/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "backends/platform/gp2xwiz/gp2xwiz-sdl.h"
#include "backends/platform/gp2xwiz/gp2xwiz-scaler.h" // TODO: Make GFX_HALF/HalfScale generic.

#include "common/mutex.h"
#include "graphics/font.h"
#include "graphics/fontman.h"
#include "graphics/scaler.h"
#include "graphics/scaler/intern.h"
#include "graphics/surface.h"

static const OSystem::GraphicsMode s_supportedGraphicsModes[] = {
	{"1x", "Fullscreen", GFX_NORMAL},
	{0, 0, 0}
};


const OSystem::GraphicsMode *OSystem_GP2XWIZ::getSupportedGraphicsModes() const {
	return s_supportedGraphicsModes;
}

int OSystem_GP2XWIZ::getDefaultGraphicsMode() const {
	return GFX_NORMAL;
}

//bool OSystem_GP2XWIZ::setGraphicsMode(const char *name) {
//	// let parent OSystem_SDL handle it
//	return setGraphicsMode(GFX_NORMAL);
//}

bool OSystem_GP2XWIZ::setGraphicsMode(int mode) {
	Common::StackLock lock(_graphicsMutex);

	assert(_transactionMode == kTransactionActive);

	if (_oldVideoMode.setup && _oldVideoMode.mode == mode)
		return true;

	int newScaleFactor = 1;

	switch(mode) {
	case GFX_NORMAL:
		newScaleFactor = 1;
		break;
    case GFX_HALF:
        newScaleFactor = 1;
        break;
	default:
		warning("unknown gfx mode %d", mode);
		return false;
	}

	_transactionDetails.normal1xScaler = (mode == GFX_NORMAL);
	if (_oldVideoMode.setup && _oldVideoMode.scaleFactor != newScaleFactor)
		_transactionDetails.needHotswap = true;

	_transactionDetails.needUpdatescreen = true;

	_videoMode.mode = mode;
	_videoMode.scaleFactor = newScaleFactor;

	return true;
}

void OSystem_GP2XWIZ::setGraphicsModeIntern() {
	Common::StackLock lock(_graphicsMutex);
	ScalerProc *newScalerProc = 0;

	switch (_videoMode.mode) {
	case GFX_NORMAL:
		newScalerProc = Normal1x;
		break;
    case GFX_HALF:
        newScalerProc = HalfScale;
        break;

	default:
		error("Unknown gfx mode %d", _videoMode.mode);
	}

	_scalerProc = newScalerProc;

	if (!_screen || !_hwscreen)
		return;

	// Blit everything to the screen
	_forceFull = true;

	// Even if the old and new scale factors are the same, we may have a
	// different scaler for the cursor now.
	blitCursor();
}


void OSystem_GP2XWIZ::initSize(uint w, uint h) {
    assert(_transactionMode == kTransactionActive);

    printf("Init Size: w=%d, h=%d\n", w, h);

	// Avoid redundant res changes
	if ((int)w == _videoMode.screenWidth && (int)h == _videoMode.screenHeight)
		return;

    _videoMode.screenWidth = w;
	_videoMode.screenHeight = h;
    if(w > 320 || h > 240){
        setGraphicsMode(GFX_HALF);
        setGraphicsModeIntern();
        toggleMouseGrab();
    }

	_cksumNum = (w * h / (8 * 8));

	_transactionDetails.sizeChanged = true;

	free(_dirtyChecksums);
	_dirtyChecksums = (uint32 *)calloc(_cksumNum * 2, sizeof(uint32));
}

bool OSystem_GP2XWIZ::loadGFXMode() {
	assert(_inited);
	_forceFull = true;

	int hwW, hwH;
    if(_videoMode.mode == GFX_HALF){
	    _videoMode.overlayWidth = _videoMode.screenWidth/2;
	    _videoMode.overlayHeight = _videoMode.screenHeight/2;
    } else {
        _videoMode.overlayWidth = _videoMode.screenWidth;
	    _videoMode.overlayHeight = _videoMode.screenHeight;
    }

	if (_videoMode.screenHeight != 200 && _videoMode.screenHeight != 400)
		_videoMode.aspectRatioCorrection = false;

	if (_videoMode.aspectRatioCorrection)
		_videoMode.overlayHeight = real2Aspect(_videoMode.overlayHeight);

    if(_videoMode.mode == GFX_HALF){
	    hwW = _videoMode.screenWidth/2;
	    hwH = effectiveScreenHeight()/2;
    } else {
        hwW = _videoMode.screenWidth;
	    hwH = effectiveScreenHeight();
    }

