/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "CacheLog.h"
#include "CacheFileOutputStream.h"

#include "CacheFile.h"
#include "CacheEntry.h"
#include "nsStreamUtils.h"
#include "nsThreadUtils.h"
#include "mozilla/DebugOnly.h"
#include <algorithm>

namespace mozilla::net {

NS_IMPL_ADDREF(CacheFileOutputStream)
NS_IMETHODIMP_(MozExternalRefCountType)
CacheFileOutputStream::Release() {
  MOZ_ASSERT(0 != mRefCnt, "dup release");
  nsrefcnt count = --mRefCnt;
  NS_LOG_RELEASE(this, count, "CacheFileOutputStream");

  if (0 == count) {
    mRefCnt = 1;
    {
      CacheFileAutoLock lock(mFile);
      mFile->RemoveOutput(this, mStatus);
    }
    delete (this);
    return 0;
  }

  return count;
}

NS_INTERFACE_MAP_BEGIN(CacheFileOutputStream)
  NS_INTERFACE_MAP_ENTRY(nsIOutputStream)
  NS_INTERFACE_MAP_ENTRY(nsIAsyncOutputStream)
  NS_INTERFACE_MAP_ENTRY(nsISeekableStream)
  NS_INTERFACE_MAP_ENTRY(nsITellableStream)
  NS_INTERFACE_MAP_ENTRY(mozilla::net::CacheFileChunkListener)
  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIOutputStream)
NS_INTERFACE_MAP_END

CacheFileOutputStream::CacheFileOutputStream(
    CacheFile* aFile, CacheOutputCloseListener* aCloseListener,
    bool aAlternativeData)
    : mFile(aFile),
      mCloseListener(aCloseListener),
      mPos(0),
      mClosed(false),
      mAlternativeData(aAlternativeData),
      mStatus(NS_OK),
      mCallbackFlags(0) {
  LOG(("CacheFileOutputStream::CacheFileOutputStream() [this=%p]", this));

  if (mAlternativeData) {
    mPos = mFile->mAltDataOffset;
  }
}

CacheFileOutputStream::~CacheFileOutputStream() {
  LOG(("CacheFileOutputStream::~CacheFileOutputStream() [this=%p]", this));
}

// nsIOutputStream
NS_IMETHODIMP
CacheFileOutputStream::Close() {
  LOG(("CacheFileOutputStream::Close() [this=%p]", this));
  return CloseWithStatus(NS_OK);
}

NS_IMETHODIMP
CacheFileOutputStream::Flush() {
  // TODO do we need to implement flush ???
  LOG(("CacheFileOutputStream::Flush() [this=%p]", this));
  return NS_OK;
}

NS_IMETHODIMP
CacheFileOutputStream::Write(const char* aBuf, uint32_t aCount,
                             uint32_t* _retval) {
  CacheFileAutoLock lock(mFile);
  mFile->AssertOwnsLock();  // For thread-safety analysis

  LOG(("CacheFileOutputStream::Write() [this=%p, count=%d]", this, aCount));

  if (mClosed) {
    LOG(
        ("CacheFileOutputStream::Write() - Stream is closed. [this=%p, "
         "status=0x%08" PRIx32 "]",
         this, static_cast<uint32_t>(mStatus)));

    return NS_FAILED(mStatus) ? mStatus : NS_BASE_STREAM_CLOSED;
  }

  if (!mFile->mSkipSizeCheck &&
      CacheObserver::EntryIsTooBig(mPos + aCount, !mFile->mMemoryOnly)) {
    LOG(("CacheFileOutputStream::Write() - Entry is too big. [this=%p]", this));

    CloseWithStatusLocked(NS_ERROR_FILE_TOO_BIG);
    return NS_ERROR_FILE_TOO_BIG;
  }

  // We use 64-bit offset when accessing the file, unfortunately we use 32-bit
  // metadata offset, so we cannot handle data bigger than 4GB.
  if (mPos + aCount > PR_UINT32_MAX) {
    LOG(("CacheFileOutputStream::Write() - Entry's size exceeds 4GB. [this=%p]",
         this));

