/**
 *
 * Compiz fade to desktop plugin
 *
 * fadedesktop.c
 *
 * Copyright (c) 2006 Robert Carr <racarr@beryl-project.org>
 * 		         2007 Danny Baumann <maniac@beryl-project.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 **/

#include <stdlib.h>
#include <string.h>
#include <compiz.h>
#include "fadedesktop_options.h"

#include <math.h>

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include <X11/Xproto.h>

typedef enum
{
	FD_STATE_OFF = 0,
	FD_STATE_OUT,
	FD_STATE_ON,
	FD_STATE_IN
} FadeDesktopState;

typedef struct _FadeDesktopDisplay
{
	int screenPrivateIndex;
} FadeDesktopDisplay;

typedef struct _FadeDesktopScreen
{
	int windowPrivateIndex;

	PreparePaintScreenProc preparePaintScreen;
	DonePaintScreenProc donePaintScreen;
	PaintWindowProc paintWindow;
	EnterShowDesktopModeProc enterShowDesktopMode;
	LeaveShowDesktopModeProc leaveShowDesktopMode;
	
	FadeDesktopState state;
	int fadeTime;
} FadeDesktopScreen;

typedef struct _FadeDesktopWindow
{
	Bool fading;
	Bool isHidden;

	GLushort opacity;
} FadeDesktopWindow;

#define GET_FADEDESKTOP_DISPLAY(d)				     \
    ((FadeDesktopDisplay *) (d)->privates[displayPrivateIndex].ptr)

#define FD_DISPLAY(d)			   \
    FadeDesktopDisplay *fd = GET_FADEDESKTOP_DISPLAY (d)

#define GET_FADEDESKTOP_SCREEN(s, fd)					 \
    ((FadeDesktopScreen *) (s)->privates[(fd)->screenPrivateIndex].ptr)

#define FD_SCREEN(s)							\
    FadeDesktopScreen *fs = GET_FADEDESKTOP_SCREEN (s, GET_FADEDESKTOP_DISPLAY (s->display))

#define GET_FADEDESKTOP_WINDOW(w, fs)					 \
    ((FadeDesktopWindow *) (w)->privates[(fs)->windowPrivateIndex].ptr)

#define FD_WINDOW(w)							\
    FadeDesktopWindow *fw = GET_FADEDESKTOP_WINDOW(w, \
					GET_FADEDESKTOP_SCREEN (w->screen, GET_FADEDESKTOP_DISPLAY (w->screen->display)))


static int displayPrivateIndex;


static void
fadeDesktopActivateEvent (CompScreen *s,
						  Bool       activating)
{
	CompOption o[2];

	o[0].type = CompOptionTypeInt;
	o[0].name = "root";
	o[0].value.i = s->root;

	o[1].type = CompOptionTypeBool;
	o[1].name = "active";
	o[1].value.b = activating;

	(*s->display->handleCompizEvent)
		(s->display, "fadedesktop", "activate", o, 2);
}

static Bool isFDWin(CompWindow *w)
{
	if (w->attrib.override_redirect)
		return FALSE;

	if (!w->managed)
		return FALSE;

	if (!matchEval(fadedesktopGetWindowMatch(w->screen), w))
		return FALSE;

	return TRUE;
}

static void 
fadeDesktopPreparePaintScreen(CompScreen *s, int msSinceLastPaint)
{
	FD_SCREEN(s);
	Bool doFade;

	fs->fadeTime -= msSinceLastPaint;
	if (fs->fadeTime < 0)
		fs->fadeTime = 0;

	if ((fs->state == FD_STATE_OUT) || (fs->state == FD_STATE_IN))
	{
		CompWindow *w;
		for (w = s->windows; w; w = w->next)
		{
			FD_WINDOW(w);

			if (fs->state == FD_STATE_OUT)
				doFade = fw->fading && w->inShowDesktopMode;
			else
				doFade = fw->fading && !w->inShowDesktopMode;

			if (doFade)
			{
			    fw->opacity = w->opacity * 
					  (float)((fs->state == FD_STATE_OUT) ? fs->fadeTime : 
				          fadedesktopGetFadetime(s) - fs->fadeTime) / 
				          (float)fadedesktopGetFadetime(s);
			}
		}
	}

