/*
 * qrencode - QR Code encoder
 *
 * Input data chunk class
 * Copyright (C) 2006-2011 Kentaro Fukuchi <kentaro@fukuchi.org>
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "qrencode.h"
#include "qrspec.h"
#include "mqrspec.h"
#include "bitstream.h"
#include "qrinput.h"

/******************************************************************************
 * Utilities
 *****************************************************************************/
int QRinput_isSplittableMode(QRencodeMode mode)
{
  return (mode >= QR_MODE_NUM && mode <= QR_MODE_KANJI);
}

/******************************************************************************
 * Entry of input data
 *****************************************************************************/

static QRinput_List *QRinput_List_newEntry(QRencodeMode mode, int size, const unsigned char *data)
{
  QRinput_List *entry;

  if(QRinput_check(mode, size, data)) {
    errno = EINVAL;
    return NULL;
  }

  entry = (QRinput_List *)malloc(sizeof(QRinput_List));
  if(entry == NULL) return NULL;

  entry->mode = mode;
  entry->size = size;
  if(size > 0) {
    entry->data = (unsigned char *)malloc(size);
    if(entry->data == NULL) {
      free(entry);
      return NULL;
    }
    memcpy(entry->data, data, size);
  }
  entry->bstream = NULL;
  entry->next = NULL;

  return entry;
}

static void QRinput_List_freeEntry(QRinput_List *entry)
{
  if(entry != NULL) {
    free(entry->data);
    BitStream_free(entry->bstream);
    free(entry);
  }
}

static QRinput_List *QRinput_List_dup(QRinput_List *entry)
{
  QRinput_List *n;

  n = (QRinput_List *)malloc(sizeof(QRinput_List));
  if(n == NULL) return NULL;

  n->mode = entry->mode;
  n->size = entry->size;
  n->data = (unsigned char *)malloc(n->size);
  if(n->data == NULL) {
    free(n);
    return NULL;
  }
  memcpy(n->data, entry->data, entry->size);
  n->bstream = NULL;
  n->next = NULL;

  return n;
}

/******************************************************************************
 * Input Data
 *****************************************************************************/

QRinput *QRinput_new(void)
{
  return QRinput_new2(0, QR_ECLEVEL_L);
}

QRinput *QRinput_new2(int version, QRecLevel level)
{
  QRinput *input;

  if(version < 0 || version > QRSPEC_VERSION_MAX || level > QR_ECLEVEL_H) {
    errno = EINVAL;
    return NULL;
  }

  input = (QRinput *)malloc(sizeof(QRinput));
  if(input == NULL) return NULL;

  input->head = NULL;
  input->tail = NULL;
  input->version = version;
  input->level = level;
  input->mqr = 0;
  input->fnc1 = 0;

  return input;
}

QRinput *QRinput_newMQR(int version, QRecLevel level)
{
  QRinput *input;

  if(version <= 0 || version > MQRSPEC_VERSION_MAX) goto INVALID;
  if((MQRspec_getECCLength(version, level) == 0)) goto INVALID;

  input = QRinput_new2(version, level);
  if(input == NULL) return NULL;

  input->mqr = 1;

  return input;

INVALID:
  errno = EINVAL;
  return NULL;
}

int QRinput_getVersion(QRinput *input)
{
  return input->version;
}

int QRinput_setVersion(QRinput *input, int version)
{
  if(input->mqr || version < 0 || version > QRSPEC_VERSION_MAX) {
    errno = EINVAL;
    return -1;
  }

  input->version = version;

  return 0;
}

QRecLevel QRinput_getErrorCorrectionLevel(QRinput *input)
{
  return input->level;
}

int QRinput_setErrorCorrectionLevel(QRinput *input, QRecLevel level)
{
  if(input->mqr || level > QR_ECLEVEL_H) {
    errno = EINVAL;
    return -1;
  }

  input->level = level;

  return 0;
}

int QRinput_setVersionAndErrorCorrectionLevel(QRinput *input, int version, QRecLevel level)
{
  if(input->mqr) {
    if(version <= 0 || version > MQRSPEC_VERSION_MAX) goto INVALID;
    if((MQRspec_getECCLength(version, level) == 0)) goto INVALID;
  } else {
    if(version < 0 || version > QRSPEC_VERSION_MAX) goto INVALID;
    if(level > QR_ECLEVEL_H) goto INVALID;
  }

  input->version = version;
  input->level = level;

  return 0;

INVALID:
  errno = EINVAL;
  return -1;
}

static void QRinput_appendEntry(QRinput *input, QRinput_List *entry)
{
  if(input->tail == NULL) {
    input->head = entry;
    input->tail = entry;
  } else {
    input->tail->next = entry;
    input->tail = entry;
  }
  entry->next = NULL;
}

int QRinput_append(QRinput *input, QRencodeMode mode, int size, const unsigned char *data)
{
  QRinput_List *entry;

  entry = QRinput_List_newEntry(mode, size, data);
  if(entry == NULL) {
    return -1;
  }

