// Copyright (c) the JPEG XL Project Authors.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file or at
// https://developers.google.com/open-source/licenses/bsd

#include <algorithm>
#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <memory>
#include <sstream>
#include <string>
#include <utility>
#include <vector>

#include "lib/base/byte_order.h"
#include "lib/base/common.h"
#include "lib/base/compiler_specific.h"
#include "lib/base/data_parallel.h"
#include "lib/base/float.h"
#include "lib/base/random.h"
#include "lib/base/span.h"
#include "lib/base/status.h"
#include "lib/base/testing.h"
#include "lib/base/types.h"
#include "lib/cms/color_encoding.h"
#include "lib/cms/color_encoding_internal.h"
#include "lib/extras/codestream_header.h"
#include "lib/extras/dec/color_hints.h"
#include "lib/extras/dec/decode.h"
#include "lib/extras/enc/encode.h"
#include "lib/extras/packed_image.h"
#include "lib/extras/test_utils.h"
#include "lib/threads/test_utils.h"

namespace jxl {

using ::jxl::test::ThreadPoolForTests;

namespace extras {

Status PnmParseSigned(Bytes str, double* v);
Status PnmParseUnsigned(Bytes str, size_t* v);

namespace {

float LoadLEFloat16(const uint8_t* p) {
  uint16_t bits16 = LoadLE16(p);
  return detail::LoadFloat16(bits16);
}

float LoadBEFloat16(const uint8_t* p) {
  uint16_t bits16 = LoadBE16(p);
  return detail::LoadFloat16(bits16);
}

size_t GetPrecision(JxlDataType data_type) {
  switch (data_type) {
    case JXL_TYPE_UINT8:
      return 8;
    case JXL_TYPE_UINT16:
      return 16;
    case JXL_TYPE_FLOAT:
      // Floating point mantissa precision
      return 24;
    case JXL_TYPE_FLOAT16:
      return 11;
    default:
      return jxl::test::Check(false), 8;
  }
}

size_t GetDataBits(JxlDataType data_type) {
  switch (data_type) {
    case JXL_TYPE_UINT8:
      return 8;
    case JXL_TYPE_UINT16:
      return 16;
    case JXL_TYPE_FLOAT:
      return 32;
    case JXL_TYPE_FLOAT16:
      return 16;
    default:
      return jxl::test::Check(false), 8;
  }
}

std::vector<double> ConvertToRGBA32(const uint8_t* pixels, size_t xsize,
                                    size_t ysize, const JxlPixelFormat& format,
                                    double factor) {
  std::vector<double> result(xsize * ysize * 4);
  size_t num_channels = format.num_channels;
  bool gray = num_channels == 1 || num_channels == 2;
  bool alpha = num_channels == 2 || num_channels == 4;
  JxlEndianness endianness = format.endianness;
  // Compute actual type:
  if (endianness == JXL_NATIVE_ENDIAN) {
    endianness = IsLittleEndian() ? JXL_LITTLE_ENDIAN : JXL_BIG_ENDIAN;
  }

  size_t stride =
      xsize * jxl::DivCeil(GetDataBits(format.data_type) * num_channels,
                           jxl::kBitsPerByte);
  if (format.align > 1) stride = jxl::RoundUpTo(stride, format.align);

