/* $Id$ */

/*
 * This file is part of OpenTTD.
 * OpenTTD 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, version 2.
 * OpenTTD 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 OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file sdl_v.cpp Implementation of the SDL video driver. */

#ifdef WITH_SDL

#include "../stdafx.h"
#include "../openttd.h"
#include "../gfx_func.h"
#include "../sdl.h"
#include "../variables.h"
#include "../rev.h"
#include "../blitter/factory.hpp"
#include "../network/network.h"
#include "../functions.h"
#include "../thread/thread.h"
#include "../genworld.h"
#include "sdl_v.h"
#include <SDL.h>

static FVideoDriver_SDL iFVideoDriver_SDL;

static SDL_Surface *_sdl_screen;
static bool _all_modes;
/** Flag used to determine if _cursor.fix_at has changed. */
static bool _last_fix_at;

/** Whether the drawing is/may be done in a separate thread. */
static bool _draw_threaded;
/** Thread used to 'draw' to the screen, i.e. push data to the screen. */
static ThreadObject *_draw_thread = NULL;
/** Mutex to keep the access to the shared memory controlled. */
static ThreadMutex *_draw_mutex = NULL;
/** Should we keep continue drawing? */
static volatile bool _draw_continue;

#define MAX_DIRTY_RECTS 100
static SDL_Rect _dirty_rects[MAX_DIRTY_RECTS];
static int _num_dirty_rects;

void VideoDriver_SDL::MakeDirty(int left, int top, int width, int height)
{
	if (_num_dirty_rects < MAX_DIRTY_RECTS) {
		_dirty_rects[_num_dirty_rects].x = left;
		_dirty_rects[_num_dirty_rects].y = top;
		_dirty_rects[_num_dirty_rects].w = width;
		_dirty_rects[_num_dirty_rects].h = height;
	}
	_num_dirty_rects++;
}

static void UpdatePalette(uint start, uint count)
{
	SDL_Color pal[256];

	for (uint i = 0; i != count; i++) {
		pal[i].r = _cur_palette[start + i].r;
		pal[i].g = _cur_palette[start + i].g;
		pal[i].b = _cur_palette[start + i].b;
		pal[i].unused = 0;
	}

	SDL_CALL SDL_SetColors(_sdl_screen, pal, start, count);
}

static void InitPalette()
{
	UpdatePalette(0, 256);
}

static void CheckPaletteAnim()
{
	if (_pal_count_dirty != 0) {
		Blitter *blitter = BlitterFactoryBase::GetCurrentBlitter();

		switch (blitter->UsePaletteAnimation()) {
			case Blitter::PALETTE_ANIMATION_VIDEO_BACKEND:
				UpdatePalette(_pal_first_dirty, _pal_count_dirty);
				break;

			case Blitter::PALETTE_ANIMATION_BLITTER:
				blitter->PaletteAnimate(_pal_first_dirty, _pal_count_dirty);
				break;

			case Blitter::PALETTE_ANIMATION_NONE:
				break;

			default:
				NOT_REACHED();
		}
		_pal_count_dirty = 0;
	}
}

static void DrawSurfaceToScreen()
{
	int n = _num_dirty_rects;
	if (n == 0) return;

	_num_dirty_rects = 0;
	if (n > MAX_DIRTY_RECTS) {
		SDL_CALL SDL_UpdateRect(_sdl_screen, 0, 0, 0, 0);
	} else {
		SDL_CALL SDL_UpdateRects(_sdl_screen, n, _dirty_rects);
	}
}

static void DrawSurfaceToScreenThread(void *)
{
	/* First wait till we 'may' start */
	_draw_mutex->BeginCritical();
	_draw_mutex->WaitForSignal();

	while (_draw_continue) {
		/* Then just draw and wait till we stop */
		DrawSurfaceToScreen();
		_draw_mutex->WaitForSignal();
	}

	_draw_mutex->EndCritical();
	_draw_thread->Exit();
}

static const Dimension _default_resolutions[] = {
	{ 640,  480},
	{ 800,  600},
	{1024,  768},
	{1152,  864},
	{1280,  800},
	{1280,  960},
	{1280, 1024},
	{1400, 1050},
	{1600, 1200},
	{1680, 1050},
	{1920, 1200}
};

static void GetVideoModes()
{
	SDL_Rect **modes = SDL_CALL SDL_ListModes(NULL, SDL_SWSURFACE | SDL_FULLSCREEN);
	if (modes == NULL) usererror("sdl: no modes available");