  QRinput_appendEntry(input, entry);

  return 0;
}

/**
 * Insert a structured-append header to the head of the input data.
 * @param input input data.
 * @param size number of structured symbols.
 * @param index index number of the symbol. (1 <= index <= size)
 * @param parity parity among input data. (NOTE: each symbol of a set of structured symbols has the same parity data)
 * @retval 0 success.
 * @retval -1 error occurred and errno is set to indeicate the error. See Execptions for the details.
 * @throw EINVAL invalid parameter.
 * @throw ENOMEM unable to allocate memory.
 */
__STATIC int QRinput_insertStructuredAppendHeader(QRinput *input, int size, int index, unsigned char parity)
{
  QRinput_List *entry;
  unsigned char buf[3];

  if(size > MAX_STRUCTURED_SYMBOLS) {
    errno = EINVAL;
    return -1;
  }
  if(index <= 0 || index > MAX_STRUCTURED_SYMBOLS) {
    errno = EINVAL;
    return -1;
  }

  buf[0] = (unsigned char)size;
  buf[1] = (unsigned char)index;
  buf[2] = parity;
  entry = QRinput_List_newEntry(QR_MODE_STRUCTURE, 3, buf);
  if(entry == NULL) {
    return -1;
  }

  entry->next = input->head;
  input->head = entry;

  return 0;
}

int QRinput_appendECIheader(QRinput *input, unsigned int ecinum)
{
  unsigned char data[4];

  if(ecinum > 999999) {
    errno = EINVAL;
    return -1;
  }

  /* We manually create byte array of ecinum because
   (unsigned char *)&ecinum may cause bus error on some architectures, */
  data[0] = ecinum & 0xff;
  data[1] = (ecinum >>  8) & 0xff;
  data[2] = (ecinum >> 16) & 0xff;
  data[3] = (ecinum >> 24) & 0xff;
  return QRinput_append(input, QR_MODE_ECI, 4, data);
}

void QRinput_free(QRinput *input)
{
  QRinput_List *list, *next;

  if(input != NULL) {
    list = input->head;
    while(list != NULL) {
      next = list->next;
      QRinput_List_freeEntry(list);
      list = next;
    }
    free(input);
  }
}

static unsigned char QRinput_calcParity(QRinput *input)
{
  unsigned char parity = 0;
  QRinput_List *list;
  int i;

  list = input->head;
  while(list != NULL) {
    if(list->mode != QR_MODE_STRUCTURE) {
      for(i=list->size-1; i>=0; i--) {
        parity ^= list->data[i];
      }
    }
    list = list->next;
  }

  return parity;
}

QRinput *QRinput_dup(QRinput *input)
{
  QRinput *n;
  QRinput_List *list, *e;

  if(input->mqr) {
    n = QRinput_newMQR(input->version, input->level);
  } else {
    n = QRinput_new2(input->version, input->level);
  }
  if(n == NULL) return NULL;

  list = input->head;
  while(list != NULL) {
    e = QRinput_List_dup(list);
    if(e == NULL) {
      QRinput_free(n);
      return NULL;
    }
    QRinput_appendEntry(n, e);
    list = list->next;
  }

  return n;
}

/******************************************************************************
 * Numeric data
 *****************************************************************************/

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeNum(int size, const char *data)
{
  int i;

  for(i=0; i<size; i++) {
    if(data[i] < '0' || data[i] > '9')
      return -1;
  }

  return 0;
}

/**
 * Estimates the length of the encoded bit stream of numeric data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeNum(int size)
{
  int w;
  int bits;

  w = size / 3;
  bits = w * 10;
  switch(size - w * 3) {
  case 1:
    bits += 4;
    break;
  case 2:
    bits += 7;
    break;
  default:
    break;
  }

  return bits;
}

/**
 * Convert the number data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_encodeModeNum(QRinput_List *entry, int version, int mqr)
{
  int words, i, ret;
  unsigned int val;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  if(mqr) {
    if(version > 1) {
      ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_NUM);
      if(ret < 0) goto ABORT;
    }
    ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_NUM, version), entry->size);
    if(ret < 0) goto ABORT;
  } else {
    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_NUM);
    if(ret < 0) goto ABORT;

    ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_NUM, version), entry->size);
    if(ret < 0) goto ABORT;
  }

  words = entry->size / 3;
  for(i=0; i<words; i++) {
    val  = (entry->data[i*3  ] - '0') * 100;
    val += (entry->data[i*3+1] - '0') * 10;
    val += (entry->data[i*3+2] - '0');

    ret = BitStream_appendNum(entry->bstream, 10, val);
    if(ret < 0) goto ABORT;
  }

  if(entry->size - words * 3 == 1) {
    val = entry->data[words*3] - '0';
    ret = BitStream_appendNum(entry->bstream, 4, val);
    if(ret < 0) goto ABORT;
  } else if(entry->size - words * 3 == 2) {
    val  = (entry->data[words*3  ] - '0') * 10;
    val += (entry->data[words*3+1] - '0');
    BitStream_appendNum(entry->bstream, 7, val);
    if(ret < 0) goto ABORT;
  }

