// Copyright (c) the JPEG XL Project Authors. All rights reserved.

//

// Use of this source code is governed by a BSD-style

// license that can be found in the LICENSE file.

#include "lib/jxl/jpeg/jpeg_data.h"

#include <jxl/types.h>

#include <algorithm>

#include <cstddef>

#include <cstdint>

#include <cstring>

#include <hwy/base.h>

#include <vector>

#include "lib/jxl/base/common.h"

#include "lib/jxl/base/printf_macros.h"

#include "lib/jxl/base/status.h"

#include "lib/jxl/common.h"  // kMaxNumPasses, JPEGXL_ENABLE_TRANSCODE_JPEG

#include "lib/jxl/field_encodings.h"

#include "lib/jxl/fields.h"

namespace jxl {

namespace jpeg {

#if JPEGXL_ENABLE_TRANSCODE_JPEG

namespace {

enum JPEGComponentType : uint32_t {

  kGray = 0,

  kYCbCr = 1,

  kRGB = 2,

  kCustom = 3,

};

struct JPEGInfo {

  size_t num_app_markers = 0;

  size_t num_com_markers = 0;

  size_t num_scans = 0;

  size_t num_intermarker = 0;

  bool has_dri = false;

};

Status VisitMarker(uint8_t* marker, Visitor* visitor, JPEGInfo* info) {

  uint32_t marker32 = *marker - 0xc0;

  JXL_RETURN_IF_ERROR(visitor->Bits(6, 0x00, &marker32));

  *marker = marker32 + 0xc0;

  if ((*marker & 0xf0) == 0xe0) {

    info->num_app_markers++;

  }

  if (*marker == 0xfe) {

    info->num_com_markers++;

  }

  if (*marker == 0xda) {

    info->num_scans++;

  }

  // We use a fake 0xff marker to signal intermarker data.

  if (*marker == 0xff) {

    info->num_intermarker++;

  }

  if (*marker == 0xdd) {

    info->has_dri = true;

  }

  return true;

}

}  // namespace

Status JPEGData::VisitFields(Visitor* visitor) {

  bool is_gray = components.size() == 1;

  JXL_RETURN_IF_ERROR(visitor->Bool(false, &is_gray));

  if (visitor->IsReading()) {

    components.resize(is_gray ? 1 : 3);

  }

  JPEGInfo info;

  if (visitor->IsReading()) {

    uint8_t marker = 0xc0;

    do {

      JXL_RETURN_IF_ERROR(VisitMarker(&marker, visitor, &info));

      marker_order.push_back(marker);

      if (marker_order.size() > 16384) {

        return JXL_FAILURE("Too many markers: %" PRIuS "\n",

                           marker_order.size());

      }

    } while (marker != 0xd9);

  } else {

    if (marker_order.size() > 16384) {

      return JXL_FAILURE("Too many markers: %" PRIuS "\n", marker_order.size());

    }

    for (uint8_t& marker : marker_order) {

      JXL_RETURN_IF_ERROR(VisitMarker(&marker, visitor, &info));

    }

    if (!marker_order.empty()) {

      // Last marker should always be EOI marker.

      JXL_ENSURE(marker_order.back() == 0xd9);

    }

  }

  // Size of the APP and COM markers.

  if (visitor->IsReading()) {

    app_data.resize(info.num_app_markers);

    app_marker_type.resize(info.num_app_markers);

    com_data.resize(info.num_com_markers);

    scan_info.resize(info.num_scans);

  }

  JXL_ENSURE(app_data.size() == info.num_app_markers);

  JXL_ENSURE(app_marker_type.size() == info.num_app_markers);

  JXL_ENSURE(com_data.size() == info.num_com_markers);

  JXL_ENSURE(scan_info.size() == info.num_scans);

  for (size_t i = 0; i < app_data.size(); i++) {

    auto& app = app_data[i];

    // Encodes up to 8 different values.

