from __future__ import division
import math
import os
import sys

import matplotlib
from matplotlib import verbose
from matplotlib.cbook import is_string_like, onetrue
from matplotlib.backend_bases import RendererBase, GraphicsContextBase, \
     FigureManagerBase, FigureCanvasBase, NavigationToolbar2, cursors
from matplotlib.backend_bases import ShowBase

from matplotlib._pylab_helpers import Gcf
from matplotlib.figure import Figure
from matplotlib.mathtext import MathTextParser
from matplotlib.widgets import SubplotTool

try:
    import qt
except ImportError:
    raise ImportError("Qt backend requires pyqt to be installed.")

backend_version = "0.9.1"
def fn_name(): return sys._getframe(1).f_code.co_name

DEBUG = False

cursord = {
    cursors.MOVE          : qt.Qt.PointingHandCursor,
    cursors.HAND          : qt.Qt.WaitCursor,
    cursors.POINTER       : qt.Qt.ArrowCursor,
    cursors.SELECT_REGION : qt.Qt.CrossCursor,
    }

def draw_if_interactive():
    """
    Is called after every pylab drawing command
    """
    if matplotlib.is_interactive():
        figManager =  Gcf.get_active()
        if figManager != None:
            figManager.canvas.draw()

def _create_qApp():
    """
    Only one qApp can exist at a time, so check before creating one
    """
    if qt.QApplication.startingUp():
        if DEBUG: print "Starting up QApplication"
        global qApp
        qApp = qt.QApplication( [" "] )
        qt.QObject.connect( qApp, qt.SIGNAL( "lastWindowClosed()" ),
                            qApp, qt.SLOT( "quit()" ) )
        #remember that matplotlib created the qApp - will be used by show()
        _create_qApp.qAppCreatedHere = True

_create_qApp.qAppCreatedHere = False

class Show(ShowBase):
    def mainloop(self):
        if _create_qApp.qAppCreatedHere:
            qt.qApp.exec_loop()

show = Show()


def new_figure_manager( num, *args, **kwargs ):
    """
    Create a new figure manager instance
    """
    FigureClass = kwargs.pop('FigureClass', Figure)
    thisFig = FigureClass( *args, **kwargs )
    canvas = FigureCanvasQT( thisFig )
    manager = FigureManagerQT( canvas, num )
    return manager


class FigureCanvasQT( qt.QWidget, FigureCanvasBase ):
    keyvald = { qt.Qt.Key_Control : 'control',
                qt.Qt.Key_Shift : 'shift',
                qt.Qt.Key_Alt : 'alt',
               }
    # left 1, middle 2, right 3
    buttond = {1:1, 2:3, 4:2}
    def __init__( self, figure ):
        if DEBUG: print 'FigureCanvasQt: ', figure
        _create_qApp()

        qt.QWidget.__init__( self, None, "QWidget figure" )
        FigureCanvasBase.__init__( self, figure )
        self.figure = figure
        self.setMouseTracking( True )

        w,h = self.get_width_height()
        self.resize( w, h )

    def enterEvent(self, event):
        FigureCanvasBase.enter_notify_event(self, event)

    def leaveEvent(self, event):
        FigureCanvasBase.leave_notify_event(self, event)

    def mousePressEvent( self, event ):
        x = event.pos().x()
        # flipy so y=0 is bottom of canvas
        y = self.figure.bbox.height - event.pos().y()
        button = self.buttond[event.button()]
        FigureCanvasBase.button_press_event( self, x, y, button )
        if DEBUG: print 'button pressed:', event.button()

    def mouseMoveEvent( self, event ):
        x = event.x()
        # flipy so y=0 is bottom of canvas
        y = self.figure.bbox.height - event.y()
        FigureCanvasBase.motion_notify_event( self, x, y )
        if DEBUG: print 'mouse move'

    def mouseReleaseEvent( self, event ):
        x = event.x()
        # flipy so y=0 is bottom of canvas
        y = self.figure.bbox.height - event.y()
        button = self.buttond[event.button()]
        FigureCanvasBase.button_release_event( self, x, y, button )
        if DEBUG: print 'button released'

    def keyPressEvent( self, event ):
        key = self._get_key( event )
        FigureCanvasBase.key_press_event( self, key )
        if DEBUG: print 'key press', key

