/*
 * qrencode - QR Code encoder
 *
 * Copyright (C) 2006-2012 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"
#include "rscode.h"
#include "split.h"
#include "mask.h"
#include "mmask.h"

/******************************************************************************
 * Raw code
 *****************************************************************************/

typedef struct {
  int dataLength;
  unsigned char *data;
  int eccLength;
  unsigned char *ecc;
} RSblock;

typedef struct {
  int version;
  int dataLength;
  int eccLength;
  unsigned char *datacode;
  unsigned char *ecccode;
  int b1;
  int blocks;
  RSblock *rsblock;
  int count;
} QRRawCode;

static void RSblock_initBlock(RSblock *block, int dl, unsigned char *data, int el, unsigned char *ecc, RS *rs)
{
  block->dataLength = dl;
  block->data = data;
  block->eccLength = el;
  block->ecc = ecc;

  encode_rs_char(rs, data, ecc);
}

static int RSblock_init(RSblock *blocks, int spec[5], unsigned char *data, unsigned char *ecc)
{
  int i;
  RSblock *block;
  unsigned char *dp, *ep;
  RS *rs;
  int el, dl;

  dl = QRspec_rsDataCodes1(spec);
  el = QRspec_rsEccCodes1(spec);
  rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
  if(rs == NULL) return -1;

  block = blocks;
  dp = data;
  ep = ecc;
  for(i=0; i<QRspec_rsBlockNum1(spec); i++) {
    RSblock_initBlock(block, dl, dp, el, ep, rs);
    dp += dl;
    ep += el;
    block++;
  }

  if(QRspec_rsBlockNum2(spec) == 0) return 0;

  dl = QRspec_rsDataCodes2(spec);
  el = QRspec_rsEccCodes2(spec);
  rs = init_rs(8, 0x11d, 0, 1, el, 255 - dl - el);
  if(rs == NULL) return -1;
  for(i=0; i<QRspec_rsBlockNum2(spec); i++) {
    RSblock_initBlock(block, dl, dp, el, ep, rs);
    dp += dl;
    ep += el;
    block++;
  }

  return 0;
}

__STATIC void QRraw_free(QRRawCode *raw);
__STATIC QRRawCode *QRraw_new(QRinput *input)
{
  QRRawCode *raw;
  int spec[5], ret;

  raw = (QRRawCode *)malloc(sizeof(QRRawCode));
  if(raw == NULL) return NULL;

  raw->datacode = QRinput_getByteStream(input);
  if(raw->datacode == NULL) {
    free(raw);
    return NULL;
  }

  QRspec_getEccSpec(input->version, input->level, spec);

  raw->version = input->version;
  raw->b1 = QRspec_rsBlockNum1(spec);
  raw->dataLength = QRspec_rsDataLength(spec);
  raw->eccLength = QRspec_rsEccLength(spec);
  raw->ecccode = (unsigned char *)malloc(raw->eccLength);
  if(raw->ecccode == NULL) {
    free(raw->datacode);
    free(raw);
    return NULL;
  }

  raw->blocks = QRspec_rsBlockNum(spec);
  raw->rsblock = (RSblock *)calloc(raw->blocks, sizeof(RSblock));
  if(raw->rsblock == NULL) {
    QRraw_free(raw);
    return NULL;
  }
  ret = RSblock_init(raw->rsblock, spec, raw->datacode, raw->ecccode);
  if(ret < 0) {
    QRraw_free(raw);
    return NULL;
  }

  raw->count = 0;

  return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
__STATIC unsigned char QRraw_getCode(QRRawCode *raw)
{
  int col, row;
  unsigned char ret;

  if(raw->count < raw->dataLength) {
    row = raw->count % raw->blocks;
    col = raw->count / raw->blocks;
    if(col >= raw->rsblock[0].dataLength) {
      row += raw->b1;
    }
    ret = raw->rsblock[row].data[col];
  } else if(raw->count < raw->dataLength + raw->eccLength) {
    row = (raw->count - raw->dataLength) % raw->blocks;
    col = (raw->count - raw->dataLength) / raw->blocks;
    ret = raw->rsblock[row].ecc[col];
  } else {
    return 0;
  }
  raw->count++;
  return ret;
}

__STATIC void QRraw_free(QRRawCode *raw)
{
  if(raw != NULL) {
    free(raw->datacode);
    free(raw->ecccode);
    free(raw->rsblock);
    free(raw);
  }
}

