# -*- coding: utf-8 -*-
"""!
@package animation.provider

@brief Animation files and bitmaps management

Classes:
 - mapwindow::BitmapProvider
 - mapwindow::BitmapRenderer
 - mapwindow::BitmapComposer
 - mapwindow::DictRefCounter
 - mapwindow::MapFilesPool
 - mapwindow::BitmapPool
 - mapwindow::CleanUp

(C) 2013 by the GRASS Development Team

This program is free software under the GNU General Public License
(>=v2). Read the file COPYING that comes with GRASS for details.

@author Anna Petrasova <kratochanna gmail.com>
"""
import os
import sys
import wx
import tempfile
from multiprocessing import Process, Queue
if __name__ == '__main__':
    sys.path.append(os.path.join(os.environ['GISBASE'], "etc", "gui", "wxpython"))

from core.gcmd import RunCommand, GException
from core.settings import UserSettings
from core.debug import Debug
from core.utils import _, CmdToTuple, autoCropImageFromFile

from animation.utils import HashCmd, HashCmds, GetFileFromCmd, GetFileFromCmds

import grass.script.core as gcore
from grass.pydispatch.signal import Signal


class BitmapProvider:
    """!Class for management of image files and bitmaps.

    There is one instance of this class in the application.
    It handles both 2D and 3D animations.
    """
    def __init__(self, bitmapPool, mapFilesPool, tempDir,
                 imageWidth=640, imageHeight=480):

        self._bitmapPool = bitmapPool
        self._mapFilesPool = mapFilesPool
        self.imageWidth = imageWidth  # width of the image to render with d.rast or d.vect
        self.imageHeight = imageHeight  # height of the image to render with d.rast or d.vect
        self._tempDir = tempDir

        self._uniqueCmds = []
        self._cmdsForComposition = []
        self._opacities = []

        self._cmds3D = []
        self._regionFor3D = None
        self._regions = []
        self._regionsForUniqueCmds = []

        self._renderer = BitmapRenderer(self._mapFilesPool, self._tempDir,
                                        self.imageWidth, self.imageHeight)
        self._composer = BitmapComposer(self._tempDir, self._mapFilesPool,
                                        self._bitmapPool, self.imageWidth,
                                        self.imageHeight)
        self.renderingStarted = Signal('BitmapProvider.renderingStarted')
        self.compositionStarted = Signal('BitmapProvider.compositionStarted')
        self.renderingContinues = Signal('BitmapProvider.renderingContinues')
        self.compositionContinues = Signal('BitmapProvider.compositionContinues')
        self.renderingFinished = Signal('BitmapProvider.renderingFinished')
        self.compositionFinished = Signal('BitmapProvider.compositionFinished')
        self.mapsLoaded = Signal('BitmapProvider.mapsLoaded')

        self._renderer.renderingContinues.connect(self.renderingContinues)
        self._composer.compositionContinues.connect(self.compositionContinues)

    def SetCmds(self, cmdsForComposition, opacities, regions=None):
        """!Sets commands to be rendered with opacity levels.
        Applies to 2D mode.

        @param cmdsForComposition list of lists of command lists
                [[['d.rast', 'map=elev_2001'], ['d.vect', 'map=points']], # g.pnmcomp
                 [['d.rast', 'map=elev_2002'], ['d.vect', 'map=points']],
                 ...]
        @param opacities list of opacity values
        @param regions list of regions
        """
        Debug.msg(2, "BitmapProvider.SetCmds: {n} lists".format(n=len(cmdsForComposition)))
        self._cmdsForComposition.extend(cmdsForComposition)
        self._opacities.extend(opacities)
        self._regions.extend(regions)

        self._getUniqueCmds()

    def SetCmds3D(self, cmds, region):
        """!Sets commands for 3D rendering.

