"""
This module contains some common functions used by :mod:`lib.agw.aui` to
manipulate colours, bitmaps, text, gradient shadings and custom dragging images
for :class:`~lib.agw.aui.auibook.AuiNotebook` tabs.
"""

__author__ = "Andrea Gavana <andrea.gavana@gmail.com>"
__date__ = "31 March 2009"


import wx

from aui_constants import *


if wx.Platform == "__WXMAC__":
    import Carbon.Appearance
    
    
def BlendColour(fg, bg, alpha):
    """
    Blends the two colour component `fg` and `bg` into one colour component, adding
    an optional alpha channel.

    :param Colour `fg`: the first colour component;
    :param Colour `bg`: the second colour component;
    :param integer `alpha`: an optional transparency value.
    """
    
    result = bg + (alpha*(fg - bg))
    
    if result < 0.0:
        result = 0.0
    if result > 255:
        result = 255
        
    return result


def StepColour(c, ialpha):
    """
    Darken/lighten the input colour `c`.

    :param Colour `c`: a colour to darken/lighten;
    :param integer `ialpha`: a transparency value.
    """
    
    if ialpha == 100:
        return c
        
    r, g, b = c.Red(), c.Green(), c.Blue()

    # ialpha is 0..200 where 0 is completely black
    # and 200 is completely white and 100 is the same
    # convert that to normal alpha 0.0 - 1.0
    ialpha = min(ialpha, 200)
    ialpha = max(ialpha, 0)
    alpha = (ialpha - 100.0)/100.0

    if ialpha > 100:
    
        # blend with white
        bg = 255
        alpha = 1.0 - alpha  # 0 = transparent fg 1 = opaque fg
    
    else:
    
        # blend with black
        bg = 0
        alpha = 1.0 + alpha  # 0 = transparent fg 1 = opaque fg
    
    r = BlendColour(r, bg, alpha)
    g = BlendColour(g, bg, alpha)
    b = BlendColour(b, bg, alpha)

    return wx.Colour(r, g, b)


def LightContrastColour(c):
    """
    Creates a new, lighter colour based on the input colour `c`.

    :param Colour `c`: the input colour to analyze.
    """

    amount = 120

    # if the colour is especially dark, then
    # make the contrast even lighter
    if c.Red() < 128 and c.Green() < 128 and c.Blue() < 128:
        amount = 160

    return StepColour(c, amount)


def ChopText(dc, text, max_size):
    """
    Chops the input `text` if its size does not fit in `max_size`, by cutting the
    text and adding ellipsis at the end.

    :param `dc`: a :class:`DC` device context;
    :param string `text`: the text to chop;
    :param integer `max_size`: the maximum size in which the text should fit.
    """
    
    # first check if the text fits with no problems
    x, y, dummy = dc.GetMultiLineTextExtent(text)
    
    if x <= max_size:
        return text

    textLen = len(text)
    last_good_length = 0
    
    for i in xrange(textLen, -1, -1):
        s = text[0:i]
        s += "..."

        x, y = dc.GetTextExtent(s)
        last_good_length = i
        
        if x < max_size:
            break

    ret = text[0:last_good_length] + "..."    
    return ret


def BitmapFromBits(bits, w, h, colour):
    """
    A utility function that creates a masked bitmap from raw bits (XBM format).

    :param string `bits`: the raw bits of the bitmap;
    :param integer `w`: the bitmap width;
    :param integer `h`: the bitmap height;
    :param Colour `colour`: the colour which will replace all white pixels in the
     raw bitmap.
    """

    img = wx.BitmapFromBits(bits, w, h).ConvertToImage()
    img.Replace(0, 0, 0, 123, 123, 123)
    img.Replace(255, 255, 255, colour.Red(), colour.Green(), colour.Blue())
    img.SetMaskColour(123, 123, 123)
    return wx.BitmapFromImage(img)


def IndentPressedBitmap(rect, button_state):
    """
    Indents the input rectangle `rect` based on the value of `button_state`.