    JXL_RETURN_IF_ERROR(

        visitor->U32(Val(0), Val(1), BitsOffset(1, 2), BitsOffset(2, 4), 0,

                     reinterpret_cast<uint32_t*>(&app_marker_type[i])));

    if (app_marker_type[i] != AppMarkerType::kUnknown &&

        app_marker_type[i] != AppMarkerType::kICC &&

        app_marker_type[i] != AppMarkerType::kExif &&

        app_marker_type[i] != AppMarkerType::kXMP) {

      return JXL_FAILURE("Unknown app marker type %u",

                         static_cast<uint32_t>(app_marker_type[i]));

    }

    uint32_t len = app.size() - 1;

    JXL_RETURN_IF_ERROR(visitor->Bits(16, 0, &len));

    if (visitor->IsReading()) app.resize(len + 1);

    if (app.size() < 3) {

      return JXL_FAILURE("Invalid marker size: %" PRIuS "\n", app.size());

    }

  }

  for (auto& com : com_data) {

    uint32_t len = com.size() - 1;

    JXL_RETURN_IF_ERROR(visitor->Bits(16, 0, &len));

    if (visitor->IsReading()) com.resize(len + 1);

    if (com.size() < 3) {

      return JXL_FAILURE("Invalid marker size: %" PRIuS "\n", com.size());

    }

  }

  uint32_t num_quant_tables = quant.size();

  JXL_RETURN_IF_ERROR(

      visitor->U32(Val(1), Val(2), Val(3), Val(4), 2, &num_quant_tables));

  if (num_quant_tables == 4) {

    return JXL_FAILURE("Invalid number of quant tables");

  }

  if (visitor->IsReading()) {

    quant.resize(num_quant_tables);

  }

  for (size_t i = 0; i < num_quant_tables; i++) {

    if (quant[i].precision > 1) {

      return JXL_FAILURE(

          "Quant tables with more than 16 bits are not supported");

    }

    JXL_RETURN_IF_ERROR(visitor->Bits(1, 0, &quant[i].precision));

    JXL_RETURN_IF_ERROR(visitor->Bits(2, i, &quant[i].index));

    JXL_RETURN_IF_ERROR(visitor->Bool(true, &quant[i].is_last));

  }

  JPEGComponentType component_type =

      components.size() == 1 && components[0].id == 1 ? JPEGComponentType::kGray

      : components.size() == 3 && components[0].id == 1 &&

              components[1].id == 2 && components[2].id == 3

          ? JPEGComponentType::kYCbCr

      : components.size() == 3 && components[0].id == 'R' &&

              components[1].id == 'G' && components[2].id == 'B'

          ? JPEGComponentType::kRGB

          : JPEGComponentType::kCustom;

  JXL_RETURN_IF_ERROR(

      visitor->Bits(2, JPEGComponentType::kYCbCr,

                    reinterpret_cast<uint32_t*>(&component_type)));

  uint32_t num_components;

  if (component_type == JPEGComponentType::kGray) {

    num_components = 1;

  } else if (component_type != JPEGComponentType::kCustom) {

    num_components = 3;

  } else {

    num_components = components.size();

    JXL_RETURN_IF_ERROR(

        visitor->U32(Val(1), Val(2), Val(3), Val(4), 3, &num_components));

    if (num_components != 1 && num_components != 3) {

      return JXL_FAILURE("Invalid number of components: %u", num_components);

    }

  }

  if (visitor->IsReading()) {

    components.resize(num_components);

  }

  if (component_type == JPEGComponentType::kCustom) {

    for (auto& component : components) {

      JXL_RETURN_IF_ERROR(visitor->Bits(8, 0, &component.id));

    }

  } else if (component_type == JPEGComponentType::kGray) {

    components[0].id = 1;

  } else if (component_type == JPEGComponentType::kRGB) {

    components[0].id = 'R';

    components[1].id = 'G';

    components[2].id = 'B';

  } else {

    components[0].id = 1;

    components[1].id = 2;

    components[2].id = 3;

  }

  size_t used_tables = 0;

  for (size_t i = 0; i < components.size(); i++) {

    JXL_RETURN_IF_ERROR(visitor->Bits(2, 0, &components[i].quant_idx));

    if (components[i].quant_idx >= quant.size()) {

      return JXL_FAILURE("Invalid quant table for component %" PRIuS ": %u\n",

                         i, components[i].quant_idx);

    }

    used_tables |= 1U << components[i].quant_idx;

  }

  for (size_t i = 0; i < quant.size(); i++) {

    if (used_tables & (1 << i)) continue;

    if (i == 0) return JXL_FAILURE("First quant table unused.");

    // Unused quant table has to be set to copy of previous quant table

    for (size_t j = 0; j < 64; j++) {

      if (quant[i].values[j] != quant[i - 1].values[j]) {

        return JXL_FAILURE("Non-trivial unused quant table");

      }

    }

  }

  uint32_t num_huff = huffman_code.size();