/******************************************************************************
 * Raw code for Micro QR Code
 *****************************************************************************/

typedef struct {
  int version;
  int dataLength;
  int eccLength;
  unsigned char *datacode;
  unsigned char *ecccode;
  RSblock *rsblock;
  int oddbits;
  int count;
} MQRRawCode;

__STATIC void MQRraw_free(MQRRawCode *raw);
__STATIC MQRRawCode *MQRraw_new(QRinput *input)
{
  MQRRawCode *raw;
  RS *rs;

  raw = (MQRRawCode *)malloc(sizeof(MQRRawCode));
  if(raw == NULL) return NULL;

  raw->version = input->version;
  raw->dataLength = MQRspec_getDataLength(input->version, input->level);
  raw->eccLength = MQRspec_getECCLength(input->version, input->level);
  raw->oddbits = raw->dataLength * 8 - MQRspec_getDataLengthBit(input->version, input->level);
  raw->datacode = QRinput_getByteStream(input);
  if(raw->datacode == NULL) {
    free(raw);
    return NULL;
  }
  raw->ecccode = (unsigned char *)malloc(raw->eccLength);
  if(raw->ecccode == NULL) {
    free(raw->datacode);
    free(raw);
    return NULL;
  }

  raw->rsblock = (RSblock *)calloc(1, sizeof(RSblock));
  if(raw->rsblock == NULL) {
    MQRraw_free(raw);
    return NULL;
  }

  rs = init_rs(8, 0x11d, 0, 1, raw->eccLength, 255 - raw->dataLength - raw->eccLength);
  if(rs == NULL) {
    MQRraw_free(raw);
    return NULL;
  }

  RSblock_initBlock(raw->rsblock, raw->dataLength, raw->datacode, raw->eccLength, raw->ecccode, rs);

  raw->count = 0;

  return raw;
}

/**
 * Return a code (byte).
 * This function can be called iteratively.
 * @param raw raw code.
 * @return code
 */
__STATIC unsigned char MQRraw_getCode(MQRRawCode *raw)
{
  unsigned char ret;

  if(raw->count < raw->dataLength) {
    ret = raw->datacode[raw->count];
  } else if(raw->count < raw->dataLength + raw->eccLength) {
    ret = raw->ecccode[raw->count - raw->dataLength];
  } else {
    return 0;
  }
  raw->count++;
  return ret;
}

__STATIC void MQRraw_free(MQRRawCode *raw)
{
  if(raw != NULL) {
    free(raw->datacode);
    free(raw->ecccode);
    free(raw->rsblock);
    free(raw);
  }
}


/******************************************************************************
 * Frame filling
 *****************************************************************************/

typedef struct {
  int width;
  unsigned char *frame;
  int x, y;
  int dir;
  int bit;
  int mqr;
} FrameFiller;

static FrameFiller *FrameFiller_new(int width, unsigned char *frame, int mqr)
{
  FrameFiller *filler;

  filler = (FrameFiller *)malloc(sizeof(FrameFiller));
  if(filler == NULL) return NULL;
  filler->width = width;
  filler->frame = frame;
  filler->x = width - 1;
  filler->y = width - 1;
  filler->dir = -1;
  filler->bit = -1;
  filler->mqr = mqr;

  return filler;
}

static unsigned char *FrameFiller_next(FrameFiller *filler)
{
  unsigned char *p;
  int x, y, w;

  if(filler->bit == -1) {
    filler->bit = 0;
    return filler->frame + filler->y * filler->width + filler->x;
  }

  x = filler->x;
  y = filler->y;
  p = filler->frame;
  w = filler->width;

  if(filler->bit == 0) {
    x--;
    filler->bit++;
  } else {
    x++;
    y += filler->dir;
    filler->bit--;
  }

  if(filler->dir < 0) {
    if(y < 0) {
      y = 0;
      x -= 2;
      filler->dir = 1;
      if(!filler->mqr && x == 6) {
        x--;
        y = 9;
      }
    }
  } else {
    if(y == w) {
      y = w - 1;
      x -= 2;
      filler->dir = -1;
      if(!filler->mqr && x == 6) {
        x--;
        y -= 8;
      }
    }
  }
  if(x < 0 || y < 0) return NULL;

  filler->x = x;
  filler->y = y;

  if(p[y * w + x] & 0x80) {
    // This tail recursion could be optimized.
    return FrameFiller_next(filler);
  }
  return &p[y * w + x];
}

