// Copyright 2026 Google LLC
//
// 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
//
//    https://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 "formats/riff/reader.h"

#include <cstddef>
#include <cstdint>
#include <string>
#include <vector>

#include "absl/status/status.h"
#include "absl/status/status_macros.h"
#include "absl/status/status_matchers.h"
#include "absl/status/statusor.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/string_view.h"
#include "formats/riff/create_riff.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "riegeli/bytes/string_reader.h"
#include "riegeli/bytes/string_writer.h"
#include "riegeli/endian/endian_writing.h"

namespace credentio {
namespace {

using ::absl_testing::IsOk;
using ::absl_testing::IsOkAndHolds;
using ::absl_testing::StatusIs;
using ::testing::ElementsAre;
using ::testing::HasSubstr;
using ::testing::IsEmpty;

constexpr uint64_t kMaxPayloadSize = 1024 * 1024 * 10;  // 10 MiB

std::string WriteRiffChunkMissingInvalidForm() {
  riegeli::StringWriter writer;
  writer.Write("RIFF");
  riegeli::WriteLittleEndian<uint32_t>(2, writer);
  writer.Write("AB");
  writer.Close();
  return writer.dest();
}

absl::StatusOr<std::vector<RiffChunk>> GetChunks(riegeli::Reader& reader) {
  std::vector<RiffChunk> chunks;
  ABSL_RETURN_IF_ERROR(
      IterateOverRiffChunks(reader, [&chunks](const RiffChunk& chunk) {
        chunks.push_back(chunk);
        return true;
      }));
  return chunks;
}

absl::StatusOr<std::vector<std::string>> ReadChunkPayloads(
    riegeli::Reader& reader, const std::vector<RiffChunk>& chunks) {
  std::vector<std::string> payloads;
  for (const auto& chunk : chunks) {
    ABSL_ASSIGN_OR_RETURN(auto payload, ReadRiffChunkData(reader, chunk));
    payloads.push_back(payload);
  }
  return payloads;
}

TEST(RiffReaderUnitTest, ReadsChunks) {
  std::string contents = credentio_riff::RiffChunk(
      "XYZW", absl::StrCat(credentio_riff::Chunk("ABCD", "first chunk"),
                           credentio_riff::Chunk("EFGH", "second chunk"),
                           credentio_riff::Chunk("IJKL", "third chunk"),
                           credentio_riff::Chunk("MNOP", "fourth chunk")));
  riegeli::StringReader<> input(contents);
  auto chunks_or = GetChunks(input);
  ASSERT_THAT(chunks_or.status(), IsOk());
  auto chunks = *chunks_or;
  ASSERT_THAT(chunks, ElementsAre(
                          RiffChunk{
                              .offset = 0,
                              .length = 92,
                              .id = "RIFF",
                              .type = "XYZW",
                              .data_offset = 12,
                              .data_length = 80,
                          },
                          RiffChunk{
                              .offset = 12,
                              .length = 20,
                              .id = "ABCD",
                              .type = "",
                              .data_offset = 20,
                              .data_length = 11,
                          },
                          RiffChunk{
                              .offset = 32,
                              .length = 20,
                              .id = "EFGH",
                              .type = "",
                              .data_offset = 40,
                              .data_length = 12,
                          },
                          RiffChunk{
                              .offset = 52,
                              .length = 20,
                              .id = "IJKL",
                              .type = "",
                              .data_offset = 60,
                              .data_length = 11,
                          },
                          RiffChunk{
                              .offset = 72,
                              .length = 20,
                              .id = "MNOP",
                              .type = "",
                              .data_offset = 80,
                              .data_length = 12,
                          }));

  // Re-reading payloads requires seeking, ReadRiffChunkData handles it.
  EXPECT_THAT(ReadChunkPayloads(input, {chunks.begin() + 1, chunks.end()}),
              IsOkAndHolds(ElementsAre("first chunk", "second chunk",
                                       "third chunk", "fourth chunk")));
}

TEST(RiffReaderUnitTest, MissingChunkTypeForChunkWithSubchunks) {
  std::string contents = WriteRiffChunkMissingInvalidForm();
  riegeli::StringReader<> input(contents);

  EXPECT_THAT(GetChunks(input),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("RIFF/LIST chunk too short")));
}

TEST(ReadChunkDataTest, SuccessfulRead) {
  std::string contents = "RIFF....WEBPVP8 ....";
  //                     01234567890123456789
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 12,
      .length = 8,
      .id = "VP8 ",
      .type = "",
      .data_offset = 12,
      .data_length = 8,
  };
  EXPECT_THAT(ReadRiffChunkData(input, chunk), IsOkAndHolds("VP8 ...."));
}

TEST(ReadChunkDataTest, ReadBeyondEOF) {
  std::string contents = "RIFF....WEBPVP8 ....";
  //                     01234567890123456789
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 12,
      .length = 8,
      .id = "VP8 ",
      .type = "",
      .data_offset = 12,
      .data_length = 10,  // Reads past end of contents
  };
  EXPECT_THAT(
      ReadRiffChunkData(input, chunk),
      StatusIs(absl::StatusCode::kDataLoss, HasSubstr("kUnexpectedEof")));
}