    :param Rect `rect`: the button bitmap rectangle;
    :param integer `button_state`: the button state.
    """

    if button_state == AUI_BUTTON_STATE_PRESSED:
        rect.x += 1
        rect.y += 1

    return rect


def GetBaseColour():
    """
    Returns the face shading colour on push buttons/backgrounds,
    mimicking as closely as possible the platform UI colours.
    """

    if wx.Platform == "__WXMAC__":

        if hasattr(wx, 'MacThemeColour'):
            base_colour = wx.MacThemeColour(Carbon.Appearance.kThemeBrushToolbarBackground)
        else:
            brush = wx.Brush(wx.BLACK)
            brush.MacSetTheme(Carbon.Appearance.kThemeBrushToolbarBackground)
            base_colour = brush.GetColour()

    else:
        
        base_colour = wx.SystemSettings.GetColour(wx.SYS_COLOUR_3DFACE)

    # the base_colour is too pale to use as our base colour,
    # so darken it a bit
    if ((255-base_colour.Red()) +
        (255-base_colour.Green()) +
        (255-base_colour.Blue()) < 60):
    
        base_colour = StepColour(base_colour, 92)
    
    return base_colour


def MakeDisabledBitmap(bitmap):
    """
    Convert the given image (in place) to a grayed-out version, appropriate for a 'disabled' appearance.

    :param Bitmap `bitmap`: the bitmap to gray-out.
    """

    anImage = bitmap.ConvertToImage()    
    factor = 0.7        # 0 < f < 1.  Higher Is Grayer
    
    if anImage.HasMask():
        maskColour = (anImage.GetMaskRed(), anImage.GetMaskGreen(), anImage.GetMaskBlue())
    else:
        maskColour = None
        
    data = map(ord, list(anImage.GetData()))

    for i in range(0, len(data), 3):
        
        pixel = (data[i], data[i+1], data[i+2])
        pixel = MakeGray(pixel, factor, maskColour)

        for x in range(3):
            data[i+x] = pixel[x]

    anImage.SetData(''.join(map(chr, data)))
    
    return anImage.ConvertToBitmap()


def MakeGray(rgbTuple, factor, maskColour):
    """
    Make a pixel grayed-out.

    If the pixel matches the `maskColour`, it won't be changed.

    :param tuple `rgbTuple`: a tuple representing a pixel colour;
    :param integer `factor`: a graying-out factor;
    :param Colour `maskColour`: a colour mask.
    """

    if rgbTuple != maskColour:
        r, g, b = rgbTuple
        return map(lambda x: int((230 - x) * factor) + x, (r, g, b))
    else:
        return rgbTuple


def Clip(a, b, c):
    """
    Clips the value in `a` based on the extremes `b` and `c`.

    :param `a`: the value to analyze;
    :param `b`: a minimum value;
    :param `c`: a maximum value.
    """

    return ((a < b and [b]) or [(a > c and [c] or [a])[0]])[0]


def LightColour(colour, percent):
    """
    Brighten input `colour` by `percent`.

    :param Colour `colour`: the colour to be brightened;
    :param integer `percent`: brightening percentage.
    """
    
    end_colour = wx.WHITE
    
    rd = end_colour.Red() - colour.Red()
    gd = end_colour.Green() - colour.Green()
    bd = end_colour.Blue() - colour.Blue()

    high = 100

    # We take the percent way of the colour from colour -. white
    i = percent
    r = colour.Red() + ((i*rd*100)/high)/100
    g = colour.Green() + ((i*gd*100)/high)/100
    b = colour.Blue() + ((i*bd*100)/high)/100
    return wx.Colour(r, g, b)


def PaneCreateStippleBitmap():
    """
    Creates a stipple bitmap to be used in a :class:`Brush`.
    
    This is used to draw sash resize hints.
    """

    data = [0, 0, 0, 192, 192, 192, 192, 192, 192, 0, 0, 0]
    img = wx.EmptyImage(2, 2)
    counter = 0
    
    for ii in xrange(2):
        for jj in xrange(2):
            img.SetRGB(ii, jj, data[counter], data[counter+1], data[counter+2])
            counter = counter + 3
    
    return img.ConvertToBitmap()


def DrawMACCloseButton(colour, backColour=None):
    """
    Draws the wxMAC tab close button using :class:`GraphicsContext`.

    :param Colour `colour`: the colour to use to draw the circle;
    :param Colour `backColour`: the optional background colour for the circle.
    """

    bmp = wx.EmptyBitmapRGBA(16, 16)
    dc = wx.MemoryDC()
    dc.SelectObject(bmp)

    gc = wx.GraphicsContext.Create(dc)    
    gc.SetBrush(wx.Brush(colour))
    path = gc.CreatePath()
    path.AddCircle(6.5, 7, 6.5)
    path.CloseSubpath()
    gc.FillPath(path)
    
    path = gc.CreatePath()
    if backColour is not None:
        pen = wx.Pen(backColour, 2)
    else:
        pen = wx.Pen("white", 2)
        
    pen.SetCap(wx.CAP_BUTT)
    pen.SetJoin(wx.JOIN_BEVEL)
    gc.SetPen(pen)
    path.MoveToPoint(3.5, 4)
    path.AddLineToPoint(9.5, 10)
    path.MoveToPoint(3.5, 10)
    path.AddLineToPoint(9.5, 4)
    path.CloseSubpath()
    gc.DrawPath(path)

    dc.SelectObject(wx.NullBitmap)
    return bmp


def DarkenBitmap(bmp, caption_colour, new_colour):
    """
    Darkens the input bitmap on wxMAC using the input colour.
    
