// 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 2007 ZXing authors
 *
 * 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 "xfa/fxbarcode/qrcode/BC_QRCoderFormatInformation.h"

#include <limits>

#include "xfa/fxbarcode/qrcode/BC_QRCoderErrorCorrectionLevel.h"
#include "xfa/fxbarcode/utils.h"

namespace {

const uint16_t FORMAT_INFO_MASK_QR = 0X5412;

struct DecodeInfo {
  uint16_t target;
  uint16_t format;
};
const DecodeInfo FORMAT_INFO_DECODE_LOOKUP[32] = {
    {0x5412, 0x00}, {0x5125, 0x01}, {0x5E7C, 0x02}, {0x5B4B, 0x03},
    {0x45F9, 0x04}, {0x40CE, 0x05}, {0x4F97, 0x06}, {0x4AA0, 0x07},
    {0x77C4, 0x08}, {0x72F3, 0x09}, {0x7DAA, 0x0A}, {0x789D, 0x0B},
    {0x662F, 0x0C}, {0x6318, 0x0D}, {0x6C41, 0x0E}, {0x6976, 0x0F},
    {0x1689, 0x10}, {0x13BE, 0x11}, {0x1CE7, 0x12}, {0x19D0, 0x13},
    {0x0762, 0x14}, {0x0255, 0x15}, {0x0D0C, 0x16}, {0x083B, 0x17},
    {0x355F, 0x18}, {0x3068, 0x19}, {0x3F31, 0x1A}, {0x3A06, 0x1B},
    {0x24B4, 0x1C}, {0x2183, 0x1D}, {0x2EDA, 0x1E}, {0x2BED, 0x1F},
};
const uint8_t BITS_SET_IN_HALF_BYTE[] = {0, 1, 1, 2, 1, 2, 2, 3,
                                         1, 2, 2, 3, 2, 3, 3, 4};

CBC_QRCoderFormatInformation* DoDecodeFormatInformation(
    int32_t maskedFormatInfo) {
  int32_t bestDifference = std::numeric_limits<int32_t>::max();
  int32_t bestFormatInfo = 0;
  for (int32_t i = 0; i < 32; ++i) {
    const DecodeInfo& decodeInfo = FORMAT_INFO_DECODE_LOOKUP[i];
    if (decodeInfo.target == maskedFormatInfo)
      return new CBC_QRCoderFormatInformation(decodeInfo.format);

    int32_t bitsDifference = CBC_QRCoderFormatInformation::NumBitsDiffering(
        maskedFormatInfo, decodeInfo.target);
    if (bitsDifference < bestDifference) {
      bestFormatInfo = decodeInfo.format;
      bestDifference = bitsDifference;
    }
  }
  if (bestDifference > 3)
    return nullptr;
  return new CBC_QRCoderFormatInformation(bestFormatInfo);
}

}  // namespace

CBC_QRCoderFormatInformation::CBC_QRCoderFormatInformation(int32_t formatInfo)
    : m_dataMask(static_cast<uint8_t>(formatInfo & 0x07)) {
  m_errorCorrectLevel =
      CBC_QRCoderErrorCorrectionLevel::ForBits((formatInfo >> 3) & 0x03);
}

CBC_QRCoderFormatInformation::~CBC_QRCoderFormatInformation() {}
int32_t CBC_QRCoderFormatInformation::NumBitsDiffering(int32_t a, int32_t b) {
  a ^= b;
  return BITS_SET_IN_HALF_BYTE[a & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 4) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 8) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 12) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 16) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 20) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 24) & 0x0F] +
         BITS_SET_IN_HALF_BYTE[(a >> 28) & 0x0F];
}
uint8_t CBC_QRCoderFormatInformation::GetDataMask() const {
  return m_dataMask;
}

// static
CBC_QRCoderErrorCorrectionLevel*
CBC_QRCoderFormatInformation::GetErrorCorrectionLevel() {
  return m_errorCorrectLevel;
}

// static
CBC_QRCoderFormatInformation*
CBC_QRCoderFormatInformation::DecodeFormatInformation(
    int32_t maskedFormatInfo) {
  CBC_QRCoderFormatInformation* formatInfo =
      DoDecodeFormatInformation(maskedFormatInfo);
  if (formatInfo)
    return formatInfo;
  return DoDecodeFormatInformation(maskedFormatInfo ^ FORMAT_INFO_MASK_QR);
}