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * Alphabet-numeric data
 *****************************************************************************/

const signed char QRinput_anTable[128] = {
  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  36, -1, -1, -1, 37, 38, -1, -1, -1, -1, 39, 40, -1, 41, 42, 43,
  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 44, -1, -1, -1, -1, -1,
  -1, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
  25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, -1, -1, -1, -1, -1,
  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1
};

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeAn(int size, const char *data)
{
  int i;

  for(i=0; i<size; i++) {
    if(QRinput_lookAnTable(data[i]) < 0)
      return -1;
  }

  return 0;
}

/**
 * Estimates the length of the encoded bit stream of alphabet-numeric data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeAn(int size)
{
  int w;
  int bits;

  w = size / 2;
  bits = w * 11;
  if(size & 1) {
    bits += 6;
  }

  return bits;
}

/**
 * Convert the alphabet-numeric data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid version.
 */
static int QRinput_encodeModeAn(QRinput_List *entry, int version, int mqr)
{
  int words, i, ret;
  unsigned int val;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  if(mqr) {
    if(version < 2) {
      errno = EINVAL;
      goto ABORT;
    }
    ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_AN);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_AN, version), entry->size);
    if(ret < 0) goto ABORT;
  } else {
    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_AN);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_AN, version), entry->size);
    if(ret < 0) goto ABORT;
  }

  words = entry->size / 2;
  for(i=0; i<words; i++) {
    val  = (unsigned int)QRinput_lookAnTable(entry->data[i*2  ]) * 45;
    val += (unsigned int)QRinput_lookAnTable(entry->data[i*2+1]);

    ret = BitStream_appendNum(entry->bstream, 11, val);
    if(ret < 0) goto ABORT;
  }

  if(entry->size & 1) {
    val = (unsigned int)QRinput_lookAnTable(entry->data[words * 2]);

    ret = BitStream_appendNum(entry->bstream, 6, val);
    if(ret < 0) goto ABORT;
  }

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * 8 bit data
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream of 8 bit data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsMode8(int size)
{
  return size * 8;
}

/**
 * Convert the 8bits data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_encodeMode8(QRinput_List *entry, int version, int mqr)
{
  int ret;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  if(mqr) {
    if(version < 3) {
      errno = EINVAL;
      goto ABORT;
    }
    ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_8);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_8, version), entry->size);
    if(ret < 0) goto ABORT;
  } else {
    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_8);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_8, version), entry->size);
    if(ret < 0) goto ABORT;
  }

  ret = BitStream_appendBytes(entry->bstream, entry->size, entry->data);
  if(ret < 0) goto ABORT;

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}


/******************************************************************************
 * Kanji data
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream of kanji data.
 * @param size
 * @return number of bits
 */
int QRinput_estimateBitsModeKanji(int size)
{
  return (size / 2) * 13;
}

/**
 * Check the input data.
 * @param size
 * @param data
 * @return result
 */
static int QRinput_checkModeKanji(int size, const unsigned char *data)
{
  int i;
  unsigned int val;

  if(size & 1)
    return -1;

  for(i=0; i<size; i+=2) {
    val = ((unsigned int)data[i] << 8) | data[i+1];
    if(val < 0x8140 || (val > 0x9ffc && val < 0xe040) || val > 0xebbf) {
      return -1;
    }
  }

  return 0;
}

/**
 * Convert the kanji data to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid version.
 */
static int QRinput_encodeModeKanji(QRinput_List *entry, int version, int mqr)
{
  int ret, i;
  unsigned int val, h;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  if(mqr) {
    if(version < 2) {
      errno = EINVAL;
      goto ABORT;
    }
    ret = BitStream_appendNum(entry->bstream, version - 1, MQRSPEC_MODEID_KANJI);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, MQRspec_lengthIndicator(QR_MODE_KANJI, version), entry->size/2);
    if(ret < 0) goto ABORT;
  } else {
    ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_KANJI);
    if(ret < 0) goto ABORT;
    ret = BitStream_appendNum(entry->bstream, QRspec_lengthIndicator(QR_MODE_KANJI, version), entry->size/2);
    if(ret < 0) goto ABORT;
  }

  for(i=0; i<entry->size; i+=2) {
    val = ((unsigned int)entry->data[i] << 8) | entry->data[i+1];
    if(val <= 0x9ffc) {
      val -= 0x8140;
    } else {
      val -= 0xc140;
    }
    h = (val >> 8) * 0xc0;
    val = (val & 0xff) + h;

    ret = BitStream_appendNum(entry->bstream, 13, val);
    if(ret < 0) goto ABORT;
  }

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * Structured Symbol
 *****************************************************************************/