	_all_modes = (SDL_CALL SDL_ListModes(NULL, SDL_SWSURFACE | (_fullscreen ? SDL_FULLSCREEN : 0)) == (void*)-1);
	if (modes == (void*)-1) {
		int n = 0;
		for (uint i = 0; i < lengthof(_default_resolutions); i++) {
			if (SDL_CALL SDL_VideoModeOK(_default_resolutions[i].width, _default_resolutions[i].height, 8, SDL_FULLSCREEN) != 0) {
				_resolutions[n] = _default_resolutions[i];
				if (++n == lengthof(_resolutions)) break;
			}
		}
		_num_resolutions = n;
	} else {
		int n = 0;
		for (int i = 0; modes[i]; i++) {
			uint w = modes[i]->w;
			uint h = modes[i]->h;
			int j;
			for (j = 0; j < n; j++) {
				if (_resolutions[j].width == w && _resolutions[j].height == h) break;
			}

			if (j == n) {
				_resolutions[j].width  = w;
				_resolutions[j].height = h;
				if (++n == lengthof(_resolutions)) break;
			}
		}
		_num_resolutions = n;
		SortResolutions(_num_resolutions);
	}
}

static void GetAvailableVideoMode(uint *w, uint *h)
{
	/* All modes available? */
	if (_all_modes || _num_resolutions == 0) return;

	/* Is the wanted mode among the available modes? */
	for (int i = 0; i != _num_resolutions; i++) {
		if (*w == _resolutions[i].width && *h == _resolutions[i].height) return;
	}

	/* Use the closest possible resolution */
	int best = 0;
	uint delta = Delta(_resolutions[0].width, *w) * Delta(_resolutions[0].height, *h);
	for (int i = 1; i != _num_resolutions; ++i) {
		uint newdelta = Delta(_resolutions[i].width, *w) * Delta(_resolutions[i].height, *h);
		if (newdelta < delta) {
			best = i;
			delta = newdelta;
		}
	}
	*w = _resolutions[best].width;
	*h = _resolutions[best].height;
}

#ifndef ICON_DIR
#define ICON_DIR "media"
#endif

#ifdef WIN32
/* Let's redefine the LoadBMP macro with because we are dynamically
 * loading SDL and need to 'SDL_CALL' all functions */
#undef SDL_LoadBMP
#define SDL_LoadBMP(file)	SDL_LoadBMP_RW(SDL_CALL SDL_RWFromFile(file, "rb"), 1)
#endif

static bool CreateMainSurface(uint w, uint h)
{
	SDL_Surface *newscreen, *icon;
	char caption[50];
	int bpp = BlitterFactoryBase::GetCurrentBlitter()->GetScreenDepth();

	GetAvailableVideoMode(&w, &h);

	DEBUG(driver, 1, "SDL: using mode %ux%ux%d", w, h, bpp);

	if (bpp == 0) usererror("Can't use a blitter that blits 0 bpp for normal visuals");

	/* Give the application an icon */
	icon = SDL_CALL SDL_LoadBMP(ICON_DIR PATHSEP "openttd.32.bmp");
	if (icon != NULL) {
		/* Get the colourkey, which will be magenta */
		uint32 rgbmap = SDL_CALL SDL_MapRGB(icon->format, 255, 0, 255);

		SDL_CALL SDL_SetColorKey(icon, SDL_SRCCOLORKEY, rgbmap);
		SDL_CALL SDL_WM_SetIcon(icon, NULL);
		SDL_CALL SDL_FreeSurface(icon);
	}

	/* DO NOT CHANGE TO HWSURFACE, IT DOES NOT WORK */
	newscreen = SDL_CALL SDL_SetVideoMode(w, h, bpp, SDL_SWSURFACE | SDL_HWPALETTE | (_fullscreen ? SDL_FULLSCREEN : SDL_RESIZABLE));
	if (newscreen == NULL) {
		DEBUG(driver, 0, "SDL: Couldn't allocate a window to draw on");
		return false;
	}

	/* Delay drawing for this cycle; the next cycle will redraw the whole screen */
	_num_dirty_rects = 0;

	_screen.width = newscreen->w;
	_screen.height = newscreen->h;
	_screen.pitch = newscreen->pitch / (bpp / 8);
	_sdl_screen = newscreen;
	InitPalette();

	snprintf(caption, sizeof(caption), "OpenTTD %s", _openttd_revision);
	SDL_CALL SDL_WM_SetCaption(caption, caption);
	SDL_CALL SDL_ShowCursor(0);

	GameSizeChanged();

	return true;
}

struct VkMapping {
	uint16 vk_from;
	byte vk_count;
	byte map_to;
};