    :param Bitmap `bmp`: the bitmap to be manipulated;
    :param Colour `caption_colour`: the colour of the pane caption;
    :param Colour `new_colour`: the colour used to darken the bitmap.
    """

    image = bmp.ConvertToImage()
    red = caption_colour.Red()/float(new_colour.Red())
    green = caption_colour.Green()/float(new_colour.Green())
    blue = caption_colour.Blue()/float(new_colour.Blue())
    image = image.AdjustChannels(red, green, blue)
    return image.ConvertToBitmap()

    
def DrawGradientRectangle(dc, rect, start_colour, end_colour, direction, offset=0, length=0):
    """
    Draws a gradient-shaded rectangle.

    :param `dc`: a :class:`DC` device context;
    :param Rect `rect`: the rectangle in which to draw the gradient;
    :param Colour `start_colour`: the first colour of the gradient;
    :param Colour `end_colour`: the second colour of the gradient;
    :param integer `direction`: the gradient direction (horizontal or vertical).
    """
    
    if direction == AUI_GRADIENT_VERTICAL:
        dc.GradientFillLinear(rect, start_colour, end_colour, wx.SOUTH)
    else:
        dc.GradientFillLinear(rect, start_colour, end_colour, wx.EAST)
        

def FindFocusDescendant(ancestor):
    """
    Find a window with the focus, that is also a descendant of the given window.
    This is used to determine the window to initially send commands to.

    :param Window `ancestor`: the window to check for ancestry.    
    """

    # Process events starting with the window with the focus, if any.
    focusWin = wx.Window.FindFocus()
    win = focusWin

    # Check if this is a descendant of this frame.
    # If not, win will be set to NULL.
    while win:
        if win == ancestor:
            break
        else:
            win = win.GetParent()

    if win is None:
        focusWin = None

    return focusWin


def GetLabelSize(dc, label, vertical):
    """
    Returns the :class:`~lib.agw.aui.auibar.AuiToolBar` item label size.

    :param string `label`: the toolbar tool label;
    :param bool `vertical`: whether the toolbar tool orientation is vertical or not.
    """

    text_width = text_height = 0

    # get the text height
    dummy, text_height = dc.GetTextExtent("ABCDHgj")
    # get the text width
    if label.strip():
        text_width, dummy = dc.GetTextExtent(label)

    if vertical:
        tmp = text_height
        text_height = text_width
        text_width = tmp

    return wx.Size(text_width, text_height)


#---------------------------------------------------------------------------
# TabDragImage implementation
# This class handles the creation of a custom image when dragging
# AuiNotebook tabs
#---------------------------------------------------------------------------

class TabDragImage(wx.DragImage):
    """
    This class handles the creation of a custom image in case of drag and drop of a notebook tab.
    """

    def __init__(self, notebook, page, button_state, tabArt):
        """
        Default class constructor.
        
        For internal use: do not call it in your code!

        :param `notebook`: an instance of :class:`~lib.agw.aui.auibook.AuiNotebook`;
        :param `page`: the dragged :class:`~lib.agw.aui.auibook.AuiNotebookPage` page;
        :param integer `button_state`: the state of the close button on the tab;
        :param `tabArt`: an instance of :class:`~lib.agw.aui.tabart.AuiDefaultTabArt` or one of its derivations.
        """

        self._backgroundColour = wx.NamedColour("pink")        
        self._bitmap = self.CreateBitmap(notebook, page, button_state, tabArt)
        wx.DragImage.__init__(self, self._bitmap)


    def CreateBitmap(self, notebook, page, button_state, tabArt):
        """
        Actually creates the drag and drop bitmap.