    def keyReleaseEvent( self, event ):
        key = self._get_key(event)
        FigureCanvasBase.key_release_event( self, key )
        if DEBUG: print 'key release', key

    def resizeEvent( self, event ):
        if DEBUG: print 'resize (%d x %d)' % (event.size().width(), event.size().height())
        qt.QWidget.resizeEvent( self, event )
        w = event.size().width()
        h = event.size().height()
        if DEBUG: print "FigureCanvasQt.resizeEvent(", w, ",", h, ")"
        dpival = self.figure.dpi
        winch = w/dpival
        hinch = h/dpival
        self.figure.set_size_inches( winch, hinch )
        self.draw()

    def resize( self, w, h ):
        # Pass through to Qt to resize the widget.
        qt.QWidget.resize( self, w, h )

        # Resize the figure by converting pixels to inches.
        pixelPerInch = self.figure.dpi
        wInch = w / pixelPerInch
        hInch = h / pixelPerInch
        self.figure.set_size_inches( wInch, hInch )

        # Redraw everything.
        self.draw()

    def sizeHint( self ):
        w, h = self.get_width_height()
        return qt.QSize( w, h )

    def minumumSizeHint( self ):
        return qt.QSize( 10, 10 )

    def _get_key( self, event ):
        if event.key() < 256:
            key = event.text().latin1()
        elif event.key() in self.keyvald:
            key = self.keyvald[ event.key() ]
        else:
            key = None

        return key

    def flush_events(self):
        qt.qApp.processEvents()

    def start_event_loop(self,timeout):
        FigureCanvasBase.start_event_loop_default(self,timeout)
    start_event_loop.__doc__=FigureCanvasBase.start_event_loop_default.__doc__

    def stop_event_loop(self):
        FigureCanvasBase.stop_event_loop_default(self)
    stop_event_loop.__doc__=FigureCanvasBase.stop_event_loop_default.__doc__

class FigureManagerQT( FigureManagerBase ):
    """
    Public attributes

    canvas      : The FigureCanvas instance
    num         : The Figure number
    toolbar     : The qt.QToolBar
    window      : The qt.QMainWindow
    """

    def __init__( self, canvas, num ):
        if DEBUG: print 'FigureManagerQT.%s' % fn_name()
        FigureManagerBase.__init__( self, canvas, num )
        self.canvas = canvas
        self.window = qt.QMainWindow( None, None, qt.Qt.WDestructiveClose )
        self.window.closeEvent = self._widgetCloseEvent

        centralWidget = qt.QWidget( self.window )
        self.canvas.reparent( centralWidget, qt.QPoint( 0, 0 ) )

        # Give the keyboard focus to the figure instead of the manager
        self.canvas.setFocusPolicy( qt.QWidget.ClickFocus )
        self.canvas.setFocus()
        self.window.setCaption( "Figure %d" % num )

        self.window._destroying = False

        self.toolbar = self._get_toolbar(self.canvas, centralWidget)

        # Use a vertical layout for the plot and the toolbar.  Set the
        # stretch to all be in the plot so the toolbar doesn't resize.
        self.layout = qt.QVBoxLayout( centralWidget )
        self.layout.addWidget( self.canvas, 1 )

        if self.toolbar:
           self.layout.addWidget( self.toolbar, 0 )

        self.window.setCentralWidget( centralWidget )

        # Reset the window height so the canvas will be the right
        # size.  This ALMOST works right.  The first issue is that the
        # height w/ a toolbar seems to be off by just a little bit (so
        # we add 4 pixels).  The second is that the total width/height
        # is slightly smaller that we actually want.  It seems like
        # the border of the window is being included in the size but
        # AFAIK there is no way to get that size.
        w = self.canvas.width()
        h = self.canvas.height()
        if self.toolbar:
           h += self.toolbar.height() + 4
        self.window.resize( w, h )

        if matplotlib.is_interactive():
            self.window.show()