	//
	// Create the surface that contains the 8 bit game data
	//
	_screen = SDL_CreateRGBSurface(SDL_SWSURFACE, _videoMode.screenWidth, _videoMode.screenHeight, 8, 0, 0, 0, 0);
	if (_screen == NULL)
		error("allocating _screen failed");

	//
	// Create the surface that contains the scaled graphics in 16 bit mode
	//

	_hwscreen = SDL_SetVideoMode(hwW, hwH, 16,
		_videoMode.fullscreen ? (SDL_FULLSCREEN|SDL_SWSURFACE) : SDL_SWSURFACE
	);
	if (_hwscreen == NULL) {
		// DON'T use error(), as this tries to bring up the debug
		// console, which WON'T WORK now that _hwscreen is hosed.

		if (!_oldVideoMode.setup) {
			warning("SDL_SetVideoMode says we can't switch to that mode (%s)", SDL_GetError());
			quit();
		} else {
			return false;
		}
	}

	//
	// Create the surface used for the graphics in 16 bit before scaling, and also the overlay
	//

	// Need some extra bytes around when using 2xSaI
	_tmpscreen = SDL_CreateRGBSurface(SDL_SWSURFACE, _videoMode.screenWidth + 3, _videoMode.screenHeight + 3,
						16,
						_hwscreen->format->Rmask,
						_hwscreen->format->Gmask,
						_hwscreen->format->Bmask,
						_hwscreen->format->Amask);

	if (_tmpscreen == NULL)
		error("allocating _tmpscreen failed");

	_overlayscreen = SDL_CreateRGBSurface(SDL_SWSURFACE, _videoMode.overlayWidth, _videoMode.overlayHeight,
						16,
						_hwscreen->format->Rmask,
						_hwscreen->format->Gmask,
						_hwscreen->format->Bmask,
						_hwscreen->format->Amask);

	if (_overlayscreen == NULL)
		error("allocating _overlayscreen failed");

	_overlayFormat.bytesPerPixel = _overlayscreen->format->BytesPerPixel;

	_overlayFormat.rLoss = _overlayscreen->format->Rloss;
	_overlayFormat.gLoss = _overlayscreen->format->Gloss;
	_overlayFormat.bLoss = _overlayscreen->format->Bloss;
	_overlayFormat.aLoss = _overlayscreen->format->Aloss;

	_overlayFormat.rShift = _overlayscreen->format->Rshift;
	_overlayFormat.gShift = _overlayscreen->format->Gshift;
	_overlayFormat.bShift = _overlayscreen->format->Bshift;
	_overlayFormat.aShift = _overlayscreen->format->Ashift;

	_tmpscreen2 = SDL_CreateRGBSurface(SDL_SWSURFACE, _videoMode.overlayWidth + 3, _videoMode.overlayHeight + 3,
						16,
						_hwscreen->format->Rmask,
						_hwscreen->format->Gmask,
						_hwscreen->format->Bmask,
						_hwscreen->format->Amask);

	if (_tmpscreen2 == NULL)
		error("allocating _tmpscreen2 failed");

#ifdef USE_OSD
	_osdSurface = SDL_CreateRGBSurface(SDL_SWSURFACE | SDL_RLEACCEL | SDL_SRCCOLORKEY | SDL_SRCALPHA,
						_hwscreen->w,
						_hwscreen->h,
						16,
						_hwscreen->format->Rmask,
						_hwscreen->format->Gmask,
						_hwscreen->format->Bmask,
						_hwscreen->format->Amask);
	if (_osdSurface == NULL)
		error("allocating _osdSurface failed");
	SDL_SetColorKey(_osdSurface, SDL_RLEACCEL | SDL_SRCCOLORKEY | SDL_SRCALPHA, kOSDColorKey);
#endif

	// keyboard cursor control, some other better place for it?
	_km.x_max = _videoMode.screenWidth * _videoMode.scaleFactor - 1;
	_km.y_max = effectiveScreenHeight() - 1;
	_km.delay_time = 25;
	_km.last_time = 0;

	// Distinguish 555 and 565 mode
	if (_hwscreen->format->Rmask == 0x7C00)
		InitScalers(555);
	else
		InitScalers(565);