#define AS(x, z) {x, 0, z}
#define AM(x, y, z, w) {x, y - x, z}

static const VkMapping _vk_mapping[] = {
	/* Pageup stuff + up/down */
	AM(SDLK_PAGEUP, SDLK_PAGEDOWN, WKC_PAGEUP, WKC_PAGEDOWN),
	AS(SDLK_UP,     WKC_UP),
	AS(SDLK_DOWN,   WKC_DOWN),
	AS(SDLK_LEFT,   WKC_LEFT),
	AS(SDLK_RIGHT,  WKC_RIGHT),

	AS(SDLK_HOME,   WKC_HOME),
	AS(SDLK_END,    WKC_END),

	AS(SDLK_INSERT, WKC_INSERT),
	AS(SDLK_DELETE, WKC_DELETE),

	/* Map letters & digits */
	AM(SDLK_a, SDLK_z, 'A', 'Z'),
	AM(SDLK_0, SDLK_9, '0', '9'),

	AS(SDLK_ESCAPE,    WKC_ESC),
	AS(SDLK_PAUSE,     WKC_PAUSE),
	AS(SDLK_BACKSPACE, WKC_BACKSPACE),

	AS(SDLK_SPACE,     WKC_SPACE),
	AS(SDLK_RETURN,    WKC_RETURN),
	AS(SDLK_TAB,       WKC_TAB),

	/* Function keys */
	AM(SDLK_F1, SDLK_F12, WKC_F1, WKC_F12),

	/* Numeric part. */
	AM(SDLK_KP0, SDLK_KP9, '0', '9'),
	AS(SDLK_KP_DIVIDE,   WKC_NUM_DIV),
	AS(SDLK_KP_MULTIPLY, WKC_NUM_MUL),
	AS(SDLK_KP_MINUS,    WKC_NUM_MINUS),
	AS(SDLK_KP_PLUS,     WKC_NUM_PLUS),
	AS(SDLK_KP_ENTER,    WKC_NUM_ENTER),
	AS(SDLK_KP_PERIOD,   WKC_NUM_DECIMAL),

	/* Other non-letter keys */
	AS(SDLK_SLASH,        WKC_SLASH),
	AS(SDLK_SEMICOLON,    WKC_SEMICOLON),
	AS(SDLK_EQUALS,       WKC_EQUALS),
	AS(SDLK_LEFTBRACKET,  WKC_L_BRACKET),
	AS(SDLK_BACKSLASH,    WKC_BACKSLASH),
	AS(SDLK_RIGHTBRACKET, WKC_R_BRACKET),

	AS(SDLK_QUOTE,   WKC_SINGLEQUOTE),
	AS(SDLK_COMMA,   WKC_COMMA),
	AS(SDLK_MINUS,   WKC_MINUS),
	AS(SDLK_PERIOD,  WKC_PERIOD)
};

static uint32 ConvertSdlKeyIntoMy(SDL_keysym *sym)
{
	const VkMapping *map;
	uint key = 0;

	for (map = _vk_mapping; map != endof(_vk_mapping); ++map) {
		if ((uint)(sym->sym - map->vk_from) <= map->vk_count) {
			key = sym->sym - map->vk_from + map->map_to;
			break;
		}
	}

	/* check scancode for BACKQUOTE key, because we want the key left of "1", not anything else (on non-US keyboards) */
#if defined(WIN32) || defined(__OS2__)
	if (sym->scancode == 41) key = WKC_BACKQUOTE;
#elif defined(__APPLE__)
	if (sym->scancode == 10) key = WKC_BACKQUOTE;
#elif defined(__MORPHOS__)
	if (sym->scancode == 0)  key = WKC_BACKQUOTE;  // yes, that key is code '0' under MorphOS :)
#elif defined(__BEOS__)
	if (sym->scancode == 17) key = WKC_BACKQUOTE;
#elif defined(__SVR4) && defined(__sun)
	if (sym->scancode == 60) key = WKC_BACKQUOTE;
	if (sym->scancode == 49) key = WKC_BACKSPACE;
#elif defined(__sgi__)
	if (sym->scancode == 22) key = WKC_BACKQUOTE;
#else
	if (sym->scancode == 49) key = WKC_BACKQUOTE;
#endif

	/* META are the command keys on mac */
	if (sym->mod & KMOD_META)  key |= WKC_META;
	if (sym->mod & KMOD_SHIFT) key |= WKC_SHIFT;
	if (sym->mod & KMOD_CTRL)  key |= WKC_CTRL;
	if (sym->mod & KMOD_ALT)   key |= WKC_ALT;

	return (key << 16) + sym->unicode;
}

static int PollEvent()
{
	SDL_Event ev;

	if (_cursor.fix_at != _last_fix_at) {
		_last_fix_at = _cursor.fix_at;
		if (_last_fix_at) {
			/* Move to centre of window */
			SDL_CALL SDL_WarpMouse(_screen.width / 2, _screen.height / 2);