        # attach a show method to the figure for pylab ease of use
        self.canvas.figure.show = lambda *args: self.window.show()

        def notify_axes_change( fig ):
           # This will be called whenever the current axes is changed
           if self.toolbar != None: self.toolbar.update()
        self.canvas.figure.add_axobserver( notify_axes_change )

    def _widgetclosed( self ):
        if self.window._destroying: return
        self.window._destroying = True
        Gcf.destroy(self.num)

    def _widgetCloseEvent( self, event ):
        self._widgetclosed()
        qt.QWidget.closeEvent( self.window, event )

    def _get_toolbar(self, canvas, parent):
        # must be inited after the window, drawingArea and figure
        # attrs are set
        if matplotlib.rcParams['toolbar'] == 'classic':
            print "Classic toolbar is not yet supported"
        elif matplotlib.rcParams['toolbar'] == 'toolbar2':
            toolbar = NavigationToolbar2QT(canvas, parent)
        else:
            toolbar = None
        return toolbar

    def resize(self, width, height):
        'set the canvas size in pixels'
        self.window.resize(width, height)

    def show(self):
        self.window.show()

    def destroy( self, *args ):
        if self.window._destroying: return
        self.window._destroying = True
        if self.toolbar: self.toolbar.destroy()
        if DEBUG: print "destroy figure manager"
        self.window.close(True)

    def set_window_title(self, title):
        self.window.setCaption(title)

class NavigationToolbar2QT( NavigationToolbar2, qt.QWidget ):
    # list of toolitems to add to the toolbar, format is:
    # text, tooltip_text, image_file, callback(str)
    toolitems = (
        ('Home', 'Reset original view', 'home.ppm', 'home'),
        ('Back', 'Back to  previous view','back.ppm', 'back'),
        ('Forward', 'Forward to next view','forward.ppm', 'forward'),
        (None, None, None, None),
        ('Pan', 'Pan axes with left mouse, zoom with right', 'move.ppm', 'pan'),
        ('Zoom', 'Zoom to rectangle','zoom_to_rect.ppm', 'zoom'),
        (None, None, None, None),
        ('Subplots', 'Configure subplots','subplots.png', 'configure_subplots'),
        ('Save', 'Save the figure','filesave.ppm', 'save_figure'),
        )

    def __init__( self, canvas, parent ):
        self.canvas = canvas
        self.buttons = {}

        qt.QWidget.__init__( self, parent )

        # Layout toolbar buttons horizontally.
        self.layout = qt.QHBoxLayout( self )
        self.layout.setMargin( 2 )

        NavigationToolbar2.__init__( self, canvas )

    def _init_toolbar( self ):
        basedir = os.path.join(matplotlib.rcParams[ 'datapath' ],'images')

        for text, tooltip_text, image_file, callback in self.toolitems:
            if text == None:
                self.layout.addSpacing( 8 )
                continue

            fname = os.path.join( basedir, image_file )
            image = qt.QPixmap()
            image.load( fname )

            button = qt.QPushButton( qt.QIconSet( image ), "", self )
            qt.QToolTip.add( button, tooltip_text )

            self.buttons[ text ] = button

            # The automatic layout doesn't look that good - it's too close
            # to the images so add a margin around it.
            margin = 4
            button.setFixedSize( image.width()+margin, image.height()+margin )

            qt.QObject.connect( button, qt.SIGNAL( 'clicked()' ),
                                getattr( self, callback ) )
            self.layout.addWidget( button )

        self.buttons[ 'Pan' ].setToggleButton( True )
        self.buttons[ 'Zoom' ].setToggleButton( True )

        # Add the x,y location widget at the right side of the toolbar
        # The stretch factor is 1 which means any resizing of the toolbar
        # will resize this label instead of the buttons.
        self.locLabel = qt.QLabel( "", self )
        self.locLabel.setAlignment( qt.Qt.AlignRight | qt.Qt.AlignVCenter )
        self.locLabel.setSizePolicy(qt.QSizePolicy(qt.QSizePolicy.Ignored,
                                                      qt.QSizePolicy.Ignored))
        self.layout.addWidget( self.locLabel, 1 )