    // We need this to tell HalfScale the pixel format.
    // TODO: Find a better home.
    screenPixelFormat = _hwscreen->format;
	return true;
}

void OSystem_GP2XWIZ::drawMouse() {
	if (!_mouseVisible || !_mouseSurface) {
		_mouseBackup.x = _mouseBackup.y = _mouseBackup.w = _mouseBackup.h = 0;
		return;
	}

	SDL_Rect dst;
	int scale;
	int width, height;
	int hotX, hotY;

    if(_videoMode.mode == GFX_HALF && !_overlayVisible){
	    dst.x = _mouseCurState.x/2;
	    dst.y = _mouseCurState.y/2;
    } else {
        dst.x = _mouseCurState.x;
	    dst.y = _mouseCurState.y;
    }

	if (!_overlayVisible) {
		scale = _videoMode.scaleFactor;
		width = _videoMode.screenWidth;
		height = _videoMode.screenHeight;
		dst.w = _mouseCurState.vW;
		dst.h = _mouseCurState.vH;
		hotX = _mouseCurState.vHotX;
		hotY = _mouseCurState.vHotY;
	} else {
		scale = 1;
		width = _videoMode.overlayWidth;
		height = _videoMode.overlayHeight;
		dst.w = _mouseCurState.rW;
		dst.h = _mouseCurState.rH;
		hotX = _mouseCurState.rHotX;
		hotY = _mouseCurState.rHotY;
	}

	// The mouse is undrawn using virtual coordinates, i.e. they may be
	// scaled and aspect-ratio corrected.

	_mouseBackup.x = dst.x - hotX;
	_mouseBackup.y = dst.y - hotY;
	_mouseBackup.w = dst.w;
	_mouseBackup.h = dst.h;

	// We draw the pre-scaled cursor image, so now we need to adjust for
	// scaling, shake position and aspect ratio correction manually.

	if (!_overlayVisible) {
		dst.y += _currentShakePos;
	}

	if (_videoMode.aspectRatioCorrection && !_overlayVisible)
		dst.y = real2Aspect(dst.y);

	dst.x = scale * dst.x - _mouseCurState.rHotX;
	dst.y = scale * dst.y - _mouseCurState.rHotY;
	dst.w = _mouseCurState.rW;
	dst.h = _mouseCurState.rH;

	// Note that SDL_BlitSurface() and addDirtyRect() will both perform any
	// clipping necessary

	if (SDL_BlitSurface(_mouseSurface, NULL, _hwscreen, &dst) != 0)
		error("SDL_BlitSurface failed: %s", SDL_GetError());

	// The screen will be updated using real surface coordinates, i.e.
	// they will not be scaled or aspect-ratio corrected.
    addDirtyRect(dst.x, dst.y, dst.w, dst.h, true);
}

void OSystem_GP2XWIZ::undrawMouse() {
	const int x = _mouseBackup.x;
	const int y = _mouseBackup.y;

	// When we switch bigger overlay off mouse jumps. Argh!
	// This is intended to prevent undrawing offscreen mouse
	if (!_overlayVisible && (x >= _videoMode.screenWidth || y >= _videoMode.screenHeight))
		return;

	if (_mouseBackup.w != 0 && _mouseBackup.h != 0){
        if(_videoMode.mode == GFX_HALF && !_overlayVisible){
		    addDirtyRect(x*2, y*2, _mouseBackup.w*2, _mouseBackup.h*2);
        } else {
            addDirtyRect(x, y, _mouseBackup.w, _mouseBackup.h);
        }
    }
}

void OSystem_GP2XWIZ::internUpdateScreen() {
	SDL_Surface *srcSurf, *origSurf;
	int height, width;
	ScalerProc *scalerProc;
	int scale1;

#if defined (DEBUG) && ! defined(_WIN32_WCE) // definitions not available for non-DEBUG here. (needed this to compile in SYMBIAN32 & linux?)
	assert(_hwscreen != NULL);
	assert(_hwscreen->map->sw_data != NULL);
#endif

	// If the shake position changed, fill the dirty area with blackness
	if (_currentShakePos != _newShakePos) {
		SDL_Rect blackrect = {0, 0, _videoMode.screenWidth * _videoMode.scaleFactor, _newShakePos * _videoMode.scaleFactor};

		if (_videoMode.aspectRatioCorrection && !_overlayVisible)
			blackrect.h = real2Aspect(blackrect.h - 1) + 1;

		SDL_FillRect(_hwscreen, &blackrect, 0);