#ifdef WITH_TESTS
extern unsigned char *FrameFiller_test(int version)
{
  int width;
  unsigned char *frame, *p;
  FrameFiller *filler;
  int i, length;

  width = QRspec_getWidth(version);
  frame = QRspec_newFrame(version);
  if(frame == NULL) return NULL;
  filler = FrameFiller_new(width, frame, 0);
  if(filler == NULL) {
    free(frame);
    return NULL;
  }
  length = QRspec_getDataLength(version, QR_ECLEVEL_L) * 8
      + QRspec_getECCLength(version, QR_ECLEVEL_L) * 8
      + QRspec_getRemainder(version);
  for(i=0; i<length; i++) {
    p = FrameFiller_next(filler);
    if(p == NULL) {
      free(filler);
      free(frame);
      return NULL;
    }
    *p = (unsigned char)(i & 0x7f) | 0x80;
  }
  free(filler);
  return frame;
}

extern unsigned char *FrameFiller_testMQR(int version)
{
  int width;
  unsigned char *frame, *p;
  FrameFiller *filler;
  int i, length;

  width = MQRspec_getWidth(version);
  frame = MQRspec_newFrame(version);
  if(frame == NULL) return NULL;
  filler = FrameFiller_new(width, frame, 1);
  if(filler == NULL) {
    free(frame);
    return NULL;
  }
  length = MQRspec_getDataLengthBit(version, QR_ECLEVEL_L)
      + MQRspec_getECCLength(version, QR_ECLEVEL_L) * 8;
  for(i=0; i<length; i++) {
    p = FrameFiller_next(filler);
    if(p == NULL) {
      fprintf(stderr, "Frame filler run over the frame!\n");
      free(filler);
      return frame;
    }
    *p = (unsigned char)(i & 0x7f) | 0x80;
  }
  free(filler);
  return frame;
}
#endif


/******************************************************************************
 * QR-code encoding
 *****************************************************************************/

__STATIC QRcode *QRcode_new(int version, int width, unsigned char *data)
{
  QRcode *qrcode;

  qrcode = (QRcode *)malloc(sizeof(QRcode));
  if(qrcode == NULL) return NULL;

  qrcode->version = version;
  qrcode->width = width;
  qrcode->data = data;

  return qrcode;
}

void QRcode_free(QRcode *qrcode)
{
  if(qrcode != NULL) {
    free(qrcode->data);
    free(qrcode);
  }
}

__STATIC QRcode *QRcode_encodeMask(QRinput *input, int mask)
{
  int width, version;
  QRRawCode *raw;
  unsigned char *frame, *masked, *p, code, bit;
  FrameFiller *filler;
  int i, j;
  QRcode *qrcode = NULL;

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

  raw = QRraw_new(input);
  if(raw == NULL) return NULL;

  version = raw->version;
  width = QRspec_getWidth(version);
  frame = QRspec_newFrame(version);
  if(frame == NULL) {
    QRraw_free(raw);
    return NULL;
  }
  filler = FrameFiller_new(width, frame, 0);
  if(filler == NULL) {
    QRraw_free(raw);
    free(frame);
    return NULL;
  }

  /* inteleaved data and ecc codes */
  for(i=0; i<raw->dataLength + raw->eccLength; i++) {
    code = QRraw_getCode(raw);
    bit = 0x80;
    for(j=0; j<8; j++) {
      p = FrameFiller_next(filler);
      if(p == NULL)  goto EXIT;
      *p = 0x02 | ((bit & code) != 0);
      bit = bit >> 1;
    }
  }
  QRraw_free(raw);
  raw = NULL;
  /* remainder bits */
  j = QRspec_getRemainder(version);
  for(i=0; i<j; i++) {
    p = FrameFiller_next(filler);
    if(p == NULL)  goto EXIT;
    *p = 0x02;
  }

  /* masking */
  if(mask == -2) { // just for debug purpose
    masked = (unsigned char *)malloc(width * width);
    memcpy(masked, frame, width * width);
  } else if(mask < 0) {
    masked = Mask_mask(width, frame, input->level);
  } else {
    masked = Mask_makeMask(width, frame, mask, input->level);
  }
  if(masked == NULL) {
    goto EXIT;
  }
  qrcode = QRcode_new(version, width, masked);