/**
 * Convert a structure symbol code to a bit stream.
 * @param entry
 * @param mqr
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw EINVAL invalid entry.
 */
static int QRinput_encodeModeStructure(QRinput_List *entry, int mqr)
{
  int ret;

  if(mqr) {
    errno = EINVAL;
    return -1;
  }
  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_STRUCTURE);
  if(ret < 0) goto ABORT;
  ret = BitStream_appendNum(entry->bstream, 4, entry->data[1] - 1);
  if(ret < 0) goto ABORT;
  ret = BitStream_appendNum(entry->bstream, 4, entry->data[0] - 1);
  if(ret < 0) goto ABORT;
  ret = BitStream_appendNum(entry->bstream, 8, entry->data[2]);
  if(ret < 0) goto ABORT;

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * FNC1
 *****************************************************************************/

static int QRinput_checkModeFNC1Second(int size, const unsigned char *data)
{
  if(size != 1) return -1;

  return 0;
}

static int QRinput_encodeModeFNC1Second(QRinput_List *entry, int version)
{
  int ret;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_FNC1SECOND);
  if(ret < 0) goto ABORT;

  ret = BitStream_appendBytes(entry->bstream, 1, entry->data);
  if(ret < 0) goto ABORT;

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * ECI header
 *****************************************************************************/
static unsigned int QRinput_decodeECIfromByteArray(unsigned char *data)
{
  int i;
  unsigned int ecinum;

  ecinum = 0;
  for(i=0; i<4; i++) {
    ecinum = ecinum << 8;
    ecinum |= data[3-i];
  }

  return ecinum;
}

int QRinput_estimateBitsModeECI(unsigned char *data)
{
  unsigned int ecinum;

  ecinum = QRinput_decodeECIfromByteArray(data);;

  /* See Table 4 of JISX 0510:2004 pp.17. */
  if(ecinum < 128) {
    return MODE_INDICATOR_SIZE + 8;
  } else if(ecinum < 16384) {
    return MODE_INDICATOR_SIZE + 16;
  } else {
    return MODE_INDICATOR_SIZE + 24;
  }
}

static int QRinput_encodeModeECI(QRinput_List *entry, int version)
{
  int ret, words;
  unsigned int ecinum, code;

  entry->bstream = BitStream_new();
  if(entry->bstream == NULL) return -1;

  ecinum = QRinput_decodeECIfromByteArray(entry->data);;

  /* See Table 4 of JISX 0510:2004 pp.17. */
  if(ecinum < 128) {
    words = 1;
    code = ecinum;
  } else if(ecinum < 16384) {
    words = 2;
    code = 0x8000 + ecinum;
  } else {
    words = 3;
    code = 0xc0000 + ecinum;
  }

  ret = BitStream_appendNum(entry->bstream, 4, QRSPEC_MODEID_ECI);
  if(ret < 0) goto ABORT;

  ret = BitStream_appendNum(entry->bstream, words * 8, code);
  if(ret < 0) goto ABORT;

  return 0;
ABORT:
  BitStream_free(entry->bstream);
  entry->bstream = NULL;
  return -1;
}

/******************************************************************************
 * Validation
 *****************************************************************************/

int QRinput_check(QRencodeMode mode, int size, const unsigned char *data)
{
  if((mode == QR_MODE_FNC1FIRST && size < 0) || size <= 0) return -1;

  switch(mode) {
  case QR_MODE_NUM:
    return QRinput_checkModeNum(size, (const char *)data);
  case QR_MODE_AN:
    return QRinput_checkModeAn(size, (const char *)data);
  case QR_MODE_KANJI:
    return QRinput_checkModeKanji(size, data);
  case QR_MODE_8:
    return 0;
  case QR_MODE_STRUCTURE:
    return 0;
  case QR_MODE_ECI:
    return 0;
  case QR_MODE_FNC1FIRST:
    return 0;
  case QR_MODE_FNC1SECOND:
    return QRinput_checkModeFNC1Second(size, data);
  case QR_MODE_NUL:
    break;
  }

  return -1;
}

/******************************************************************************
 * Estimation of the bit length
 *****************************************************************************/

/**
 * Estimates the length of the encoded bit stream on the current version.
 * @param entry
 * @param version version of the symbol
 * @param mqr
 * @return number of bits
 */
static int QRinput_estimateBitStreamSizeOfEntry(QRinput_List *entry, int version, int mqr)
{
  int bits = 0;
  int l, m;
  int num;

  if(version == 0) version = 1;

  switch(entry->mode) {
  case QR_MODE_NUM:
    bits = QRinput_estimateBitsModeNum(entry->size);
    break;
  case QR_MODE_AN:
    bits = QRinput_estimateBitsModeAn(entry->size);
    break;
  case QR_MODE_8:
    bits = QRinput_estimateBitsMode8(entry->size);
    break;
  case QR_MODE_KANJI:
    bits = QRinput_estimateBitsModeKanji(entry->size);
    break;
  case QR_MODE_STRUCTURE:
    return STRUCTURE_HEADER_SIZE;
  case QR_MODE_ECI:
    bits = QRinput_estimateBitsModeECI(entry->data);
    break;
  case QR_MODE_FNC1FIRST:
    return MODE_INDICATOR_SIZE;
    break;
  case QR_MODE_FNC1SECOND:
    return MODE_INDICATOR_SIZE + 8;
  default:
    return 0;
  }

