/* 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 "base/plugins.h"

#include "common/system.h"
#include "common/savefile.h"

#include "engines/advancedDetector.h"

#include "wage/wage.h"

namespace Wage {

const char *WageEngine::getGameFile() const {
	return _gameDescription->filesDescriptions[0].fileName;
}

} // End of namespace Wage

class WageMetaEngine : public AdvancedMetaEngine {
public:
	const char *getName() const override {
		return "wage";
	}

	Common::Error createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const override;

	bool hasFeature(MetaEngineFeature f) const override;
	SaveStateList listSaves(const char *target) const override;
	int getMaximumSaveSlot() const override;
	void removeSaveState(const char *target, int slot) const override;
};

bool WageMetaEngine::hasFeature(MetaEngineFeature f) const {
	return
		(f == kSupportsListSaves) ||
		(f == kSupportsLoadingDuringStartup) ||
		(f == kSupportsDeleteSave) ||
		(f == kSimpleSavesNames);
}

bool Wage::WageEngine::hasFeature(EngineFeature f) const {
	return
		(f == kSupportsReturnToLauncher) ||
		(f == kSupportsLoadingDuringRuntime) ||
		(f == kSupportsSavingDuringRuntime);
}

Common::Error WageMetaEngine::createInstance(OSystem *syst, Engine **engine, const ADGameDescription *desc) const {
	*engine = new Wage::WageEngine(syst, desc);
	return Common::kNoError;
}

SaveStateList WageMetaEngine::listSaves(const char *target) const {
	const uint32 WAGEflag = MKTAG('W','A','G','E');
	Common::SaveFileManager *saveFileMan = g_system->getSavefileManager();
	Common::StringArray filenames;
	char saveDesc[128] = {0};
	Common::String pattern = target;
	pattern += ".###";

	filenames = saveFileMan->listSavefiles(pattern);

	SaveStateList saveList;
	for (Common::StringArray::const_iterator file = filenames.begin(); file != filenames.end(); ++file) {
		// Obtain the last 3 digits of the filename, since they correspond to the save slot
		int slotNum = atoi(file->c_str() + file->size() - 3);

		if (slotNum >= 0 && slotNum <= 999) {
			Common::InSaveFile *in = saveFileMan->openForLoading(*file);
			if (in) {
				saveDesc[0] = 0;
				in->seek(in->size() - 8);
				uint32 offset = in->readUint32BE();
				uint32 type = in->readUint32BE();
				if (type == WAGEflag) {
					in->seek(offset);

					type = in->readUint32BE();
					if (type == WAGEflag) {
						in->read(saveDesc, 127);
					}
				}
				saveList.push_back(SaveStateDescriptor(this, slotNum, saveDesc));
				delete in;
			}
		}
	}

	// Sort saves based on slot number.
	Common::sort(saveList.begin(), saveList.end(), SaveStateDescriptorSlotComparator());
	return saveList;
}

int WageMetaEngine::getMaximumSaveSlot() const { return 999; }

void WageMetaEngine::removeSaveState(const char *target, int slot) const {
	g_system->getSavefileManager()->removeSavefile(Common::String::format("%s.%03d", target, slot));
}

#if PLUGIN_ENABLED_DYNAMIC(WAGE)
	REGISTER_PLUGIN_DYNAMIC(WAGE, PLUGIN_TYPE_ENGINE, WageMetaEngine);
#else
	REGISTER_PLUGIN_STATIC(WAGE, PLUGIN_TYPE_ENGINE, WageMetaEngine);
#endif

namespace Wage {

bool WageEngine::canLoadGameStateCurrently() {
	return true;
}

bool WageEngine::canSaveGameStateCurrently() {
	return true;
}

} // End of namespace Wage
