// Copyright 2014 The Chromium 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 "cobalt/media/formats/mp4/box_reader.h"

#include <stdint.h>
#include <string.h>

#include <memory>

#include "base/logging.h"
#include "cobalt/media/base/mock_media_log.h"
#include "cobalt/media/formats/mp4/box_definitions.h"
#include "cobalt/media/formats/mp4/rcheck.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

using ::testing::HasSubstr;
using ::testing::StrictMock;

namespace media {
namespace mp4 {

static const uint8_t kSkipBox[] = {
    // Top-level test box containing three children
    0x00, 0x00, 0x00, 0x40, 's', 'k', 'i', 'p', 0x01, 0x02, 0x03, 0x04, 0x05,
    0x06, 0x07, 0x08, 0xf9, 0x0a, 0x0b, 0x0c, 0xfd, 0x0e, 0x0f, 0x10,
    // Ordinary (8-byte header) child box
    0x00, 0x00, 0x00, 0x0c, 'p', 's', 's', 'h', 0xde, 0xad, 0xbe, 0xef,
    // Extended-size header child box
    0x00, 0x00, 0x00, 0x01, 'p', 's', 's', 'h', 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x14, 0xfa, 0xce, 0xca, 0xfe,
    // Empty free box
    0x00, 0x00, 0x00, 0x08, 'f', 'r', 'e', 'e',
    // Trailing garbage
    0x00};

struct FreeBox : Box {
  bool Parse(BoxReader* reader) override { return true; }
  FourCC BoxType() const override { return FOURCC_FREE; }
};

struct PsshBox : Box {
  uint32_t val;

  bool Parse(BoxReader* reader) override { return reader->Read4(&val); }
  FourCC BoxType() const override { return FOURCC_PSSH; }
};

struct SkipBox : Box {
  uint8_t a, b;
  uint16_t c;
  int32_t d;
  int64_t e;

  std::vector<PsshBox> kids;
  FreeBox mpty;

  bool Parse(BoxReader* reader) override {
    RCHECK(reader->ReadFullBoxHeader() && reader->Read1(&a) &&
           reader->Read1(&b) && reader->Read2(&c) && reader->Read4s(&d) &&
           reader->Read4sInto8s(&e));
    return reader->ScanChildren() && reader->ReadChildren(&kids) &&
           reader->MaybeReadChild(&mpty);
  }
  FourCC BoxType() const override { return FOURCC_SKIP; }

  SkipBox();
  ~SkipBox() OVERRIDE;
};

SkipBox::SkipBox() {}
SkipBox::~SkipBox() {}

class BoxReaderTest : public testing::Test {
 public:
  BoxReaderTest() : media_log_(new StrictMock<MockMediaLog>()) {}

 protected:
  std::vector<uint8_t> GetBuf() {
    return std::vector<uint8_t>(kSkipBox, kSkipBox + sizeof(kSkipBox));
  }

  void TestTopLevelBox(const uint8_t* data, int size, uint32_t fourCC) {
    std::vector<uint8_t> buf(data, data + size);

    bool err;
    std::unique_ptr<BoxReader> reader(
        BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));

    EXPECT_FALSE(err);
    EXPECT_TRUE(reader);
    EXPECT_EQ(fourCC, reader->type());
    EXPECT_EQ(reader->size(), static_cast<uint64_t>(size));
  }

  scoped_refptr<StrictMock<MockMediaLog>> media_log_;
};

TEST_F(BoxReaderTest, ExpectedOperationTest) {
  std::vector<uint8_t> buf = GetBuf();
  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));
  EXPECT_FALSE(err);
  EXPECT_TRUE(reader.get());

  SkipBox box;
  EXPECT_TRUE(box.Parse(reader.get()));
  EXPECT_EQ(0x01, reader->version());
  EXPECT_EQ(0x020304u, reader->flags());
  EXPECT_EQ(0x05, box.a);
  EXPECT_EQ(0x06, box.b);
  EXPECT_EQ(0x0708, box.c);
  EXPECT_EQ(static_cast<int32_t>(0xf90a0b0c), box.d);
  EXPECT_EQ(static_cast<int32_t>(0xfd0e0f10), box.e);

  EXPECT_EQ(2u, box.kids.size());
  EXPECT_EQ(0xdeadbeef, box.kids[0].val);
  EXPECT_EQ(0xfacecafe, box.kids[1].val);

