/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012 Synergy Si Ltd.
 * Copyright (C) 2002 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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/>.
 */

#pragma once

#include "base/String.h"
#include "common/basic_types.h"

//! Unicode utility functions
/*!
This class provides functions for converting between various Unicode
encodings and the current locale encoding.
*/
class Unicode {
public:
	//! @name accessors
	//@{

	//! Test UTF-8 string for validity
	/*!
	Returns true iff the string contains a valid sequence of UTF-8
	encoded characters.
	*/
	static bool			isUTF8(const String&);

	//! Convert from UTF-8 to UCS-2 encoding
	/*!
	Convert from UTF-8 to UCS-2.  If errors is not NULL then *errors
	is set to true iff any character could not be encoded in UCS-2.
	Decoding errors do not set *errors.
	*/
	static String		UTF8ToUCS2(const String&, bool* errors = NULL);

	//! Convert from UTF-8 to UCS-4 encoding
	/*!
	Convert from UTF-8 to UCS-4.  If errors is not NULL then *errors
	is set to true iff any character could not be encoded in UCS-4.
	Decoding errors do not set *errors.
	*/
	static String		UTF8ToUCS4(const String&, bool* errors = NULL);

	//! Convert from UTF-8 to UTF-16 encoding
	/*!
	Convert from UTF-8 to UTF-16.  If errors is not NULL then *errors
	is set to true iff any character could not be encoded in UTF-16.
	Decoding errors do not set *errors.
	*/
	static String		UTF8ToUTF16(const String&, bool* errors = NULL);

	//! Convert from UTF-8 to UTF-32 encoding
	/*!
	Convert from UTF-8 to UTF-32.  If errors is not NULL then *errors
	is set to true iff any character could not be encoded in UTF-32.
	Decoding errors do not set *errors.
	*/
	static String		UTF8ToUTF32(const String&, bool* errors = NULL);

	//! Convert from UTF-8 to the current locale encoding
	/*!
	Convert from UTF-8 to the current locale encoding.  If errors is not
	NULL then *errors is set to true iff any character could not be encoded.
	Decoding errors do not set *errors.
	*/
	static String		UTF8ToText(const String&, bool* errors = NULL);

	//! Convert from UCS-2 to UTF-8
	/*!
	Convert from UCS-2 to UTF-8.  If errors is not NULL then *errors is
	set to true iff any character could not be decoded.
	*/
	static String		UCS2ToUTF8(const String&, bool* errors = NULL);

	//! Convert from UCS-4 to UTF-8
	/*!
	Convert from UCS-4 to UTF-8.  If errors is not NULL then *errors is
	set to true iff any character could not be decoded.
	*/
	static String		UCS4ToUTF8(const String&, bool* errors = NULL);

	//! Convert from UTF-16 to UTF-8
	/*!
	Convert from UTF-16 to UTF-8.  If errors is not NULL then *errors is
	set to true iff any character could not be decoded.
	*/
	static String		UTF16ToUTF8(const String&, bool* errors = NULL);

	//! Convert from UTF-32 to UTF-8
	/*!
	Convert from UTF-32 to UTF-8.  If errors is not NULL then *errors is
	set to true iff any character could not be decoded.
	*/
	static String		UTF32ToUTF8(const String&, bool* errors = NULL);

	//! Convert from the current locale encoding to UTF-8
	/*!
	Convert from the current locale encoding to UTF-8.  If errors is not
	NULL then *errors is set to true iff any character could not be decoded.
	*/
	static String		textToUTF8(const String&, bool* errors = NULL);

	//@}

private:
	// convert UTF8 to wchar_t string (using whatever encoding is native
	// to the platform).  caller must delete[] the returned string.  the
	// string is *not* nul terminated;  the length (in characters) is
	// returned in size.
	static wchar_t*		UTF8ToWideChar(const String&,
							UInt32& size, bool* errors);

	// convert nul terminated wchar_t string (in platform's native
	// encoding) to UTF8.
	static String		wideCharToUTF8(const wchar_t*,
							UInt32 size, bool* errors);

	// internal conversion to UTF8
	static String		doUCS2ToUTF8(const UInt8* src, UInt32 n, bool* errors);
	static String		doUCS4ToUTF8(const UInt8* src, UInt32 n, bool* errors);
	static String		doUTF16ToUTF8(const UInt8* src, UInt32 n, bool* errors);
	static String		doUTF32ToUTF8(const UInt8* src, UInt32 n, bool* errors);

	// convert characters to/from UTF8
	static UInt32		fromUTF8(const UInt8*& src, UInt32& size);
	static void			toUTF8(String& dst, UInt32 c, bool* errors);

private:
	static UInt32		s_invalid;
	static UInt32		s_replacement;
};
