/* $Id$ */

/** @file genworld.cpp */

#include "stdafx.h"
#include "openttd.h"
#include "functions.h"
#include "player.h"
#include "table/sprites.h"
#include "variables.h"
#include "thread.h"
#include "genworld.h"
#include "gfx.h"
#include "gfxinit.h"
#include "gui.h"
#include "network/network.h"
#include "debug.h"
#include "settings.h"
#include "heightmap.h"
#include "date.h"

void GenerateLandscape(byte mode);
void GenerateClearTile(void);
void GenerateIndustries(void);
void GenerateUnmovables(void);
bool GenerateTowns(void);
void GenerateTrees(void);

void StartupEconomy(void);
void StartupPlayers(void);
void StartupDisasters(void);

void InitializeGame(int mode, uint size_x, uint size_y);

void ConvertGroundTilesIntoWaterTiles(void);

/* Please only use this variable in genworld.h and genworld.c and
 *  nowhere else. For speed improvements we need it to be global, but
 *  in no way the meaning of it is to use it anywhere else besides
 *  in the genworld.h and genworld.c! -- TrueLight */
gw_info _gw;

/**
 * Set the status of the Paint flag.
 *  If it is true, the thread will hold with any futher generating till
 *  the drawing of the screen is done. This is handled by
 *  SetGeneratingWorldProgress(), so calling that function will stall
 *  from time to time.
 */
void SetGeneratingWorldPaintStatus(bool status)
{
	_gw.wait_for_draw = status;
}

/**
 * Returns true if the thread wants the main program to do a (full) paint.
 *  If this returns false, please do not update the screen. Because we are
 *  writing in a thread, it can cause damaged data (reading and writing the
 *  same tile at the same time).
 */
bool IsGeneratingWorldReadyForPaint(void)
{
	/* If we are in quit_thread mode, ignore this and always return false. This
	 *  forces the screen to not be drawn, and the GUI not to wait for a draw. */
	if (!_gw.active || _gw.quit_thread || !_gw.threaded) return false;

	return _gw.wait_for_draw;
}

/**
 * Tells if the world generation is done in a thread or not.
 */
bool IsGenerateWorldThreaded(void)
{
	return _gw.threaded && !_gw.quit_thread;
}

/**
 * The internal, real, generate function.
 */
static void *_GenerateWorld(void *arg)
{
	_generating_world = true;
	if (_network_dedicated) DEBUG(net, 0, "Generating map, please wait...");
	/* Set the Random() seed to generation_seed so we produce the same map with the same seed */
	if (_patches.generation_seed == GENERATE_NEW_SEED) _patches.generation_seed = _patches_newgame.generation_seed = InteractiveRandom();
	_random_seeds[0][0] = _random_seeds[0][1] = _patches.generation_seed;
	SetGeneratingWorldProgress(GWP_MAP_INIT, 2);
	SetObjectToPlace(SPR_CURSOR_ZZZ, PAL_NONE, 0, WC_MAIN_WINDOW, 0);

	IncreaseGeneratingWorldProgress(GWP_MAP_INIT);
	/* Must start economy early because of the costs. */
	StartupEconomy();

	/* Don't generate landscape items when in the scenario editor. */
	if (_gw.mode == GW_EMPTY) {
		SetGeneratingWorldProgress(GWP_UNMOVABLE, 1);

		/* Make the map the height of the patch setting */
		if (_game_mode != GM_MENU) FlatEmptyWorld(_patches.se_flat_world_height);

		ConvertGroundTilesIntoWaterTiles();
		IncreaseGeneratingWorldProgress(GWP_UNMOVABLE);
	} else {
		GenerateLandscape(_gw.mode);
		GenerateClearTile();

		/* only generate towns, tree and industries in newgame mode. */
		if (_game_mode != GM_EDITOR) {
			GenerateTowns();
			GenerateIndustries();
			GenerateUnmovables();
			GenerateTrees();
		}
	}

	/* These are probably pointless when inside the scenario editor. */
	SetGeneratingWorldProgress(GWP_GAME_INIT, 3);
	StartupPlayers();
	IncreaseGeneratingWorldProgress(GWP_GAME_INIT);
	StartupEngines();
	IncreaseGeneratingWorldProgress(GWP_GAME_INIT);
	StartupDisasters();
	_generating_world = false;

	/* No need to run the tile loop in the scenario editor. */
	if (_gw.mode != GW_EMPTY) {
		uint i;

		SetGeneratingWorldProgress(GWP_RUNTILELOOP, 0x500);
		for (i = 0; i < 0x500; i++) {
			RunTileLoop();
			IncreaseGeneratingWorldProgress(GWP_RUNTILELOOP);
		}
	}

	ResetObjectToPlace();
	SetLocalPlayer(_gw.lp);

