/*Copyright (C) 2010  Armin Preiml

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 <iostream>
#include <iconv.h>
#include <errno.h>

string convertToUTF8(string input)
{
    string output = "";

    //create convert description
    //FIXME: I guess it's ISO-8859-1 encoded
    iconv_t cd = iconv_open("UTF-8", "ISO-8859-1");

    if (cd == (iconv_t)-1)  //error handling
    {
    cerr << "Convert to UTF-8 failed: ";

    switch (errno)      //detailed error messages (maybe it contains too much detail :)
    {
        case EMFILE:
        cerr << "{OPEN_MAX} files descriptors are currently open in the calling process.\n";
        case ENFILE:
        cerr << "Too many files are currently open in the system. \n";
        case ENOMEM:
        cerr << "Insufficient storage space is available. \n";
        case EINVAL:
        cerr << "The conversion specified by fromcode and tocode is not supported by the implementation. \n";

        default:
        cerr << "WTF?\n";
    }

    }
    else
    {
    size_t inputSize = input.size();

    if (inputSize)  //input is not empty
    {
        //convert function doesn't accept const char *, therefore copy content into an char *
        char * inputBufferStart = new char[inputSize];
        char *inputBuffer = inputBufferStart;
        strncpy(inputBuffer, input.c_str(), inputSize);

        size_t inputBytesLeft = inputSize;  //bytes to convert

        //FIXME: can't determine exact size_t
        //In the german version of morrowind characters like äöü aren't counted by strlen
        size_t outputSize = inputSize*2;
        size_t outputBytesLeft = outputSize;

        char *outputBufferStart = new char[outputSize];
        char *outputBuffer = outputBufferStart;

        if (iconv(cd, &inputBuffer, &inputBytesLeft, &outputBuffer, &outputBytesLeft) == (size_t)-1)
        {
        switch (errno) {

            case EILSEQ:
            cout << "Invalid multibyte sequence.\n";
            break;
            case EINVAL:
            cout << "Incomplete multibyte sequence.\n";
            break;
            case E2BIG:
            cout << "No more room.\n";
            break;
            default:
            cout << "DUNNO\n";
        }

        }
        else
        {
        //outputBytesLeft was decreased for every byte which was written to the buffer
        output = string(outputBufferStart, outputSize - outputBytesLeft);
        }

        delete [] inputBufferStart;
        delete [] outputBufferStart;
    }
    }

    iconv_close (cd);

    return output;
}