// Copyright (c) 2013 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.

#ifndef WEBKIT_FILEAPI_UPLOAD_FILE_SYSTEM_FILE_ELEMENT_READER_H_
#define WEBKIT_FILEAPI_UPLOAD_FILE_SYSTEM_FILE_ELEMENT_READER_H_

#include "base/memory/weak_ptr.h"
#include "base/time.h"
#include "googleurl/src/gurl.h"
#include "net/base/upload_element_reader.h"
#include "webkit/storage/webkit_storage_export.h"

namespace webkit_blob {
class FileStreamReader;
}

namespace fileapi {

class FileSystemContext;

// An UploadElementReader implementation for filesystem file.
class WEBKIT_STORAGE_EXPORT UploadFileSystemFileElementReader
    : public net::UploadElementReader {
 public:
  UploadFileSystemFileElementReader(
      FileSystemContext* file_system_context,
      const GURL& url,
      uint64 range_offset,
      uint64 range_length,
      const base::Time& expected_modification_time);
  virtual ~UploadFileSystemFileElementReader();

  // UploadElementReader overrides:
  virtual int Init(const net::CompletionCallback& callback) OVERRIDE;
  virtual uint64 GetContentLength() const OVERRIDE;
  virtual uint64 BytesRemaining() const OVERRIDE;
  virtual int Read(net::IOBuffer* buf,
                   int buf_length,
                   const net::CompletionCallback& callback) OVERRIDE;

 private:
  void OnGetLength(const net::CompletionCallback& callback, int64 result);
  void OnRead(const net::CompletionCallback& callback, int result);

  scoped_refptr<FileSystemContext> file_system_context_;
  const GURL url_;
  const uint64 range_offset_;
  const uint64 range_length_;
  const base::Time expected_modification_time_;

  scoped_ptr<webkit_blob::FileStreamReader> stream_reader_;

  uint64 stream_length_;
  uint64 position_;

  base::WeakPtrFactory<UploadFileSystemFileElementReader> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(UploadFileSystemFileElementReader);
};

}  // namespace fileapi

#endif  // WEBKIT_FILEAPI_UPLOAD_FILE_SYSTEM_FILE_ELEMENT_READER_H_