		} else {
			/* Restore position */
			SDL_CALL SDL_WarpMouse(_cursor.pos.x, _cursor.pos.y);
		}
	}

	if (!SDL_CALL SDL_PollEvent(&ev)) return -2;

	switch (ev.type) {
		case SDL_MOUSEMOTION:
			if (_cursor.fix_at) {
				int dx = ev.motion.x - _screen.width / 2;
				int dy = ev.motion.y - _screen.height / 2;
				if (dx != 0 || dy != 0) {
					_cursor.delta.x = dx;
					_cursor.delta.y = dy;
					SDL_CALL SDL_WarpMouse(_screen.width / 2, _screen.height / 2);
				}
			} else {
				_cursor.delta.x = ev.motion.x - _cursor.pos.x;
				_cursor.delta.y = ev.motion.y - _cursor.pos.y;
				_cursor.pos.x = ev.motion.x;
				_cursor.pos.y = ev.motion.y;
				_cursor.dirty = true;
			}
			HandleMouseEvents();
			break;

		case SDL_MOUSEBUTTONDOWN:
			if (_rightclick_emulate && SDL_CALL SDL_GetModState() & KMOD_CTRL) {
				ev.button.button = SDL_BUTTON_RIGHT;
			}

			switch (ev.button.button) {
				case SDL_BUTTON_LEFT:
					_left_button_down = true;
					break;

				case SDL_BUTTON_RIGHT:
					_right_button_down = true;
					_right_button_clicked = true;
					break;

				case SDL_BUTTON_WHEELUP:   _cursor.wheel--; break;
				case SDL_BUTTON_WHEELDOWN: _cursor.wheel++; break;

				default: break;
			}
			HandleMouseEvents();
			break;

		case SDL_MOUSEBUTTONUP:
			if (_rightclick_emulate) {
				_right_button_down = false;
				_left_button_down = false;
				_left_button_clicked = false;
			} else if (ev.button.button == SDL_BUTTON_LEFT) {
				_left_button_down = false;
				_left_button_clicked = false;
			} else if (ev.button.button == SDL_BUTTON_RIGHT) {
				_right_button_down = false;
			}
			HandleMouseEvents();
			break;

		case SDL_ACTIVEEVENT:
			if (!(ev.active.state & SDL_APPMOUSEFOCUS)) break;

			if (ev.active.gain) { // mouse entered the window, enable cursor
				_cursor.in_window = true;
			} else {
				UndrawMouseCursor(); // mouse left the window, undraw cursor
				_cursor.in_window = false;
			}
			break;

		case SDL_QUIT:
			HandleExitGameRequest();
			break;

		case SDL_KEYDOWN: // Toggle full-screen on ALT + ENTER/F
			if ((ev.key.keysym.mod & (KMOD_ALT | KMOD_META)) &&
					(ev.key.keysym.sym == SDLK_RETURN || ev.key.keysym.sym == SDLK_f)) {
				ToggleFullScreen(!_fullscreen);
			} else {
				HandleKeypress(ConvertSdlKeyIntoMy(&ev.key.keysym));
			}
			break;

		case SDL_VIDEORESIZE: {
			int w = max(ev.resize.w, 64);
			int h = max(ev.resize.h, 64);
			ChangeResInGame(w, h);
			break;
		}
	}
	return -1;
}

const char *VideoDriver_SDL::Start(const char * const *parm)
{
	char buf[30];

	const char *s = SdlOpen(SDL_INIT_VIDEO);
	if (s != NULL) return s;

	GetVideoModes();
	if (!CreateMainSurface(_cur_resolution.width, _cur_resolution.height)) {
		return SDL_CALL SDL_GetError();
	}

	SDL_CALL SDL_VideoDriverName(buf, 30);
	DEBUG(driver, 1, "SDL: using driver '%s'", buf);

	MarkWholeScreenDirty();

	SDL_CALL SDL_EnableKeyRepeat(SDL_DEFAULT_REPEAT_DELAY, SDL_DEFAULT_REPEAT_INTERVAL);
	SDL_CALL SDL_EnableUNICODE(1);

