/*
** config.cpp
**
** This file is part of mkxp.
**
** Copyright (C) 2013 Jonas Kulla <Nyocurio@gmail.com>
**
** mkxp 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.
**
** mkxp 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 mkxp.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "config.h"

#include <boost/program_options/options_description.hpp>
#include <boost/program_options/parsers.hpp>
#include <boost/program_options/variables_map.hpp>

#include <fstream>
#include <stdint.h>

#include "debugwriter.h"
#include "util.h"

#ifdef INI_ENCODING
extern "C" {
#include <libguess.h>
}
#include <iconv.h>
#include <errno.h>
#endif

/* http://stackoverflow.com/a/1031773 */
static bool validUtf8(const char *string)
{
	const uint8_t *bytes = (uint8_t*) string;

	while(*bytes)
	{
		if( (/* ASCII
			  * use bytes[0] <= 0x7F to allow ASCII control characters */
				bytes[0] == 0x09 ||
				bytes[0] == 0x0A ||
				bytes[0] == 0x0D ||
				(0x20 <= bytes[0] && bytes[0] <= 0x7E)
			)
		) {
			bytes += 1;
			continue;
		}

		if( (/* non-overlong 2-byte */
				(0xC2 <= bytes[0] && bytes[0] <= 0xDF) &&
				(0x80 <= bytes[1] && bytes[1] <= 0xBF)
			)
		) {
			bytes += 2;
			continue;
		}

		if( (/* excluding overlongs */
				bytes[0] == 0xE0 &&
				(0xA0 <= bytes[1] && bytes[1] <= 0xBF) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF)
			) ||
			(/* straight 3-byte */
				((0xE1 <= bytes[0] && bytes[0] <= 0xEC) ||
					bytes[0] == 0xEE ||
					bytes[0] == 0xEF) &&
				(0x80 <= bytes[1] && bytes[1] <= 0xBF) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF)
			) ||
			(/* excluding surrogates */
				bytes[0] == 0xED &&
				(0x80 <= bytes[1] && bytes[1] <= 0x9F) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF)
			)
		) {
			bytes += 3;
			continue;
		}

		if( (/* planes 1-3 */
				bytes[0] == 0xF0 &&
				(0x90 <= bytes[1] && bytes[1] <= 0xBF) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF) &&
				(0x80 <= bytes[3] && bytes[3] <= 0xBF)
			) ||
			(/* planes 4-15 */
				(0xF1 <= bytes[0] && bytes[0] <= 0xF3) &&
				(0x80 <= bytes[1] && bytes[1] <= 0xBF) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF) &&
				(0x80 <= bytes[3] && bytes[3] <= 0xBF)
			) ||
			(/* plane 16 */
				bytes[0] == 0xF4 &&
				(0x80 <= bytes[1] && bytes[1] <= 0x8F) &&
				(0x80 <= bytes[2] && bytes[2] <= 0xBF) &&
				(0x80 <= bytes[3] && bytes[3] <= 0xBF)
			)
		) {
			bytes += 4;
			continue;
		}

		return false;
	}

	return true;
}

typedef std::vector<std::string> StringVec;
namespace po = boost::program_options;

Config::Config()
    : debugMode(false),
      winResizable(false),
      fullscreen(false),
      fixedAspectRatio(true),
      smoothScaling(false),
      vsync(false),
      defScreenW(DEF_SCREEN_W),
      defScreenH(DEF_SCREEN_H),
      fixedFramerate(0),
      frameSkip(true),
      solidFonts(false),
      gameFolder("."),
      anyAltToggleFS(false),
      allowSymlinks(false),
      pathCache(true),
      useScriptNames(false)
{
	midi.chorus = false;
	midi.reverb = false;
	SE.sourceCount = 6;
}

void Config::read(int argc, char *argv[])
{
#define PO_DESC_ALL \
	PO_DESC(debugMode, bool) \
	PO_DESC(winResizable, bool) \
	PO_DESC(fullscreen, bool) \
	PO_DESC(fixedAspectRatio, bool) \
	PO_DESC(smoothScaling, bool) \
	PO_DESC(vsync, bool) \
	PO_DESC(defScreenW, int) \
	PO_DESC(defScreenH, int) \
	PO_DESC(fixedFramerate, int) \
	PO_DESC(frameSkip, bool) \
	PO_DESC(solidFonts, bool) \
	PO_DESC(gameFolder, std::string) \
	PO_DESC(anyAltToggleFS, bool) \
	PO_DESC(allowSymlinks, bool) \
	PO_DESC(iconPath, std::string) \
	PO_DESC(titleLanguage, std::string) \
	PO_DESC(midi.soundFont, std::string) \
	PO_DESC(midi.chorus, bool) \
	PO_DESC(midi.reverb, bool) \
	PO_DESC(SE.sourceCount, int) \
	PO_DESC(customScript, std::string) \
	PO_DESC(pathCache, bool) \
	PO_DESC(useScriptNames, bool)