  if (format.data_type == JXL_TYPE_UINT8) {
    // Multiplier to bring to 0-1.0 range
    double mul = factor > 0.0 ? factor : 1.0 / 255.0;
    for (size_t y = 0; y < ysize; ++y) {
      for (size_t x = 0; x < xsize; ++x) {
        size_t j = (y * xsize + x) * 4;
        size_t i = y * stride + x * num_channels;
        double r = pixels[i];
        double g = gray ? r : pixels[i + 1];
        double b = gray ? r : pixels[i + 2];
        double a = alpha ? pixels[i + num_channels - 1] : 255;
        result[j + 0] = r * mul;
        result[j + 1] = g * mul;
        result[j + 2] = b * mul;
        result[j + 3] = a * mul;
      }
    }
  } else if (format.data_type == JXL_TYPE_UINT16) {
    jxl::test::Check(endianness != JXL_NATIVE_ENDIAN);
    // Multiplier to bring to 0-1.0 range
    double mul = factor > 0.0 ? factor : 1.0 / 65535.0;
    for (size_t y = 0; y < ysize; ++y) {
      for (size_t x = 0; x < xsize; ++x) {
        size_t j = (y * xsize + x) * 4;
        size_t i = y * stride + x * num_channels * 2;
        double r;
        double g;
        double b;
        double a;
        if (endianness == JXL_BIG_ENDIAN) {
          r = (pixels[i + 0] << 8) + pixels[i + 1];
          g = gray ? r : (pixels[i + 2] << 8) + pixels[i + 3];
          b = gray ? r : (pixels[i + 4] << 8) + pixels[i + 5];
          a = alpha ? (pixels[i + num_channels * 2 - 2] << 8) +
                          pixels[i + num_channels * 2 - 1]
                    : 65535;
        } else {
          r = (pixels[i + 1] << 8) + pixels[i + 0];
          g = gray ? r : (pixels[i + 3] << 8) + pixels[i + 2];
          b = gray ? r : (pixels[i + 5] << 8) + pixels[i + 4];
          a = alpha ? (pixels[i + num_channels * 2 - 1] << 8) +
                          pixels[i + num_channels * 2 - 2]
                    : 65535;
        }
        result[j + 0] = r * mul;
        result[j + 1] = g * mul;
        result[j + 2] = b * mul;
        result[j + 3] = a * mul;
      }
    }
  } else if (format.data_type == JXL_TYPE_FLOAT) {
    jxl::test::Check(endianness != JXL_NATIVE_ENDIAN);
    for (size_t y = 0; y < ysize; ++y) {
      for (size_t x = 0; x < xsize; ++x) {
        size_t j = (y * xsize + x) * 4;
        size_t i = y * stride + x * num_channels * 4;
        double r;
        double g;
        double b;
        double a;
        if (endianness == JXL_BIG_ENDIAN) {
          r = LoadBEFloat(pixels + i);
          g = gray ? r : LoadBEFloat(pixels + i + 4);
          b = gray ? r : LoadBEFloat(pixels + i + 8);
          a = alpha ? LoadBEFloat(pixels + i + num_channels * 4 - 4) : 1.0;
        } else {
          r = LoadLEFloat(pixels + i);
          g = gray ? r : LoadLEFloat(pixels + i + 4);
          b = gray ? r : LoadLEFloat(pixels + i + 8);
          a = alpha ? LoadLEFloat(pixels + i + num_channels * 4 - 4) : 1.0;
        }
        result[j + 0] = r;
        result[j + 1] = g;
        result[j + 2] = b;
        result[j + 3] = a;
      }
    }
  } else if (format.data_type == JXL_TYPE_FLOAT16) {
    ::jxl::test::Check(endianness != JXL_NATIVE_ENDIAN);
    for (size_t y = 0; y < ysize; ++y) {
      for (size_t x = 0; x < xsize; ++x) {
        size_t j = (y * xsize + x) * 4;
        size_t i = y * stride + x * num_channels * 2;
        double r;
        double g;
        double b;
        double a;
        if (endianness == JXL_BIG_ENDIAN) {
          r = LoadBEFloat16(pixels + i);
          g = gray ? r : LoadBEFloat16(pixels + i + 2);
          b = gray ? r : LoadBEFloat16(pixels + i + 4);
          a = alpha ? LoadBEFloat16(pixels + i + num_channels * 2 - 2) : 1.0;
        } else {
          r = LoadLEFloat16(pixels + i);
          g = gray ? r : LoadLEFloat16(pixels + i + 2);
          b = gray ? r : LoadLEFloat16(pixels + i + 4);
          a = alpha ? LoadLEFloat16(pixels + i + num_channels * 2 - 2) : 1.0;
        }
        result[j + 0] = r;
        result[j + 1] = g;
        result[j + 2] = b;
        result[j + 3] = a;
      }
    }
  } else {
    ::jxl::test::Check(false);  // Unsupported type
  }
  return result;
}

