// 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.

#ifndef CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_PROXY_H_
#define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_PROXY_H_

#include "chrome/browser/chromeos/drive/file_errors.h"
#include "webkit/browser/fileapi/remote_file_system_proxy.h"

namespace fileapi {
class FileSystemURL;
}  // namespace fileapi

namespace drive {

class FileSystemInterface;
class ResourceEntry;

typedef std::vector<ResourceEntry> ResourceEntryVector;

namespace internal {
class FileApiWorker;
}  // namespace internal

// Implementation of File API's remote file system proxy for Drive-backed
// file system.
class FileSystemProxy : public fileapi::RemoteFileSystemProxyInterface {
 public:
  using fileapi::RemoteFileSystemProxyInterface::OpenFileCallback;

  // |file_system| is the FileSystem instance owned by DriveIntegrationService.
  explicit FileSystemProxy(FileSystemInterface* file_system);

  // Detaches this instance from |file_system_|.
  // Method calls may result in no-op after calling this method.
  // This method must be called on UI thread.
  void DetachFromFileSystem();

  // fileapi::RemoteFileSystemProxyInterface overrides.
  virtual void GetFileInfo(
      const fileapi::FileSystemURL& url,
      const fileapi::FileSystemOperation::GetMetadataCallback&
          callback) OVERRIDE;
  virtual void Copy(
      const fileapi::FileSystemURL& src_url,
      const fileapi::FileSystemURL& dest_url,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void Move(
      const fileapi::FileSystemURL& src_url,
      const fileapi::FileSystemURL& dest_url,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void ReadDirectory(const fileapi::FileSystemURL& url,
     const fileapi::FileSystemOperation::ReadDirectoryCallback&
         callback) OVERRIDE;
  virtual void Remove(
      const fileapi::FileSystemURL& url, bool recursive,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void CreateDirectory(
      const fileapi::FileSystemURL& file_url,
      bool exclusive,
      bool recursive,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void CreateFile(
      const fileapi::FileSystemURL& file_url,
      bool exclusive,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void Truncate(
      const fileapi::FileSystemURL& file_url, int64 length,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual void CreateSnapshotFile(
      const fileapi::FileSystemURL& url,
      const fileapi::FileSystemOperation::SnapshotFileCallback&
      callback) OVERRIDE;
  virtual void CreateWritableSnapshotFile(
      const fileapi::FileSystemURL& url,
      const fileapi::WritableSnapshotFile& callback) OVERRIDE;
  virtual void OpenFile(
      const fileapi::FileSystemURL& url,
      int file_flags,
      base::ProcessHandle peer_handle,
      const OpenFileCallback& callback) OVERRIDE;
  virtual void NotifyCloseFile(const fileapi::FileSystemURL& url) OVERRIDE;
  virtual void TouchFile(
      const fileapi::FileSystemURL& url,
      const base::Time& last_access_time,
      const base::Time& last_modified_time,
      const fileapi::FileSystemOperation::StatusCallback& callback)
          OVERRIDE;
  virtual scoped_ptr<webkit_blob::FileStreamReader> CreateFileStreamReader(
      base::SequencedTaskRunner* file_task_runner,
      const fileapi::FileSystemURL& url,
      int64 offset,
      const base::Time& expected_modification_time) OVERRIDE;

 protected:
  virtual ~FileSystemProxy();

 private:
  // Checks if a given |url| belongs to this file system. If it does,
  // the call will return true and fill in |file_path| with a file path of
  // a corresponding element within this file system.
  static bool ValidateUrl(const fileapi::FileSystemURL& url,
                          base::FilePath* file_path);

  // Helper method to call methods of FileSystem. This method aborts
  // method calls in case DetachFromFileSystem() has been called.
  void CallFileSystemMethodOnUIThread(const base::Closure& method_call);

  // Used to implement CallFileSystemMethodOnUIThread.
  void CallFileSystemMethodOnUIThreadInternal(
      const base::Closure& method_call);

  // Helper method to call drive::filapi_internal functions. This method
  // aborts calls in case DetachFromFileSystem() has been called.
  void CallFileApiInternalFunctionOnUIThread(
      const base::Callback<void(FileSystemInterface*)>& function);

  // Used to implement CallFileApiFunctionOnUIThread.
  void CallFileApiInternalFunctionOnUIThreadInternal(
      const base::Callback<void(FileSystemInterface*)>& function);

  // Helper callback for relaying reply for CreateWritableSnapshotFile() to
  // the calling thread.
  void OnCreateWritableSnapshotFile(
      const base::FilePath& virtual_path,
      const fileapi::WritableSnapshotFile& callback,
      FileError result,
      const base::FilePath& local_path);

  // Helper callback for closing the local cache file and committing the dirty
  // flag. This is triggered when the callback for CreateWritableSnapshotFile
  // released the refcounted reference to the file.
  void CloseWritableSnapshotFile(
      const base::FilePath& virtual_path,
      const base::FilePath& local_path);

  // Returns |file_system_| on UI thread.
  FileSystemInterface* GetFileSystemOnUIThread();

  FileSystemInterface* file_system_;
};

}  // namespace drive

#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_PROXY_H_