/* $Id$ */

/*
 * 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 gfxinit.cpp Initializing of the (GRF) graphics. */

#include "stdafx.h"
#include "fios.h"
#include "newgrf.h"
#include "3rdparty/md5/md5.h"
#include "fontcache.h"
#include "gfx_func.h"
#include "settings_type.h"

/* The type of set we're replacing */
#define SET_TYPE "graphics"
#include "base_media_func.h"

#include "table/sprites.h"
#include "table/palette_convert.h"

/** The currently used palette */
PaletteType _use_palette = PAL_AUTODETECT;
/** Whether the given NewGRFs must get a palette remap or not. */
bool _palette_remap_grf[MAX_FILE_SLOTS];
/** Palette map to go from the !_use_palette to the _use_palette */
const byte *_palette_remap = NULL;
/** Palette map to go from the _use_palette to the !_use_palette */
const byte *_palette_reverse_remap = NULL;

#include "table/landscape_sprite.h"

static const SpriteID * const _landscape_spriteindexes[] = {
	_landscape_spriteindexes_1,
	_landscape_spriteindexes_2,
	_landscape_spriteindexes_3,
};

static uint LoadGrfFile(const char *filename, uint load_index, int file_index)
{
	uint load_index_org = load_index;
	uint sprite_id = 0;

	FioOpenFile(file_index, filename);

	DEBUG(sprite, 2, "Reading grf-file '%s'", filename);

	while (LoadNextSprite(load_index, file_index, sprite_id)) {
		load_index++;
		sprite_id++;
		if (load_index >= MAX_SPRITES) {
			usererror("Too many sprites. Recompile with higher MAX_SPRITES value or remove some custom GRF files.");
		}
	}
	DEBUG(sprite, 2, "Currently %i sprites are loaded", load_index);

	return load_index - load_index_org;
}


static void LoadSpritesIndexed(int file_index, uint *sprite_id, const SpriteID *index_tbl)
{
	uint start;
	while ((start = *index_tbl++) != END) {
		uint end = *index_tbl++;

		do {
			bool b = LoadNextSprite(start, file_index, *sprite_id);
			assert(b);
			(*sprite_id)++;
		} while (++start <= end);
	}
}

static void LoadGrfIndexed(const char *filename, const SpriteID *index_tbl, int file_index)
{
	uint sprite_id = 0;

	FioOpenFile(file_index, filename);

	DEBUG(sprite, 2, "Reading indexed grf-file '%s'", filename);

	LoadSpritesIndexed(file_index, &sprite_id, index_tbl);
}

/**
 * Checks whether the MD5 checksums of the files are correct.
 *
 * @note Also checks sample.cat and other required non-NewGRF GRFs for corruption.
 */
void CheckExternalFiles()
{
	if (BaseGraphics::GetUsedSet() == NULL || BaseSounds::GetUsedSet() == NULL) return;

	BaseGraphics::DeterminePalette();
	const GraphicsSet *used_set = BaseGraphics::GetUsedSet();

	DEBUG(grf, 1, "Using the %s base graphics set with the %s palette", used_set->name, _use_palette == PAL_DOS ? "DOS" : "Windows");

	static const size_t ERROR_MESSAGE_LENGTH = 256;
	static const size_t MISSING_FILE_MESSAGE_LENGTH = 128;

	/* Allocate for a message for each missing file and for one error
	 * message per set.
	 */
	char error_msg[MISSING_FILE_MESSAGE_LENGTH * (GraphicsSet::NUM_FILES + SoundsSet::NUM_FILES) + 2 * ERROR_MESSAGE_LENGTH];
	error_msg[0] = '\0';
	char *add_pos = error_msg;
	const char *last = lastof(error_msg);