TEST(ReadChunkDataTest, EmptyChunk) {
  std::string contents = "RIFF....WEBPVP8 ....";
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 12,
      .length = 0,
      .id = "VP8 ",
      .type = "",
      .data_offset = 12,
      .data_length = 0,
  };
  EXPECT_THAT(ReadRiffChunkData(input, chunk), IsOkAndHolds(IsEmpty()));
}

TEST(ReadChunkDataTest, ReadAtEOF) {
  std::string contents = "RIFF....WEBPVP8 ....";
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 20,
      .length = 0,
      .id = "....",
      .type = "",
      .data_offset = 20,
      .data_length = 0,
  };
  EXPECT_THAT(ReadRiffChunkData(input, chunk), IsOkAndHolds(IsEmpty()));
}

TEST(ReadChunkDataTest, InvalidDataOffset) {
  std::string contents = "RIFF....WEBPVP8 ....";
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 12,
      .length = 8,
      .id = "VP8 ",
      .type = "",
      .data_offset = 100,  // Past EOF
      .data_length = 1,
  };
  EXPECT_THAT(ReadRiffChunkData(input, chunk),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("Failed to seek to chunk data offset")));
}

TEST(ReadChunkDataTest, ChunkTooLarge) {
  std::string contents = "";  // Not actually read in this test
  riegeli::StringReader<> input(contents);
  RiffChunk chunk = {
      .offset = 12,
      .length = kMaxPayloadSize + 9,
      .id = "C2PA",
      .type = "",
      .data_offset = 20,
      .data_length = kMaxPayloadSize + 1,
  };
  EXPECT_THAT(ReadRiffChunkData(input, chunk),
              StatusIs(absl::StatusCode::kInvalidArgument,
                       HasSubstr("RIFF C2PA chunk is too large to extract")));
}

TEST(RiffReaderUnitTest, ProcessorConsumesDataOfContainer) {
  std::string contents =
      credentio_riff::RiffChunk("WAVE", credentio_riff::ListChunk("INFO", "x"));
  riegeli::StringReader<> input(contents);

  auto processor = [&input](const RiffChunk& chunk) -> absl::StatusOr<bool> {
    if (chunk.id == "LIST") {
      std::string data;
      if (!input.Read(1, data)) {
        return absl::DataLossError("failed to read");
      }
      EXPECT_EQ(data, "x");
    }
    return true;
  };

  EXPECT_THAT(IterateOverRiffChunks(input, processor), IsOk());
}

TEST(RiffReaderUnitTest, OddContainerWithOddSubchunkAtEnd) {
  riegeli::StringWriter writer;
  writer.Write("RIFF");
  riegeli::WriteLittleEndian<uint32_t>(26, writer);
  writer.Write("WAVE");
  writer.Write("LIST");
  riegeli::WriteLittleEndian<uint32_t>(13, writer);
  writer.Write("INFO");
  writer.Write("ISFT");
  riegeli::WriteLittleEndian<uint32_t>(1, writer);
  writer.Write("a");
  writer.Write('\0');  // LIST pad
  writer.Close();
  std::string contents = writer.dest();

  riegeli::StringReader<> input(contents);
  auto chunks_or = GetChunks(input);
  ASSERT_THAT(chunks_or.status(), IsOk());
  auto chunks = *chunks_or;
  ASSERT_THAT(chunks, ElementsAre(
                          RiffChunk{
                              .offset = 0,
                              .length = 34,
                              .id = "RIFF",
                              .type = "WAVE",
                              .data_offset = 12,
                              .data_length = 22,
                          },
                          RiffChunk{
                              .offset = 12,
                              .length = 22,
                              .id = "LIST",
                              .type = "INFO",
                              .data_offset = 24,
                              .data_length = 9,
                          },
                          RiffChunk{
                              .offset = 24,
                              .length = 10,
                              .id = "ISFT",
                              .type = "",
                              .data_offset = 32,
                              .data_length = 1,
                          }));
}

class NoSizeReader : public riegeli::Reader {
 public:
  bool SupportsSize() override { return false; }
  bool PullSlow(size_t min_length, size_t recommended_length) override {
    return false;
  }
};

TEST(RiffReaderTest, IterateOverRiffChunksRequiresSize) {
  NoSizeReader reader;
  EXPECT_THAT(
      IterateOverRiffChunks(reader, [](const RiffChunk&) { return true; }),
      StatusIs(absl::StatusCode::kInvalidArgument,
               HasSubstr("reader size cannot be determined")));
}

TEST(RiffReaderTest, OverflowChunkSizeNoInfiniteLoop) {
  riegeli::StringWriter writer;
  writer.Write("RIFF");
  riegeli::WriteLittleEndian<uint32_t>(20, writer);
  writer.Write("WAVE");
  writer.Write("JUNK");
  riegeli::WriteLittleEndian<uint32_t>(0xFFFFFFF8, writer);
  writer.Close();
  std::string contents = writer.dest();

  riegeli::StringReader<> input(contents);
  EXPECT_THAT(
      IterateOverRiffChunks(input, [](const RiffChunk&) { return true; }),
      StatusIs(absl::StatusCode::kInvalidArgument,
               HasSubstr("RIFF chunk extends beyond the end of the file")));
}

}  // namespace
}  // namespace credentio