/* 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 2
 * 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 *
 */

#include "common/system.h"

#include "sci/sci.h"	// for INCLUDE_OLDGFX
#include "sci/debug.h"	// for g_debug_sleeptime_factor
#include "sci/event.h"

#include "sci/engine/state.h"
#include "sci/engine/selector.h"
#include "sci/engine/vm.h"
#include "sci/engine/script.h"
#include "sci/engine/message.h"

namespace Sci {

// Maps half-width single-byte SJIS to full-width double-byte SJIS
// Note: SSCI maps 0x5C (the Yen symbol) to 0x005C, which terminates
// the string with the leading 0x00 byte. We map Yen to 0x818F.
static const uint16 s_halfWidthSJISMap[256] = {
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0x81A8, 0x81A9, 0x81AA, 0x81AB,
	0x8140, 0x8149, 0x818D, 0x8194, 0x8190, 0x8193, 0x8195, 0x818C,
	0x8169, 0x816A, 0x8196, 0x817B, 0x8143, 0x817C, 0x8144, 0x815E,
	0x824F, 0x8250, 0x8251, 0x8252, 0x8253, 0x8254, 0x8255, 0x8256,
	0x8257, 0x8258, 0x8146, 0x8147, 0x8183, 0x8181, 0x8184, 0x8148,
	0x8197, 0x8260, 0x8261, 0x8262, 0x8263, 0x8264, 0x8265, 0x8266,
	0x8267, 0x8268, 0x8269, 0x826A, 0x826B, 0x826C, 0x826D, 0x826E,
	0x826F, 0x8270, 0x8271, 0x8272, 0x8273, 0x8274, 0x8275, 0x8276,
	0x8277, 0x8278, 0x8279, 0x816D, 0x818F /* 0x005C */, 0x816E, 0x814F, 0x8151,
	0x8280, 0x8281, 0x8282, 0x8283, 0x8284, 0x8285, 0x8286, 0x8287,
	0x8288, 0x8289, 0x828A, 0x828B, 0x828C, 0x828D, 0x828E, 0x828F,
	0x8290, 0x8291, 0x8292, 0x8293, 0x8294, 0x8295, 0x8296, 0x8297,
	0x8298, 0x8299, 0x829A, 0x816F, 0x8162, 0x8170, 0x8160, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0x8140, 0x8142, 0x8175, 0x8176, 0x8141, 0x8145, 0x8392, 0x8340,
	0x8342, 0x8344, 0x8346, 0x8348, 0x8383, 0x8385, 0x8387, 0x8362,
	0x815C, 0x8341, 0x8343, 0x8345, 0x8347, 0x8349, 0x834A, 0x834C,
	0x834E, 0x8350, 0x8352, 0x8354, 0x8356, 0x8358, 0x835A, 0x835C,
	0x835E, 0x8360, 0x8363, 0x8365, 0x8367, 0x8369, 0x836A, 0x836B,
	0x836C, 0x836D, 0x836E, 0x8371, 0x8374, 0x8377, 0x837A, 0x837D,
	0x837E, 0x8380, 0x8381, 0x8382, 0x8384, 0x8386, 0x8388, 0x8389,
	0x838A, 0x838B, 0x838C, 0x838D, 0x838F, 0x8393, 0x814A, 0x814B,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

EngineState::EngineState(SegManager *segMan)
: _segMan(segMan), _dirseeker() {

	reset(false);
}

EngineState::~EngineState() {
	delete _msgState;
}

void EngineState::reset(bool isRestoring) {
#ifdef USE_OLD_MUSIC_FUNCTIONS
	sfx_init_flags = 0;
#endif

	if (!isRestoring) {
		_memorySegmentSize = 0;
		_soundCmd = 0;

		_fileHandles.resize(5);

		abortScriptProcessing = kAbortNone;
	}

	executionStackBase = 0;
	_executionStackPosChanged = false;
	stack_base = 0;
	stack_top = 0;

	restAdjust = 0;

	r_acc = NULL_REG;
	r_prev = NULL_REG;

	lastWaitTime = 0;

	gcCountDown = 0;

	_throttleCounter = 0;
	_throttleLastTime = 0;
	_throttleTrigger = false;

	scriptStepCounter = 0;
	scriptGCInterval = GC_INTERVAL;
}

void EngineState::wait(int16 ticks) {
	uint32 time = g_system->getMillis();
	r_acc = make_reg(0, ((long)time - (long)lastWaitTime) * 60 / 1000);
	lastWaitTime = time;

	ticks *= g_debug_sleeptime_factor;
	g_sci->sleep(ticks * 1000 / 60);
}

void EngineState::initGlobals() {
	Script *script_000 = _segMan->getScript(1);
	
	if (!script_000->_localsBlock)
		error("Script 0 has no locals block");

	variablesSegment[VAR_GLOBAL] = script_000->_localsSegment;
	variablesBase[VAR_GLOBAL] = variables[VAR_GLOBAL] = script_000->_localsBlock->_locals.begin();
	variablesMax[VAR_GLOBAL] = script_000->_localsBlock->_locals.size();
}

uint16 EngineState::currentRoomNumber() const {
	return variables[VAR_GLOBAL][13].toUint16();
}