        @param cmds list of commands m.nviz.image (cmd as a list)
        @param region for 3D rendering
        """
        Debug.msg(2, "BitmapProvider.SetCmds3D: {c} commands".format(c=len(cmds)))
        self._cmds3D = cmds
        self._regionFor3D = region

    def _getUniqueCmds(self):
        """!Returns list of unique commands.
        Takes into account the region assigned."""
        unique = list()
        for cmdList, region in zip(self._cmdsForComposition, self._regions):
            for cmd in cmdList:
                if region:
                    unique.append((tuple(cmd), tuple(sorted(region.items()))))
                else:
                    unique.append((tuple(cmd), None))
        unique = list(set(unique))
        self._uniqueCmds = [cmdAndRegion[0] for cmdAndRegion in unique]
        self._regionsForUniqueCmds.extend([dict(cmdAndRegion[1]) if cmdAndRegion[1] else None
                                           for cmdAndRegion in unique])

    def Unload(self):
        """!Unloads currently loaded data.
        Needs to be called before setting new data.
        """
        Debug.msg(2, "BitmapProvider.Unload")
        if self._cmdsForComposition:
            for cmd, region in zip(self._uniqueCmds, self._regionsForUniqueCmds):
                del self._mapFilesPool[HashCmd(cmd, region)]

            for cmdList, region in zip(self._cmdsForComposition, self._regions):
                del self._bitmapPool[HashCmds(cmdList, region)]
            self._uniqueCmds = []
            self._cmdsForComposition = []
            self._opacities = []
            self._regions = []
            self._regionsForUniqueCmds = []
        if self._cmds3D:
            self._cmds3D = []
            self._regionFor3D = None

    def _dryRender(self, uniqueCmds, regions, force):
        """!Determines how many files will be rendered.

        @param uniqueCmds list of commands which are to be rendered
        @param force if forced rerendering
        @param regions list of regions assigned to the commands
        """
        count = 0
        for cmd, region in zip(uniqueCmds, regions):
            filename = GetFileFromCmd(self._tempDir, cmd, region)
            if not force and os.path.exists(filename) and \
               self._mapFilesPool.GetSize(HashCmd(cmd, region)) == (self.imageWidth, self.imageHeight):
                continue
            count += 1

        Debug.msg(3, "BitmapProvider._dryRender: {c} files to be rendered".format(c=count))

        return count

    def _dryCompose(self, cmdLists, regions, force):
        """!Determines how many lists of (commands) files
        will be composed (with g.pnmcomp).

        @param cmdLists list of commands lists which are to be composed
        @param regions list of regions assigned to the commands
        @param force if forced rerendering
        """
        count = 0
        for cmdList, region in zip(cmdLists, regions):
            if not force and HashCmds(cmdList, region) in self._bitmapPool and \
                self._bitmapPool[HashCmds(cmdList, region)].GetSize() == (self.imageWidth,
                                                                          self.imageHeight):
                continue
            count += 1

        Debug.msg(2, "BitmapProvider._dryCompose: {c} files to be composed".format(c=count))

        return count

    def Load(self, force=False, bgcolor=(255, 255, 255), nprocs=4):
        """!Loads data, both 2D and 3D. In case of 2D, it creates composites,
        even when there is only 1 layer to compose (to be changed for speedup)

        @param force if True reload all data, otherwise only missing data
        @param bgcolor background color as a tuple of 3 values 0 to 255
        @param nprocs number of procs to be used for rendering
        """
        Debug.msg(2, "BitmapProvider.Load: "
                     "force={f}, bgcolor={b}, nprocs={n}".format(f=force,
                                                                 b=bgcolor,
                                                                 n=nprocs))
        cmds = []
        regions = []
        if self._uniqueCmds:
            cmds.extend(self._uniqueCmds)
            regions.extend(self._regionsForUniqueCmds)
        if self._cmds3D:
            cmds.extend(self._cmds3D)
            regions.extend([None] * len(self._cmds3D))

        count = self._dryRender(cmds, regions, force=force)
        self.renderingStarted.emit(count=count)

        # create no data bitmap
        if None not in self._bitmapPool or force:
            self._bitmapPool[None] = createNoDataBitmap(self.imageWidth, self.imageHeight)

        ok = self._renderer.Render(cmds, regions, regionFor3D=self._regionFor3D,
                                   bgcolor=bgcolor, force=force, nprocs=nprocs)
        self.renderingFinished.emit()
        if not ok:
            self.mapsLoaded.emit()  # what to do here?
            return
        if self._cmdsForComposition:
            count = self._dryCompose(self._cmdsForComposition, self._regions, force=force)
            self.compositionStarted.emit(count=count)
            self._composer.Compose(self._cmdsForComposition, self._regions, self._opacities,
                                   bgcolor=bgcolor, force=force, nprocs=nprocs)
            self.compositionFinished.emit()
        if self._cmds3D:
            for cmd in self._cmds3D:
                self._bitmapPool[HashCmds([cmd], None)] = \
                    wx.Bitmap(GetFileFromCmd(self._tempDir, cmd, None))