	UNWRAP (fs, s, preparePaintScreen);
	(*s->preparePaintScreen) (s, msSinceLastPaint);
	WRAP (fs, s, preparePaintScreen, fadeDesktopPreparePaintScreen);
}

static void fadeDesktopDonePaintScreen(CompScreen *s)
{
	FD_SCREEN(s);

	if ((fs->state == FD_STATE_OUT) || (fs->state == FD_STATE_IN))
	{
		if (fs->fadeTime <= 0)
		{
			CompWindow *w;
			Bool isStillSD = FALSE;

			for (w = s->windows; w; w = w->next)
			{
				FD_WINDOW(w);
				if (fw->fading)
				{
					if (fs->state == FD_STATE_OUT)
					{
						hideWindow(w);
						fw->isHidden = TRUE;
					}
					fw->fading = FALSE;
				}
				if (w->inShowDesktopMode)
					isStillSD = TRUE;
			}

			if ((fs->state == FD_STATE_OUT) || isStillSD)
				fs->state = FD_STATE_ON;
			else
				fs->state = FD_STATE_OFF;
			fadeDesktopActivateEvent (s, FALSE);
		}
		else
			damageScreen(s);
	}

	UNWRAP (fs, s, donePaintScreen);
	(*s->donePaintScreen)(s);
	WRAP (fs, s, donePaintScreen, fadeDesktopDonePaintScreen);
}

static Bool fadeDesktopPaintWindow (CompWindow *w, 
				    const WindowPaintAttrib *attrib,
				    const CompTransform *transform, 
				    Region region,
				    unsigned int mask)
{
	Bool status;
	CompScreen *s = w->screen;
	FD_WINDOW(w);
	FD_SCREEN(s);

	if (fw->fading || fw->isHidden)
	{
		WindowPaintAttrib wAttrib = *attrib;
		wAttrib.opacity = fw->opacity;

		UNWRAP (fs, s, paintWindow);
		status = (*s->paintWindow) (w, &wAttrib, transform, region, mask);
		WRAP (fs, s, paintWindow, fadeDesktopPaintWindow);
	}
	else
	{
		UNWRAP (fs, s, paintWindow);
		status = (*s->paintWindow) (w, attrib, transform, region, mask);
		WRAP (fs, s, paintWindow, fadeDesktopPaintWindow);
	}

	return status;
}

static void fadeDesktopEnterShowDesktopMode(CompScreen *s)
{
	FD_SCREEN(s);
	CompWindow *w;

	if ((fs->state == FD_STATE_OFF) || (fs->state == FD_STATE_IN))
	{
		if (fs->state == FD_STATE_OFF)
			fadeDesktopActivateEvent (s, TRUE);

		fs->state = FD_STATE_OUT;
		fs->fadeTime = fadedesktopGetFadetime(s) - fs->fadeTime;

		for (w = s->windows; w; w = w->next)
		{
			if (isFDWin(w))
			{
				FD_WINDOW(w);

				fw->fading = TRUE;
				w->inShowDesktopMode = TRUE;
				fw->opacity = w->opacity;
			}
		}

		damageScreen(s);
	}

        UNWRAP(fs, s, enterShowDesktopMode);
        (*s->enterShowDesktopMode)(s);
        WRAP(fs, s, enterShowDesktopMode, fadeDesktopEnterShowDesktopMode);
}

static void fadeDesktopLeaveShowDesktopMode(CompScreen *s, CompWindow *w)
{
	FD_SCREEN(s);

	if (fs->state != FD_STATE_OFF)
	{
		CompWindow *cw;

		if (fs->state != FD_STATE_IN)
		{
			if (fs->state == FD_STATE_ON)
				fadeDesktopActivateEvent (s, TRUE);

			fs->state = FD_STATE_IN;
			fs->fadeTime = fadedesktopGetFadetime(s) - fs->fadeTime;
		}

		for (cw = s->windows; cw; cw = cw->next)
		{
			if (w && (w->id != cw->id))
				continue;