  // Accounting for the extra byte outside of the box above
  EXPECT_EQ(buf.size(), static_cast<uint64_t>(reader->size() + 1));
}

TEST_F(BoxReaderTest, OuterTooShortTest) {
  std::vector<uint8_t> buf = GetBuf();
  bool err;

  // Create a soft failure by truncating the outer box.
  std::unique_ptr<BoxReader> r(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size() - 2, media_log_, &err));

  EXPECT_FALSE(err);
  EXPECT_FALSE(r.get());
}

TEST_F(BoxReaderTest, InnerTooLongTest) {
  std::vector<uint8_t> buf = GetBuf();
  bool err;

  // Make an inner box too big for its outer box.
  buf[25] = 1;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));

  SkipBox box;
  EXPECT_FALSE(box.Parse(reader.get()));
}

TEST_F(BoxReaderTest, WrongFourCCTest) {
  std::vector<uint8_t> buf = GetBuf();
  bool err;

  // Set an unrecognized top-level FourCC.
  buf[4] = 0x44;
  buf[5] = 0x41;
  buf[6] = 0x4c;
  buf[7] = 0x45;

  EXPECT_MEDIA_LOG(HasSubstr("Unrecognized top-level box type DALE"));

  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));
  EXPECT_FALSE(reader.get());
  EXPECT_TRUE(err);
}

TEST_F(BoxReaderTest, ScanChildrenTest) {
  std::vector<uint8_t> buf = GetBuf();
  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));

  EXPECT_TRUE(reader->SkipBytes(16) && reader->ScanChildren());

  FreeBox free;
  EXPECT_TRUE(reader->ReadChild(&free));
  EXPECT_FALSE(reader->ReadChild(&free));
  EXPECT_TRUE(reader->MaybeReadChild(&free));

  std::vector<PsshBox> kids;

  EXPECT_TRUE(reader->ReadChildren(&kids));
  EXPECT_EQ(2u, kids.size());
  kids.clear();
  EXPECT_FALSE(reader->ReadChildren(&kids));
  EXPECT_TRUE(reader->MaybeReadChildren(&kids));
}

TEST_F(BoxReaderTest, ReadAllChildrenTest) {
  std::vector<uint8_t> buf = GetBuf();
  // Modify buffer to exclude its last 'free' box
  buf[3] = 0x38;
  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(&buf[0], buf.size(), media_log_, &err));

  std::vector<PsshBox> kids;
  EXPECT_TRUE(reader->SkipBytes(16) && reader->ReadAllChildren(&kids));
  EXPECT_EQ(2u, kids.size());
  EXPECT_EQ(kids[0].val, 0xdeadbeef);  // Ensure order is preserved
}

TEST_F(BoxReaderTest, SkippingBloc) {
  static const uint8_t kData[] = {0x00, 0x00, 0x00, 0x09, 'b',
                                  'l',  'o',  'c',  0x00};

  TestTopLevelBox(kData, sizeof(kData), FOURCC_BLOC);
}

TEST_F(BoxReaderTest, SkippingEmsg) {
  static const uint8_t kData[] = {
      0x00, 0x00, 0x00, 0x24, 'e', 'm', 's', 'g',
      0x00,                    // version = 0
      0x00, 0x00, 0x00,        // flags = 0
      0x61, 0x00,              // scheme_id_uri = "a"
      0x61, 0x00,              // value = "a"
      0x00, 0x00, 0x00, 0x01,  // timescale = 1
      0x00, 0x00, 0x00, 0x02,  // presentation_time_delta = 2
      0x00, 0x00, 0x00, 0x03,  // event_duration = 3
      0x00, 0x00, 0x00, 0x04,  // id = 4
      0x05, 0x06, 0x07, 0x08,  // message_data[4] = 0x05060708
  };

  TestTopLevelBox(kData, sizeof(kData), FOURCC_EMSG);
}

TEST_F(BoxReaderTest, SkippingUuid) {
  static const uint8_t kData[] = {
      0x00, 0x00, 0x00, 0x19, 'u',  'u',  'i',  'd',
      0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08,
      0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, 0x10,  // usertype
      0x00,
  };