    CloseWithStatusLocked(NS_ERROR_FILE_TOO_BIG);
    return NS_ERROR_FILE_TOO_BIG;
  }

  *_retval = aCount;

  while (aCount) {
    EnsureCorrectChunk(false);
    if (NS_FAILED(mStatus)) {
      return mStatus;
    }

    FillHole();
    if (NS_FAILED(mStatus)) {
      return mStatus;
    }

    uint32_t chunkOffset = mPos - (mPos / kChunkSize) * kChunkSize;
    uint32_t canWrite = kChunkSize - chunkOffset;
    uint32_t thisWrite = std::min(static_cast<uint32_t>(canWrite), aCount);

    CacheFileChunkWriteHandle hnd =
        mChunk->GetWriteHandle(chunkOffset + thisWrite);
    if (!hnd.Buf()) {
      CloseWithStatusLocked(NS_ERROR_OUT_OF_MEMORY);
      return NS_ERROR_OUT_OF_MEMORY;
    }

    memcpy(hnd.Buf() + chunkOffset, aBuf, thisWrite);
    hnd.UpdateDataSize(chunkOffset, thisWrite);

    mPos += thisWrite;
    aBuf += thisWrite;
    aCount -= thisWrite;
  }

  EnsureCorrectChunk(true);

  LOG(("CacheFileOutputStream::Write() - Wrote %d bytes [this=%p]", *_retval,
       this));

  return NS_OK;
}

NS_IMETHODIMP
CacheFileOutputStream::WriteFrom(nsIInputStream* aFromStream, uint32_t aCount,
                                 uint32_t* _retval) {
  LOG(
      ("CacheFileOutputStream::WriteFrom() - NOT_IMPLEMENTED [this=%p, from=%p"
       ", count=%d]",
       this, aFromStream, aCount));

  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
CacheFileOutputStream::WriteSegments(nsReadSegmentFun aReader, void* aClosure,
                                     uint32_t aCount, uint32_t* _retval) {
  LOG(
      ("CacheFileOutputStream::WriteSegments() - NOT_IMPLEMENTED [this=%p, "
       "count=%d]",
       this, aCount));

  return NS_ERROR_NOT_IMPLEMENTED;
}

NS_IMETHODIMP
CacheFileOutputStream::IsNonBlocking(bool* _retval) {
  *_retval = false;
  return NS_OK;
}

// nsIAsyncOutputStream
NS_IMETHODIMP
CacheFileOutputStream::CloseWithStatus(nsresult aStatus) {
  CacheFileAutoLock lock(mFile);

  LOG(("CacheFileOutputStream::CloseWithStatus() [this=%p, aStatus=0x%08" PRIx32
       "]",
       this, static_cast<uint32_t>(aStatus)));

  return CloseWithStatusLocked(aStatus);
}

nsresult CacheFileOutputStream::CloseWithStatusLocked(nsresult aStatus) {
  LOG(
      ("CacheFileOutputStream::CloseWithStatusLocked() [this=%p, "
       "aStatus=0x%08" PRIx32 "]",
       this, static_cast<uint32_t>(aStatus)));

  if (mClosed) {
    MOZ_ASSERT(!mCallback);
    return NS_OK;
  }

  mClosed = true;
  mStatus = NS_FAILED(aStatus) ? aStatus : NS_BASE_STREAM_CLOSED;

  if (mChunk) {
    ReleaseChunk();
  }

  if (mCallback) {
    NotifyListener();
  }

  mFile->RemoveOutput(this, mStatus);

  return NS_OK;
}

NS_IMETHODIMP
CacheFileOutputStream::AsyncWait(nsIOutputStreamCallback* aCallback,
                                 uint32_t aFlags, uint32_t aRequestedCount,
                                 nsIEventTarget* aEventTarget) {
  CacheFileAutoLock lock(mFile);

  LOG(
      ("CacheFileOutputStream::AsyncWait() [this=%p, callback=%p, flags=%d, "
       "requestedCount=%d, eventTarget=%p]",
       this, aCallback, aFlags, aRequestedCount, aEventTarget));

  mCallback = aCallback;
  mCallbackFlags = aFlags;
  mCallbackTarget = aEventTarget;

  if (!mCallback) return NS_OK;