Span<const uint8_t> MakeSpan(const char* str) {
  return Bytes(reinterpret_cast<const uint8_t*>(str), strlen(str));
}

std::string ExtensionFromCodec(Codec codec, const bool is_gray,
                               const bool has_alpha,
                               const size_t bits_per_sample) {
  switch (codec) {
    case Codec::kJPG:
      return ".jpg";
    case Codec::kPGX:
      return ".pgx";
    case Codec::kPNG:
      return ".png";
    case Codec::kPNM:
      if (bits_per_sample == 32) return ".pfm";
      if (has_alpha) return ".pam";
      return is_gray ? ".pgm" : ".ppm";
    case Codec::kEXR:
      return ".exr";
    default:
      return std::string();
  }
}

void VerifySameImage(const PackedImage& im0, size_t bits_per_sample0,
                     const PackedImage& im1, size_t bits_per_sample1,
                     bool lossless = true) {
  ASSERT_EQ(im0.xsize, im1.xsize);
  ASSERT_EQ(im0.ysize, im1.ysize);
  ASSERT_EQ(im0.format.num_channels, im1.format.num_channels);
  auto get_factor = [](JxlPixelFormat f, size_t bits) -> double {
    return 1.0 / ((1u << std::min(GetPrecision(f.data_type), bits)) - 1);
  };
  double factor0 = get_factor(im0.format, bits_per_sample0);
  double factor1 = get_factor(im1.format, bits_per_sample1);
  const auto* pixels0 = static_cast<const uint8_t*>(im0.pixels());
  const auto* pixels1 = static_cast<const uint8_t*>(im1.pixels());
  auto rgba0 =
      ConvertToRGBA32(pixels0, im0.xsize, im0.ysize, im0.format, factor0);
  auto rgba1 =
      ConvertToRGBA32(pixels1, im1.xsize, im1.ysize, im1.format, factor1);
  double tolerance =
      lossless ? 0.5 * std::min(factor0, factor1) : 3.0f / 255.0f;
  if (bits_per_sample0 == 32 || bits_per_sample1 == 32) {
    tolerance = 0.5 * std::max(factor0, factor1);
  }
  for (size_t y = 0; y < im0.ysize; ++y) {
    for (size_t x = 0; x < im0.xsize; ++x) {
      for (size_t c = 0; c < im0.format.num_channels; ++c) {
        size_t ix = (y * im0.xsize + x) * 4 + c;
        double val0 = rgba0[ix];
        double val1 = rgba1[ix];
        ASSERT_NEAR(val1, val0, tolerance)
            << "y = " << y << " x = " << x << " c = " << c;
      }
    }
  }
}

JxlColorEncoding CreateTestColorEncoding(bool is_gray) {
  JxlColorEncoding c;
  c.color_space = is_gray ? JXL_COLOR_SPACE_GRAY : JXL_COLOR_SPACE_RGB;
  c.white_point = JXL_WHITE_POINT_D65;
  c.primaries = JXL_PRIMARIES_P3;
  c.rendering_intent = JXL_RENDERING_INTENT_RELATIVE;
  c.transfer_function = JXL_TRANSFER_FUNCTION_LINEAR;
  // Roundtrip through internal color encoding to fill in primaries and white
  // point CIE xy coordinates.
  ColorEncoding c_internal;
  EXPECT_TRUE(c_internal.FromExternal(c));
  c = c_internal.ToExternal();
  return c;
}

std::vector<uint8_t> GenerateICC(JxlColorEncoding color_encoding) {
  ColorEncoding c;
  EXPECT_TRUE(c.FromExternal(color_encoding));
  EXPECT_TRUE(!c.ICC().empty());
  return c.ICC();
}

