// 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 CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FILE_SYSTEM_H_
#define CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FILE_SYSTEM_H_

#include <string>

#include "base/basictypes.h"
#include "base/callback_forward.h"
#include "base/files/scoped_temp_dir.h"
#include "base/memory/scoped_ptr.h"
#include "chrome/browser/chromeos/drive/file_errors.h"
#include "chrome/browser/chromeos/drive/file_system_interface.h"
#include "google_apis/drive/gdata_errorcode.h"

namespace google_apis {

class AboutResource;
class FileResource;

}  // namespace google_apis

namespace drive {

class DriveServiceInterface;
class FileSystemObserver;
class ResourceEntry;

namespace test_util {

// This class implements a fake FileSystem which acts like a real Drive
// file system with FakeDriveService, for testing purpose.
// Note that this class doesn't support "caching" at the moment, so the number
// of interactions to the FakeDriveService may be bigger than the real
// implementation.
// Currently most methods are empty (not implemented).
class FakeFileSystem : public FileSystemInterface {
 public:
  explicit FakeFileSystem(DriveServiceInterface* drive_service);
  ~FakeFileSystem() override;

  // FileSystemInterface Overrides.
  void AddObserver(FileSystemObserver* observer) override;
  void RemoveObserver(FileSystemObserver* observer) override;
  void CheckForUpdates() override;
  void TransferFileFromLocalToRemote(
      const base::FilePath& local_src_file_path,
      const base::FilePath& remote_dest_file_path,
      const FileOperationCallback& callback) override;
  void OpenFile(const base::FilePath& file_path,
                OpenMode open_mode,
                const std::string& mime_type,
                const OpenFileCallback& callback) override;
  void Copy(const base::FilePath& src_file_path,
            const base::FilePath& dest_file_path,
            bool preserve_last_modified,
            const FileOperationCallback& callback) override;
  void Move(const base::FilePath& src_file_path,
            const base::FilePath& dest_file_path,
            const FileOperationCallback& callback) override;
  void Remove(const base::FilePath& file_path,
              bool is_recursive,
              const FileOperationCallback& callback) override;
  void CreateDirectory(const base::FilePath& directory_path,
                       bool is_exclusive,
                       bool is_recursive,
                       const FileOperationCallback& callback) override;
  void CreateFile(const base::FilePath& file_path,
                  bool is_exclusive,
                  const std::string& mime_type,
                  const FileOperationCallback& callback) override;
  void TouchFile(const base::FilePath& file_path,
                 const base::Time& last_access_time,
                 const base::Time& last_modified_time,
                 const FileOperationCallback& callback) override;
  void TruncateFile(const base::FilePath& file_path,
                    int64 length,
                    const FileOperationCallback& callback) override;
  void Pin(const base::FilePath& file_path,
           const FileOperationCallback& callback) override;
  void Unpin(const base::FilePath& file_path,
             const FileOperationCallback& callback) override;
  void GetFile(const base::FilePath& file_path,
               const GetFileCallback& callback) override;
  void GetFileForSaving(const base::FilePath& file_path,
                        const GetFileCallback& callback) override;
  base::Closure GetFileContent(
      const base::FilePath& file_path,
      const GetFileContentInitializedCallback& initialized_callback,
      const google_apis::GetContentCallback& get_content_callback,
      const FileOperationCallback& completion_callback) override;
  void GetResourceEntry(const base::FilePath& file_path,
                        const GetResourceEntryCallback& callback) override;
  void ReadDirectory(const base::FilePath& file_path,
                     const ReadDirectoryEntriesCallback& entries_callback,
                     const FileOperationCallback& completion_callback) override;
  void Search(const std::string& search_query,
              const GURL& next_link,
              const SearchCallback& callback) override;
  void SearchMetadata(const std::string& query,
                      int options,
                      int at_most_num_matches,
                      const SearchMetadataCallback& callback) override;
  void SearchByHashes(const std::vector<std::string>& hashes,
                      const SearchByHashesCallback& callback) override;
  void GetAvailableSpace(const GetAvailableSpaceCallback& callback) override;
  void GetShareUrl(const base::FilePath& file_path,
                   const GURL& embed_origin,
                   const GetShareUrlCallback& callback) override;
  void GetMetadata(const GetFilesystemMetadataCallback& callback) override;
  void MarkCacheFileAsMounted(const base::FilePath& drive_file_path,
                              const MarkMountedCallback& callback) override;
  void MarkCacheFileAsUnmounted(const base::FilePath& cache_file_path,
                                const FileOperationCallback& callback) override;
  void AddPermission(const base::FilePath& drive_file_path,
                     const std::string& email,
                     google_apis::drive::PermissionRole role,
                     const FileOperationCallback& callback) override;
  void Reset(const FileOperationCallback& callback) override;
  void GetPathFromResourceId(const std::string& resource_id,
                             const GetFilePathCallback& callback) override;