	if (used_set->GetNumInvalid() != 0) {
		/* Not all files were loaded succesfully, see which ones */
		add_pos += seprintf(add_pos, last, "Trying to load graphics set '%s', but it is incomplete. The game will probably not run correctly until you properly install this set or select another one. See section 4.1 of readme.txt.\n\nThe following files are corrupted or missing:\n", used_set->name);
		for (uint i = 0; i < GraphicsSet::NUM_FILES; i++) {
			MD5File::ChecksumResult res = used_set->files[i].CheckMD5(DATA_DIR);
			if (res != MD5File::CR_MATCH) add_pos += seprintf(add_pos, last, "\t%s is %s (%s)\n", used_set->files[i].filename, res == MD5File::CR_MISMATCH ? "corrupt" : "missing", used_set->files[i].missing_warning);
		}
		add_pos += seprintf(add_pos, last, "\n");
	}

	const SoundsSet *sounds_set = BaseSounds::GetUsedSet();
	if (sounds_set->GetNumInvalid() != 0) {
		add_pos += seprintf(add_pos, last, "Trying to load sound set '%s', but it is incomplete. The game will probably not run correctly until you properly install this set or select another one. See section 4.1 of readme.txt.\n\nThe following files are corrupted or missing:\n", sounds_set->name);

		assert_compile(SoundsSet::NUM_FILES == 1);
		/* No need to loop each file, as long as there is only a single
		 * sound file. */
		add_pos += seprintf(add_pos, last, "\t%s is %s (%s)\n", sounds_set->files->filename, sounds_set->files->CheckMD5(DATA_DIR) == MD5File::CR_MISMATCH ? "corrupt" : "missing", sounds_set->files->missing_warning);
	}

	if (add_pos != error_msg) ShowInfoF("%s", error_msg);
}


static void LoadSpriteTables()
{
	memset(_palette_remap_grf, 0, sizeof(_palette_remap_grf));
	uint i = FIRST_GRF_SLOT;
	const GraphicsSet *used_set = BaseGraphics::GetUsedSet();

	_palette_remap_grf[i] = (_use_palette != used_set->palette);
	LoadGrfFile(used_set->files[GFT_BASE].filename, 0, i++);

	/*
	 * The second basic file always starts at the given location and does
	 * contain a different amount of sprites depending on the "type"; DOS
	 * has a few sprites less. However, we do not care about those missing
	 * sprites as they are not shown anyway (logos in intro game).
	 */
	_palette_remap_grf[i] = (_use_palette != used_set->palette);
	LoadGrfFile(used_set->files[GFT_LOGOS].filename, 4793, i++);

	/*
	 * Load additional sprites for climates other than temperate.
	 * This overwrites some of the temperate sprites, such as foundations
	 * and the ground sprites.
	 */
	if (_settings_game.game_creation.landscape != LT_TEMPERATE) {
		_palette_remap_grf[i] = (_use_palette != used_set->palette);
		LoadGrfIndexed(
			used_set->files[GFT_ARCTIC + _settings_game.game_creation.landscape - 1].filename,
			_landscape_spriteindexes[_settings_game.game_creation.landscape - 1],
			i++
		);
	}

	/* Initialize the unicode to sprite mapping table */
	InitializeUnicodeGlyphMap();

	/*
	 * Load the base NewGRF with OTTD required graphics as first NewGRF.
	 * However, we do not want it to show up in the list of used NewGRFs,
	 * so we have to manually add it, and then remove it later.
	 */
	GRFConfig *top = _grfconfig;
	GRFConfig *master = new GRFConfig(used_set->files[GFT_EXTRA].filename);
	FillGRFDetails(master, false);
	master->palette = (used_set->palette == PAL_WINDOWS) ? GRFP_USE_WINDOWS : GRFP_USE_DOS;
	ClrBit(master->flags, GCF_INIT_ONLY);
	master->next = top;
	_grfconfig = master;

	LoadNewGRF(SPR_NEWGRFS_BASE, i);

	/* Free and remove the top element. */
	delete master;
	_grfconfig = top;
}


void GfxLoadSprites()
{
	DEBUG(sprite, 2, "Loading sprite set %d", _settings_game.game_creation.landscape);