	_draw_threaded = GetDriverParam(parm, "no_threads") == NULL && GetDriverParam(parm, "no_thread") == NULL;

	return NULL;
}

void VideoDriver_SDL::Stop()
{
	SdlClose(SDL_INIT_VIDEO);
}

void VideoDriver_SDL::MainLoop()
{
	uint32 cur_ticks = SDL_CALL SDL_GetTicks();
	uint32 last_cur_ticks = cur_ticks;
	uint32 next_tick = cur_ticks + 30;
	uint32 pal_tick = 0;
	uint32 mod;
	int numkeys;
	Uint8 *keys;

	if (_draw_threaded) {
		/* Initialise the mutex first, because that's the thing we *need*
		 * directly in the newly created thread. */
		_draw_mutex = ThreadMutex::New();
		if (_draw_mutex == NULL) {
			_draw_threaded = false;
		} else {
			_draw_mutex->BeginCritical();
			_draw_continue = true;

			_draw_threaded = ThreadObject::New(&DrawSurfaceToScreenThread, NULL, &_draw_thread);

			/* Free the mutex if we won't be able to use it. */
			if (!_draw_threaded) {
				_draw_mutex->EndCritical();
				delete _draw_mutex;
			}
		}
	}

	DEBUG(driver, 1, "SDL: using %sthreads", _draw_threaded ? "" : "no ");

	for (;;) {
		uint32 prev_cur_ticks = cur_ticks; // to check for wrapping
		InteractiveRandom(); // randomness

		while (PollEvent() == -1) {}
		if (_exit_game) break;

		mod = SDL_CALL SDL_GetModState();
		keys = SDL_CALL SDL_GetKeyState(&numkeys);
#if defined(_DEBUG)
		if (_shift_pressed)
#else
		/* Speedup when pressing tab, except when using ALT+TAB
		 * to switch to another application */
		if (keys[SDLK_TAB] && (mod & KMOD_ALT) == 0)
#endif
		{
			if (!_networking && _game_mode != GM_MENU) _fast_forward |= 2;
		} else if (_fast_forward & 2) {
			_fast_forward = 0;
		}

		cur_ticks = SDL_CALL SDL_GetTicks();
		if (cur_ticks >= next_tick || (_fast_forward && !_pause_mode) || cur_ticks < prev_cur_ticks) {
			_realtime_tick += cur_ticks - last_cur_ticks;
			last_cur_ticks = cur_ticks;
			next_tick = cur_ticks + 30;

			bool old_ctrl_pressed = _ctrl_pressed;

			_ctrl_pressed  = !!(mod & KMOD_CTRL);
			_shift_pressed = !!(mod & KMOD_SHIFT);

			/* determine which directional keys are down */
			_dirkeys =
				(keys[SDLK_LEFT]  ? 1 : 0) |
				(keys[SDLK_UP]    ? 2 : 0) |
				(keys[SDLK_RIGHT] ? 4 : 0) |
				(keys[SDLK_DOWN]  ? 8 : 0);

			if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();

			/* The gameloop is the part that can run asynchroniously. The rest
			 * except sleeping can't. */
			if (_draw_threaded) _draw_mutex->EndCritical();

			GameLoop();

			if (_draw_threaded) _draw_mutex->BeginCritical();

			_screen.dst_ptr = _sdl_screen->pixels;
			UpdateWindows();
			if (++pal_tick > 4) {
				CheckPaletteAnim();
				pal_tick = 1;
			}

			/* End of the critical part. */
			if (_draw_threaded && !IsGeneratingWorld()) {
				_draw_mutex->SendSignal();
			} else {
				/* Oh, we didn't have threads, then just draw unthreaded */
				DrawSurfaceToScreen();
			}
		} else {
			/* Release the thread while sleeping */
			if (_draw_threaded) _draw_mutex->EndCritical();
			CSleep(1);
			if (_draw_threaded) _draw_mutex->BeginCritical();
		}
	}

	if (_draw_threaded) {
		_draw_continue = false;
		/* Sending signal if there is no thread blocked
		 * is very valid and results in noop */
		_draw_mutex->SendSignal();
		_draw_mutex->EndCritical();
		_draw_thread->Join();

		delete _draw_mutex;
		delete _draw_thread;
	}
}

bool VideoDriver_SDL::ChangeResolution(int w, int h)
{
	return CreateMainSurface(w, h);
}

bool VideoDriver_SDL::ToggleFullscreen(bool fullscreen)
{
	_fullscreen = fullscreen;
	GetVideoModes(); // get the list of available video modes
	if (_num_resolutions == 0 || !this->ChangeResolution(_cur_resolution.width, _cur_resolution.height)) {
		/* switching resolution failed, put back full_screen to original status */
		_fullscreen ^= true;
		return false;
	}
	return true;
}

#endif /* WITH_SDL */