        self.mapsLoaded.emit()

    def RequestStopRendering(self):
        """!Requests to stop rendering/composition"""
        Debug.msg(2, "BitmapProvider.RequestStopRendering")
        self._renderer.RequestStopRendering()
        self._composer.RequestStopComposing()

    def GetBitmap(self, dataId):
        """!Returns bitmap with given key
        or 'no data' bitmap if no such key exists.

        @param dataId name of bitmap
        """
        try:
            bitmap = self._bitmapPool[dataId]
        except KeyError:
            bitmap = self._bitmapPool[None]
        return bitmap

    def WindowSizeChanged(self, width, height):
        """!Sets size when size of related window changes."""
        Debug.msg(5, "BitmapProvider.WindowSizeChanged: w={w}, h={h}".format(w=width, h=height))

        self.imageWidth, self.imageHeight = width, height

        self._composer.imageWidth = self._renderer.imageWidth = width
        self._composer.imageHeight = self._renderer.imageHeight = height

    def LoadOverlay(self, cmd):
        """!Creates raster legend with d.legend

        @param cmd d.legend command as a list

        @return bitmap with legend
        """
        Debug.msg(5, "BitmapProvider.LoadOverlay: cmd={c}".format(c=cmd))

        fileHandler, filename = tempfile.mkstemp(suffix=".png")
        os.close(fileHandler)
        # Set the environment variables for this process
        _setEnvironment(self.imageWidth, self.imageHeight, filename,
                        transparent=True, bgcolor=(0, 0, 0))

        Debug.msg(1, "Render raster legend " + str(filename))
        cmdTuple = CmdToTuple(cmd)
        returncode, stdout, messages = read2_command(cmdTuple[0], **cmdTuple[1])

        if returncode == 0:
            return wx.BitmapFromImage(autoCropImageFromFile(filename))
        else:
            os.remove(filename)
            raise GException(messages)


class BitmapRenderer:
    """!Class which renderes 2D and 3D images to files."""
    def __init__(self, mapFilesPool, tempDir,
                 imageWidth, imageHeight):
        self._mapFilesPool = mapFilesPool
        self._tempDir = tempDir
        self.imageWidth = imageWidth
        self.imageHeight = imageHeight

        self.renderingContinues = Signal('BitmapRenderer.renderingContinues')
        self._stopRendering = False
        self._isRendering = False

    def Render(self, cmdList, regions, regionFor3D, bgcolor, force, nprocs):
        """!Renders all maps and stores files.

        @param cmdList list of rendering commands to run
        @param regions regions for 2D rendering assigned to commands
        @param regionFor3D region for setting 3D view
        @param bgcolor background color as a tuple of 3 values 0 to 255
        @param force if True reload all data, otherwise only missing data
        @param nprocs number of procs to be used for rendering
        """
        Debug.msg(3, "BitmapRenderer.Render")
        count = 0

        # Variables for parallel rendering
        proc_count = 0
        proc_list = []
        queue_list = []
        cmd_list = []

        filteredCmdList = []
        for cmd, region in zip(cmdList, regions):
            filename = GetFileFromCmd(self._tempDir, cmd, region)
            if not force and os.path.exists(filename) and \
               self._mapFilesPool.GetSize(HashCmd(cmd, region)) == (self.imageWidth, self.imageHeight):
                # for reference counting
                self._mapFilesPool[HashCmd(cmd, region)] = filename
                continue
            filteredCmdList.append((cmd, region))

        mapNum = len(filteredCmdList)
        stopped = False
        self._isRendering = True
        for cmd, region in filteredCmdList:
            count += 1