  if(mqr) {
    l = QRspec_lengthIndicator(entry->mode, version);
    m = version - 1;
    bits += l + m;
  } else {
    l = QRspec_lengthIndicator(entry->mode, version);
    m = 1 << l;
    num = (entry->size + m - 1) / m;

    bits += num * (MODE_INDICATOR_SIZE + l);
  }

  return bits;
}

/**
 * Estimates the length of the encoded bit stream of the data.
 * @param input input data
 * @param version version of the symbol
 * @return number of bits
 */
__STATIC int QRinput_estimateBitStreamSize(QRinput *input, int version)
{
  QRinput_List *list;
  int bits = 0;

  list = input->head;
  while(list != NULL) {
    bits += QRinput_estimateBitStreamSizeOfEntry(list, version, input->mqr);
    list = list->next;
  }

  return bits;
}

/**
 * Estimates the required version number of the symbol.
 * @param input input data
 * @return required version number
 */
static int QRinput_estimateVersion(QRinput *input)
{
  int bits;
  int version, prev;

  version = 0;
  do {
    prev = version;
    bits = QRinput_estimateBitStreamSize(input, prev);
    version = QRspec_getMinimumVersion((bits + 7) / 8, input->level);
    if (version < 0) {
      return -1;
    }
  } while (version > prev);

  return version;
}

/**
 * Returns required length in bytes for specified mode, version and bits.
 * @param mode
 * @param version
 * @param bits
 * @return required length of code words in bytes.
 */
__STATIC int QRinput_lengthOfCode(QRencodeMode mode, int version, int bits)
{
  int payload, size, chunks, remain, maxsize;

  payload = bits - 4 - QRspec_lengthIndicator(mode, version);
  switch(mode) {
  case QR_MODE_NUM:
    chunks = payload / 10;
    remain = payload - chunks * 10;
    size = chunks * 3;
    if(remain >= 7) {
      size += 2;
    } else if(remain >= 4) {
      size += 1;
    }
    break;
  case QR_MODE_AN:
    chunks = payload / 11;
    remain = payload - chunks * 11;
    size = chunks * 2;
    if(remain >= 6) size++;
    break;
  case QR_MODE_8:
    size = payload / 8;
    break;
  case QR_MODE_KANJI:
    size = (payload / 13) * 2;
    break;
  case QR_MODE_STRUCTURE:
    size = payload / 8;
    break;
  default:
    size = 0;
    break;
  }
  maxsize = QRspec_maximumWords(mode, version);
  if(size < 0) size = 0;
  if(maxsize > 0 && size > maxsize) size = maxsize;

  return size;
}

/******************************************************************************
 * Data conversion
 *****************************************************************************/

/**
 * Convert the input data in the data chunk to a bit stream.
 * @param entry
 * @return number of bits (>0) or -1 for failure.
 */
static int QRinput_encodeBitStream(QRinput_List *entry, int version, int mqr)
{
  int words, ret;
  QRinput_List *st1 = NULL, *st2 = NULL;

  if(entry->bstream != NULL) {
    BitStream_free(entry->bstream);
    entry->bstream = NULL;
  }

  words = QRspec_maximumWords(entry->mode, version);
  if(words != 0 && entry->size > words) {
    st1 = QRinput_List_newEntry(entry->mode, words, entry->data);
    if(st1 == NULL) goto ABORT;
    st2 = QRinput_List_newEntry(entry->mode, entry->size - words, &entry->data[words]);
    if(st2 == NULL) goto ABORT;

    ret = QRinput_encodeBitStream(st1, version, mqr);
    if(ret < 0) goto ABORT;
    ret = QRinput_encodeBitStream(st2, version, mqr);
    if(ret < 0) goto ABORT;
    entry->bstream = BitStream_new();
    if(entry->bstream == NULL) goto ABORT;
    ret = BitStream_append(entry->bstream, st1->bstream);
    if(ret < 0) goto ABORT;
    ret = BitStream_append(entry->bstream, st2->bstream);
    if(ret < 0) goto ABORT;
    QRinput_List_freeEntry(st1);
    QRinput_List_freeEntry(st2);
  } else {
    ret = 0;
    switch(entry->mode) {
    case QR_MODE_NUM:
      ret = QRinput_encodeModeNum(entry, version, mqr);
      break;
    case QR_MODE_AN:
      ret = QRinput_encodeModeAn(entry, version, mqr);
      break;
    case QR_MODE_8:
      ret = QRinput_encodeMode8(entry, version, mqr);
      break;
    case QR_MODE_KANJI:
      ret = QRinput_encodeModeKanji(entry, version, mqr);
      break;
    case QR_MODE_STRUCTURE:
      ret = QRinput_encodeModeStructure(entry, mqr);
      break;
    case QR_MODE_ECI:
      ret = QRinput_encodeModeECI(entry, version);
      break;
    case QR_MODE_FNC1SECOND:
      ret = QRinput_encodeModeFNC1Second(entry, version);
    default:
      break;
    }
    if(ret < 0) return -1;
  }

  return BitStream_size(entry->bstream);
ABORT:
  QRinput_List_freeEntry(st1);
  QRinput_List_freeEntry(st2);
  return -1;
}

