// Copyright 2014 PDFium Authors. All rights reserved.
// 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 2006-2007 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_HighLevelEncoder.h"

#include <limits>
#include <memory>
#include <vector>

#include "core/fxcrt/fx_extension.h"
#include "fxbarcode/common/BC_CommonBitMatrix.h"
#include "fxbarcode/datamatrix/BC_ASCIIEncoder.h"
#include "fxbarcode/datamatrix/BC_Base256Encoder.h"
#include "fxbarcode/datamatrix/BC_C40Encoder.h"
#include "fxbarcode/datamatrix/BC_EdifactEncoder.h"
#include "fxbarcode/datamatrix/BC_Encoder.h"
#include "fxbarcode/datamatrix/BC_EncoderContext.h"
#include "fxbarcode/datamatrix/BC_SymbolInfo.h"
#include "fxbarcode/datamatrix/BC_TextEncoder.h"
#include "fxbarcode/datamatrix/BC_X12Encoder.h"
#include "third_party/base/ptr_util.h"

namespace {

const wchar_t kPad = 129;
const wchar_t kMacro05 = 236;
const wchar_t kMacro06 = 237;
const wchar_t kMacro05Header[] = L"[)>05";
const wchar_t kMacro06Header[] = L"[)>06";
const wchar_t kMacroTrailer = 0x0004;

wchar_t Randomize253State(wchar_t ch, int32_t codewordPosition) {
  int32_t pseudoRandom = ((149 * codewordPosition) % 253) + 1;
  int32_t tempVariable = ch + pseudoRandom;
  return tempVariable <= 254 ? static_cast<wchar_t>(tempVariable)
                             : static_cast<wchar_t>(tempVariable - 254);
}

int32_t FindMinimums(const std::vector<float>& charCounts,
                     std::vector<int32_t>* intCharCounts,
                     std::vector<uint8_t>* mins) {
  for (size_t i = 0; i < mins->size(); ++i)
    (*mins)[i] = 0;

  int32_t min = std::numeric_limits<int32_t>::max();
  for (size_t i = 0; i < 6; ++i) {
    int32_t current = static_cast<int32_t>(ceil(charCounts[i]));
    (*intCharCounts)[i] = current;
    if (min > current) {
      min = current;
      for (size_t j = 0; j < mins->size(); j++)
        (*mins)[j] = 0;
    }
    if (min == current)
      (*mins)[i]++;
  }
  return min;
}

int32_t GetMinimumCount(const std::vector<uint8_t>& mins) {
  ASSERT(mins.size() == 6);
  int32_t count = 0;
  for (int32_t i = 0; i < 6; ++i)
    count += mins[i];
  return count;
}

bool IsNativeC40(wchar_t ch) {
  return (ch == ' ') || (ch >= '0' && ch <= '9') || (ch >= 'A' && ch <= 'Z');
}

bool IsNativeText(wchar_t ch) {
  return (ch == ' ') || (ch >= '0' && ch <= '9') || (ch >= 'a' && ch <= 'z');
}

bool IsX12TermSep(wchar_t ch) {
  return (ch == '\r') || (ch == '*') || (ch == '>');
}

bool IsNativeX12(wchar_t ch) {
  return IsX12TermSep(ch) || (ch == ' ') || (ch >= '0' && ch <= '9') ||
         (ch >= 'A' && ch <= 'Z');
}

bool IsNativeEDIFACT(wchar_t ch) {
  return ch >= ' ' && ch <= '^';
}

}  // namespace

// static
WideString CBC_HighLevelEncoder::EncodeHighLevel(const WideString& msg,
                                                 bool bAllowRectangular) {
  CBC_EncoderContext context(msg, bAllowRectangular);
  if (context.HasCharactersOutsideISO88591Encoding())
    return WideString();

  if (msg.Last() == kMacroTrailer) {
    WideString left = msg.Left(6);
    if (left == kMacro05Header) {
      context.writeCodeword(kMacro05);
      context.setSkipAtEnd(2);
      context.m_pos += 6;
    } else if (left == kMacro06Header) {
      context.writeCodeword(kMacro06);
      context.setSkipAtEnd(2);
      context.m_pos += 6;
    }
  }