            # Queue object for interprocess communication
            q = Queue()
            # The separate render process
            if cmd[0] == 'm.nviz.image':
                p = Process(target=RenderProcess3D,
                            args=(self.imageWidth, self.imageHeight, self._tempDir,
                                  cmd, regionFor3D, bgcolor, q))
            else:
                p = Process(target=RenderProcess2D,
                            args=(self.imageWidth, self.imageHeight, self._tempDir,
                                  cmd, region, bgcolor, q))
            p.start()

            queue_list.append(q)
            proc_list.append(p)
            cmd_list.append((cmd, region))

            proc_count += 1
            # Wait for all running processes and read/store the created images
            if proc_count == nprocs or count == mapNum:
                for i in range(len(cmd_list)):
                    proc_list[i].join()
                    filename = queue_list[i].get()
                    self._mapFilesPool[HashCmd(cmd_list[i][0], cmd_list[i][1])] = filename
                    self._mapFilesPool.SetSize(HashCmd(cmd_list[i][0], cmd_list[i][1]),
                                               (self.imageWidth, self.imageHeight))

                proc_count = 0
                proc_list = []
                queue_list = []
                cmd_list = []

            self.renderingContinues.emit(current=count, text=_("Rendering map layers"))
            if self._stopRendering:
                self._stopRendering = False
                stopped = True
                break

        self._isRendering = False
        return not stopped

    def RequestStopRendering(self):
        """!Requests to stop rendering."""
        if self._isRendering:
            self._stopRendering = True


class BitmapComposer:
    """!Class which handles the composition of image files with g.pnmcomp."""
    def __init__(self, tempDir, mapFilesPool, bitmapPool,
                 imageWidth, imageHeight):
        self._mapFilesPool = mapFilesPool
        self._bitmapPool = bitmapPool
        self._tempDir = tempDir
        self.imageWidth = imageWidth
        self.imageHeight = imageHeight

        self.compositionContinues = Signal('BitmapComposer.composingContinues')
        self._stopComposing = False
        self._isComposing = False

    def Compose(self, cmdLists, regions, opacityList, bgcolor, force, nprocs):
        """!Performs the composition of ppm/pgm files.

        @param cmdLisst lists of rendering commands lists to compose
        @param regions regions for 2D rendering assigned to commands
        @param opacityList list of lists of opacity values
        @param bgcolor background color as a tuple of 3 values 0 to 255
        @param force if True reload all data, otherwise only missing data
        @param nprocs number of procs to be used for rendering
        """
        Debug.msg(3, "BitmapComposer.Compose")

        count = 0

        # Variables for parallel rendering
        proc_count = 0
        proc_list = []
        queue_list = []
        cmd_lists = []

        filteredCmdLists = []
        for cmdList, region in zip(cmdLists, regions):
            if not force and HashCmds(cmdList, region) in self._bitmapPool and \
                self._bitmapPool[HashCmds(cmdList, region)].GetSize() == (self.imageWidth,
                                                                          self.imageHeight):
                # TODO: find a better way than to assign the same to increase the reference
                self._bitmapPool[HashCmds(cmdList, region)] = self._bitmapPool[HashCmds(cmdList, region)]
                continue
            filteredCmdLists.append((cmdList, region))

        num = len(filteredCmdLists)

        self._isComposing = True
        for cmdList, region in filteredCmdLists:
            count += 1
            # Queue object for interprocess communication
            q = Queue()
            # The separate render process
            p = Process(target=CompositeProcess,
                        args=(self.imageWidth, self.imageHeight, self._tempDir,
                              cmdList, region, opacityList, bgcolor, q))
            p.start()

            queue_list.append(q)
            proc_list.append(p)
            cmd_lists.append((cmdList, region))

            proc_count += 1

            # Wait for all running processes and read/store the created images
            if proc_count == nprocs or count == num:
                for i in range(len(cmd_lists)):
                    proc_list[i].join()
                    filename = queue_list[i].get()
                    if filename is None:
                        self._bitmapPool[HashCmds(cmd_lists[i][0], cmd_lists[i][1])] = \
                            createNoDataBitmap(self.imageWidth, self.imageHeight,
                                               text="Failed to render")
                    else:
                        self._bitmapPool[HashCmds(cmd_lists[i][0], cmd_lists[i][1])] = \
                            wx.BitmapFromImage(wx.Image(filename))
                        os.remove(filename)
                proc_count = 0
                proc_list = []
                queue_list = []
                cmd_lists = []

            self.compositionContinues.emit(current=count, text=_("Overlaying map layers"))
            if self._stopComposing:
                self._stopComposing = False
                break

        self._isComposing = False

    def RequestStopComposing(self):
        """!Requests to stop the composition."""
        if self._isComposing:
            self._stopComposing = True


def RenderProcess2D(imageWidth, imageHeight, tempDir, cmd, region, bgcolor, fileQueue):
    """!Render raster or vector files as ppm image and write the
       resulting ppm filename in the provided file queue