/**
 * Convert the input data to a bit stream.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_createBitStream(QRinput *input)
{
  QRinput_List *list;
  int bits, total = 0;

  list = input->head;
  while(list != NULL) {
    bits = QRinput_encodeBitStream(list, input->version, input->mqr);
    if(bits < 0) return -1;
    total += bits;
    list = list->next;
  }

  return total;
}

/**
 * Convert the input data to a bit stream.
 * When the version number is given and that is not sufficient, it is increased
 * automatically.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ENOMEM unable to allocate memory.
 * @throw ERANGE input is too large.
 */
static int QRinput_convertData(QRinput *input)
{
  int bits;
  int ver;

  ver = QRinput_estimateVersion(input);
  if(ver > QRinput_getVersion(input)) {
    QRinput_setVersion(input, ver);
  }

  for(;;) {
    bits = QRinput_createBitStream(input);
    if(bits < 0) return -1;
    ver = QRspec_getMinimumVersion((bits + 7) / 8, input->level);
    if(ver < 0) {
      errno = ERANGE;
      return -1;
    } else if(ver > QRinput_getVersion(input)) {
      QRinput_setVersion(input, ver);
    } else {
      break;
    }
  }

  return 0;
}

/**
 * Append padding bits for the input data.
 * @param bstream Bitstream to be appended.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ERANGE input data is too large.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_appendPaddingBit(BitStream *bstream, QRinput *input)
{
  int bits, maxbits, words, maxwords, i, ret;
  BitStream *padding = NULL;
  unsigned char *padbuf;
  int padlen;

  bits = BitStream_size(bstream);
  maxwords = QRspec_getDataLength(input->version, input->level);
  maxbits = maxwords * 8;

  if(maxbits < bits) {
    errno = ERANGE;
    return -1;
  }
  if(maxbits == bits) {
    return 0;
  }

  if(maxbits - bits <= 4) {
    ret = BitStream_appendNum(bstream, maxbits - bits, 0);
    goto DONE;
  }

  words = (bits + 4 + 7) / 8;

  padding = BitStream_new();
  if(padding == NULL) return -1;
  ret = BitStream_appendNum(padding, words * 8 - bits, 0);
  if(ret < 0) goto DONE;

  padlen = maxwords - words;
  if(padlen > 0) {
    padbuf = (unsigned char *)malloc(padlen);
    if(padbuf == NULL) {
      ret = -1;
      goto DONE;
    }
    for(i=0; i<padlen; i++) {
      padbuf[i] = (i&1)?0x11:0xec;
    }
    ret = BitStream_appendBytes(padding, padlen, padbuf);
    free(padbuf);
    if(ret < 0) {
      goto DONE;
    }
  }

  ret = BitStream_append(bstream, padding);

DONE:
  BitStream_free(padding);
  return ret;
}

/**
 * Append padding bits for the input data - Micro QR Code version.
 * @param bstream Bitstream to be appended.
 * @param input input data.
 * @retval 0 success
 * @retval -1 an error occurred and errno is set to indeicate the error.
 *            See Execptions for the details.
 * @throw ERANGE input data is too large.
 * @throw ENOMEM unable to allocate memory.
 */
static int QRinput_appendPaddingBitMQR(BitStream *bstream, QRinput *input)
{
  int bits, maxbits, words, maxwords, i, ret, termbits;
  BitStream *padding = NULL;
  unsigned char *padbuf;
  int padlen;

  bits = BitStream_size(bstream);
  maxbits = MQRspec_getDataLengthBit(input->version, input->level);
  maxwords = maxbits / 8;

  if(maxbits < bits) {
    errno = ERANGE;
    return -1;
  }
  if(maxbits == bits) {
    return 0;
  }

  termbits = input->version * 2 + 1;

  if(maxbits - bits <= termbits) {
    ret = BitStream_appendNum(bstream, maxbits - bits, 0);
    goto DONE;
  }

  bits += termbits;

  words = (bits + 7) / 8;
  if(maxbits - words * 8 > 0) {
    termbits += words * 8 - bits;
    if(words == maxwords) termbits += maxbits - words * 8;
  } else {
    termbits += words * 8 - bits;
  }
  padding = BitStream_new();
  if(padding == NULL) return -1;
  ret = BitStream_appendNum(padding, termbits, 0);
  if(ret < 0) goto DONE;

  padlen = maxwords - words;
  if(padlen > 0) {
    padbuf = (unsigned char *)malloc(padlen);
    if(padbuf == NULL) {
      ret = -1;
      goto DONE;
    }
    for(i=0; i<padlen; i++) {
      padbuf[i] = (i&1)?0x11:0xec;
    }
    ret = BitStream_appendBytes(padding, padlen, padbuf);
    free(padbuf);
    if(ret < 0) {
      goto DONE;
    }
    termbits = maxbits - maxwords * 8;
    if(termbits > 0) {
      ret = BitStream_appendNum(padding, termbits, 0);
      if(ret < 0) goto DONE;
    }
  }

  ret = BitStream_append(bstream, padding);

