/*
    Brainuino Aleph

    Copyright (C) 2012  Dmitry Mikhirev

    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 "utf8.h"
#include <string.h>

utf8::utf8 (char* input)
{
  bytes = strlen(input);
  string = strdup(input);
  chars = 0;
  for (_index = 0; _index < bytes; _index++) {
    if ((string[_index] & 0x80) == 0x00) {
      chars++;
    } else if ((string[_index] & 0x20) == 0x00) {
      chars++;
      _index ++;
    } else if ((string[_index] & 0x10) == 0x00) {
      chars++;
      _index += 2;
    } else if ((string[_index] & 0x08) == 0x00) {
      chars++;
      _index += 3;
    }
  }
  _index = 0;
}

utf8::~utf8 ()
{
  free(string);
}

int32_t utf8::get()
{
  int32_t code;
  if ((string[_index] & 0x80) == 0) {
    code = int32_t(string[_index]);
    _index++;
  } else if ((string[_index] & 0x20) == 0) {
    code = int32_t(string[_index] & 0x1f) << 6 | int32_t(string[_index+1] & 0x3f);
    _index += 2;
  } else if ((string[_index] & 0x10) == 0) {
    code = int32_t(string[_index] & 0xf) << 12 | int32_t(string[_index+1] & 0x3f) << 6 | int32_t(string[_index+2] & 0x3f);
    _index += 3;
  } else if ((string[_index] & 0x8) == 0) {
    code = int32_t(string[_index] & 0x7) << 18 | int32_t(string[_index+1] & 0x3f) << 12 | int32_t(string[_index+2] & 0x3f) << 6 | int32_t(string[_index+3] & 0x3f);
  }
  if (_index >= bytes) _index = 0;
  return code;
}