void StoreRandomValue(uint8_t* out, Rng* rng, JxlPixelFormat format,
                      size_t bits_per_sample) {
  uint64_t max_val = (1ull << bits_per_sample) - 1;
  if (format.data_type == JXL_TYPE_UINT8) {
    *out = rng->UniformU(0, max_val);
  } else if (format.data_type == JXL_TYPE_UINT16) {
    uint32_t val = rng->UniformU(0, max_val);
    if (format.endianness == JXL_BIG_ENDIAN) {
      StoreBE16(val, out);
    } else {
      StoreLE16(val, out);
    }
  } else {
    ASSERT_EQ(format.data_type, JXL_TYPE_FLOAT);
    float val = rng->UniformF(0.0, 1.0);
    uint32_t uval;
    memcpy(&uval, &val, 4);
    if (format.endianness == JXL_BIG_ENDIAN) {
      StoreBE32(uval, out);
    } else {
      StoreLE32(uval, out);
    }
  }
}

void FillPackedImage(size_t bits_per_sample, PackedImage* image) {
  JxlPixelFormat format = image->format;
  size_t bytes_per_channel = PackedImage::BitsPerChannel(format.data_type) / 8;
  uint8_t* out = static_cast<uint8_t*>(image->pixels());
  size_t stride = image->xsize * format.num_channels * bytes_per_channel;
  ASSERT_EQ(image->pixels_size, image->ysize * stride);
  Rng rng(129);
  for (size_t y = 0; y < image->ysize; ++y) {
    for (size_t x = 0; x < image->xsize; ++x) {
      for (size_t c = 0; c < format.num_channels; ++c) {
        StoreRandomValue(out, &rng, format, bits_per_sample);
        out += bytes_per_channel;
      }
    }
  }
}

struct TestImageParams {
  Codec codec;
  size_t xsize;
  size_t ysize;
  size_t bits_per_sample;
  bool is_gray;
  bool add_alpha;
  bool big_endian;
  bool add_extra_channels;

  bool ShouldTestRoundtrip() const {
    if (codec == Codec::kPNG) {
      return bits_per_sample <= 16;
    } else if (codec == Codec::kPNM) {
      // TODO(szabadka) Make PNM encoder endianness-aware.
      return ((bits_per_sample <= 16 && big_endian) ||
              (bits_per_sample == 32 && !add_alpha && !big_endian));
    } else if (codec == Codec::kPGX) {
      return ((bits_per_sample == 8 || bits_per_sample == 16) && is_gray &&
              !add_alpha);
    } else if (codec == Codec::kEXR) {
#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \
    defined(THREAD_SANITIZER)
      // OpenEXR 2.3 has a memory leak in IlmThread_2_3::ThreadPool
      return false;
#else
      return bits_per_sample == 32 && !is_gray;
#endif
    } else if (codec == Codec::kJPG) {
      return bits_per_sample == 8 && !add_alpha;
    } else {
      return false;
    }
  }

  JxlPixelFormat PixelFormat() const {
    JxlPixelFormat format;
    format.num_channels = (is_gray ? 1 : 3) + (add_alpha ? 1 : 0);
    format.data_type = (bits_per_sample == 32 ? JXL_TYPE_FLOAT
                        : bits_per_sample > 8 ? JXL_TYPE_UINT16
                                              : JXL_TYPE_UINT8);
    format.endianness = big_endian ? JXL_BIG_ENDIAN : JXL_LITTLE_ENDIAN;
    format.align = 0;
    return format;
  }

  std::string DebugString() const {
    std::ostringstream os;
    os << "bps:" << bits_per_sample << " gr:" << is_gray << " al:" << add_alpha
       << " be: " << big_endian << " ec: " << add_extra_channels;
    return os.str();
  }
};

void CreateTestImage(const TestImageParams& params, PackedPixelFile* ppf) {
  ppf->info.xsize = params.xsize;
  ppf->info.ysize = params.ysize;
  ppf->info.bits_per_sample = params.bits_per_sample;
  ppf->info.exponent_bits_per_sample = params.bits_per_sample == 32 ? 8 : 0;
  ppf->info.num_color_channels = params.is_gray ? 1 : 3;
  ppf->info.alpha_bits = params.add_alpha ? params.bits_per_sample : 0;
  ppf->info.alpha_premultiplied = TO_JXL_BOOL(params.codec == Codec::kEXR);