	GfxInitSpriteMem();
	LoadSpriteTables();
	GfxInitPalettes();
}

bool GraphicsSet::FillSetDetails(IniFile *ini, const char *path, const char *full_filename)
{
	bool ret = this->BaseSet<GraphicsSet, MAX_GFT, DATA_DIR>::FillSetDetails(ini, path, full_filename, false);
	if (ret) {
		IniGroup *metadata = ini->GetGroup("metadata");
		IniItem *item;

		fetch_metadata("palette");
		this->palette = (*item->value == 'D' || *item->value == 'd') ? PAL_DOS : PAL_WINDOWS;
	}
	return ret;
}


/**
 * Calculate and check the MD5 hash of the supplied filename.
 * @param subdir The sub directory to get the files from
 * @return
 *  CR_MATCH if the MD5 hash matches
 *  CR_MISMATCH if the MD5 does not match
 *  CR_NO_FILE if the file misses
 */
MD5File::ChecksumResult MD5File::CheckMD5(Subdirectory subdir) const
{
	size_t size;
	FILE *f = FioFOpenFile(this->filename, "rb", subdir, &size);

	if (f == NULL) return CR_NO_FILE;

	Md5 checksum;
	uint8 buffer[1024];
	uint8 digest[16];
	size_t len;

	while ((len = fread(buffer, 1, (size > sizeof(buffer)) ? sizeof(buffer) : size, f)) != 0 && size != 0) {
		size -= len;
		checksum.Append(buffer, len);
	}

	FioFCloseFile(f);

	checksum.Finish(digest);
	return memcmp(this->hash, digest, sizeof(this->hash)) == 0 ? CR_MATCH : CR_MISMATCH;
}

/** Names corresponding to the GraphicsFileType */
static const char * const _graphics_file_names[] = { "base", "logos", "arctic", "tropical", "toyland", "extra" };

/** Implementation */
template <class T, size_t Tnum_files, Subdirectory Tsubdir>
/* static */ const char * const *BaseSet<T, Tnum_files, Tsubdir>::file_names = _graphics_file_names;

extern void UpdateNewGRFConfigPalette();

/**
 * Determine the palette that has to be used.
 *  - forced palette via command line -> leave it that way
 *  - otherwise -> palette based on the graphics pack
 */
/* static */ void BaseGraphics::DeterminePalette()
{
	assert(BaseGraphics::used_set != NULL);
	if (_use_palette >= MAX_PAL) _use_palette = BaseGraphics::used_set->palette;

	switch (_use_palette) {
		case PAL_DOS:
			_palette_remap = _palmap_w2d;
			_palette_reverse_remap = _palmap_d2w;
			break;

		case PAL_WINDOWS:
			_palette_remap = _palmap_d2w;
			_palette_reverse_remap = _palmap_w2d;
			break;

		default:
			NOT_REACHED();
	}

	UpdateNewGRFConfigPalette();
}

template <class Tbase_set>
/* static */ bool BaseMedia<Tbase_set>::DetermineBestSet()
{
	if (BaseMedia<Tbase_set>::used_set != NULL) return true;

	const Tbase_set *best = NULL;
	for (const Tbase_set *c = BaseMedia<Tbase_set>::available_sets; c != NULL; c = c->next) {
		/* Skip unuseable sets */
		if (c->GetNumMissing() != 0) continue;

		if (best == NULL ||
				(best->fallback && !c->fallback) ||
				best->valid_files < c->valid_files ||
				(best->valid_files == c->valid_files && (
					(best->shortname == c->shortname && best->version < c->version) ||
					(best->palette != _use_palette && c->palette == _use_palette)))) {
			best = c;
		}
	}

	BaseMedia<Tbase_set>::used_set = best;
	return BaseMedia<Tbase_set>::used_set != NULL;
}

template <class Tbase_set>
/* static */ const char *BaseMedia<Tbase_set>::GetExtension()
{
	return ".obg"; // OpenTTD Base Graphics
}

INSTANTIATE_BASE_MEDIA_METHODS(BaseMedia<GraphicsSet>, GraphicsSet)