  JXL_RETURN_IF_ERROR(visitor->U32(Val(4), BitsOffset(3, 2), BitsOffset(4, 10),

                                   BitsOffset(6, 26), 4, &num_huff));

  if (visitor->IsReading()) {

    huffman_code.resize(num_huff);

  }

  for (JPEGHuffmanCode& hc : huffman_code) {

    bool is_ac = ((hc.slot_id >> 4) != 0);

    uint32_t id = hc.slot_id & 0xF;

    JXL_RETURN_IF_ERROR(visitor->Bool(false, &is_ac));

    JXL_RETURN_IF_ERROR(visitor->Bits(2, 0, &id));

    hc.slot_id = (static_cast<uint32_t>(is_ac) << 4) | id;

    JXL_RETURN_IF_ERROR(visitor->Bool(true, &hc.is_last));

    size_t num_symbols = 0;

    for (size_t i = 0; i <= 16; i++) {

      JXL_RETURN_IF_ERROR(visitor->U32(Val(0), Val(1), BitsOffset(3, 2),

                                       Bits(8), 0, &hc.counts[i]));

      num_symbols += hc.counts[i];

    }

    if (num_symbols == 0) {

      // Actually, at least 2 symbols are required, since one of them is EOI.

      // This case is used to represent an empty DHT marker.

      continue;

    }

    if (num_symbols > hc.values.size()) {

      return JXL_FAILURE("Huffman code too large (%" PRIuS ")", num_symbols);

    }

    // Presence flags for 4 * 64 + 1 values.

    uint64_t value_slots[5] = {};

    for (size_t i = 0; i < num_symbols; i++) {

      // Goes up to 256, included. Might have the same symbol appear twice...

      JXL_RETURN_IF_ERROR(visitor->U32(Bits(2), BitsOffset(2, 4),

                                       BitsOffset(4, 8), BitsOffset(8, 1), 0,

                                       &hc.values[i]));

      value_slots[hc.values[i] >> 6] |= static_cast<uint64_t>(1)

                                        << (hc.values[i] & 0x3F);

    }

    if (hc.values[num_symbols - 1] != kJpegHuffmanAlphabetSize) {

      return JXL_FAILURE("Missing EOI symbol");

    }

    // Last element, denoting EOI, have to be 1 after the loop.

    JXL_ENSURE(value_slots[4] == 1);

    size_t num_values = 1;

    for (size_t i = 0; i < 4; ++i) num_values += hwy::PopCount(value_slots[i]);

    if (num_values != num_symbols) {

      return JXL_FAILURE("Duplicate Huffman symbols");

    }

    if (!is_ac) {

      bool only_dc = ((value_slots[0] >> kJpegDCAlphabetSize) | value_slots[1] |

                      value_slots[2] | value_slots[3]) == 0;

      if (!only_dc) return JXL_FAILURE("Huffman symbols out of DC range");

    }

  }

  for (auto& scan : scan_info) {

    JXL_RETURN_IF_ERROR(

        visitor->U32(Val(1), Val(2), Val(3), Val(4), 1, &scan.num_components));

    if (scan.num_components >= 4) {

      return JXL_FAILURE("Invalid number of components in SOS marker");

    }

    JXL_RETURN_IF_ERROR(visitor->Bits(6, 0, &scan.Ss));

    JXL_RETURN_IF_ERROR(visitor->Bits(6, 63, &scan.Se));

    JXL_RETURN_IF_ERROR(visitor->Bits(4, 0, &scan.Al));

    JXL_RETURN_IF_ERROR(visitor->Bits(4, 0, &scan.Ah));

    for (size_t i = 0; i < scan.num_components; i++) {

      JXL_RETURN_IF_ERROR(visitor->Bits(2, 0, &scan.components[i].comp_idx));

      if (scan.components[i].comp_idx >= components.size()) {

        return JXL_FAILURE("Invalid component idx in SOS marker");

      }

      JXL_RETURN_IF_ERROR(visitor->Bits(2, 0, &scan.components[i].ac_tbl_idx));

      JXL_RETURN_IF_ERROR(visitor->Bits(2, 0, &scan.components[i].dc_tbl_idx));

    }

    // TODO(veluca): actually set and use this value.

