/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012-2016 Symless 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 LICENSE 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 "arch/IArchString.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 = nullptr, IArchString::EWideCharEncoding encoding = IArchString::kPlatformDetermined);

    //@}

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, 
                            IArchString::EWideCharEncoding encoding = IArchString::kPlatformDetermined);

    // 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;
};