DONE:
  BitStream_free(padding);
  return ret;
}

static int QRinput_insertFNC1Header(QRinput *input)
{
  QRinput_List *entry = NULL;

  if(input->fnc1 == 1) {
    entry = QRinput_List_newEntry(QR_MODE_FNC1FIRST, 0, NULL);
  } else if(input->fnc1 == 2) {
    entry = QRinput_List_newEntry(QR_MODE_FNC1SECOND, 1, &(input->appid));
  }
  if(entry == NULL) {
    return -1;
  }

  if(input->head->mode != QR_MODE_STRUCTURE || input->head->mode != QR_MODE_ECI) {
    entry->next = input->head;
    input->head = entry;
  } else {
    entry->next = input->head->next;
    input->head->next = entry;
  }

  return 0;
}

/**
 * Merge all bit streams in the input data.
 * @param input input data.
 * @return merged bit stream
 */

__STATIC BitStream *QRinput_mergeBitStream(QRinput *input)
{
  BitStream *bstream;
  QRinput_List *list;
  int ret;

  if(input->mqr) {
    if(QRinput_createBitStream(input) < 0) {
      return NULL;
    }
  } else {
    if(input->fnc1) {
      if(QRinput_insertFNC1Header(input) < 0) {
        return NULL;
      }
    }
    if(QRinput_convertData(input) < 0) {
      return NULL;
    }
  }

  bstream = BitStream_new();
  if(bstream == NULL) return NULL;

  list = input->head;
  while(list != NULL) {
    ret = BitStream_append(bstream, list->bstream);
    if(ret < 0) {
      BitStream_free(bstream);
      return NULL;
    }
    list = list->next;
  }

  return bstream;
}

/**
 * Merge all bit streams in the input data and append padding bits
 * @param input input data.
 * @return padded merged bit stream
 */

__STATIC BitStream *QRinput_getBitStream(QRinput *input)
{
  BitStream *bstream;
  int ret;

  bstream = QRinput_mergeBitStream(input);
  if(bstream == NULL) {
    return NULL;
  }
  if(input->mqr) {
    ret = QRinput_appendPaddingBitMQR(bstream, input);
  } else {
    ret = QRinput_appendPaddingBit(bstream, input);
  }
  if(ret < 0) {
    BitStream_free(bstream);
    return NULL;
  }

  return bstream;
}

/**
 * Pack all bit streams padding bits into a byte array.
 * @param input input data.
 * @return padded merged byte stream
 */

unsigned char *QRinput_getByteStream(QRinput *input)
{
  BitStream *bstream;
  unsigned char *array;

  bstream = QRinput_getBitStream(input);
  if(bstream == NULL) {
    return NULL;
  }
  array = BitStream_toByte(bstream);
  BitStream_free(bstream);

  return array;
}

/******************************************************************************
 * Structured input data
 *****************************************************************************/

static QRinput_InputList *QRinput_InputList_newEntry(QRinput *input)
{
  QRinput_InputList *entry;

  entry = (QRinput_InputList *)malloc(sizeof(QRinput_InputList));
  if(entry == NULL) return NULL;

  entry->input = input;
  entry->next = NULL;

  return entry;
}

static void QRinput_InputList_freeEntry(QRinput_InputList *entry)
{
  if(entry != NULL) {
    QRinput_free(entry->input);
    free(entry);
  }
}

QRinput_Struct *QRinput_Struct_new(void)
{
  QRinput_Struct *s;

  s = (QRinput_Struct *)malloc(sizeof(QRinput_Struct));
  if(s == NULL) return NULL;

  s->size = 0;
  s->parity = -1;
  s->head = NULL;
  s->tail = NULL;

  return s;
}

void QRinput_Struct_setParity(QRinput_Struct *s, unsigned char parity)
{
  s->parity = (int)parity;
}

int QRinput_Struct_appendInput(QRinput_Struct *s, QRinput *input)
{
  QRinput_InputList *e;

  if(input->mqr) {
    errno = EINVAL;
    return -1;
  }

  e = QRinput_InputList_newEntry(input);
  if(e == NULL) return -1;

  s->size++;
  if(s->tail == NULL) {
    s->head = e;
    s->tail = e;
  } else {
    s->tail->next = e;
    s->tail = e;
  }

  return s->size;
}

void QRinput_Struct_free(QRinput_Struct *s)
{
  QRinput_InputList *list, *next;

  if(s != NULL) {
    list = s->head;
    while(list != NULL) {
      next = list->next;
      QRinput_InputList_freeEntry(list);
      list = next;
    }
    free(s);
  }
}

static unsigned char QRinput_Struct_calcParity(QRinput_Struct *s)
{
  QRinput_InputList *list;
  unsigned char parity = 0;

  list = s->head;
  while(list != NULL) {
    parity ^= QRinput_calcParity(list->input);
    list = list->next;
  }