    @param imageWidth image width
    @param imageHeight image height
    @param tempDir directory for rendering
    @param cmd d.rast/d.vect command as a list
    @param region region as a dict or None
    @param bgcolor background color as a tuple of 3 values 0 to 255
    @param fileQueue the inter process communication queue
    storing the file name of the image
    """

    filename = GetFileFromCmd(tempDir, cmd, region)
    transparency = True

    # Set the environment variables for this process
    _setEnvironment(imageWidth, imageHeight, filename,
                    transparent=transparency, bgcolor=bgcolor)
    if region:
        os.environ['GRASS_REGION'] = gcore.region_env(**region)
    cmdTuple = CmdToTuple(cmd)
    returncode, stdout, messages = read2_command(cmdTuple[0], **cmdTuple[1])
    if returncode != 0:
        gcore.warning("Rendering failed:\n" + messages)
        fileQueue.put(None)
        if region:
            os.environ.pop('GRASS_REGION')
        os.remove(filename)
        return

    if region:
        os.environ.pop('GRASS_REGION')
    fileQueue.put(filename)


def RenderProcess3D(imageWidth, imageHeight, tempDir, cmd, region, bgcolor, fileQueue):
    """!Renders image with m.nviz.image and writes the
       resulting ppm filename in the provided file queue

    @param imageWidth image width
    @param imageHeight image height
    @param tempDir directory for rendering
    @param cmd m.nviz.image command as a list
    @param region region as a dict
    @param bgcolor background color as a tuple of 3 values 0 to 255
    @param fileQueue the inter process communication queue
    storing the file name of the image
    """

    filename = GetFileFromCmd(tempDir, cmd, None)
    os.environ['GRASS_REGION'] = gcore.region_env(region3d=True, **region)
    Debug.msg(1, "Render image to file " + str(filename))

    cmdTuple = CmdToTuple(cmd)
    cmdTuple[1]['output'] = os.path.splitext(filename)[0]
    # set size
    cmdTuple[1]['size'] = '%d,%d' % (imageWidth, imageHeight)
    # set format
    cmdTuple[1]['format'] = 'ppm'
    cmdTuple[1]['bgcolor'] = bgcolor = ':'.join([str(part) for part in bgcolor])
    returncode, stdout, messages = read2_command(cmdTuple[0], **cmdTuple[1])
    if returncode != 0:
        gcore.warning("Rendering failed:\n" + messages)
        fileQueue.put(None)
        os.environ.pop('GRASS_REGION')
        return

    os.environ.pop('GRASS_REGION')
    fileQueue.put(filename)


def CompositeProcess(imageWidth, imageHeight, tempDir, cmdList, region, opacities, bgcolor, fileQueue):
    """!Performs the composition of image ppm files and writes the
       resulting ppm filename in the provided file queue

    @param imageWidth image width
    @param imageHeight image height
    @param tempDir directory for rendering
    @param cmdList list of d.rast/d.vect commands
    @param region region as a dict or None
    @param opacities list of opacities
    @param bgcolor background color as a tuple of 3 values 0 to 255
    @param fileQueue the inter process communication queue
    storing the file name of the image
    """

    maps = []
    masks = []
    for cmd in cmdList:
        maps.append(GetFileFromCmd(tempDir, cmd, region))
        masks.append(GetFileFromCmd(tempDir, cmd, region, 'pgm'))
    filename = GetFileFromCmds(tempDir, cmdList, region)
    # Set the environment variables for this process
    _setEnvironment(imageWidth, imageHeight, filename,
                    transparent=False, bgcolor=bgcolor)

    opacities = [str(op) for op in opacities]
    bgcolor = ':'.join([str(part) for part in bgcolor])
    returncode, stdout, messages = read2_command('g.pnmcomp',
                                                 overwrite=True,
                                                 input='%s' % ",".join(reversed(maps)),
                                                 mask='%s' % ",".join(reversed(masks)),
                                                 opacity='%s' % ",".join(reversed(opacities)),
                                                 bgcolor=bgcolor,
                                                 width=imageWidth,
                                                 height=imageHeight,
                                                 output=filename)

