/*
 * qrencode - QR Code encoder
 *
 * Input data splitter.
 * Copyright (C) 2006-2011 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * The following data / specifications are taken from
 * "Two dimensional symbol -- QR-code -- Basic Specification" (JIS X0510:2004)
 *  or
 * "Automatic identification and data capture techniques --
 *  QR Code 2005 bar code symbology specification" (ISO/IEC 18004:2006)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#if HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "qrencode.h"
#include "qrinput.h"
#include "qrspec.h"
#include "split.h"

#define isdigit(__c__) ((unsigned char)((signed char)(__c__) - '0') < 10)
#define isalnum(__c__) (QRinput_lookAnTable(__c__) >= 0)

#if !HAVE_STRDUP
#undef strdup
char *strdup(const char *s)
{
  size_t len = strlen(s) + 1;
  void *new = malloc(len);
  if(new == NULL) return NULL;
  return (char *)memcpy(new, s, len);
}
#endif

static QRencodeMode Split_identifyMode(const char *string, QRencodeMode hint)
{
  unsigned char c, d;
  unsigned int word;

  c = string[0];

  if(c == '\0') return QR_MODE_NUL;
  if(isdigit(c)) {
    return QR_MODE_NUM;
  } else if(isalnum(c)) {
    return QR_MODE_AN;
  } else if(hint == QR_MODE_KANJI) {
    d = string[1];
    if(d != '\0') {
      word = ((unsigned int)c << 8) | d;
      if((word >= 0x8140 && word <= 0x9ffc) || (word >= 0xe040 && word <= 0xebbf)) {
        return QR_MODE_KANJI;
      }
    }
  }

  return QR_MODE_8;
}

static int Split_eatNum(const char *string, QRinput *input, QRencodeMode hint);
static int Split_eatAn(const char *string, QRinput *input, QRencodeMode hint);
static int Split_eat8(const char *string, QRinput *input, QRencodeMode hint);
static int Split_eatKanji(const char *string, QRinput *input, QRencodeMode hint);

static int Split_eatNum(const char *string, QRinput *input,QRencodeMode hint)
{
  const char *p;
  int ret;
  int run;
  int dif;
  int ln;
  QRencodeMode mode;

  ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

  p = string;
  while(isdigit(*p)) {
    p++;
  }
  run = p - string;
  mode = Split_identifyMode(p, hint);
  if(mode == QR_MODE_8) {
    dif = QRinput_estimateBitsModeNum(run) + 4 + ln
        + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
        - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;
    if(dif > 0) {
      return Split_eat8(string, input, hint);
    }
  }
  if(mode == QR_MODE_AN) {
    dif = QRinput_estimateBitsModeNum(run) + 4 + ln
        + QRinput_estimateBitsModeAn(1) /* + 4 + la */
        - QRinput_estimateBitsModeAn(run + 1) /* - 4 - la */;
    if(dif > 0) {
      return Split_eatAn(string, input, hint);
    }
  }

  ret = QRinput_append(input, QR_MODE_NUM, run, (unsigned char *)string);
  if(ret < 0) return -1;

  return run;
}

static int Split_eatAn(const char *string, QRinput *input, QRencodeMode hint)
{
  const char *p, *q;
  int ret;
  int run;
  int dif;
  int la, ln;

  la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
  ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

  p = string;
  while(isalnum(*p)) {
    if(isdigit(*p)) {
      q = p;
      while(isdigit(*q)) {
        q++;
      }
      dif = QRinput_estimateBitsModeAn(p - string) /* + 4 + la */
          + QRinput_estimateBitsModeNum(q - p) + 4 + ln
          - QRinput_estimateBitsModeAn(q - string) /* - 4 - la */;
      if(dif < 0) {
        break;
      } else {
        p = q;
      }
    } else {
      p++;
    }
  }

  run = p - string;

  if(*p && !isalnum(*p)) {
    dif = QRinput_estimateBitsModeAn(run) + 4 + la
        + QRinput_estimateBitsMode8(1) /* + 4 + l8 */
        - QRinput_estimateBitsMode8(run + 1) /* - 4 - l8 */;
    if(dif > 0) {
      return Split_eat8(string, input, hint);
    }
  }

