// Copyright (c) 2012 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 "net/base/upload_data_stream.h"

#include "base/callback_helpers.h"
#include "base/logging.h"
#include "net/base/io_buffer.h"
#include "net/base/net_errors.h"

namespace net {

UploadDataStream::UploadDataStream(bool is_chunked, int64 identifier)
    : total_size_(0),
      current_position_(0),
      identifier_(identifier),
      is_chunked_(is_chunked),
      initialized_successfully_(false),
      is_eof_(false) {
}

UploadDataStream::~UploadDataStream() {
}

int UploadDataStream::Init(const CompletionCallback& callback) {
  Reset();
  DCHECK(!initialized_successfully_);
  DCHECK(callback_.is_null());
  DCHECK(!callback.is_null() || IsInMemory());
  int result = InitInternal();
  if (result == ERR_IO_PENDING) {
    DCHECK(!IsInMemory());
    callback_ = callback;
  } else {
    OnInitCompleted(result);
  }
  return result;
}

int UploadDataStream::Read(IOBuffer* buf,
                           int buf_len,
                           const CompletionCallback& callback) {
  DCHECK(!callback.is_null() || IsInMemory());
  DCHECK(initialized_successfully_);
  DCHECK_GT(buf_len, 0);
  if (is_eof_)
    return 0;
  int result = ReadInternal(buf, buf_len);
  if (result == ERR_IO_PENDING) {
    DCHECK(!IsInMemory());
    callback_ = callback;
  } else {
    OnReadCompleted(result);
  }
  return result;
}

bool UploadDataStream::IsEOF() const {
  DCHECK(initialized_successfully_);
  DCHECK(is_chunked_ || is_eof_ == (current_position_ == total_size_));
  return is_eof_;
}

void UploadDataStream::Reset() {
  current_position_ = 0;
  initialized_successfully_ = false;
  is_eof_ = false;
  total_size_ = 0;
  callback_.Reset();
  ResetInternal();
}

void UploadDataStream::SetSize(uint64 size) {
  DCHECK(!initialized_successfully_);
  DCHECK(!is_chunked_);
  total_size_ = size;
}

void UploadDataStream::SetIsFinalChunk() {
  DCHECK(initialized_successfully_);
  DCHECK(is_chunked_);
  DCHECK(!is_eof_);
  is_eof_ = true;
}

bool UploadDataStream::IsInMemory() const {
  return false;
}

const ScopedVector<UploadElementReader>*
UploadDataStream::GetElementReaders() const {
  return NULL;
}

void UploadDataStream::OnInitCompleted(int result) {
  DCHECK_NE(ERR_IO_PENDING, result);
  DCHECK(!initialized_successfully_);
  DCHECK_EQ(0u, current_position_);
  DCHECK(!is_eof_);

  if (result == OK) {
    initialized_successfully_ = true;
    if (!is_chunked_ && total_size_ == 0)
      is_eof_ = true;
  }
  if (!callback_.is_null())
    base::ResetAndReturn(&callback_).Run(result);
}

void UploadDataStream::OnReadCompleted(int result) {
  DCHECK_GE(result, 0);
  DCHECK(initialized_successfully_);

  current_position_ += result;
  if (!is_chunked_) {
    DCHECK_LE(current_position_, total_size_);
    if (current_position_ == total_size_)
      is_eof_ = true;
  }

  DCHECK(result > 0 || is_eof_);

  if (!callback_.is_null())
    base::ResetAndReturn(&callback_).Run(result);
}

}  // namespace net