// Copyright 2014 The PDFium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
// Original code is licensed as follows:
/*
 * Copyright 2006 Jeremias Maerki.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fxbarcode/datamatrix/BC_ErrorCorrection.h"

#include <stdint.h>

#include <algorithm>
#include <vector>

#include "core/fxcrt/check.h"
#include "core/fxcrt/fixed_size_data_vector.h"
#include "fxbarcode/datamatrix/BC_Encoder.h"
#include "fxbarcode/datamatrix/BC_SymbolInfo.h"

namespace {

const uint8_t FACTOR_SETS[] = {5,  7,  10, 11, 12, 14, 18, 20,
                               24, 28, 36, 42, 48, 56, 62, 68};

const uint8_t FACTORS_0[5] = {228, 48, 15, 111, 62};
const uint8_t FACTORS_1[7] = {23, 68, 144, 134, 240, 92, 254};
const uint8_t FACTORS_2[10] = {28, 24, 185, 166, 223, 248, 116, 255, 110, 61};
const uint8_t FACTORS_3[11] = {175, 138, 205, 12, 194, 168,
                               39,  245, 60,  97, 120};

const uint8_t FACTORS_4[12] = {41,  153, 158, 91,  61,  42,
                               142, 213, 97,  178, 100, 242};

const uint8_t FACTORS_5[14] = {156, 97,  192, 252, 95,  9,  157,
                               119, 138, 45,  18,  186, 83, 185};

const uint8_t FACTORS_6[18] = {83,  195, 100, 39, 188, 75,  66, 61, 241,
                               213, 109, 129, 94, 254, 225, 48, 90, 188};

const uint8_t FACTORS_7[20] = {15,  195, 244, 9,  233, 71, 168, 2,   188, 160,
                               153, 145, 253, 79, 108, 82, 27,  174, 186, 172};

const uint8_t FACTORS_8[24] = {52,  190, 88,  205, 109, 39, 176, 21,
                               155, 197, 251, 223, 155, 21, 5,   172,
                               254, 124, 12,  181, 184, 96, 50,  193};

const uint8_t FACTORS_9[28] = {211, 231, 43,  97,  71,  96,  103, 174, 37,  151,
                               170, 53,  75,  34,  249, 121, 17,  138, 110, 213,
                               141, 136, 120, 151, 233, 168, 93,  255};

const uint8_t FACTORS_10[36] = {245, 127, 242, 218, 130, 250, 162, 181, 102,
                                120, 84,  179, 220, 251, 80,  182, 229, 18,
                                2,   4,   68,  33,  101, 137, 95,  119, 115,
                                44,  175, 184, 59,  25,  225, 98,  81,  112};

const uint8_t FACTORS_11[42] = {
    77,  193, 137, 31,  19,  38,  22,  153, 247, 105, 122, 2,   245, 133,
    242, 8,   175, 95,  100, 9,   167, 105, 214, 111, 57,  121, 21,  1,
    253, 57,  54,  101, 248, 202, 69,  50,  150, 177, 226, 5,   9,   5};

const uint8_t FACTORS_12[48] = {
    245, 132, 172, 223, 96,  32,  117, 22,  238, 133, 238, 231,
    205, 188, 237, 87,  191, 106, 16,  147, 118, 23,  37,  90,
    170, 205, 131, 88,  120, 100, 66,  138, 186, 240, 82,  44,
    176, 87,  187, 147, 160, 175, 69,  213, 92,  253, 225, 19};

const uint8_t FACTORS_13[56] = {
    175, 9,   223, 238, 12,  17,  220, 208, 100, 29,  175, 170, 230, 192,
    215, 235, 150, 159, 36,  223, 38,  200, 132, 54,  228, 146, 218, 234,
    117, 203, 29,  232, 144, 238, 22,  150, 201, 117, 62,  207, 164, 13,
    137, 245, 127, 67,  247, 28,  155, 43,  203, 107, 233, 53,  143, 46};

const uint8_t FACTORS_14[62] = {
    242, 93,  169, 50,  144, 210, 39,  118, 202, 188, 201, 189, 143,
    108, 196, 37,  185, 112, 134, 230, 245, 63,  197, 190, 250, 106,
    185, 221, 175, 64,  114, 71,  161, 44,  147, 6,   27,  218, 51,
    63,  87,  10,  40,  130, 188, 17,  163, 31,  176, 170, 4,   107,
    232, 7,   94,  166, 224, 124, 86,  47,  11,  204};

