

        if element["name"] != "ROOT":
            text += "</ul></li>"
        return text

    @exportRpc("loadData")
    def loadData(self, datafile):
        """Load a data file. The argument is a path relative to the DataPath
        pointing to the dataset to load.

        Returns True if the dataset was loaded successfully, otherwise returns
        False.

        If the dataset is loaded, this methods setups the visualization
        pipelines for interactive probing all loaded datasets.
        """

        datafile = os.path.join(_DataProber.DataPath, datafile)
        log.msg("Loading data-file", datafile, logLevel=logging.DEBUG)
        reader = simple.OpenDataFile(datafile)
        if not reader:
            return False
        rep = simple.Show(reader, Representation="Wireframe")
        probe = simple.PlotOverLine(Source = "High Resolution Line Source")

        item = {}
        item["Reader"] = reader
        item["ReaderRepresentation"] = rep
        item["Probe"] = probe
        item["name"] = os.path.split(datafile)[1]
        _DataProber.PipelineObjects.append(item)

    @exportRpc("loadDatasets")
    def loadDatasets(self, datafiles):
        # initially, we'll only support loading 1 dataset.
        for item in _DataProber.PipelineObjects:
            simple.Delete(item["Probe"])
            simple.Delete(item["ReaderRepresentation"])
            simple.Delete(item["Reader"])
        _DataProber.PipelineObjects = []

        for path in datafiles:
            self.loadData(path)
        bounds = self.update3DWidget()
        self.resetCameraWithBounds(bounds)
        simple.Render()
        return True

    @exportRpc("getProbeData")
    def getProbeData(self):
        """Returns probe-data from all readers. The returned datastructure has
            the following syntax.
            [
                {
                    "name"      : "<name>",
                    "headers"   : [ "foo", "time", "bar" ],
                    "data"      : [ [3, "2009-11-04", 1], [...], ...]
                },
                { ... }, ...
            ]
        """
        retVal = []
        for item in _DataProber.PipelineObjects:
            name = item["name"]
            probe = item["Probe"]
            probe.Source.Point1 = _DataProber.Widget.Point1WorldPosition
            probe.Source.Point2 = _DataProber.Widget.Point2WorldPosition
            print "Probing ", probe.Source.Point1, probe.Source.Point2
            simple.UpdatePipeline(time=_DataProber.View.ViewTime, proxy=probe)

            # fetch probe result from root node.
            do = simple.servermanager.Fetch(probe, 0)
            data = vtkWebUtilities.WriteAttributesToJavaScript(
                vtk.vtkDataObject.POINT, do)
            headers = vtkWebUtilities.WriteAttributeHeadersToJavaScript(
                vtk.vtkDataObject.POINT, do)
            # process the strings returned by vtkPVWebUtilities to generate
            # Python objects
            nan = "_nan_"
            data = eval(data)
            headers = eval(headers)
            retVal.append({ "name": name,
                            "headers": headers,
                            "data" : data })
        return retVal

    def resetCameraWithBounds(self, bounds):
        if vtk.vtkMath.AreBoundsInitialized(bounds):
            _DataProber.View.SMProxy.ResetCamera(bounds)
            _DataProber.View.CenterOfRotation = [
                (bounds[0] + bounds[1]) * 0.5,
                (bounds[2] + bounds[3]) * 0.5,
                (bounds[4] + bounds[5]) * 0.5]

    @exportRpc("getDatabase")
    def getDatabase(self):
        return _DataProber.Database

    @exportRpc("getDatabaseAsHTML")
    def getDatabaseAsHTML(self):
        return _DataProber.toHTML(_DataProber.Database)

    @exportRpc("goToNext")
    def goToNext(self):
        oldTime = self.View.ViewTime
        simple.GetAnimationScene().GoToNext()
        if oldTime != self.View.ViewTime:
            self.factory.dispatch("http://vtk.org/event#probeDataChanged", True)
            return True
        return False

    @exportRpc("goToPrev")
    def goToPrev(self):
        oldTime = self.View.ViewTime
        simple.GetAnimationScene().GoToPrevious()
        if oldTime != self.View.ViewTime:
            self.factory.dispatch("http://vtk.org/event#probeDataChanged", True)
            return True
        return False

# =============================================================================
# Main: Parse args and start server
# =============================================================================

if __name__ == "__main__":
    # Create argument parser
    parser = argparse.ArgumentParser(description="ParaView Web Data-Prober")

    # Add default arguments
    server.add_arguments(parser)

    # Add local arguments
    parser.add_argument("--data-dir", help="path to data directory", dest="path")

    # Exctract arguments
    args = parser.parse_args()

    # Configure our current application
    _DataProber.DataPath = args.path
    _DataProber.setupApplication()
    _DataProber.authKey = args.authKey

    # Start server
    server.start_webserver(options=args, protocol=_DataProber)