    if returncode != 0:
        gcore.warning("Rendering composite failed:\n" + messages)
        fileQueue.put(None)
        os.remove(filename)
        return

    fileQueue.put(filename)


class DictRefCounter:
    """!Base class storing map files/bitmaps (emulates dictionary).
        Counts the references to know which files/bitmaps to delete."""
    def __init__(self):
        self.dictionary = {}
        self.referenceCount = {}

    def __getitem__(self, key):
        return self.dictionary[key]

    def __setitem__(self, key, value):
        self.dictionary[key] = value
        if key not in self.referenceCount:
            self.referenceCount[key] = 1
        else:
            self.referenceCount[key] += 1
        Debug.msg(5, 'DictRefCounter.__setitem__: +1 for key {k}'.format(k=key))

    def __contains__(self, key):
        return key in self.dictionary

    def __delitem__(self, key):
        self.referenceCount[key] -= 1
        Debug.msg(5, 'DictRefCounter.__delitem__: -1 for key {k}'.format(k=key))

    def keys(self):
        return self.dictionary.keys()

    def Clear(self):
        """!Clears items which are not needed any more."""
        Debug.msg(4, 'DictRefCounter.Clear')
        for key in self.dictionary.keys():
            if key is not None:
                if self.referenceCount[key] <= 0:
                    del self.dictionary[key]
                    del self.referenceCount[key]


class MapFilesPool(DictRefCounter):
    """!Stores rendered images as files."""
    def __init__(self):
        DictRefCounter.__init__(self)
        self.size = {}

    def SetSize(self, key, size):
        self.size[key] = size

    def GetSize(self, key):
        return self.size[key]

    def Clear(self):
        """!Removes files which are not needed anymore.
        Removes both ppm and pgm.
        """
        Debug.msg(4, 'MapFilesPool.Clear')

        for key in self.dictionary.keys():
            if self.referenceCount[key] <= 0:
                name, ext = os.path.splitext(self.dictionary[key])
                os.remove(self.dictionary[key])
                if ext == '.ppm':
                    os.remove(name + '.pgm')
                del self.dictionary[key]
                del self.referenceCount[key]
                del self.size[key]


class BitmapPool(DictRefCounter):
    """!Class storing bitmaps (emulates dictionary)"""
    def __init__(self):
        DictRefCounter.__init__(self)


class CleanUp:
    """!Responsible for cleaning up the files."""
    def __init__(self, tempDir):
        self._tempDir = tempDir

    def __call__(self):
        import shutil
        if os.path.exists(self._tempDir):
            try:
                shutil.rmtree(self._tempDir)
                Debug.msg(5, 'CleanUp: removed directory {t}'.format(t=self._tempDir))
            except OSError:
                gcore.warning(_("Directory {t} not removed.").format(t=self._tempDir))


def _setEnvironment(width, height, filename, transparent, bgcolor):
    """!Sets environmental variables for 2D rendering.

    @param width rendering width
    @param height rendering height
    @param filename file name
    @param transparent use transparency
    @param bgcolor background color as a tuple of 3 values 0 to 255
    """
    Debug.msg(5, "_setEnvironment: width={w}, height={h}, "
                 "filename={f}, transparent={t}, bgcolor={b}".format(w=width,
                                                                     h=height,
                                                                     f=filename,
                                                                     t=transparent,
                                                                     b=bgcolor))

    os.environ['GRASS_WIDTH'] = str(width)
    os.environ['GRASS_HEIGHT'] = str(height)
    driver = UserSettings.Get(group='display', key='driver', subkey='type')
    os.environ['GRASS_RENDER_IMMEDIATE'] = driver
    os.environ['GRASS_BACKGROUNDCOLOR'] = '{r:02x}{g:02x}{b:02x}'.format(r=bgcolor[0],
                                                                         g=bgcolor[1],
                                                                         b=bgcolor[2])
    os.environ['GRASS_TRUECOLOR'] = "TRUE"
    if transparent:
        os.environ['GRASS_TRANSPARENT'] = "TRUE"
    else:
        os.environ['GRASS_TRANSPARENT'] = "FALSE"
    os.environ['GRASS_PNGFILE'] = str(filename)


def createNoDataBitmap(imageWidth, imageHeight, text="No data"):
    """!Creates 'no data' bitmap.

