/*
 * 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; version 2 of the License.
 *
 * 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 St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Authors: Manuel Mausz (manuel@mausz.at)
 *          Christian Raschko (c.raschko@netcore.at)
 */

//Header
#include "base64.h"

//Libraries
#include <ctype.h>

static const wxString base64_chars =
  _T("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
  _T("abcdefghijklmnopqrstuvwxyz")
  _T("0123456789+/");


static inline bool is_base64(unsigned char c)
{
  return (isalnum(c) || (c == '+') || (c == '/'));
}

wxString Base64Encode(char const* bytes_to_encode, unsigned int in_len)
{
  wxString ret;
  int i = 0;
  int j = 0;
  unsigned char char_array_3[3];
  unsigned char char_array_4[4];

  while (in_len--)
  {
    char_array_3[i++] = *(bytes_to_encode++);
    if (i == 3) {
      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
      char_array_4[3] = char_array_3[2] & 0x3f;

      for(i = 0; i < 4; i++)
        ret += base64_chars[char_array_4[i]];
      i = 0;
    }
  }

  if (i)
  {
    for(j = i; j < 3; j++)
      char_array_3[j] = '\0';

    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
    char_array_4[3] = char_array_3[2] & 0x3f;

    for (j = 0; j < i + 1; j++)
      ret += base64_chars[char_array_4[j]];

    while(i++ < 3)
      ret += '=';
  }

  return ret;

}

wxString Base64Decode(wxString const& encoded_string)
{
  int in_len = encoded_string.size();
  int i = 0;
  int j = 0;
  int in_ = 0;
  unsigned char char_array_4[4], char_array_3[3];
  wxString ret;

  while (in_len-- && encoded_string[in_] != '=' && is_base64(encoded_string[in_]))
  {
    char_array_4[i++] = encoded_string[in_];
    in_++;
    if (i ==4)
    {
      for (i = 0; i < 4; i++)
        char_array_4[i] = base64_chars.find(char_array_4[i]);

      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      for (i = 0; i < 3; i++)
        ret += char_array_3[i];
      i = 0;
    }
  }

  if (i)
  {
    for (j = i; j < 4; j++)
      char_array_4[j] = 0;

    for (j = 0; j < 4; j++)
      char_array_4[j] = base64_chars.find(char_array_4[j]);

    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

    for (j = 0; j < i - 1; j++)
      ret += char_array_3[j];
  }

  return ret;
}