EXIT:
  QRraw_free(raw);
  free(filler);
  free(frame);
  return qrcode;
}

__STATIC QRcode *QRcode_encodeMaskMQR(QRinput *input, int mask)
{
  int width, version;
  MQRRawCode *raw;
  unsigned char *frame, *masked, *p, code, bit;
  FrameFiller *filler;
  int i, j;
  QRcode *qrcode = NULL;

  if(!input->mqr) {
    errno = EINVAL;
    return NULL;
  }
  if(input->version <= 0 || input->version > MQRSPEC_VERSION_MAX) {
    errno = EINVAL;
    return NULL;
  }
  if(input->level > QR_ECLEVEL_Q) {
    errno = EINVAL;
    return NULL;
  }

  raw = MQRraw_new(input);
  if(raw == NULL) return NULL;

  version = raw->version;
  width = MQRspec_getWidth(version);
  frame = MQRspec_newFrame(version);
  if(frame == NULL) {
    MQRraw_free(raw);
    return NULL;
  }
  filler = FrameFiller_new(width, frame, 1);
  if(filler == NULL) {
    MQRraw_free(raw);
    free(frame);
    return NULL;
  }

  /* inteleaved data and ecc codes */
  for(i=0; i<raw->dataLength + raw->eccLength; i++) {
    code = MQRraw_getCode(raw);
    if(raw->oddbits && i == raw->dataLength - 1) {
      bit = 1 << raw->oddbits;
      for(j=0; j<raw->oddbits; j++) {
        p = FrameFiller_next(filler);
        if(p == NULL) goto EXIT;
        *p = 0x02 | ((bit & code) != 0);
        bit = bit >> 1;
      }
    } else {
      bit = 0x80;
      for(j=0; j<8; j++) {
        p = FrameFiller_next(filler);
        if(p == NULL) goto EXIT;
        *p = 0x02 | ((bit & code) != 0);
        bit = bit >> 1;
      }
    }
  }
  MQRraw_free(raw);
  raw = NULL;

  /* masking */
  if(mask < 0) {
    masked = MMask_mask(version, frame, input->level);
  } else {
    masked = MMask_makeMask(version, frame, mask, input->level);
  }
  if(masked == NULL) {
    goto EXIT;
  }

  qrcode = QRcode_new(version, width, masked);

EXIT:
  MQRraw_free(raw);
  free(filler);
  free(frame);
  return qrcode;
}

QRcode *QRcode_encodeInput(QRinput *input)
{
  if(input->mqr) {
    return QRcode_encodeMaskMQR(input, -1);
  } else {
    return QRcode_encodeMask(input, -1);
  }
}

static QRcode *QRcode_encodeStringReal(const char *string, int version, QRecLevel level, int mqr, QRencodeMode hint, int casesensitive)
{
  QRinput *input;
  QRcode *code;
  int ret;

  if(string == NULL) {
    errno = EINVAL;
    return NULL;
  }
  if(hint != QR_MODE_8 && hint != QR_MODE_KANJI) {
    errno = EINVAL;
    return NULL;
  }

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

  ret = Split_splitStringToQRinput(string, input, hint, casesensitive);
  if(ret < 0) {
    QRinput_free(input);
    return NULL;
  }
  code = QRcode_encodeInput(input);
  QRinput_free(input);

  return code;
}

QRcode *QRcode_encodeString(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
  return QRcode_encodeStringReal(string, version, level, 0, hint, casesensitive);
}

QRcode *QRcode_encodeStringMQR(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
  return QRcode_encodeStringReal(string, version, level, 1, hint, casesensitive);
}

static QRcode *QRcode_encodeDataReal(const unsigned char *data, int length, int version, QRecLevel level, int mqr)
{
  QRinput *input;
  QRcode *code;
  int ret;

  if(data == NULL || length == 0) {
    errno = EINVAL;
    return NULL;
  }

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

  ret = QRinput_append(input, QR_MODE_8, length, data);
  if(ret < 0) {
    QRinput_free(input);
    return NULL;
  }
  code = QRcode_encodeInput(input);
  QRinput_free(input);

  return code;
}

QRcode *QRcode_encodeData(int size, const unsigned char *data, int version, QRecLevel level)
{
  return QRcode_encodeDataReal(data, size, version, level, 0);
}

QRcode *QRcode_encodeString8bit(const char *string, int version, QRecLevel level)
{
  if(string == NULL) {
    errno = EINVAL;
    return NULL;
  }
  return QRcode_encodeDataReal((unsigned char *)string, strlen(string), version, level, 0);
}

QRcode *QRcode_encodeDataMQR(int size, const unsigned char *data, int version, QRecLevel level)
{
  return QRcode_encodeDataReal(data, size, version, level, 1);
}

QRcode *QRcode_encodeString8bitMQR(const char *string, int version, QRecLevel level)
{
  if(string == NULL) {
    errno = EINVAL;
    return NULL;
  }
  return QRcode_encodeDataReal((unsigned char *)string, strlen(string), version, level, 1);
}