  std::vector<std::unique_ptr<CBC_Encoder>> encoders;
  encoders.push_back(pdfium::MakeUnique<CBC_ASCIIEncoder>());
  encoders.push_back(pdfium::MakeUnique<CBC_C40Encoder>());
  encoders.push_back(pdfium::MakeUnique<CBC_TextEncoder>());
  encoders.push_back(pdfium::MakeUnique<CBC_X12Encoder>());
  encoders.push_back(pdfium::MakeUnique<CBC_EdifactEncoder>());
  encoders.push_back(pdfium::MakeUnique<CBC_Base256Encoder>());
  int32_t encodingMode = ASCII_ENCODATION;
  while (context.hasMoreCharacters()) {
    if (!encoders[encodingMode]->Encode(&context))
      return WideString();

    if (context.m_newEncoding >= 0) {
      encodingMode = context.m_newEncoding;
      context.resetEncoderSignal();
    }
  }
  size_t len = context.m_codewords.GetLength();
  if (!context.UpdateSymbolInfo())
    return WideString();

  size_t capacity = context.m_symbolInfo->dataCapacity();
  if (len < capacity) {
    if (encodingMode != ASCII_ENCODATION &&
        encodingMode != BASE256_ENCODATION) {
      context.writeCodeword(0x00fe);
    }
  }
  WideString codewords = context.m_codewords;
  if (codewords.GetLength() < capacity)
    codewords += kPad;

  while (codewords.GetLength() < capacity)
    codewords += Randomize253State(kPad, codewords.GetLength() + 1);

  ASSERT(!codewords.IsEmpty());
  return codewords;
}

// static
int32_t CBC_HighLevelEncoder::LookAheadTest(const WideString& msg,
                                            size_t startpos,
                                            int32_t currentMode) {
  if (startpos >= msg.GetLength())
    return currentMode;

  std::vector<float> charCounts;
  if (currentMode == ASCII_ENCODATION) {
    charCounts = {0, 1, 1, 1, 1, 1.25f};
  } else {
    charCounts = {1, 2, 2, 2, 2, 2.25f};
    charCounts[currentMode] = 0;
  }
  size_t charsProcessed = 0;
  while (true) {
    if ((startpos + charsProcessed) == msg.GetLength()) {
      std::vector<uint8_t> mins(6);
      std::vector<int32_t> intCharCounts(6);
      int32_t min = FindMinimums(charCounts, &intCharCounts, &mins);
      int32_t minCount = GetMinimumCount(mins);
      if (intCharCounts[ASCII_ENCODATION] == min)
        return ASCII_ENCODATION;
      if (minCount == 1 && mins[BASE256_ENCODATION] > 0)
        return BASE256_ENCODATION;
      if (minCount == 1 && mins[EDIFACT_ENCODATION] > 0)
        return EDIFACT_ENCODATION;
      if (minCount == 1 && mins[TEXT_ENCODATION] > 0)
        return TEXT_ENCODATION;
      if (minCount == 1 && mins[X12_ENCODATION] > 0)
        return X12_ENCODATION;
      return C40_ENCODATION;
    }

    wchar_t c = msg[startpos + charsProcessed];
    charsProcessed++;
    if (FXSYS_IsDecimalDigit(c)) {
      charCounts[ASCII_ENCODATION] += 0.5;
    } else if (IsExtendedASCII(c)) {
      charCounts[ASCII_ENCODATION] = ceilf(charCounts[ASCII_ENCODATION]);
      charCounts[ASCII_ENCODATION] += 2;
    } else {
      charCounts[ASCII_ENCODATION] = ceilf(charCounts[ASCII_ENCODATION]);
      charCounts[ASCII_ENCODATION]++;
    }