  QRinput_Struct_setParity(s, parity);

  return parity;
}

static int QRinput_List_shrinkEntry(QRinput_List *entry, int bytes)
{
  unsigned char *data;

  data = (unsigned char *)malloc(bytes);
  if(data == NULL) return -1;

  memcpy(data, entry->data, bytes);
  free(entry->data);
  entry->data = data;
  entry->size = bytes;

  return 0;
}

__STATIC int QRinput_splitEntry(QRinput_List *entry, int bytes)
{
  QRinput_List *e;
  int ret;

  e = QRinput_List_newEntry(entry->mode, entry->size - bytes, entry->data + bytes);
  if(e == NULL) {
    return -1;
  }

  ret = QRinput_List_shrinkEntry(entry, bytes);
  if(ret < 0) {
    QRinput_List_freeEntry(e);
    return -1;
  }

  e->next = entry->next;
  entry->next = e;

  return 0;
}

QRinput_Struct *QRinput_splitQRinputToStruct(QRinput *input)
{
  QRinput *p;
  QRinput_Struct *s;
  int bits, maxbits, nextbits, bytes, ret;
  QRinput_List *list, *next, *prev;

  if(input->mqr) {
    errno = EINVAL;
    return NULL;
  }

  s = QRinput_Struct_new();
  if(s == NULL) return NULL;

  input = QRinput_dup(input);
  if(input == NULL) {
    QRinput_Struct_free(s);
    return NULL;
  }

  QRinput_Struct_setParity(s, QRinput_calcParity(input));
  maxbits = QRspec_getDataLength(input->version, input->level) * 8 - STRUCTURE_HEADER_SIZE;

  if(maxbits <= 0) {
    QRinput_Struct_free(s);
    QRinput_free(input);
    return NULL;
  }

  bits = 0;
  list = input->head;
  prev = NULL;
  while(list != NULL) {
    nextbits = QRinput_estimateBitStreamSizeOfEntry(list, input->version, input->mqr);
    if(bits + nextbits <= maxbits) {
      ret = QRinput_encodeBitStream(list, input->version, input->mqr);
      if(ret < 0) goto ABORT;
      bits += ret;
      prev = list;
      list = list->next;
    } else {
      bytes = QRinput_lengthOfCode(list->mode, input->version, maxbits - bits);
      if(bytes > 0) {
        /* Splits this entry into 2 entries. */
        ret = QRinput_splitEntry(list, bytes);
        if(ret < 0) goto ABORT;
        /* First half is the tail of the current input. */
        next = list->next;
        list->next = NULL;
        /* Second half is the head of the next input, p.*/
        p = QRinput_new2(input->version, input->level);
        if(p == NULL) goto ABORT;
        p->head = next;
        /* Renew QRinput.tail. */
        p->tail = input->tail;
        input->tail = list;
        /* Point to the next entry. */
        prev = list;
        list = next;
      } else {
        /* Current entry will go to the next input. */
        prev->next = NULL;
        p = QRinput_new2(input->version, input->level);
        if(p == NULL) goto ABORT;
        p->head = list;
        p->tail = input->tail;
        input->tail = prev;
      }
      ret = QRinput_Struct_appendInput(s, input);
      if(ret < 0) goto ABORT;
      input = p;
      bits = 0;
    }
  }
  QRinput_Struct_appendInput(s, input);
  if(s->size > MAX_STRUCTURED_SYMBOLS) {
    QRinput_Struct_free(s);
    errno = ERANGE;
    return NULL;
  }
  ret = QRinput_Struct_insertStructuredAppendHeaders(s);
  if(ret < 0) {
    QRinput_Struct_free(s);
    return NULL;
  }

  return s;

ABORT:
  QRinput_free(input);
  QRinput_Struct_free(s);
  return NULL;
}

int QRinput_Struct_insertStructuredAppendHeaders(QRinput_Struct *s)
{
  int num, i;
  QRinput_InputList *list;

  if(s->parity < 0) {
    QRinput_Struct_calcParity(s);
  }
  num = 0;
  list = s->head;
  while(list != NULL) {
    num++;
    list = list->next;
  }
  i = 1;
  list = s->head;
  while(list != NULL) {
    if(QRinput_insertStructuredAppendHeader(list->input, num, i, s->parity))
      return -1;
    i++;
    list = list->next;
  }

  return 0;
}

/******************************************************************************
 * Extended encoding mode (FNC1 and ECI)
 *****************************************************************************/

int QRinput_setFNC1First(QRinput *input)
{
  if(input->mqr) {
    errno = EINVAL;
    return -1;
  }
  input->fnc1 = 1;

  return 0;
}

int QRinput_setFNC1Second(QRinput *input, unsigned char appid)
{
  if(input->mqr) {
    errno = EINVAL;
    return -1;
  }
  input->fnc1 = 2;
  input->appid = appid;

  return 0;
}