/******************************************************************************
 * Structured QR-code encoding
 *****************************************************************************/

static QRcode_List *QRcode_List_newEntry(void)
{
  QRcode_List *entry;

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

  entry->next = NULL;
  entry->code = NULL;

  return entry;
}

static void QRcode_List_freeEntry(QRcode_List *entry)
{
  if(entry != NULL) {
    QRcode_free(entry->code);
    free(entry);
  }
}

void QRcode_List_free(QRcode_List *qrlist)
{
  QRcode_List *list = qrlist, *next;

  while(list != NULL) {
    next = list->next;
    QRcode_List_freeEntry(list);
    list = next;
  }
}

int QRcode_List_size(QRcode_List *qrlist)
{
  QRcode_List *list = qrlist;
  int size = 0;

  while(list != NULL) {
    size++;
    list = list->next;
  }

  return size;
}

#if 0
static unsigned char QRcode_parity(const char *str, int size)
{
  unsigned char parity = 0;
  int i;

  for(i=0; i<size; i++) {
    parity ^= str[i];
  }

  return parity;
}
#endif

QRcode_List *QRcode_encodeInputStructured(QRinput_Struct *s)
{
  QRcode_List *head = NULL;
  QRcode_List *tail = NULL;
  QRcode_List *entry;
  QRinput_InputList *list = s->head;

  while(list != NULL) {
    if(head == NULL) {
      entry = QRcode_List_newEntry();
      if(entry == NULL) goto ABORT;
      head = entry;
      tail = head;
    } else {
      entry = QRcode_List_newEntry();
      if(entry == NULL) goto ABORT;
      tail->next = entry;
      tail = tail->next;
    }
    tail->code = QRcode_encodeInput(list->input);
    if(tail->code == NULL) {
      goto ABORT;
    }
    list = list->next;
  }

  return head;
ABORT:
  QRcode_List_free(head);
  return NULL;
}

static QRcode_List *QRcode_encodeInputToStructured(QRinput *input)
{
  QRinput_Struct *s;
  QRcode_List *codes;

  s = QRinput_splitQRinputToStruct(input);
  if(s == NULL) return NULL;

  codes = QRcode_encodeInputStructured(s);
  QRinput_Struct_free(s);

  return codes;
}

static QRcode_List *QRcode_encodeDataStructuredReal(
    int size, const unsigned char *data,
    int version, QRecLevel level,
    int eightbit, QRencodeMode hint, int casesensitive)
{
  QRinput *input;
  QRcode_List *codes;
  int ret;

  if(version <= 0) {
    errno = EINVAL;
    return NULL;
  }
  if(!eightbit && (hint != QR_MODE_8 && hint != QR_MODE_KANJI)) {
    errno = EINVAL;
    return NULL;
  }

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

  if(eightbit) {
    ret = QRinput_append(input, QR_MODE_8, size, data);
  } else {
    ret = Split_splitStringToQRinput((char *)data, input, hint, casesensitive);
  }
  if(ret < 0) {
    QRinput_free(input);
    return NULL;
  }
  codes = QRcode_encodeInputToStructured(input);
  QRinput_free(input);

  return codes;
}

QRcode_List *QRcode_encodeDataStructured(int size, const unsigned char *data, int version, QRecLevel level) {
  return QRcode_encodeDataStructuredReal(size, data, version, level, 1, QR_MODE_NUL, 0);
}

QRcode_List *QRcode_encodeString8bitStructured(const char *string, int version, QRecLevel level) {
  if(string == NULL) {
    errno = EINVAL;
    return NULL;
  }
  return QRcode_encodeDataStructured(strlen(string), (unsigned char *)string, version, level);
}

QRcode_List *QRcode_encodeStringStructured(const char *string, int version, QRecLevel level, QRencodeMode hint, int casesensitive)
{
  if(string == NULL) {
    errno = EINVAL;
    return NULL;
  }
  return QRcode_encodeDataStructuredReal(strlen(string), (unsigned char *)string, version, level, 0, hint, casesensitive);
}

/******************************************************************************
 * System utilities
 *****************************************************************************/

void QRcode_APIVersion(int *major_version, int *minor_version, int *micro_version)
{
  if(major_version != NULL) {
    *major_version = MAJOR_VERSION;
  }
  if(minor_version != NULL) {
    *minor_version = MINOR_VERSION;
  }
  if(micro_version != NULL) {
    *micro_version = MICRO_VERSION;
  }
}

char *QRcode_APIVersionString(void)
{
  return VERSION;
}

void QRcode_clearCache(void)
{
  QRspec_clearCache();
  MQRspec_clearCache();
  free_rs_cache();
}