    if (IsNativeC40(c))
      charCounts[C40_ENCODATION] += 2.0f / 3.0f;
    else if (IsExtendedASCII(c))
      charCounts[C40_ENCODATION] += 8.0f / 3.0f;
    else
      charCounts[C40_ENCODATION] += 4.0f / 3.0f;

    if (IsNativeText(c))
      charCounts[TEXT_ENCODATION] += 2.0f / 3.0f;
    else if (IsExtendedASCII(c))
      charCounts[TEXT_ENCODATION] += 8.0f / 3.0f;
    else
      charCounts[TEXT_ENCODATION] += 4.0f / 3.0f;

    if (IsNativeX12(c))
      charCounts[X12_ENCODATION] += 2.0f / 3.0f;
    else if (IsExtendedASCII(c))
      charCounts[X12_ENCODATION] += 13.0f / 3.0f;
    else
      charCounts[X12_ENCODATION] += 10.0f / 3.0f;

    if (IsNativeEDIFACT(c))
      charCounts[EDIFACT_ENCODATION] += 3.0f / 4.0f;
    else if (IsExtendedASCII(c))
      charCounts[EDIFACT_ENCODATION] += 17.0f / 4.0f;
    else
      charCounts[EDIFACT_ENCODATION] += 13.0f / 4.0f;

    charCounts[BASE256_ENCODATION]++;
    if (charsProcessed < 4)
      continue;

    std::vector<int32_t> intCharCounts(6);
    std::vector<uint8_t> mins(6);
    FindMinimums(charCounts, &intCharCounts, &mins);
    int32_t minCount = GetMinimumCount(mins);
    if (intCharCounts[ASCII_ENCODATION] < intCharCounts[BASE256_ENCODATION] &&
        intCharCounts[ASCII_ENCODATION] < intCharCounts[C40_ENCODATION] &&
        intCharCounts[ASCII_ENCODATION] < intCharCounts[TEXT_ENCODATION] &&
        intCharCounts[ASCII_ENCODATION] < intCharCounts[X12_ENCODATION] &&
        intCharCounts[ASCII_ENCODATION] < intCharCounts[EDIFACT_ENCODATION]) {
      return ASCII_ENCODATION;
    }
    if (intCharCounts[BASE256_ENCODATION] < intCharCounts[ASCII_ENCODATION] ||
        (mins[C40_ENCODATION] + mins[TEXT_ENCODATION] + mins[X12_ENCODATION] +
         mins[EDIFACT_ENCODATION]) == 0) {
      return BASE256_ENCODATION;
    }
    if (minCount == 1 && mins[EDIFACT_ENCODATION] > 0)
      return EDIFACT_ENCODATION;
    if (minCount == 1 && mins[TEXT_ENCODATION] > 0)
      return TEXT_ENCODATION;
    if (minCount == 1 && mins[X12_ENCODATION] > 0)
      return X12_ENCODATION;
    if (intCharCounts[C40_ENCODATION] + 1 < intCharCounts[ASCII_ENCODATION] &&
        intCharCounts[C40_ENCODATION] + 1 < intCharCounts[BASE256_ENCODATION] &&
        intCharCounts[C40_ENCODATION] + 1 < intCharCounts[EDIFACT_ENCODATION] &&
        intCharCounts[C40_ENCODATION] + 1 < intCharCounts[TEXT_ENCODATION]) {
      if (intCharCounts[C40_ENCODATION] < intCharCounts[X12_ENCODATION])
        return C40_ENCODATION;
      if (intCharCounts[C40_ENCODATION] == intCharCounts[X12_ENCODATION]) {
        size_t p = startpos + charsProcessed + 1;
        while (p < msg.GetLength()) {
          wchar_t tc = msg[p];
          if (IsX12TermSep(tc))
            return X12_ENCODATION;
          if (!IsNativeX12(tc))
            break;
          p++;
        }
        return C40_ENCODATION;
      }
    }
  }
}

// static
bool CBC_HighLevelEncoder::IsExtendedASCII(wchar_t ch) {
  return ch >= 128 && ch <= 255;
}