#include "gtest/gtest.h"

#include "nsCOMPtr.h"
#include "nsIPipe.h"
#include "nsStreamUtils.h"
#include "nsString.h"
#include "nsStringStream.h"
#include "mozilla/net/PartiallySeekableInputStream.h"

using mozilla::net::PartiallySeekableInputStream;

class NonSeekableStream final : public nsIInputStream
{
  nsCOMPtr<nsIInputStream> mStream;

public:
  NS_DECL_THREADSAFE_ISUPPORTS

  explicit NonSeekableStream(const nsACString& aBuffer)
  {
    NS_NewCStringInputStream(getter_AddRefs(mStream), aBuffer);
  }

  NS_IMETHOD
  Available(uint64_t* aLength) override
  {
    return mStream->Available(aLength);
  }

  NS_IMETHOD
  Read(char* aBuffer, uint32_t aCount, uint32_t* aReadCount) override
  {
    return mStream->Read(aBuffer, aCount, aReadCount);
  }

  NS_IMETHOD
  ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
               uint32_t aCount, uint32_t *aResult) override
  {
    return mStream->ReadSegments(aWriter, aClosure, aCount, aResult);
  }

  NS_IMETHOD
  Close() override
  {
    return mStream->Close();
  }

  NS_IMETHOD
  IsNonBlocking(bool* aNonBlocking) override
  {
    return mStream->IsNonBlocking(aNonBlocking);
  }

private:
  ~NonSeekableStream() {}
};

NS_IMPL_ISUPPORTS(NonSeekableStream, nsIInputStream)

// Helper function for creating a non-seekable nsIInputStream + a
// PartiallySeekableInputStream.
PartiallySeekableInputStream*
CreateStream(uint32_t aSize, uint64_t aStreamSize, nsCString& aBuffer)
{
  aBuffer.SetLength(aSize);
  for (uint32_t i = 0; i < aSize; ++i) {
    aBuffer.BeginWriting()[i] = i % 10;
  }

  RefPtr<NonSeekableStream> stream = new NonSeekableStream(aBuffer);
  return new PartiallySeekableInputStream(stream.forget(), aStreamSize);
}

// Simple reading.
TEST(TestPartiallySeekableInputStream, SimpleRead) {
  const size_t kBufSize = 10;

  nsCString buf;
  RefPtr<PartiallySeekableInputStream> psi = CreateStream(kBufSize, 5, buf);

  uint64_t length;
  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)kBufSize, length);

  char buf2[kBufSize];
  uint32_t count;
  ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
  ASSERT_EQ(count, buf.Length());
  ASSERT_TRUE(nsCString(buf.get(), kBufSize).Equals(nsCString(buf2, count)));

  // At this point, after reading more than the buffer size, seek is not
  // allowed.
  ASSERT_EQ(NS_ERROR_NOT_IMPLEMENTED,
            psi->Seek(nsISeekableStream::NS_SEEK_SET, 0));

  ASSERT_EQ(NS_ERROR_NOT_IMPLEMENTED,
            psi->Seek(nsISeekableStream::NS_SEEK_END, 0));

  ASSERT_EQ(NS_ERROR_NOT_IMPLEMENTED,
            psi->Seek(nsISeekableStream::NS_SEEK_CUR, 0));

  // Position is at the end of the stream.
  int64_t pos;
  ASSERT_EQ(NS_OK, psi->Tell(&pos));
  ASSERT_EQ((int64_t)kBufSize, pos);
}

// Simple seek
TEST(TestPartiallySeekableInputStream, SimpleSeek) {
  const size_t kBufSize = 10;

  nsCString buf;
  RefPtr<PartiallySeekableInputStream> psi = CreateStream(kBufSize, 5, buf);

  uint64_t length;
  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)kBufSize, length);

  uint32_t count;

  {
    char buf2[3];
    ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
    ASSERT_EQ(count, sizeof(buf2));
    ASSERT_TRUE(nsCString(buf.get(), sizeof(buf2)).Equals(nsCString(buf2, sizeof(buf2))));

    int64_t pos;
    ASSERT_EQ(NS_OK, psi->Tell(&pos));
    ASSERT_EQ((int64_t)sizeof(buf2), pos);

    uint64_t length;
    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize - sizeof(buf2), length);
  }

  // Let's seek back to the beginning using NS_SEEK_SET
  ASSERT_EQ(NS_OK, psi->Seek(nsISeekableStream::NS_SEEK_SET, 0));

  {
    uint64_t length;
    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize, length);

    char buf2[3];
    ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
    ASSERT_EQ(count, sizeof(buf2));
    ASSERT_TRUE(nsCString(buf.get(), sizeof(buf2)).Equals(nsCString(buf2, sizeof(buf2))));

    int64_t pos;
    ASSERT_EQ(NS_OK, psi->Tell(&pos));
    ASSERT_EQ((int64_t)sizeof(buf2), pos);

    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize - sizeof(buf2), length);
  }

  // Let's seek back of 2 bytes using NS_SEEK_CUR
  ASSERT_EQ(NS_OK, psi->Seek(nsISeekableStream::NS_SEEK_CUR, -2));

  {
    uint64_t length;
    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize - 1, length);

    char buf2[3];
    ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
    ASSERT_EQ(count, sizeof(buf2));
    ASSERT_TRUE(nsCString(buf.get() + 1, sizeof(buf2)).Equals(nsCString(buf2, sizeof(buf2))));

    int64_t pos;
    ASSERT_EQ(NS_OK, psi->Tell(&pos));
    ASSERT_EQ((int64_t)sizeof(buf2) + 1, pos);

    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize - sizeof(buf2) - 1, length);
  }

  // Let's seek back to the beginning using NS_SEEK_SET
  ASSERT_EQ(NS_OK, psi->Seek(nsISeekableStream::NS_SEEK_SET, 0));

  {
    uint64_t length;
    ASSERT_EQ(NS_OK, psi->Available(&length));
    ASSERT_EQ((uint64_t)kBufSize, length);

    char buf2[kBufSize];
    ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
    ASSERT_EQ(count, buf.Length());
    ASSERT_TRUE(nsCString(buf.get(), kBufSize).Equals(nsCString(buf2, count)));
  }
}

// Full in cache
TEST(TestPartiallySeekableInputStream, FullCachedSeek) {
  const size_t kBufSize = 10;

  nsCString buf;
  RefPtr<PartiallySeekableInputStream> psi = CreateStream(kBufSize, 4096, buf);

  uint64_t length;
  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)kBufSize, length);

  char buf2[kBufSize];
  uint32_t count;
  ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
  ASSERT_EQ(count, buf.Length());
  ASSERT_TRUE(nsCString(buf.get(), kBufSize).Equals(nsCString(buf2, count)));

  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)0, length);

  ASSERT_EQ(NS_OK, psi->Seek(nsISeekableStream::NS_SEEK_SET, 0));

  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)kBufSize, length);

  ASSERT_EQ(NS_OK, psi->Read(buf2, sizeof(buf2), &count));
  ASSERT_EQ(count, buf.Length());
  ASSERT_TRUE(nsCString(buf.get(), kBufSize).Equals(nsCString(buf2, count)));

  ASSERT_EQ(NS_OK, psi->Available(&length));
  ASSERT_EQ((uint64_t)0, length);
}