		_currentShakePos = _newShakePos;

		_forceFull = true;
	}

	// Check whether the palette was changed in the meantime and update the
	// screen surface accordingly.
	if (_screen && _paletteDirtyEnd != 0) {
		SDL_SetColors(_screen, _currentPalette + _paletteDirtyStart,
			_paletteDirtyStart,
			_paletteDirtyEnd - _paletteDirtyStart);

		_paletteDirtyEnd = 0;

		_forceFull = true;
	}

#ifdef USE_OSD
	// OSD visible (i.e. non-transparent)?
	if (_osdAlpha != SDL_ALPHA_TRANSPARENT) {
		// Updated alpha value
		const int diff = SDL_GetTicks() - _osdFadeStartTime;
		if (diff > 0) {
			if (diff >= kOSDFadeOutDuration) {
				// Back to full transparency
				_osdAlpha = SDL_ALPHA_TRANSPARENT;
			} else {
				// Do a linear fade out...
				const int startAlpha = SDL_ALPHA_TRANSPARENT + kOSDInitialAlpha * (SDL_ALPHA_OPAQUE - SDL_ALPHA_TRANSPARENT) / 100;
				_osdAlpha = startAlpha + diff * (SDL_ALPHA_TRANSPARENT - startAlpha) / kOSDFadeOutDuration;
			}
			SDL_SetAlpha(_osdSurface, SDL_RLEACCEL | SDL_SRCCOLORKEY | SDL_SRCALPHA, _osdAlpha);
			_forceFull = true;
		}
	}
#endif

	if (!_overlayVisible) {
		origSurf = _screen;
		srcSurf = _tmpscreen;
		width = _videoMode.screenWidth;
		height = _videoMode.screenHeight;
		scalerProc = _scalerProc;
		scale1 = _videoMode.scaleFactor;
	} else {
		origSurf = _overlayscreen;
		srcSurf = _tmpscreen2;
		width = _videoMode.overlayWidth;
		height = _videoMode.overlayHeight;
		scalerProc = Normal1x;

		scale1 = 1;
	}

	// Add the area covered by the mouse cursor to the list of dirty rects if
	// we have to redraw the mouse.
	if (_mouseNeedsRedraw)
		undrawMouse();

	// Force a full redraw if requested
	if (_forceFull) {
		_numDirtyRects = 1;
		_dirtyRectList[0].x = 0;
		_dirtyRectList[0].y = 0;
		_dirtyRectList[0].w = width;
		_dirtyRectList[0].h = height;
	}

	// Only draw anything if necessary
	if (_numDirtyRects > 0 || _mouseNeedsRedraw) {
		SDL_Rect *r;
		SDL_Rect dst;
		uint32 srcPitch, dstPitch;
		SDL_Rect *lastRect = _dirtyRectList + _numDirtyRects;

		for (r = _dirtyRectList; r != lastRect; ++r) {
			dst = *r;
			dst.x++;	// Shift rect by one since 2xSai needs to acces the data around
			dst.y++;	// any pixel to scale it, and we want to avoid mem access crashes.

			if (SDL_BlitSurface(origSurf, r, srcSurf, &dst) != 0)
				error("SDL_BlitSurface failed: %s", SDL_GetError());
		}

		SDL_LockSurface(srcSurf);
		SDL_LockSurface(_hwscreen);

		srcPitch = srcSurf->pitch;
		dstPitch = _hwscreen->pitch;

		for (r = _dirtyRectList; r != lastRect; ++r) {
			register int dst_y = r->y + _currentShakePos;
			register int dst_h = 0;
            register int dst_w = r->w;
			register int orig_dst_y = 0;
			register int dst_x = r->x;
            register int src_y;
            register int src_x;

			if (dst_y < height) {
				dst_h = r->h;
				if (dst_h > height - dst_y)
					dst_h = height - dst_y;

				orig_dst_y = dst_y;
                src_x = dst_x;
                src_y = dst_y;

				if (_videoMode.aspectRatioCorrection && !_overlayVisible)
					dst_y = real2Aspect(dst_y);

				assert(scalerProc != NULL);

                if(_videoMode.mode == GFX_HALF && scalerProc == HalfScale){
                    if(dst_x%2==1){
                        dst_x--;
                        dst_w++;
                    }
                    if(dst_y%2==1){
                        dst_y--;
                        dst_h++;
                    }
                    src_x = dst_x;
                    src_y = dst_y;
                    dst_x /= 2;
                    dst_y /= 2;
                }
                scalerProc((byte *)srcSurf->pixels + (src_x * 2 + 2) + (src_y + 1) * srcPitch, srcPitch,
						   (byte *)_hwscreen->pixels + dst_x * 2 + dst_y * dstPitch, dstPitch, dst_w, dst_h);
			}
            if(_videoMode.mode == GFX_HALF && scalerProc == HalfScale){
			    r->x = dst_x;
			    r->y = dst_y;
			    r->w = r->w/2;
			    r->h = dst_h/2;
            } else {
			    r->y = dst_y;
			    r->w = r->w;
			    r->h = dst_h;
            }