        :param `notebook`: an instance of :class:`~lib.agw.aui.auibook.AuiNotebook`;
        :param `page`: the dragged :class:`~lib.agw.aui.auibook.AuiNotebookPage` page;
        :param integer `button_state`: the state of the close button on the tab;
        :param `tabArt`: an instance of :class:`~lib.agw.aui.tabart.AuiDefaultTabArt` or one of its derivations.
        """

        control = page.control
        memory = wx.MemoryDC(wx.EmptyBitmap(1, 1))

        tab_size, x_extent = tabArt.GetTabSize(memory, notebook, page.caption, page.bitmap, page.active,
                                               button_state, control)
            
        tab_width, tab_height = tab_size
        rect = wx.Rect(0, 0, tab_width, tab_height)

        bitmap = wx.EmptyBitmap(tab_width+1, tab_height+1)
        memory.SelectObject(bitmap)

        if wx.Platform == "__WXMAC__":
            memory.SetBackground(wx.TRANSPARENT_BRUSH)
        else:
            memory.SetBackground(wx.Brush(self._backgroundColour))
            
        memory.SetBackgroundMode(wx.TRANSPARENT)
        memory.Clear()

        paint_control = wx.Platform != "__WXMAC__"
        tabArt.DrawTab(memory, notebook, page, rect, button_state, paint_control=paint_control)
        
        memory.SetBrush(wx.TRANSPARENT_BRUSH)
        memory.SetPen(wx.BLACK_PEN)
        memory.DrawRoundedRectangle(0, 0, tab_width+1, tab_height+1, 2)

        memory.SelectObject(wx.NullBitmap)
        
        # Gtk and Windows unfortunatly don't do so well with transparent
        # drawing so this hack corrects the image to have a transparent
        # background.
        if wx.Platform != '__WXMAC__':
            timg = bitmap.ConvertToImage()
            if not timg.HasAlpha():
                timg.InitAlpha()
            for y in xrange(timg.GetHeight()):
                for x in xrange(timg.GetWidth()):
                    pix = wx.Colour(timg.GetRed(x, y),
                                    timg.GetGreen(x, y),
                                    timg.GetBlue(x, y))
                    if pix == self._backgroundColour:
                        timg.SetAlpha(x, y, 0)
            bitmap = timg.ConvertToBitmap()
        return bitmap        


def GetDockingImage(direction, useAero, center):
    """
    Returns the correct name of the docking bitmap depending on the input parameters.

    :param bool `useAero`: whether :class:`~lib.agw.aui.framemanager.AuiManager` is using
     Aero-style or Whidbey-style docking images or not;
    :param bool `center`: whether we are looking for the center diamond-shaped bitmap or not. 
    """

    suffix = (center and [""] or ["_single"])[0]
    prefix = ""
    if useAero == 2:
        # Whidbey docking guides
        prefix = "whidbey_"
    elif useAero == 1:
        # Aero docking style
        prefix = "aero_"
        
    if direction == wx.TOP:
        bmp_unfocus = eval("%sup%s"%(prefix, suffix)).GetBitmap()
        bmp_focus = eval("%sup_focus%s"%(prefix, suffix)).GetBitmap()
    elif direction == wx.BOTTOM:
        bmp_unfocus = eval("%sdown%s"%(prefix, suffix)).GetBitmap()
        bmp_focus = eval("%sdown_focus%s"%(prefix, suffix)).GetBitmap()
    elif direction == wx.LEFT:
        bmp_unfocus = eval("%sleft%s"%(prefix, suffix)).GetBitmap()
        bmp_focus = eval("%sleft_focus%s"%(prefix, suffix)).GetBitmap()
    elif direction == wx.RIGHT:
        bmp_unfocus = eval("%sright%s"%(prefix, suffix)).GetBitmap()
        bmp_focus = eval("%sright_focus%s"%(prefix, suffix)).GetBitmap()
    else:
        bmp_unfocus = eval("%stab%s"%(prefix, suffix)).GetBitmap()
        bmp_focus = eval("%stab_focus%s"%(prefix, suffix)).GetBitmap()

    return bmp_unfocus, bmp_focus


def TakeScreenShot(rect):
    """
    Takes a screenshot of the screen at given position and size (`rect`).

    :param Rect `rect`: the screen rectangle for which we want to take a screenshot.
    """

    # Create a DC for the whole screen area
    dcScreen = wx.ScreenDC()

    # Create a Bitmap that will later on hold the screenshot image
    # Note that the Bitmap must have a size big enough to hold the screenshot
    # -1 means using the current default colour depth
    bmp = wx.EmptyBitmap(rect.width, rect.height)

    # Create a memory DC that will be used for actually taking the screenshot
    memDC = wx.MemoryDC()

    # Tell the memory DC to use our Bitmap
    # all drawing action on the memory DC will go to the Bitmap now
    memDC.SelectObject(bmp)