        # reference holder for subplots_adjust window
        self.adj_window = None


    def destroy( self ):
        for text, tooltip_text, image_file, callback in self.toolitems:
            if text is not None:
                qt.QObject.disconnect( self.buttons[ text ],
                                       qt.SIGNAL( 'clicked()' ),
                                       getattr( self, callback ) )

    def pan( self, *args ):
        self.buttons[ 'Zoom' ].setOn( False )
        NavigationToolbar2.pan( self, *args )

    def zoom( self, *args ):
        self.buttons[ 'Pan' ].setOn( False )
        NavigationToolbar2.zoom( self, *args )

    def dynamic_update( self ):
        self.canvas.draw()

    def set_message( self, s ):
        self.locLabel.setText( s )

    def set_cursor( self, cursor ):
        if DEBUG: print 'Set cursor' , cursor
        qt.QApplication.restoreOverrideCursor()
        qt.QApplication.setOverrideCursor( qt.QCursor( cursord[cursor] ) )

    def draw_rubberband( self, event, x0, y0, x1, y1 ):
        height = self.canvas.figure.bbox.height
        y1 = height - y1
        y0 = height - y0

        w = abs(x1 - x0)
        h = abs(y1 - y0)

        rect = [ int(val)for val in min(x0,x1), min(y0, y1), w, h ]
        self.canvas.drawRectangle( rect )

    def configure_subplots(self):
        self.adj_window = qt.QMainWindow(None, None, qt.Qt.WDestructiveClose)
        win = self.adj_window
        win.setCaption("Subplot Configuration Tool")

        toolfig = Figure(figsize=(6,3))
        toolfig.subplots_adjust(top=0.9)
        w = int (toolfig.bbox.width)
        h = int (toolfig.bbox.height)

        canvas = self._get_canvas(toolfig)
        tool = SubplotTool(self.canvas.figure, toolfig)
        centralWidget = qt.QWidget(win)
        canvas.reparent(centralWidget, qt.QPoint(0, 0))
        win.setCentralWidget(centralWidget)

        layout = qt.QVBoxLayout(centralWidget)
        layout.addWidget(canvas, 1)

        win.resize(w, h)
        canvas.setFocus()
        win.show()

    def _get_canvas(self, fig):
        return FigureCanvasQT(fig)

    def save_figure(self, *args):
        filetypes = self.canvas.get_supported_filetypes_grouped()
        sorted_filetypes = filetypes.items()
        sorted_filetypes.sort()
        default_filetype = self.canvas.get_default_filetype()

        start = "image." + default_filetype
        filters = []
        selectedFilter = None
        for name, exts in sorted_filetypes:
            exts_list = " ".join(['*.%s' % ext for ext in exts])
            filter = '%s (%s)' % (name, exts_list)
            if default_filetype in exts:
                selectedFilter = filter
            filters.append(filter)
        filters = ';;'.join(filters)

        fname = qt.QFileDialog.getSaveFileName(
            start, filters, self, "Save image", "Choose a filename to save to",
            selectedFilter)
        if fname:
            try:
                self.canvas.print_figure( unicode(fname) )
            except Exception, e:
                qt.QMessageBox.critical(
                    self, "Error saving file", str(e),
                    qt.QMessageBox.Ok, qt.QMessageBox.NoButton)

    def set_history_buttons( self ):
        canBackward = ( self._views._pos > 0 )
        canForward = ( self._views._pos < len( self._views._elements ) - 1 )
        self.buttons[ 'Back' ].setEnabled( canBackward )
        self.buttons[ 'Forward' ].setEnabled( canForward )

# set icon used when windows are minimized
try:
    # TODO: This is badly broken
    qt.window_set_default_icon_from_file (
        os.path.join( matplotlib.rcParams['datapath'], 'images', 'matplotlib.svg' ) )
except:
    verbose.report( 'Could not load matplotlib icon: %s' % sys.exc_info()[1] )


def error_msg_qt( msg, parent=None ):
    if not is_string_like( msg ):
        msg = ','.join( map( str,msg ) )

    qt.QMessageBox.warning( None, "Matplotlib", msg, qt.QMessageBox.Ok )

def exception_handler( type, value, tb ):
    """Handle uncaught exceptions
    It does not catch SystemExit
    """
    msg = ''
    # get the filename attribute if available (for IOError)
    if hasattr(value, 'filename') and value.filename != None:
        msg = value.filename + ': '
    if hasattr(value, 'strerror') and value.strerror != None:
        msg += value.strerror
    else:
        msg += str(value)

    if len( msg ) : error_msg_qt( msg )


FigureManager = FigureManagerQT