const uint8_t FACTORS_15[68] = {
    220, 228, 173, 89,  251, 149, 159, 56,  89,  33,  147, 244, 154, 36,
    73,  127, 213, 136, 248, 180, 234, 197, 158, 177, 68,  122, 93,  213,
    15,  160, 227, 236, 66,  139, 153, 185, 202, 167, 179, 25,  220, 232,
    96,  210, 231, 136, 223, 239, 181, 241, 59,  52,  172, 25,  49,  232,
    211, 189, 64,  54,  108, 153, 132, 63,  96,  103, 82,  186};

const uint8_t* const FACTORS[16] = {
    FACTORS_0,  FACTORS_1,  FACTORS_2,  FACTORS_3, FACTORS_4,  FACTORS_5,
    FACTORS_6,  FACTORS_7,  FACTORS_8,  FACTORS_9, FACTORS_10, FACTORS_11,
    FACTORS_12, FACTORS_13, FACTORS_14, FACTORS_15};

constexpr uint8_t LOG[256] = {
    0,   0,   1,   240, 2,   225, 241, 53,  3,   38,  226, 133, 242, 43,  54,
    210, 4,   195, 39,  114, 227, 106, 134, 28,  243, 140, 44,  23,  55,  118,
    211, 234, 5,   219, 196, 96,  40,  222, 115, 103, 228, 78,  107, 125, 135,
    8,   29,  162, 244, 186, 141, 180, 45,  99,  24,  49,  56,  13,  119, 153,
    212, 199, 235, 91,  6,   76,  220, 217, 197, 11,  97,  184, 41,  36,  223,
    253, 116, 138, 104, 193, 229, 86,  79,  171, 108, 165, 126, 145, 136, 34,
    9,   74,  30,  32,  163, 84,  245, 173, 187, 204, 142, 81,  181, 190, 46,
    88,  100, 159, 25,  231, 50,  207, 57,  147, 14,  67,  120, 128, 154, 248,
    213, 167, 200, 63,  236, 110, 92,  176, 7,   161, 77,  124, 221, 102, 218,
    95,  198, 90,  12,  152, 98,  48,  185, 179, 42,  209, 37,  132, 224, 52,
    254, 239, 117, 233, 139, 22,  105, 27,  194, 113, 230, 206, 87,  158, 80,
    189, 172, 203, 109, 175, 166, 62,  127, 247, 146, 66,  137, 192, 35,  252,
    10,  183, 75,  216, 31,  83,  33,  73,  164, 144, 85,  170, 246, 65,  174,
    61,  188, 202, 205, 157, 143, 169, 82,  72,  182, 215, 191, 251, 47,  178,
    89,  151, 101, 94,  160, 123, 26,  112, 232, 21,  51,  238, 208, 131, 58,
    69,  148, 18,  15,  16,  68,  17,  121, 149, 129, 19,  155, 59,  249, 70,
    214, 250, 168, 71,  201, 156, 64,  60,  237, 130, 111, 20,  93,  122, 177,
    150};

constexpr uint8_t ALOG[256] = {
    1,   2,   4,   8,   16,  32,  64,  128, 45,  90,  180, 69,  138, 57,  114,
    228, 229, 231, 227, 235, 251, 219, 155, 27,  54,  108, 216, 157, 23,  46,
    92,  184, 93,  186, 89,  178, 73,  146, 9,   18,  36,  72,  144, 13,  26,
    52,  104, 208, 141, 55,  110, 220, 149, 7,   14,  28,  56,  112, 224, 237,
    247, 195, 171, 123, 246, 193, 175, 115, 230, 225, 239, 243, 203, 187, 91,
    182, 65,  130, 41,  82,  164, 101, 202, 185, 95,  190, 81,  162, 105, 210,
    137, 63,  126, 252, 213, 135, 35,  70,  140, 53,  106, 212, 133, 39,  78,
    156, 21,  42,  84,  168, 125, 250, 217, 159, 19,  38,  76,  152, 29,  58,
    116, 232, 253, 215, 131, 43,  86,  172, 117, 234, 249, 223, 147, 11,  22,
    44,  88,  176, 77,  154, 25,  50,  100, 200, 189, 87,  174, 113, 226, 233,
    255, 211, 139, 59,  118, 236, 245, 199, 163, 107, 214, 129, 47,  94,  188,
    85,  170, 121, 242, 201, 191, 83,  166, 97,  194, 169, 127, 254, 209, 143,
    51,  102, 204, 181, 71,  142, 49,  98,  196, 165, 103, 206, 177, 79,  158,
    17,  34,  68,  136, 61,  122, 244, 197, 167, 99,  198, 161, 111, 222, 145,
    15,  30,  60,  120, 240, 205, 183, 67,  134, 33,  66,  132, 37,  74,  148,
    5,   10,  20,  40,  80,  160, 109, 218, 153, 31,  62,  124, 248, 221, 151,
    3,   6,   12,  24,  48,  96,  192, 173, 119, 238, 241, 207, 179, 75,  150,
    0};