#ifndef DISABLE_SCALERS
			if (_videoMode.aspectRatioCorrection && orig_dst_y < height && !_overlayVisible)
				r->h = stretch200To240((uint8 *) _hwscreen->pixels, dstPitch, r->w, r->h, r->x, r->y, orig_dst_y * scale1);
#endif
		}
		SDL_UnlockSurface(srcSurf);
		SDL_UnlockSurface(_hwscreen);

		// Readjust the dirty rect list in case we are doing a full update.
		// This is necessary if shaking is active.
		if (_forceFull) {
			_dirtyRectList[0].y = 0;
			_dirtyRectList[0].h = (_videoMode.mode == GFX_HALF) ? effectiveScreenHeight()/2 : effectiveScreenHeight();
		}

		drawMouse();

#ifdef USE_OSD
		if (_osdAlpha != SDL_ALPHA_TRANSPARENT) {
			SDL_BlitSurface(_osdSurface, 0, _hwscreen, 0);
		}
#endif
		// Finally, blit all our changes to the screen
		SDL_UpdateRects(_hwscreen, _numDirtyRects, _dirtyRectList);
	}

	_numDirtyRects = 0;
	_forceFull = false;
	_mouseNeedsRedraw = false;
}


#pragma mark -
#pragma mark --- Overloaded Overlays ---
#pragma mark -

void OSystem_GP2XWIZ::showOverlay() {
	assert (_transactionMode == kTransactionNone);

	int x, y;

	if (_overlayVisible)
		return;

	_overlayVisible = true;

    if(_videoMode.mode == GFX_HALF){
        _mouseCurState.x /= 2;
        _mouseCurState.y /= 2;
    }

	// Since resolution could change, put mouse to adjusted position
	// Fixes bug #1349059
	x = _mouseCurState.x * _videoMode.scaleFactor;
	if (_videoMode.aspectRatioCorrection)
		y = real2Aspect(_mouseCurState.y) * _videoMode.scaleFactor;
	else
		y = _mouseCurState.y * _videoMode.scaleFactor;

	warpMouse(x, y);

	clearOverlay();
}

void OSystem_GP2XWIZ::hideOverlay() {
	assert (_transactionMode == kTransactionNone);

	if (!_overlayVisible)
		return;

	int x, y;

	_overlayVisible = false;

    if(_videoMode.mode == GFX_HALF){
        _mouseCurState.x *= 2;
        _mouseCurState.y *= 2;
    }

	// Since resolution could change, put mouse to adjusted position
	// Fixes bug #1349059
	x = _mouseCurState.x / _videoMode.scaleFactor;
	y = _mouseCurState.y / _videoMode.scaleFactor;
	if (_videoMode.aspectRatioCorrection)
		y = aspect2Real(y);

	warpMouse(x, y);

	clearOverlay();

	_forceFull = true;
}

void OSystem_GP2XWIZ::warpMouse(int x, int y) {
	int y1 = y;

	if (_videoMode.aspectRatioCorrection && !_overlayVisible)
		y1 = real2Aspect(y);

	if (_mouseCurState.x != x || _mouseCurState.y != y) {
        if(_videoMode.mode == GFX_HALF && !_overlayVisible){
            x /= 2;
            y /= 2;
        }
		if (!_overlayVisible)
			SDL_WarpMouse(x * _videoMode.scaleFactor, y1 * _videoMode.scaleFactor);
		else
			SDL_WarpMouse(x, y1);

		// SDL_WarpMouse() generates a mouse movement event, so
		// setMousePos() would be called eventually. However, the
		// cannon script in CoMI calls this function twice each time
		// the cannon is reloaded. Unless we update the mouse position
		// immediately the second call is ignored, causing the cannon
		// to change its aim.

		setMousePos(x, y);
	}
}