  // The stream is blocking so it is writable at any time
  if (mClosed || !(aFlags & WAIT_CLOSURE_ONLY)) NotifyListener();

  return NS_OK;
}

// nsISeekableStream
NS_IMETHODIMP
CacheFileOutputStream::Seek(int32_t whence, int64_t offset) {
  CacheFileAutoLock lock(mFile);
  mFile->AssertOwnsLock();  // For thread-safety analysis

  LOG(("CacheFileOutputStream::Seek() [this=%p, whence=%d, offset=%" PRId64 "]",
       this, whence, offset));

  if (mClosed) {
    LOG(("CacheFileOutputStream::Seek() - Stream is closed. [this=%p]", this));
    return NS_BASE_STREAM_CLOSED;
  }

  int64_t newPos = offset;
  switch (whence) {
    case NS_SEEK_SET:
      if (mAlternativeData) {
        newPos += mFile->mAltDataOffset;
      }
      break;
    case NS_SEEK_CUR:
      newPos += mPos;
      break;
    case NS_SEEK_END:
      if (mAlternativeData) {
        newPos += mFile->mDataSize;
      } else {
        newPos += mFile->mAltDataOffset;
      }
      break;
    default:
      NS_ERROR("invalid whence");
      return NS_ERROR_INVALID_ARG;
  }
  mPos = newPos;
  EnsureCorrectChunk(true);

  LOG(("CacheFileOutputStream::Seek() [this=%p, pos=%" PRId64 "]", this, mPos));
  return NS_OK;
}

NS_IMETHODIMP
CacheFileOutputStream::SetEOF() {
  MOZ_ASSERT(false, "CacheFileOutputStream::SetEOF() not implemented");
  // Right now we don't use SetEOF(). If we ever need this method, we need
  // to think about what to do with input streams that already points beyond
  // new EOF.
  return NS_ERROR_NOT_IMPLEMENTED;
}

// nsITellableStream
NS_IMETHODIMP
CacheFileOutputStream::Tell(int64_t* _retval) {
  CacheFileAutoLock lock(mFile);
  mFile->AssertOwnsLock();  // For thread-safety analysis

  if (mClosed) {
    LOG(("CacheFileOutputStream::Tell() - Stream is closed. [this=%p]", this));
    return NS_BASE_STREAM_CLOSED;
  }

  *_retval = mPos;

  if (mAlternativeData) {
    *_retval -= mFile->mAltDataOffset;
  }

  LOG(("CacheFileOutputStream::Tell() [this=%p, retval=%" PRId64 "]", this,
       *_retval));
  return NS_OK;
}

// CacheFileChunkListener
nsresult CacheFileOutputStream::OnChunkRead(nsresult aResult,
                                            CacheFileChunk* aChunk) {
  MOZ_CRASH("CacheFileOutputStream::OnChunkRead should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult CacheFileOutputStream::OnChunkWritten(nsresult aResult,
                                               CacheFileChunk* aChunk) {
  MOZ_CRASH("CacheFileOutputStream::OnChunkWritten should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult CacheFileOutputStream::OnChunkAvailable(nsresult aResult,
                                                 uint32_t aChunkIdx,
                                                 CacheFileChunk* aChunk) {
  MOZ_CRASH("CacheFileOutputStream::OnChunkAvailable should not be called!");
  return NS_ERROR_UNEXPECTED;
}

nsresult CacheFileOutputStream::OnChunkUpdated(CacheFileChunk* aChunk) {
  MOZ_CRASH("CacheFileOutputStream::OnChunkUpdated should not be called!");
  return NS_ERROR_UNEXPECTED;
}

void CacheFileOutputStream::NotifyCloseListener() {
  RefPtr<CacheOutputCloseListener> listener;
  listener.swap(mCloseListener);
  if (!listener) return;

  listener->OnOutputClosed();
}

void CacheFileOutputStream::ReleaseChunk() {
  mFile->AssertOwnsLock();

  LOG(("CacheFileOutputStream::ReleaseChunk() [this=%p, idx=%d]", this,
       mChunk->Index()));