 private:
  // Helpers of GetFileContent.
  // How the method works:
  // 1) Gets ResourceEntry of the path.
  // 2) Look at if there is a cache file or not. If found return it.
  // 3) Otherwise start DownloadFile.
  // 4) Runs the |completion_callback| upon the download completion.
  void GetFileContentAfterGetResourceEntry(
      const GetFileContentInitializedCallback& initialized_callback,
      const google_apis::GetContentCallback& get_content_callback,
      const FileOperationCallback& completion_callback,
      FileError error,
      scoped_ptr<ResourceEntry> entry);
  void GetFileContentAfterGetFileResource(
      const GetFileContentInitializedCallback& initialized_callback,
      const google_apis::GetContentCallback& get_content_callback,
      const FileOperationCallback& completion_callback,
      google_apis::GDataErrorCode gdata_error,
      scoped_ptr<google_apis::FileResource> gdata_entry);
  void GetFileContentAfterDownloadFile(
      const FileOperationCallback& completion_callback,
      google_apis::GDataErrorCode gdata_error,
      const base::FilePath& temp_file);

  // Helpers of GetResourceEntry.
  // How the method works:
  // 1) If the path is root, gets AboutResrouce from the drive service
  //    and create ResourceEntry.
  // 2-1) Otherwise, gets the parent's ResourceEntry by recursive call.
  // 2-2) Then, gets the resource list by restricting the parent with its id.
  // 2-3) Search the results based on title, and return the ResourceEntry.
  // Note that adding suffix (e.g. " (2)") for files sharing a same name is
  // not supported in FakeFileSystem. Thus, even if the server has
  // files sharing the same name under a directory, the second (or later)
  // file cannot be taken with the suffixed name.
  void GetResourceEntryAfterGetAboutResource(
      const GetResourceEntryCallback& callback,
      google_apis::GDataErrorCode gdata_error,
      scoped_ptr<google_apis::AboutResource> about_resource);
  void GetResourceEntryAfterGetParentEntryInfo(
      const base::FilePath& base_name,
      const GetResourceEntryCallback& callback,
      FileError error,
      scoped_ptr<ResourceEntry> parent_entry);
  void GetResourceEntryAfterGetFileList(
      const base::FilePath& base_name,
      const GetResourceEntryCallback& callback,
      google_apis::GDataErrorCode gdata_error,
      scoped_ptr<google_apis::FileList> file_list);

  DriveServiceInterface* drive_service_;  // Not owned.
  base::ScopedTempDir cache_dir_;

  // Note: This should remain the last member so it'll be destroyed and
  // invalidate the weak pointers before any other members are destroyed.
  base::WeakPtrFactory<FakeFileSystem> weak_ptr_factory_;

  DISALLOW_COPY_AND_ASSIGN(FakeFileSystem);
};

}  // namespace test_util
}  // namespace drive

#endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FAKE_FILE_SYSTEM_H_