  JxlColorEncoding color_encoding = CreateTestColorEncoding(params.is_gray);
  ppf->icc = GenerateICC(color_encoding);
  ppf->color_encoding = color_encoding;

  JXL_TEST_ASSIGN_OR_DIE(
      PackedFrame frame,
      PackedFrame::Create(params.xsize, params.ysize, params.PixelFormat()));
  FillPackedImage(params.bits_per_sample, &frame.color);
  if (params.add_extra_channels) {
    for (size_t i = 0; i < 7; ++i) {
      JxlPixelFormat ec_format = params.PixelFormat();
      ec_format.num_channels = 1;
      JXL_TEST_ASSIGN_OR_DIE(
          PackedImage ec,
          PackedImage::Create(params.xsize, params.ysize, ec_format));
      FillPackedImage(params.bits_per_sample, &ec);
      frame.extra_channels.emplace_back(std::move(ec));
      PackedExtraChannel pec;
      pec.ec_info.bits_per_sample = params.bits_per_sample;
      pec.ec_info.type = static_cast<JxlExtraChannelType>(i);
      ppf->extra_channels_info.emplace_back(std::move(pec));
    }
  }
  ppf->frames.emplace_back(std::move(frame));
}

// Ensures reading a newly written file leads to the same image pixels.
void TestRoundTrip(const TestImageParams& params, ThreadPool* pool) {
  if (!params.ShouldTestRoundtrip()) return;

  std::string extension = ExtensionFromCodec(
      params.codec, params.is_gray, params.add_alpha, params.bits_per_sample);
  printf("Codec %s %s\n", extension.c_str(), params.DebugString().c_str());

  if (!CanDecode(params.codec)) {
    fprintf(stderr, "Skipping test because of missing decoding support.\n");
    return;
  }
  auto encoder = Encoder::FromExtension(extension);
  if (!encoder) {
    fprintf(stderr, "Skipping test because of missing encoding support.\n");
    return;
  }

  PackedPixelFile ppf_in;
  CreateTestImage(params, &ppf_in);
  EncodedImage encoded;
  ASSERT_TRUE(encoder->Encode(ppf_in, &encoded, pool));
  ASSERT_EQ(encoded.bitstreams.size(), 1);

  PackedPixelFile ppf_out;
  ColorHints color_hints;
  if (params.codec == Codec::kPNM || params.codec == Codec::kPGX) {
    color_hints.Add("color_space",
                    params.is_gray ? "Gra_D65_Rel_SRG" : "RGB_D65_SRG_Rel_SRG");
  }
  ASSERT_TRUE(DecodeBytes(Bytes(encoded.bitstreams[0]), color_hints, &ppf_out));
  if (params.codec == Codec::kPNG && ppf_out.icc.empty()) {
    // Decoding a PNG may drop the ICC profile if there's a valid cICP chunk.
    // Rendering intent is not preserved in this case.
    EXPECT_EQ(ppf_in.color_encoding.color_space,
              ppf_out.color_encoding.color_space);
    EXPECT_EQ(ppf_in.color_encoding.white_point,
              ppf_out.color_encoding.white_point);
    if (ppf_in.color_encoding.color_space != JXL_COLOR_SPACE_GRAY) {
      EXPECT_EQ(ppf_in.color_encoding.primaries,
                ppf_out.color_encoding.primaries);
    }
    EXPECT_EQ(ppf_in.color_encoding.transfer_function,
              ppf_out.color_encoding.transfer_function);
    EXPECT_EQ(ppf_out.color_encoding.rendering_intent,
              JXL_RENDERING_INTENT_RELATIVE);
  } else if (params.codec != Codec::kPNM && params.codec != Codec::kPGX &&
             params.codec != Codec::kEXR) {
    EXPECT_EQ(ppf_in.icc, ppf_out.icc);
  }