  // If the chunk didn't write any data we need to remove hash for this chunk
  // that was added when the chunk was created in CacheFile::GetChunkLocked.
  if (mChunk->DataSize() == 0) {
    // It must be due to a failure, we don't create a new chunk when we don't
    // have data to write.
    MOZ_ASSERT(NS_FAILED(mChunk->GetStatus()));
    mFile->mMetadata->RemoveHash(mChunk->Index());
  }

  mFile->ReleaseOutsideLock(std::move(mChunk));
}

void CacheFileOutputStream::EnsureCorrectChunk(bool aReleaseOnly) {
  mFile->AssertOwnsLock();

  LOG(("CacheFileOutputStream::EnsureCorrectChunk() [this=%p, releaseOnly=%d]",
       this, aReleaseOnly));

  uint32_t chunkIdx = mPos / kChunkSize;

  if (mChunk) {
    if (mChunk->Index() == chunkIdx) {
      // we have a correct chunk
      LOG(
          ("CacheFileOutputStream::EnsureCorrectChunk() - Have correct chunk "
           "[this=%p, idx=%d]",
           this, chunkIdx));

      return;
    }
    ReleaseChunk();
  }

  if (aReleaseOnly) return;

  nsresult rv;
  rv = mFile->GetChunkLocked(chunkIdx, CacheFile::WRITER, nullptr,
                             getter_AddRefs(mChunk));
  if (NS_FAILED(rv)) {
    LOG(
        ("CacheFileOutputStream::EnsureCorrectChunk() - GetChunkLocked failed. "
         "[this=%p, idx=%d, rv=0x%08" PRIx32 "]",
         this, chunkIdx, static_cast<uint32_t>(rv)));
    CloseWithStatusLocked(rv);
  }
}

void CacheFileOutputStream::FillHole() {
  mFile->AssertOwnsLock();

  MOZ_ASSERT(mChunk);
  MOZ_ASSERT(mPos / kChunkSize == mChunk->Index());

  uint32_t pos = mPos - (mPos / kChunkSize) * kChunkSize;
  if (mChunk->DataSize() >= pos) return;

  LOG(
      ("CacheFileOutputStream::FillHole() - Zeroing hole in chunk %d, range "
       "%d-%d [this=%p]",
       mChunk->Index(), mChunk->DataSize(), pos - 1, this));

  CacheFileChunkWriteHandle hnd = mChunk->GetWriteHandle(pos);
  if (!hnd.Buf()) {
    CloseWithStatusLocked(NS_ERROR_OUT_OF_MEMORY);
    return;
  }

  uint32_t offset = hnd.DataSize();
  memset(hnd.Buf() + offset, 0, pos - offset);
  hnd.UpdateDataSize(offset, pos - offset);
}

void CacheFileOutputStream::NotifyListener() {
  mFile->AssertOwnsLock();

  LOG(("CacheFileOutputStream::NotifyListener() [this=%p]", this));

  MOZ_ASSERT(mCallback);

  if (!mCallbackTarget) {
    mCallbackTarget = CacheFileIOManager::IOTarget();
    if (!mCallbackTarget) {
      LOG(
          ("CacheFileOutputStream::NotifyListener() - Cannot get Cache I/O "
           "thread! Using main thread for callback."));
      mCallbackTarget = GetMainThreadEventTarget();
    }
  }

  nsCOMPtr<nsIOutputStreamCallback> asyncCallback =
      NS_NewOutputStreamReadyEvent(mCallback, mCallbackTarget);

  mCallback = nullptr;
  mCallbackTarget = nullptr;

  asyncCallback->OnOutputStreamReady(this);
}

// Memory reporting

size_t CacheFileOutputStream::SizeOfIncludingThis(
    mozilla::MallocSizeOf mallocSizeOf) const {
  // Everything the stream keeps a reference to is already reported somewhere
  // else.
  // mFile reports itself.
  // mChunk reported as part of CacheFile.
  // mCloseListener is CacheEntry, already reported.
  // mCallback is usually CacheFile or a class that is reported elsewhere.
  return mallocSizeOf(this);
}

}  // namespace mozilla::net