/* 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 "kyra/gui/gui.h"
#include "kyra/kyra_v1.h"
#include "kyra/engine/util.h"

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


namespace Kyra {

GUI::GUI(KyraEngine_v1 *kyra) : _vm(kyra), _screen(kyra ? kyra->screen() : nullptr) {
	_saveSlotsListUpdateNeeded = true;
	_savegameListSize = 0;
	_savegameList = nullptr;
}

GUI::~GUI() {
	if (_savegameList) {
		for (int i = 0; i < _savegameListSize; i++)
			delete[] _savegameList[i];
		delete[] _savegameList;
		_savegameList = nullptr;
	}
}

void GUI::updateSaveFileList(Common::String targetName, bool excludeQuickSaves) {
	Common::String pattern = targetName + ".###";
	Common::StringArray saveFileList = _vm->_saveFileMan->listSavefiles(pattern);
	_saveSlots.clear();

	for (Common::StringArray::const_iterator i = saveFileList.begin(); i != saveFileList.end(); ++i) {
		// The last 3 digits of the filename correspond to the save slot.
		const int slotNum = atoi(i->c_str() + i->size() - 3);
		if (excludeQuickSaves && slotNum >= 990)
			continue;
		_saveSlots.push_back(slotNum);
	}

	if (_saveSlots.begin() == _saveSlots.end())
		return;

	sortSaveSlots();
}

void GUI::sortSaveSlots() {
	Common::sort(_saveSlots.begin(), _saveSlots.end(), Common::Less<int>());
	if (_saveSlots.size() > 2)
		Common::sort(_saveSlots.begin() + 1, _saveSlots.end(), Common::Greater<int>());
}

int GUI::getNextSavegameSlot() {
	Common::InSaveFile *in;

	int start = _vm->game() == GI_LOL ? 0 : 1;

	for (int i = start; i < 990; i++) {
		if ((in = _vm->_saveFileMan->openForLoading(_vm->getSavegameFilename(i))))
			delete in;
		else
			return i;
	}
	warning("Didn't save: Ran out of saveGame filenames");
	return 0;
}

void GUI::updateSaveSlotsList(Common::String targetName, bool force) {
	if (!_saveSlotsListUpdateNeeded && !force)
		return;

	_saveSlotsListUpdateNeeded = false;

	if (_savegameList) {
		for (int i = 0; i < _savegameListSize; i++)
			delete[] _savegameList[i];
		delete[] _savegameList;
	}

	updateSaveFileList(targetName, true);
	int numSaves = _savegameListSize = _saveSlots.size();
	bool allowEmptySlots = (_vm->game() == GI_EOB1 || _vm->game() == GI_EOB2);

	if (_savegameListSize) {
		if (allowEmptySlots)
			_savegameListSize = 990;

		KyraEngine_v1::SaveHeader header;
		Common::InSaveFile *in;

		_savegameList = new char*[_savegameListSize]();

		for (int i = 0; i < numSaves; i++) {
			in = _vm->openSaveForReading(_vm->getSavegameFilename(targetName, _saveSlots[i]).c_str(), header, targetName == _vm->_targetName);
			char **listEntry = &_savegameList[allowEmptySlots ? _saveSlots[i] : i];
			if (in) {
				uint buffSize = header.description.size() + 1;
				*listEntry = new char[buffSize];
				Common::strlcpy(*listEntry, header.description.c_str(), buffSize);
				// Ingame auto-generated Japanese EOB SegaCD savegame descriptions have a special 1-byte encoding that
				// does not survive this conversion. And the rest of the characters in these descriptions do not require it.
				if (!(_vm->gameFlags().platform == Common::kPlatformSegaCD && _vm->gameFlags().lang == Common::JA_JPN && Common::String(*listEntry).contains('\r')))
					Util::convertString_GUItoKYRA(*listEntry, buffSize,
								      _vm->gameFlags().lang == Common::ZH_TWN ? Common::CodePage::kBig5 : Common::CodePage::kDos850);
				delete in;
			} else {
				*listEntry = nullptr;
				error("GUI::updateSavegameList(): Unexpected missing save file for slot: %d.", _saveSlots[i]);
			}
		}

	} else {
		_savegameList = nullptr;
	}
}

} // End of namespace Kyra