  ret = QRinput_append(input, QR_MODE_AN, run, (unsigned char *)string);
  if(ret < 0) return -1;

  return run;
}

static int Split_eatKanji(const char *string, QRinput *input, QRencodeMode hint)
{
  const char *p;
  int ret;
  int run;

  p = string;
  while(Split_identifyMode(p, hint) == QR_MODE_KANJI) {
    p += 2;
  }
  run = p - string;
  ret = QRinput_append(input, QR_MODE_KANJI, run, (unsigned char *)string);
  if(ret < 0) return -1;

  return run;
}

static int Split_eat8(const char *string, QRinput *input, QRencodeMode hint)
{
  const char *p, *q;
  QRencodeMode mode;
  int ret;
  int run;
  int dif;
  int la, ln;

  la = QRspec_lengthIndicator(QR_MODE_AN, input->version);
  ln = QRspec_lengthIndicator(QR_MODE_NUM, input->version);

  p = string + 1;
  while(*p != '\0') {
    mode = Split_identifyMode(p, hint);
    if(mode == QR_MODE_KANJI) {
      break;
    }
    if(mode == QR_MODE_NUM) {
      q = p;
      while(isdigit(*q)) {
        q++;
      }
      dif = QRinput_estimateBitsMode8(p - string) /* + 4 + l8 */
          + QRinput_estimateBitsModeNum(q - p) + 4 + ln
          - QRinput_estimateBitsMode8(q - string) /* - 4 - l8 */;
      if(dif < 0) {
        break;
      } else {
        p = q;
      }
    } else if(mode == QR_MODE_AN) {
      q = p;
      while(isalnum(*q)) {
        q++;
      }
      dif = QRinput_estimateBitsMode8(p - string) /* + 4 + l8 */
          + QRinput_estimateBitsModeAn(q - p) + 4 + la
          - QRinput_estimateBitsMode8(q - string) /* - 4 - l8 */;
      if(dif < 0) {
        break;
      } else {
        p = q;
      }
    } else {
      p++;
    }
  }

  run = p - string;
  ret = QRinput_append(input, QR_MODE_8, run, (unsigned char *)string);
  if(ret < 0) return -1;

  return run;
}

static int Split_splitString(const char *string, QRinput *input,
                             QRencodeMode hint)
{
  int length;
  QRencodeMode mode;

  if(*string == '\0') return 0;

  mode = Split_identifyMode(string, hint);
  if(mode == QR_MODE_NUM) {
    length = Split_eatNum(string, input, hint);
  } else if(mode == QR_MODE_AN) {
    length = Split_eatAn(string, input, hint);
  } else if(mode == QR_MODE_KANJI && hint == QR_MODE_KANJI) {
    length = Split_eatKanji(string, input, hint);
  } else {
    length = Split_eat8(string, input, hint);
  }
  if(length == 0) return 0;
  if(length < 0) return -1;
  return Split_splitString(&string[length], input, hint);
}

static char *dupAndToUpper(const char *str, QRencodeMode hint)
{
  char *newstr, *p;
  QRencodeMode mode;

  newstr = strdup(str);
  if(newstr == NULL) return NULL;

  p = newstr;
  while(*p != '\0') {
    mode = Split_identifyMode(p, hint);
    if(mode == QR_MODE_KANJI) {
      p += 2;
    } else {
      if (*p >= 'a' && *p <= 'z') {
        *p = (char)((int)*p - 32);
      }
      p++;
    }
  }

  return newstr;
}

int Split_splitStringToQRinput(const char *string, QRinput *input,
                               QRencodeMode hint, int casesensitive)
{
  char *newstr;
  int ret;

  if(string == NULL || *string == '\0') {
    errno = EINVAL;
    return -1;
  }
  if(!casesensitive) {
    newstr = dupAndToUpper(string, hint);
    if(newstr == NULL) return -1;
    ret = Split_splitString(newstr, input, hint);
    free(newstr);
  } else {
    ret = Split_splitString(string, input, hint);
  }

  return ret;
}