			FD_WINDOW(cw);
			if (fw->isHidden)
			{
				cw->inShowDesktopMode = FALSE;
				showWindow(cw);
				fw->isHidden = FALSE;
				fw->fading = TRUE;
			}
			else if (fw->fading)
			{
				cw->inShowDesktopMode = FALSE;
			}
		}

		damageScreen(s);
	}

       UNWRAP (fs, s, leaveShowDesktopMode); 
        (*s->leaveShowDesktopMode)(s, w);
        WRAP (fs, s, leaveShowDesktopMode, fadeDesktopLeaveShowDesktopMode);
}

static Bool fadeDesktopInit(CompPlugin *p)
{
	displayPrivateIndex = allocateDisplayPrivateIndex();
	if (displayPrivateIndex < 0)
		return FALSE;
	
	return TRUE;
}


static void fadeDesktopFini(CompPlugin *p)
{
	if (displayPrivateIndex >= 0)
		freeDisplayPrivateIndex(displayPrivateIndex);
}

static Bool fadeDesktopInitDisplay(CompPlugin *p, CompDisplay *d)
{
	FadeDesktopDisplay *fd;
	fd = malloc(sizeof(FadeDesktopDisplay));
	if (!fd)
		return FALSE;
	fd->screenPrivateIndex = allocateScreenPrivateIndex(d);
	if (fd->screenPrivateIndex < 0)
	{
		free(fd);
		return FALSE;
	}
	
	d->privates[displayPrivateIndex].ptr = fd;
	return TRUE;
}

static void fadeDesktopFiniDisplay(CompPlugin *p, CompDisplay *d)
{
	FD_DISPLAY(d);
	freeScreenPrivateIndex(d, fd->screenPrivateIndex);
	free(fd);
}

static Bool fadeDesktopInitScreen(CompPlugin *p, CompScreen *s)
{
	FadeDesktopScreen *fs;
	FD_DISPLAY(s->display);

	fs = malloc(sizeof(FadeDesktopScreen));
	if (!fs)
		return FALSE;

	fs->windowPrivateIndex = allocateWindowPrivateIndex(s);	
	if (fs->windowPrivateIndex < 0)
	{
		free(fs);
		return FALSE;
	}

	fs->state = FD_STATE_OFF;
	fs->fadeTime = 0;

	WRAP(fs, s, paintWindow, fadeDesktopPaintWindow);
	WRAP(fs, s, preparePaintScreen, fadeDesktopPreparePaintScreen);
	WRAP(fs, s, donePaintScreen, fadeDesktopDonePaintScreen);
	WRAP(fs, s, enterShowDesktopMode, fadeDesktopEnterShowDesktopMode);
	WRAP(fs, s, leaveShowDesktopMode, fadeDesktopLeaveShowDesktopMode);

	s->privates[fd->screenPrivateIndex].ptr = fs;

	return TRUE;
	
}

static void fadeDesktopFiniScreen(CompPlugin *p, CompScreen *s)
{
	FD_SCREEN(s);
	
	UNWRAP(fs, s, paintWindow);
	UNWRAP(fs, s, preparePaintScreen);
	UNWRAP(fs, s, donePaintScreen);
	UNWRAP(fs, s, enterShowDesktopMode);
	UNWRAP(fs, s, leaveShowDesktopMode);
	
	freeWindowPrivateIndex(s, fs->windowPrivateIndex);
	
	free (fs);
}

static Bool fadeDesktopInitWindow(CompPlugin *p, CompWindow *w)
{
	FadeDesktopWindow *fw;
	FD_SCREEN(w->screen);

	fw = malloc(sizeof(FadeDesktopWindow));
	if (!fw)
		return FALSE;

	fw->isHidden = FALSE;
	fw->fading = FALSE;
	
	w->privates[fs->windowPrivateIndex].ptr = fw;

	return TRUE;
	
}

static void fadeDesktopFiniWindow(CompPlugin *p, CompWindow *w)
{
	FD_WINDOW(w);
	
	free (fw);
}

static int fadeDesktopGetVersion(CompPlugin *p, int version)
{
	return ABIVERSION;
}

static CompPluginVTable fadeDesktopVTable = {
	"fadedesktop",
	fadeDesktopGetVersion,
	0,
	fadeDesktopInit,
	fadeDesktopFini,
	fadeDesktopInitDisplay,
	fadeDesktopFiniDisplay,
	fadeDesktopInitScreen,
	fadeDesktopFiniScreen,
	fadeDesktopInitWindow,
	fadeDesktopFiniWindow,
	NULL,
	NULL,
	NULL,
	NULL
};

CompPluginVTable * getCompPluginInfo(void)
{
	return &fadeDesktopVTable;
}