	SetGeneratingWorldProgress(GWP_GAME_START, 1);
	/* Call any callback */
	if (_gw.proc != NULL) _gw.proc();
	IncreaseGeneratingWorldProgress(GWP_GAME_START);

	if (_cursor.sprite == SPR_CURSOR_ZZZ) SetMouseCursor(SPR_CURSOR_MOUSE, PAL_NONE);
	/* Show all vital windows again, because we have hidden them */
	if (_gw.threaded && _game_mode != GM_MENU) ShowVitalWindows();
	_gw.active   = false;
	_gw.thread   = NULL;
	_gw.proc     = NULL;
	_gw.threaded = false;

	DeleteWindowById(WC_GENERATE_PROGRESS_WINDOW, 0);
	MarkWholeScreenDirty();

	if (_network_dedicated) DEBUG(net, 0, "Map generated, starting game");

	return NULL;
}

/**
 * Set here the function, if any, that you want to be called when landscape
 *  generation is done.
 */
void GenerateWorldSetCallback(gw_done_proc *proc)
{
	_gw.proc = proc;
}

/**
 * Set here the function, if any, that you want to be called when landscape
 *  generation is aborted.
 */
void GenerateWorldSetAbortCallback(gw_abort_proc *proc)
{
	_gw.abortp = proc;
}

/**
 * This will wait for the thread to finish up his work. It will not continue
 *  till the work is done.
 */
void WaitTillGeneratedWorld(void)
{
	if (_gw.thread == NULL) return;
	_gw.quit_thread = true;
	OTTDJoinThread((OTTDThread*)_gw.thread);
	_gw.thread   = NULL;
	_gw.threaded = false;
}

/**
 * Initializes the abortion process
 */
void AbortGeneratingWorld(void)
{
	_gw.abort = true;
}

/**
 * Is the generation being aborted?
 */
bool IsGeneratingWorldAborted(void)
{
	return _gw.abort;
}

/**
 * Really handle the abortion, i.e. clean up some of the mess
 */
void HandleGeneratingWorldAbortion(void)
{
	/* Clean up - in SE create an empty map, otherwise, go to intro menu */
	_switch_mode = (_game_mode == GM_EDITOR) ? SM_EDITOR : SM_MENU;

	if (_gw.abortp != NULL) _gw.abortp();

	if (_cursor.sprite == SPR_CURSOR_ZZZ) SetMouseCursor(SPR_CURSOR_MOUSE, PAL_NONE);
	/* Show all vital windows again, because we have hidden them */
	if (_gw.threaded && _game_mode != GM_MENU) ShowVitalWindows();
	_gw.active   = false;
	_gw.thread   = NULL;
	_gw.proc     = NULL;
	_gw.abortp   = NULL;
	_gw.threaded = false;

	DeleteWindowById(WC_GENERATE_PROGRESS_WINDOW, 0);
	MarkWholeScreenDirty();

	OTTDExitThread();
}

/**
 * Generate a world.
 * @param mode The mode of world generation (see GenerateWorldModes).
 * @param size_x The X-size of the map.
 * @param size_y The Y-size of the map.
 */
void GenerateWorld(int mode, uint size_x, uint size_y)
{
	if (_gw.active) return;
	_gw.mode   = mode;
	_gw.size_x = size_x;
	_gw.size_y = size_y;
	_gw.active = true;
	_gw.abort  = false;
	_gw.abortp = NULL;
	_gw.lp     = _local_player;
	_gw.wait_for_draw = false;
	_gw.quit_thread   = false;
	_gw.threaded      = true;

	/* This disables some commands and stuff */
	SetLocalPlayer(PLAYER_SPECTATOR);
	/* Make sure everything is done via OWNER_NONE */
	_current_player = OWNER_NONE;

	/* Set the date before loading sprites as some newgrfs check it */
	SetDate(ConvertYMDToDate(_patches.starting_year, 0, 1));

	/* Load the right landscape stuff */
	GfxLoadSprites();
	LoadStringWidthTable();

	InitializeGame(IG_NONE, _gw.size_x, _gw.size_y);
	PrepareGenerateWorldProgress();

	/* Re-init the windowing system */
	ResetWindowSystem();

	/* Create toolbars */
	SetupColorsAndInitialWindow();

	if (_network_dedicated ||
	    (_gw.thread = OTTDCreateThread(&_GenerateWorld, NULL)) == NULL) {
		DEBUG(misc, 1, "Cannot create genworld thread, reverting to single-threaded mode");
		_gw.threaded = false;
		_GenerateWorld(NULL);
		return;
	}

	/* Remove any open window */
	DeleteAllNonVitalWindows();
	/* Hide vital windows, because we don't allow to use them */
	HideVitalWindows();

	/* Don't show the dialog if we don't have a thread */
	ShowGenerateWorldProgress();

	/* Centre the view on the map */
	if (FindWindowById(WC_MAIN_WINDOW, 0) != NULL) {
		ScrollMainWindowToTile(TileXY(MapSizeX() / 2, MapSizeY() / 2));
	}
}