  TestTopLevelBox(kData, sizeof(kData), FOURCC_UUID);
}

TEST_F(BoxReaderTest, NestedBoxWithHugeSize) {
  // This data is not a valid 'emsg' box. It is just used as a top-level box
  // as ReadTopLevelBox() has a restricted set of boxes it allows. |kData|
  // contains all the bytes as specified by the 'emsg' header size.
  // The nested box ('junk') has a large size that was chosen to catch
  // integer overflows. The nested box should not specify more than the
  // number of remaining bytes in the enclosing box.
  static const uint8_t kData[] = {
      0x00, 0x00, 0x00, 0x24, 'e',  'm',  's',  'g',   // outer box
      0x7f, 0xff, 0xff, 0xff, 'j',  'u',  'n',  'k',   // nested box
      0x00, 0x01, 0x00, 0xff, 0xff, 0x00, 0x3b, 0x03,  // random data for rest
      0x00, 0x01, 0x00, 0x03, 0x00, 0x03, 0x00, 0x04, 0x05, 0x06, 0x07, 0x08};

  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(kData, sizeof(kData), media_log_, &err));

  EXPECT_FALSE(err);
  EXPECT_TRUE(reader);
  EXPECT_EQ(FOURCC_EMSG, reader->type());
  EXPECT_FALSE(reader->ScanChildren());
}

TEST_F(BoxReaderTest, ScanChildrenWithInvalidChild) {
  // This data is not a valid 'emsg' box. It is just used as a top-level box
  // as ReadTopLevelBox() has a restricted set of boxes it allows.
  // The nested 'elst' box is used as it includes a count of EditListEntry's.
  // The sample specifies a large number of EditListEntry's, but only 1 is
  // actually included in the box. This test verifies that the code checks
  // properly that the buffer contains the specified number of EditListEntry's
  // (does not cause an int32_t overflow when checking that the bytes are
  // available, and does not read past the end of the buffer).
  static const uint8_t kData[] = {
      0x00, 0x00, 0x00, 0x2c, 'e',  'm',  's',  'g',  // outer box
      0x00, 0x00, 0x00, 0x24, 'e',  'l',  's',  't',  // nested box
      0x01, 0x00, 0x00, 0x00,                         // version = 1, flags = 0
      0xff, 0xff, 0xff, 0xff,  // count = max, but only 1 actually included
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(kData, sizeof(kData), media_log_, &err));

  EXPECT_FALSE(err);
  EXPECT_TRUE(reader);
  EXPECT_EQ(FOURCC_EMSG, reader->type());
  EXPECT_TRUE(reader->ScanChildren());

  // 'elst' specifies lots of EditListEntry's but only includes 1. Thus
  // parsing it should fail.
  EditList child;
  EXPECT_FALSE(reader->ReadChild(&child));
}

TEST_F(BoxReaderTest, ReadAllChildrenWithInvalidChild) {
  // This data is not a valid 'emsg' box. It is just used as a top-level box
  // as ReadTopLevelBox() has a restricted set of boxes it allows.
  // The nested 'trun' box is used as it includes a count of the number
  // of samples. The data specifies a large number of samples, but only 1
  // is actually included in the box. Verifying that the large count does not
  // cause an int32_t overflow which would allow parsing of TrackFragmentRun
  // to read past the end of the buffer.
  static const uint8_t kData[] = {
      0x00, 0x00, 0x00, 0x28, 'e',  'm',  's',  'g',  // outer box
      0x00, 0x00, 0x00, 0x20, 't',  'r',  'u',  'n',  // nested box
      0x00, 0x00, 0x0f, 0x00,  // version = 0, flags = samples present
      0xff, 0xff, 0xff, 0xff,  // count = max, but only 1 actually included
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
      0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};

  bool err;
  std::unique_ptr<BoxReader> reader(
      BoxReader::ReadTopLevelBox(kData, sizeof(kData), media_log_, &err));

  EXPECT_FALSE(err);
  EXPECT_TRUE(reader);
  EXPECT_EQ(FOURCC_EMSG, reader->type());

  // Reading the child should fail since the number of samples specified
  // doesn't match what is in the box.
  std::vector<TrackFragmentRun> children;
  EXPECT_FALSE(reader->ReadAllChildrenAndCheckFourCC(&children));
}

}  // namespace mp4
}  // namespace media