    # Blit (in this case copy) the actual screen on the memory DC
    # and thus the Bitmap
    memDC.Blit( 0,            # Copy to this X coordinate
                0,            # Copy to this Y coordinate
                rect.width,   # Copy this width
                rect.height,  # Copy this height
                dcScreen,     # From where do we copy?
                rect.x,       # What's the X offset in the original DC?
                rect.y        # What's the Y offset in the original DC?
                )

    # Select the Bitmap out of the memory DC by selecting a new
    # uninitialized Bitmap
    memDC.SelectObject(wx.NullBitmap)

    return bmp


def RescaleScreenShot(bmp, thumbnail_size=200):
    """
    Rescales a bitmap to be `thumbnail_size` pixels wide (or tall) at maximum.

    :param Bitmap `bmp`: the bitmap to rescale;
    :param integer `thumbnail_size`: the maximum size of every page thumbnail.
    """

    bmpW, bmpH = bmp.GetWidth(), bmp.GetHeight()
    img = bmp.ConvertToImage()

    newW, newH = bmpW, bmpH
    
    if bmpW > bmpH:
        if bmpW > thumbnail_size:
            ratio = bmpW/float(thumbnail_size)
            newW, newH = int(bmpW/ratio), int(bmpH/ratio)
            img.Rescale(newW, newH, wx.IMAGE_QUALITY_HIGH)
    else:
        if bmpH > thumbnail_size:
            ratio = bmpH/float(thumbnail_size)
            newW, newH = int(bmpW/ratio), int(bmpH/ratio)
            img.Rescale(newW, newH, wx.IMAGE_QUALITY_HIGH)

    newBmp = img.ConvertToBitmap()
    otherBmp = wx.EmptyBitmap(newW+5, newH+5)    

    memDC = wx.MemoryDC()
    memDC.SelectObject(otherBmp)
    memDC.SetBackground(wx.WHITE_BRUSH)
    memDC.Clear()
    
    memDC.SetPen(wx.TRANSPARENT_PEN)

    pos = 0
    for i in xrange(5, 0, -1):
        brush = wx.Brush(wx.Colour(50*i, 50*i, 50*i))
        memDC.SetBrush(brush)
        memDC.DrawRoundedRectangle(0, 0, newW+5-pos, newH+5-pos, 2)
        pos += 1

    memDC.DrawBitmap(newBmp, 0, 0, True)
     
    # Select the Bitmap out of the memory DC by selecting a new
    # uninitialized Bitmap
    memDC.SelectObject(wx.NullBitmap)

    return otherBmp


def GetSlidingPoints(rect, size, direction):
    """
    Returns the point at which the sliding in and out of a minimized pane begins.

    :param Rect `rect`: the :class:`~lib.agw.aui.auibar.AuiToolBar` tool screen rectangle;
    :param Size `size`: the pane window size;
    :param integer `direction`: the pane docking direction.
    """

    if direction == AUI_DOCK_LEFT:
        startX, startY = rect.x + rect.width + 2, rect.y
    elif direction == AUI_DOCK_TOP:
        startX, startY = rect.x, rect.y + rect.height + 2
    elif direction == AUI_DOCK_RIGHT:
        startX, startY = rect.x - size.x - 2, rect.y
    elif direction == AUI_DOCK_BOTTOM:
        startX, startY = rect.x, rect.y - size.y - 2
    else:
        raise Exception("How did we get here?")

    caption_height = wx.SystemSettings.GetMetric(wx.SYS_CAPTION_Y)
    frame_border_x = wx.SystemSettings.GetMetric(wx.SYS_FRAMESIZE_X)
    frame_border_y = wx.SystemSettings.GetMetric(wx.SYS_FRAMESIZE_Y)
    
    stopX = size.x + caption_height + frame_border_x
    stopY = size.x + frame_border_y
    
    return startX, startY, stopX, stopY


def CopyAttributes(newArt, oldArt):
    """
    Copies pens, brushes, colours and fonts from the old tab art to the new one.

    :param `newArt`: the new instance of :class:`~lib.agw.aui.tabart.AuiDefaultTabArt`;
    :param `oldArt`: the old instance of :class:`~lib.agw.aui.tabart.AuiDefaultTabArt`.
    """    
    
    attrs = dir(oldArt)

    for attr in attrs:
        if attr.startswith("_") and (attr.endswith("_colour") or attr.endswith("_font") or \
                                     attr.endswith("_font") or attr.endswith("_brush") or \
                                     attr.endswith("Pen") or attr.endswith("_pen")):
            setattr(newArt, attr, getattr(oldArt, attr))

    return newArt            