void EngineState::setRoomNumber(uint16 roomNumber) {
	variables[VAR_GLOBAL][13] = make_reg(0, roomNumber);
}

void EngineState::shrinkStackToBase() {
	uint size = executionStackBase + 1;
	assert(_executionStack.size() >= size);
	Common::List<ExecStack>::iterator iter = _executionStack.begin();
	for (uint i = 0; i < size; ++i)
		++iter;
	_executionStack.erase(iter, _executionStack.end());
}

static kLanguage charToLanguage(const char c) {
	switch (c) {
	case 'F':
		return K_LANG_FRENCH;
	case 'S':
		return K_LANG_SPANISH;
	case 'I':
		return K_LANG_ITALIAN;
	case 'G':
		return K_LANG_GERMAN;
	case 'J':
	case 'j':
		return K_LANG_JAPANESE;
	case 'P':
		return K_LANG_PORTUGUESE;
	default:
		return K_LANG_NONE;
	}
}

Common::String SciEngine::getSciLanguageString(const char *str, kLanguage lang, kLanguage *lang2) const {
	kLanguage secondLang = K_LANG_NONE;

	const char *seeker = str;
	while (*seeker) {
		if ((*seeker == '%') || (*seeker == '#')) {
			secondLang = charToLanguage(*(seeker + 1));

			if (secondLang != K_LANG_NONE)
				break;
		}

		++seeker;
	}

	// Return the secondary language found in the string
	if (lang2)
		*lang2 = secondLang;

	if (secondLang == lang) {
		if (*(++seeker) == 'J') {
			// Japanese including Kanji, displayed with system font
			// Convert half-width characters to full-width equivalents
			Common::String fullWidth;
			byte c;

			while ((c = *(++seeker))) {
				uint16 mappedChar = s_halfWidthSJISMap[c];
				if (mappedChar) {
					fullWidth += mappedChar >> 8;
					fullWidth += mappedChar & 0xFF;
				} else {
					// Copy double-byte character
					char c2 = *(++seeker);
					if (!c2) {
						error("SJIS character %02X is missing second byte", c);
						break;
					}
					fullWidth += c;
					fullWidth += c2;
				}
			}

			return fullWidth;
		} else {
			return Common::String(seeker + 1);
		}
	}

	if (seeker)
		return Common::String(str, seeker - str);
	else
		return Common::String(str);
}

kLanguage SciEngine::getSciLanguage() {
	kLanguage lang = (kLanguage)_resMan->getAudioLanguage();
	if (lang != K_LANG_NONE)
		return lang;

	lang = K_LANG_ENGLISH;

	if (SELECTOR(printLang) != -1) {
		lang = (kLanguage)readSelectorValue(_gamestate->_segMan, _gameObj, SELECTOR(printLang));

		if ((getSciVersion() >= SCI_VERSION_1_1) || (lang == K_LANG_NONE)) {
			// If language is set to none, we use the language from the game detector.
			// SSCI reads this from resource.cfg (early games do not have a language
			// setting in resource.cfg, but instead have the secondary language number
			// hardcoded in the game script).
			// SCI1.1 games always use the language setting from the config file
			// (essentially disabling runtime language switching).
			// Note: only a limited number of multilanguage games have been tested
			// so far, so this information may not be 100% accurate.
			switch (getLanguage()) {
			case Common::FR_FRA:
				lang = K_LANG_FRENCH;
				break;
			case Common::ES_ESP:
				lang = K_LANG_SPANISH;
				break;
			case Common::IT_ITA:
				lang = K_LANG_ITALIAN;
				break;
			case Common::DE_DEU:
				lang = K_LANG_GERMAN;
				break;
			case Common::JA_JPN:
				lang = K_LANG_JAPANESE;
				break;
			case Common::PT_BRA:
				lang = K_LANG_PORTUGUESE;
				break;
			default:
				lang = K_LANG_ENGLISH;
			}
		}
	}

	return lang;
}

void SciEngine::setSciLanguage(kLanguage lang) {
	if (SELECTOR(printLang) != -1)
		writeSelectorValue(_gamestate->_segMan, _gameObj, SELECTOR(printLang), lang);
}

void SciEngine::setSciLanguage() {
	setSciLanguage(getSciLanguage());
}

Common::String SciEngine::strSplit(const char *str, const char *sep) {
	kLanguage lang = getSciLanguage();
	kLanguage subLang = K_LANG_NONE;

	if (SELECTOR(subtitleLang) != -1) {
		subLang = (kLanguage)readSelectorValue(_gamestate->_segMan, _gameObj, SELECTOR(subtitleLang));
	}

	kLanguage secondLang;
	Common::String retval = getSciLanguageString(str, lang, &secondLang);

	// Don't add subtitle when separator is not set, subtitle language is not set, or
	// string contains only one language
	if ((sep == NULL) || (subLang == K_LANG_NONE) || (secondLang == K_LANG_NONE))
		return retval;

	// Add subtitle, unless the subtitle language doesn't match the languages in the string
	if ((subLang == K_LANG_ENGLISH) || (subLang == secondLang)) {
		retval += sep;
		retval += getSciLanguageString(str, subLang);
	}

	return retval;
}

} // End of namespace Sci