    JXL_RETURN_IF_ERROR(visitor->U32(Val(0), Val(1), Val(2), BitsOffset(3, 3),

                                     kMaxNumPasses - 1,

                                     &scan.last_needed_pass));

  }

  // From here on, this is data that is not strictly necessary to get a valid

  // JPEG, but necessary for bit-exact JPEG reconstruction.

  if (info.has_dri) {

    JXL_RETURN_IF_ERROR(visitor->Bits(16, 0, &restart_interval));

  }

  for (auto& scan : scan_info) {

    uint32_t num_reset_points = scan.reset_points.size();

    JXL_RETURN_IF_ERROR(visitor->U32(Val(0), BitsOffset(2, 1), BitsOffset(4, 4),

                                     BitsOffset(16, 20), 0, &num_reset_points));

    if (visitor->IsReading()) {

      scan.reset_points.resize(num_reset_points);

    }

    int last_block_idx = -1;

    for (auto& block_idx : scan.reset_points) {

      block_idx -= last_block_idx + 1;

      JXL_RETURN_IF_ERROR(visitor->U32(Val(0), BitsOffset(3, 1),

                                       BitsOffset(5, 9), BitsOffset(28, 41), 0,

                                       &block_idx));

      block_idx += last_block_idx + 1;

      if (block_idx >= (3u << 26)) {

        // At most 8K x 8K x num_channels blocks are possible in a JPEG.

        // So valid block indices are below 3 * 2^26.

        return JXL_FAILURE("Invalid block ID: %u", block_idx);

      }

      last_block_idx = block_idx;

    }

    uint32_t num_extra_zero_runs = scan.extra_zero_runs.size();

    JXL_RETURN_IF_ERROR(visitor->U32(Val(0), BitsOffset(2, 1), BitsOffset(4, 4),

                                     BitsOffset(16, 20), 0,

                                     &num_extra_zero_runs));

    if (visitor->IsReading()) {

      scan.extra_zero_runs.resize(num_extra_zero_runs);

    }

    last_block_idx = -1;

    for (auto& extra_zero_run : scan.extra_zero_runs) {

      uint32_t& block_idx = extra_zero_run.block_idx;

      JXL_RETURN_IF_ERROR(visitor->U32(Val(1), BitsOffset(2, 2),

                                       BitsOffset(4, 5), BitsOffset(8, 20), 1,

                                       &extra_zero_run.num_extra_zero_runs));

      block_idx -= last_block_idx + 1;

      JXL_RETURN_IF_ERROR(visitor->U32(Val(0), BitsOffset(3, 1),

                                       BitsOffset(5, 9), BitsOffset(28, 41), 0,

                                       &block_idx));

      block_idx += last_block_idx + 1;

      if (block_idx > (3u << 26)) {

        return JXL_FAILURE("Invalid block ID: %u", block_idx);

      }

      last_block_idx = block_idx;

    }

  }

  std::vector<uint32_t> inter_marker_data_sizes;

  inter_marker_data_sizes.reserve(info.num_intermarker);

  for (size_t i = 0; i < info.num_intermarker; ++i) {

    uint32_t len = visitor->IsReading() ? 0 : inter_marker_data[i].size();

    JXL_RETURN_IF_ERROR(visitor->Bits(16, 0, &len));

    if (visitor->IsReading()) inter_marker_data_sizes.emplace_back(len);

  }

  uint32_t tail_data_len = tail_data.size();

  if (!visitor->IsReading() && tail_data_len > 4260096) {

    return JXL_FAILURE("Tail data too large (max size = 4260096, size = %u)",

                       tail_data_len);

  }

  JXL_RETURN_IF_ERROR(visitor->U32(Val(0), BitsOffset(8, 1),

                                   BitsOffset(16, 257), BitsOffset(22, 65793),

                                   0, &tail_data_len));

  JXL_RETURN_IF_ERROR(visitor->Bool(false, &has_zero_padding_bit));

  if (has_zero_padding_bit) {

    uint32_t nbit = padding_bits.size();

    JXL_RETURN_IF_ERROR(visitor->Bits(24, 0, &nbit));

    if (visitor->IsReading()) {

      JXL_RETURN_IF_ERROR(CheckHasEnoughBits(visitor, nbit));

      padding_bits.reserve(std::min<uint32_t>(1024u, nbit));

      for (uint32_t i = 0; i < nbit; i++) {

        bool bbit = false;

        JXL_RETURN_IF_ERROR(visitor->Bool(false, &bbit));

        padding_bits.push_back(TO_JXL_BOOL(bbit));

      }

    } else {

      for (uint8_t& bit : padding_bits) {

        bool bbit = FROM_JXL_BOOL(bit);

        JXL_RETURN_IF_ERROR(visitor->Bool(false, &bbit));

        bit = TO_JXL_BOOL(bbit);