    Used when requested bitmap is not available (loading data was not successful) or
    we want to show 'no data' bitmap.

    @param imageWidth image width
    @param imageHeight image height
    """
    Debug.msg(4, "createNoDataBitmap: w={w}, h={h}, text={t}".format(w=imageWidth,
                                                                     h=imageHeight,
                                                                     t=text))
    bitmap = wx.EmptyBitmap(imageWidth, imageHeight)
    dc = wx.MemoryDC()
    dc.SelectObject(bitmap)
    dc.Clear()
    text = _(text)
    dc.SetFont(wx.Font(pointSize=40, family=wx.FONTFAMILY_SCRIPT,
                       style=wx.FONTSTYLE_NORMAL, weight=wx.FONTWEIGHT_BOLD))
    tw, th = dc.GetTextExtent(text)
    dc.DrawText(text, (imageWidth - tw) / 2, (imageHeight - th) / 2)
    dc.SelectObject(wx.NullBitmap)
    return bitmap


def read2_command(*args, **kwargs):
    kwargs['stdout'] = gcore.PIPE
    kwargs['stderr'] = gcore.PIPE
    ps = gcore.start_command(*args, **kwargs)
    stdout, stderr = ps.communicate()
    return ps.returncode, stdout, stderr


def test():
    import shutil

    from core.layerlist import LayerList, Layer
    from animation.data import AnimLayer
    from animation.utils import layerListToCmdsMatrix
    import grass.temporal as tgis
    tgis.init()

    layerList = LayerList()
    layer = AnimLayer()
    layer.mapType = 'strds'
    layer.name = 'JR'
    layer.cmd = ['d.rast', 'map=elev_2007_1m']
    layerList.AddLayer(layer)

    layer = Layer()
    layer.mapType = 'vect'
    layer.name = 'buildings_2009_approx'
    layer.cmd = ['d.vect', 'map=buildings_2009_approx',
                 'color=grey']
    layer.opacity = 50
    layerList.AddLayer(layer)

    bPool = BitmapPool()
    mapFilesPool = MapFilesPool()

    tempDir = '/tmp/test'
    if os.path.exists(tempDir):
        shutil.rmtree(tempDir)
    os.mkdir(tempDir)
    # comment this line to keep the directory after prgm ends
#    cleanUp = CleanUp(tempDir)
#    import atexit
#    atexit.register(cleanUp)

    prov = BitmapProvider(bPool, mapFilesPool, tempDir,
                          imageWidth=640, imageHeight=480)
    prov.renderingStarted.connect(
        lambda count: sys.stdout.write("Total number of maps: {c}\n".format(c=count)))
    prov.renderingContinues.connect(
        lambda current, text: sys.stdout.write("Current number: {c}\n".format(c=current)))
    prov.compositionStarted.connect(
        lambda count: sys.stdout.write("Composition: total number of maps: {c}\n".format(c=count)))
    prov.compositionContinues.connect(
        lambda current, text: sys.stdout.write("Composition: Current number: {c}\n".format(c=current)))
    prov.mapsLoaded.connect(
        lambda: sys.stdout.write("Maps loading finished\n"))
    cmdMatrix = layerListToCmdsMatrix(layerList)
    prov.SetCmds(cmdMatrix, [l.opacity for l in layerList])
    app = wx.App()

    prov.Load(bgcolor=(13, 156, 230), nprocs=4)

    for key in bPool.keys():
        if key is not None:
            bPool[key].SaveFile(os.path.join(tempDir, key + '.png'), wx.BITMAP_TYPE_PNG)
#    prov.Unload()
#    prov.SetCmds(cmdMatrix, [l.opacity for l in layerList])
#    prov.Load(bgcolor=(13, 156, 230))
#    prov.Unload()
#    newList = LayerList()
#    prov.SetCmds(layerListToCmdsMatrix(newList), [l.opacity for l in newList])
#    prov.Load()
#    prov.Unload()
#    mapFilesPool.Clear()
#    bPool.Clear()
#    print bPool.keys(), mapFilesPool.keys()


if __name__ == '__main__':
    test()