// Not gonna take your shit boost
#define GUARD_ALL( exp ) try { exp } catch(...) {}

#define PO_DESC(key, type) (#key, po::value< type >()->default_value(key))

	po::options_description podesc;
	podesc.add_options()
	        PO_DESC_ALL
	        ("preloadScript", po::value<StringVec>()->composing())
	        ("RTP", po::value<StringVec>()->composing())
	        ("fontSub", po::value<StringVec>()->composing())
	        ("rubyLoadpath", po::value<StringVec>()->composing())
	        ;

	po::variables_map vm;

	/* Parse command line options */
	po::parsed_options cmdPo =
	    po::command_line_parser(argc, argv).options(podesc)
	                                       .allow_unregistered()
	                                       .run();

	GUARD_ALL( po::store(cmdPo, vm); )

	/* Parse configuration file (mkxp.conf) */
	std::ifstream confFile;
	confFile.open("mkxp.conf");

	if (confFile)
	{
		GUARD_ALL( po::store(po::parse_config_file(confFile, podesc, true), vm); )
	}

	confFile.close();

	po::notify(vm);

#undef PO_DESC
#define PO_DESC(key, type) GUARD_ALL( key = vm[#key].as< type >(); )

	PO_DESC_ALL;

	GUARD_ALL( preloadScripts = vm["preloadScript"].as<StringVec>(); );

	GUARD_ALL( rtps = vm["RTP"].as<StringVec>(); );

	GUARD_ALL( fontSubs = vm["fontSub"].as<StringVec>(); );

	GUARD_ALL( rubyLoadpaths = vm["rubyLoadpath"].as<StringVec>(); )

#undef PO_DESC
#undef PO_DESC_ALL

	SE.sourceCount = clamp(SE.sourceCount, 1, 64);
}

static std::string baseName(const std::string &path)
{
	size_t pos = path.find_last_of("/\\");

	if (pos == path.npos)
		return path;

	return path.substr(pos + 1);
}

void Config::readGameINI()
{
	if (!customScript.empty())
	{
		game.title = baseName(customScript);
		return;
	}

	po::options_description podesc;
	podesc.add_options()
	        ("Game.Title", po::value<std::string>())
	        ("Game.Scripts", po::value<std::string>())
	        ;

	std::string iniPath = gameFolder + "/Game.ini";

	std::ifstream iniFile;
	iniFile.open((iniPath).c_str());

	po::variables_map vm;
	GUARD_ALL( po::store(po::parse_config_file(iniFile, podesc, true), vm); )
	po::notify(vm);

	iniFile.close();

	GUARD_ALL( game.title = vm["Game.Title"].as<std::string>(); );
	GUARD_ALL( game.scripts = vm["Game.Scripts"].as<std::string>(); );

	strReplace(game.scripts, '\\', '/');

#ifdef INI_ENCODING
	/* Can add more later */
	const char *languages[] =
	{
		titleLanguage.c_str(),
		GUESS_REGION_JP, /* Japanese */
		GUESS_REGION_KR, /* Korean */
		GUESS_REGION_CN, /* Chinese */
		0
	};

	bool convSuccess = true;

	/* Verify that the game title is UTF-8, and if not,
	 * try to determine the encoding and convert to UTF-8 */
	if (!validUtf8(game.title.c_str()))
	{
		const char *encoding = 0;
		convSuccess = false;

		for (size_t i = 0; languages[i]; ++i)
		{
			encoding = libguess_determine_encoding(game.title.c_str(),
			                                       game.title.size(),
			                                       languages[i]);
			if (encoding)
				break;
		}

		if (encoding)
		{
			iconv_t cd = iconv_open("UTF-8", encoding);

			size_t inLen = game.title.size();
			size_t outLen = inLen * 4;
			std::string buf(outLen, '\0');
			char *inPtr = const_cast<char*>(game.title.c_str());
			char *outPtr = const_cast<char*>(buf.c_str());

			errno = 0;
			size_t result = iconv(cd, &inPtr, &inLen, &outPtr, &outLen);

			iconv_close(cd);

			if (result != (size_t) -1 && errno == 0)
			{
				buf.resize(buf.size()-outLen);
				game.title = buf;
				convSuccess = true;
			}
		}
	}

	if (!convSuccess)
		game.title.clear();
#else
	if (!validUtf8(game.title.c_str()))
		game.title.clear();
#endif

	if (game.title.empty())
		game.title = baseName(gameFolder);
}