WideString CreateECCBlock(const WideString& codewords, size_t numECWords) {
  DCHECK(numECWords > 0);

  const size_t len = codewords.GetLength();
  static constexpr size_t kFactorTableNum = std::size(FACTOR_SETS);
  size_t table = 0;
  while (table < kFactorTableNum && FACTOR_SETS[table] != numECWords)
    ++table;

  if (table >= kFactorTableNum)
    return WideString();

  auto ecc = FixedSizeDataVector<uint16_t>::Zeroed(numECWords);
  pdfium::span<uint16_t> ecc_span = ecc.span();
  for (size_t i = 0; i < len; ++i) {
    uint16_t m = ecc_span[numECWords - 1] ^ codewords[i];
    for (int32_t j = numECWords - 1; j > 0; --j) {
      if (m != 0 && FACTORS[table][j] != 0) {
        ecc_span[j] = static_cast<uint16_t>(
            ecc_span[j - 1] ^ ALOG[(LOG[m] + LOG[FACTORS[table][j]]) % 255]);
      } else {
        ecc_span[j] = ecc_span[j - 1];
      }
    }
    if (m != 0 && FACTORS[table][0] != 0) {
      ecc_span[0] =
          static_cast<uint16_t>(ALOG[(LOG[m] + LOG[FACTORS[table][0]]) % 255]);
    } else {
      ecc_span[0] = 0;
    }
  }
  WideString strecc;
  strecc.Reserve(numECWords);
  for (size_t i = 0; i < numECWords; ++i)
    strecc.InsertAtBack(static_cast<wchar_t>(ecc_span[numECWords - i - 1]));

  DCHECK(!strecc.IsEmpty());
  return strecc;
}

}  // namespace

WideString CBC_ErrorCorrection::EncodeECC200(const WideString& codewords,
                                             const CBC_SymbolInfo* symbolInfo) {
  if (codewords.GetLength() != symbolInfo->data_capacity())
    return WideString();

  WideString sb = codewords;
  size_t blockCount = symbolInfo->GetInterleavedBlockCount();
  if (blockCount == 1) {
    WideString ecc = CreateECCBlock(codewords, symbolInfo->error_codewords());
    if (ecc.IsEmpty())
      return WideString();
    sb += ecc;
  } else {
    std::vector<size_t> dataSizes(blockCount);
    std::vector<size_t> errorSizes(blockCount);
    std::vector<size_t> startPos(blockCount);
    for (size_t i = 0; i < blockCount; ++i) {
      dataSizes[i] = symbolInfo->GetDataLengthForInterleavedBlock();
      errorSizes[i] = symbolInfo->GetErrorLengthForInterleavedBlock();
      startPos[i] = i > 0 ? startPos[i - 1] + dataSizes[i] : 0;
    }

    size_t max_error_sizes =
        *std::max_element(errorSizes.begin(), errorSizes.end()) * blockCount;
    sb.Reserve(sb.GetLength() + max_error_sizes);
    for (size_t i = 0; i < max_error_sizes; ++i)
      sb.InsertAtBack(0);

    for (size_t block = 0; block < blockCount; ++block) {
      WideString temp;
      if (symbolInfo->data_capacity() > block)
        temp.Reserve((symbolInfo->data_capacity() - block / blockCount) + 1);
      for (size_t d = block; d < symbolInfo->data_capacity(); d += blockCount)
        temp.InsertAtBack(static_cast<wchar_t>(codewords[d]));

      WideString ecc = CreateECCBlock(temp, errorSizes[block]);
      if (ecc.IsEmpty())
        return WideString();

      for (size_t pos = 0, i = block; i < errorSizes[block] * blockCount;
           ++pos, i += blockCount) {
        sb.SetAt(symbolInfo->data_capacity() + i, ecc[pos]);
      }
    }
  }
  DCHECK(!sb.IsEmpty());
  return sb;
}