  ASSERT_EQ(ppf_out.frames.size(), 1);
  const auto& frame_in = ppf_in.frames[0];
  const auto& frame_out = ppf_out.frames[0];
  VerifySameImage(frame_in.color, ppf_in.info.bits_per_sample, frame_out.color,
                  ppf_out.info.bits_per_sample,
                  /*lossless=*/params.codec != Codec::kJPG);
  ASSERT_EQ(frame_in.extra_channels.size(), frame_out.extra_channels.size());
  ASSERT_EQ(ppf_out.extra_channels_info.size(),
            frame_out.extra_channels.size());
  for (size_t i = 0; i < frame_in.extra_channels.size(); ++i) {
    VerifySameImage(frame_in.extra_channels[i], ppf_in.info.bits_per_sample,
                    frame_out.extra_channels[i], ppf_out.info.bits_per_sample,
                    /*lossless=*/true);
    EXPECT_EQ(ppf_out.extra_channels_info[i].ec_info.type,
              ppf_in.extra_channels_info[i].ec_info.type);
  }
}

TEST(CodecTest, TestRoundTrip) {
  ThreadPoolForTests pool(12);

  TestImageParams params;
  params.xsize = 7;
  params.ysize = 4;

  for (Codec codec :
       {Codec::kPNG, Codec::kPNM, Codec::kPGX, Codec::kEXR, Codec::kJPG}) {
    for (int bits_per_sample : {4, 8, 10, 12, 16, 32}) {
      for (bool is_gray : {false, true}) {
        for (bool add_alpha : {false, true}) {
          for (bool big_endian : {false, true}) {
            params.codec = codec;
            params.bits_per_sample = static_cast<size_t>(bits_per_sample);
            params.is_gray = is_gray;
            params.add_alpha = add_alpha;
            params.big_endian = big_endian;
            params.add_extra_channels = false;
            TestRoundTrip(params, pool.get());
            if (codec == Codec::kPNM && add_alpha) {
              params.add_extra_channels = true;
              TestRoundTrip(params, pool.get());
            }
          }
        }
      }
    }
  }
}

TEST(CodecTest, LosslessPNMRoundtrip) {
  ThreadPoolForTests pool(12);

  static const char* kChannels[] = {"", "g", "ga", "rgb", "rgba"};
  static const char* kExtension[] = {"", ".pgm", ".pam", ".ppm", ".pam"};
  for (size_t bit_depth = 1; bit_depth <= 16; ++bit_depth) {
    for (size_t channels = 1; channels <= 4; ++channels) {
      if (bit_depth == 1 && (channels == 2 || channels == 4)) continue;
      std::string extension(kExtension[channels]);
      std::string filename = "jxl/flower/flower_small." +
                             std::string(kChannels[channels]) + ".depth" +
                             std::to_string(bit_depth) + extension;
      const std::vector<uint8_t> orig = jxl::test::ReadTestData(filename);

      PackedPixelFile ppf;
      ColorHints color_hints;
      color_hints.Add("color_space",
                      channels < 3 ? "Gra_D65_Rel_SRG" : "RGB_D65_SRG_Rel_SRG");
      ASSERT_TRUE(DecodeBytes(Bytes(orig), color_hints, &ppf));

      EncodedImage encoded;
      auto encoder = Encoder::FromExtension(extension);
      ASSERT_TRUE(encoder.get());
      ASSERT_TRUE(encoder->Encode(ppf, &encoded, pool.get()));
      ASSERT_EQ(encoded.bitstreams.size(), 1);
      ASSERT_EQ(orig.size(), encoded.bitstreams[0].size());
      EXPECT_EQ(0,
                memcmp(orig.data(), encoded.bitstreams[0].data(), orig.size()));
    }
  }
}