      }

    }

  }

  {

    size_t dht_index = 0;

    size_t scan_index = 0;

    bool is_progressive = false;

    bool ac_ok[kMaxHuffmanTables] = {false};

    bool dc_ok[kMaxHuffmanTables] = {false};

    for (uint8_t marker : marker_order) {

      if (marker == 0xC2) {

        is_progressive = true;

      } else if (marker == 0xC4) {

        for (; dht_index < huffman_code.size();) {

          const JPEGHuffmanCode& huff = huffman_code[dht_index++];

          size_t index = huff.slot_id;

          if (index & 0x10) {

            index -= 0x10;

            ac_ok[index] = true;

          } else {

            dc_ok[index] = true;

          }

          if (huff.is_last) break;

        }

      } else if (marker == 0xDA) {

        const JPEGScanInfo& si = scan_info[scan_index++];

        for (size_t i = 0; i < si.num_components; ++i) {

          const JPEGComponentScanInfo& csi = si.components[i];

          size_t dc_tbl_idx = csi.dc_tbl_idx;

          size_t ac_tbl_idx = csi.ac_tbl_idx;

          bool want_dc = !is_progressive || (si.Ss == 0);

          if (want_dc && !dc_ok[dc_tbl_idx]) {

            return JXL_FAILURE("DC Huffman table used before defined");

          }

          bool want_ac = !is_progressive || (si.Ss != 0) || (si.Se != 0);

          if (want_ac && !ac_ok[ac_tbl_idx]) {

            return JXL_FAILURE("AC Huffman table used before defined");

          }

        }

      }

    }

  }

  // Apply postponed actions.

  if (visitor->IsReading()) {

    tail_data.resize(tail_data_len);

    JXL_ENSURE(inter_marker_data_sizes.size() == info.num_intermarker);

    inter_marker_data.reserve(info.num_intermarker);

    for (size_t i = 0; i < info.num_intermarker; ++i) {

      inter_marker_data.emplace_back(inter_marker_data_sizes[i]);

    }

  }

  return true;

}

#endif  // JPEGXL_ENABLE_TRANSCODE_JPEG

void JPEGData::CalculateMcuSize(const JPEGScanInfo& scan, int* MCUs_per_row,

                                int* MCU_rows) const {

  const bool is_interleaved = (scan.num_components > 1);

  const JPEGComponent& base_component = components[scan.components[0].comp_idx];

  // h_group / v_group act as numerators for converting number of blocks to

  // number of MCU. In interleaved mode it is 1, so MCU is represented with

  // max_*_samp_factor blocks. In non-interleaved mode we choose numerator to

  // be the samping factor, consequently MCU is always represented with single

  // block.

  const int h_group = is_interleaved ? 1 : base_component.h_samp_factor;

  const int v_group = is_interleaved ? 1 : base_component.v_samp_factor;

  int max_h_samp_factor = 1;

  int max_v_samp_factor = 1;

  for (const auto& c : components) {

    max_h_samp_factor = std::max(c.h_samp_factor, max_h_samp_factor);

    max_v_samp_factor = std::max(c.v_samp_factor, max_v_samp_factor);

  }

  *MCUs_per_row = DivCeil(width * h_group, 8 * max_h_samp_factor);

  *MCU_rows = DivCeil(height * v_group, 8 * max_v_samp_factor);

}

#if JPEGXL_ENABLE_TRANSCODE_JPEG

Status SetJPEGDataFromICC(const std::vector<uint8_t>& icc,

                          jpeg::JPEGData* jpeg_data) {

  size_t icc_pos = 0;

  for (size_t i = 0; i < jpeg_data->app_data.size(); i++) {

    if (jpeg_data->app_marker_type[i] != jpeg::AppMarkerType::kICC) {

      continue;

    }

    size_t len = jpeg_data->app_data[i].size() - 17;

    if (icc_pos + len > icc.size()) {

      return JXL_FAILURE(

          "ICC length is less than APP markers: requested %" PRIuS

          " more bytes, "

          "%" PRIuS " available",

          len, icc.size() - icc_pos);

    }

    memcpy(&jpeg_data->app_data[i][17], icc.data() + icc_pos, len);

    icc_pos += len;

  }

  if (icc_pos != icc.size() && icc_pos != 0) {

    return JXL_FAILURE("ICC length is more than APP markers");

  }

  return true;

}

#endif  // JPEGXL_ENABLE_TRANSCODE_JPEG

}  // namespace jpeg

}  // namespace jxl