/* 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 3 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, see <http://www.gnu.org/licenses/>.
 *
 */

#include "ags/detection.h"
#include "ags/game_scanner.h"
#include "ags/shared/ac/game_setup_struct.h"
#include "ags/shared/core/asset_manager.h"
#include "ags/shared/util/multi_file_lib.h"
#include "ags/shared/util/string.h"
#include "ags/engine/main/game_file.h"
#include "ags/globals.h"
#include "common/config-manager.h"
#include "common/file.h"
#include "common/hashmap.h"
#include "common/md5.h"

namespace AGS3 {
/**
 * When detection is compiled dynamically, detection tables end up in detection plugin and
 * engine cannot link to them so don't include the feature instead of duplicating the data
 */
#ifdef DETECTION_STATIC

extern bool define_gamedata_location(const AGS::Shared::String &exe_path);
extern bool engine_try_init_gamedata(AGS::Shared::String gamepak_path);


void GameScanner::scan(const Common::Path &startFolder) {
	detectClashes();

	Common::FSNode folder(startFolder);
	scanFolder(folder);

	if (!_oldGames.empty()) {
		debug("// Pre 2.5 games that aren't supported");
		for (EntryArray::iterator it = _oldGames.begin(); it != _oldGames.end(); ++it) {
			debug("UNSUPPORTED_GAME_ENTRY(\"\", \"%s\", \"%s\", %u),",
			      it->_filename.c_str(), it->_md5.c_str(), (uint32)it->_filesize);
		}
		debugN("\n");
	}

	debug("// 2.5+ games that should be supported");
	Common::HashMap<Common::String, bool> gameDescs;
	for (EntryArray::iterator it = _games.begin(); it != _games.end(); ++it) {
		if (!gameDescs.contains(it->_id))
			debug("{ \"%s\", \"%s\" },", it->_id.c_str(), it->_gameName.c_str());
		gameDescs[it->_id] = true;
	}
	debugN("\n");

	for (EntryArray::iterator it = _games.begin(); it != _games.end(); ++it) {
		debug("GAME_ENTRY(\"%s\", \"%s\", \"%s\", %u),",
		      it->_id.c_str(), it->_filename.c_str(),
		      it->_md5.c_str(), (uint32)it->_filesize);
	}
	debugN("\n");
}

void GameScanner::scanFolder(const Common::FSNode &folder) {
	Common::FSList fslist;
	folder.getChildren(fslist, Common::FSNode::kListAll);

	for (uint idx = 0; idx < fslist.size(); ++idx) {
		Common::FSNode node = fslist[idx];
		Common::String filename = node.getName();

		if (node.isDirectory()) {
			scanFolder(node);
		} else if (filename.hasSuffixIgnoreCase(".exe") ||
		           filename.hasSuffixIgnoreCase(".ags") ||
		           filename.equalsIgnoreCase("ac2game.dat")) {
			Common::Path path = node.getPath();
			scanFile(path);
		}
	}
}

void GameScanner::scanFile(const Common::Path &filename) {
#ifdef TODO
	Common::File f;
	Common::FSNode fsNode(filename);
	if (!f.open(fsNode))
		return;

	int32 size = f.size();
	Common::String md5 = Common::computeStreamMD5AsString(f, 5000);

	// Check if it's an already known game
	const ::AGS::AGSGameDescription *gameP = ::AGS::GAME_DESCRIPTIONS;
	for (; gameP->desc.gameId; ++gameP) {
		if (size == gameP->desc.filesDescriptions[0].fileSize &&
		        md5 == gameP->desc.filesDescriptions[0].md5)
			// Known game, so skip
			return;
	}

	// Check the game file
	AGS::Shared::AssetLibInfo lib;
	AGS::Shared::StreamScummVMFile *stream = new AGS::Shared::StreamScummVMFile(&f);
	if (AGS::Shared::AssetManager::ReadDataFileTOC(stream, lib) != AGS::Shared::kAssetNoError)
		return;
	f.close();

	AGS::Shared::AssetManager::DestroyInstance();
	AGS::Shared::AssetManager::CreateInstance();
	AGS::Shared::AssetManager::SetDataFile(filename);

	if (!engine_try_init_gamedata(filename))
		return;

	AGS::Shared::HError err = preload_game_data();
	if (!err) {
		if (err->Code() == AGS::Shared::kMGFErr_FormatVersionTooOld) {
			Entry e;
			e._filename = fsNode.getName();
			e._filename.toLowercase();
			e._filesize = size;
			e._md5 = md5;

			_oldGames.push_back(e);
		}
	} else {
		// Add an entry for the found game
		Entry e;
		e._filename = fsNode.getName();
		e._filename.toLowercase();
		e._filesize = size;
		e._gameName = _GP(game).gamename;
		e._id = convertGameNameToId(e._gameName);
		e._md5 = md5;

		_games.push_back(e);
	}
#else
	error("TODO: GameScanner::scanFile");
#endif
}

Common::String GameScanner::convertGameNameToId(const Common::String &name) {
	Common::String result;

	for (uint idx = 0; idx < name.size(); ++idx) {
		char c = name[idx];
		if (Common::isDigit(c) || (tolower(c) >= 'a' && tolower(c) <= 'z'))
			result += tolower(c);
	}

	return result;
}

void GameScanner::detectClashes() {
	Common::HashMap<Common::String, bool> gameIds;
	Common::HashMap<Common::String, bool> gameNames;

	const PlainGameDescriptor *nameP = ::AGS::GAME_NAMES;
	for (; nameP->gameId; ++nameP) {
		if (gameIds.contains(nameP->gameId))
			debug("Duplicate game Id: %s", nameP->gameId);
		gameIds[nameP->gameId] = true;

		if (gameNames.contains(nameP->description))
			debug("Duplicate game name: %s", nameP->description);
		gameNames[nameP->description] = true;
	}
}
#endif

} // namespace AGS3