TEST(CodecTest, TestPNM) {
  size_t u = 77777;  // Initialized to wrong value.
  double d = 77.77;
// Failing to parse invalid strings results in a crash if `JXL_CRASH_ON_ERROR`
// is defined and hence the tests fail. Therefore we only run these tests if
// `JXL_CRASH_ON_ERROR` is not defined.
#if (!JXL_CRASH_ON_ERROR)
  ASSERT_FALSE(PnmParseUnsigned(MakeSpan(""), &u));
  ASSERT_FALSE(PnmParseUnsigned(MakeSpan("+"), &u));
  ASSERT_FALSE(PnmParseUnsigned(MakeSpan("-"), &u));
  ASSERT_FALSE(PnmParseUnsigned(MakeSpan("A"), &u));

  ASSERT_FALSE(PnmParseSigned(MakeSpan(""), &d));
  ASSERT_FALSE(PnmParseSigned(MakeSpan("+"), &d));
  ASSERT_FALSE(PnmParseSigned(MakeSpan("-"), &d));
  ASSERT_FALSE(PnmParseSigned(MakeSpan("A"), &d));
#endif
  ASSERT_TRUE(PnmParseUnsigned(MakeSpan("1"), &u));
  ASSERT_TRUE(u == 1);

  ASSERT_TRUE(PnmParseUnsigned(MakeSpan("32"), &u));
  ASSERT_TRUE(u == 32);

  ASSERT_TRUE(PnmParseSigned(MakeSpan("1"), &d));
  ASSERT_TRUE(d == 1.0);
  ASSERT_TRUE(PnmParseSigned(MakeSpan("+2"), &d));
  ASSERT_TRUE(d == 2.0);
  ASSERT_TRUE(PnmParseSigned(MakeSpan("-3"), &d));
  ASSERT_TRUE(std::abs(d - -3.0) < 1E-15);
  ASSERT_TRUE(PnmParseSigned(MakeSpan("3.141592"), &d));
  ASSERT_TRUE(std::abs(d - 3.141592) < 1E-15);
  ASSERT_TRUE(PnmParseSigned(MakeSpan("-3.141592"), &d));
  ASSERT_TRUE(std::abs(d - -3.141592) < 1E-15);
}

TEST(CodecTest, EncodeToPNG) {
  ThreadPool* const pool = nullptr;

  std::unique_ptr<Encoder> png_encoder = Encoder::FromExtension(".png");
  if (!png_encoder) {
    fprintf(stderr, "Skipping test because of missing codec support.\n");
    return;
  }

  const std::vector<uint8_t> original_png = jxl::test::ReadTestData(
      "external/wesaturate/500px/tmshre_riaphotographs_srgb8.png");
  PackedPixelFile ppf;
  ASSERT_TRUE(extras::DecodeBytes(Bytes(original_png), ColorHints(), &ppf));

  const JxlPixelFormat& format = ppf.frames.front().color.format;
  const auto& format_matcher = [&format](const JxlPixelFormat& candidate) {
    return (candidate.num_channels == format.num_channels) &&
           (candidate.data_type == format.data_type) &&
           (candidate.endianness == format.endianness);
  };
  const auto formats = png_encoder->AcceptedFormats();
  ASSERT_TRUE(std::any_of(formats.begin(), formats.end(), format_matcher));
  EncodedImage encoded_png;
  ASSERT_TRUE(png_encoder->Encode(ppf, &encoded_png, pool));
  EXPECT_TRUE(encoded_png.icc.empty());
  ASSERT_EQ(encoded_png.bitstreams.size(), 1);

  PackedPixelFile decoded_ppf;
  ASSERT_TRUE(extras::DecodeBytes(Bytes(encoded_png.bitstreams.front()),
                                  ColorHints(), &decoded_ppf));

  ASSERT_EQ(decoded_ppf.info.bits_per_sample, ppf.info.bits_per_sample);
  ASSERT_EQ(decoded_ppf.frames.size(), 1);
  VerifySameImage(ppf.frames[0].color, ppf.info.bits_per_sample,
                  decoded_ppf.frames[0].color,
                  decoded_ppf.info.bits_per_sample);
}

}  // namespace
}  // namespace extras
}  // namespace jxl
