/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 */

#ifndef WebFileSystem_h
#define WebFileSystem_h

#include "WebCommon.h"
#include "WebFileSystemCallbacks.h"
#include "WebFileSystemType.h"
#include "WebURL.h"

namespace blink {

class WebFileWriter;
class WebFileWriterClient;

class WebFileSystem {
public:
    enum Type {
        TypeTemporary,
        TypePersistent,

        // Indicates an isolated filesystem which only exposes a set of files.
        TypeIsolated,

        // Indicates a non-sandboxed filesystem.
        TypeExternal,
    };

    // Opens a FileSystem.
    // WebFileSystemCallbacks::didOpenFileSystem() must be called with
    // a name and root path for the requested FileSystem when the operation
    // is completed successfully. WebFileSystemCallbacks::didFail() must be
    // called otherwise.
    virtual void openFileSystem(const WebURL& storagePartition, const WebFileSystemType, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Resolves a filesystem URL.
    // WebFileSystemCallbacks::didSucceed() must be called with filesystem
    // information (name, root path and type) and file metadata (file path and
    // file type) when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void resolveURL(const WebURL& fileSystemURL, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Deletes FileSystem.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation
    // is completed successfully. WebFileSystemCallbacks::didFail() must be
    // called otherwise.
    // All in-flight operations and following operations may fail after the
    // FileSystem is deleted.
    virtual void deleteFileSystem(const WebURL& storagePartition, const WebFileSystemType, WebFileSystemCallbacks) { }

    // Moves a file or directory at |srcPath| to |destPath|.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void move(const WebURL& srcPath, const WebURL& destPath, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Copies a file or directory at |srcPath| to |destPath|.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void copy(const WebURL& srcPath, const WebURL& destPath, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Deletes a file or directory at a given |path|.
    // It is an error to try to remove a directory that is not empty.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void remove(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Deletes a file or directory recursively at a given |path|.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void removeRecursively(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Retrieves the metadata information of the file or directory at the given |path|.
    // This may not always return the local platform path in remote filesystem cases.
    // WebFileSystemCallbacks::didReadMetadata() must be called with a valid metadata when the retrieval is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void readMetadata(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Creates a file at given |path|.
    // If the |path| doesn't exist, it creates a new file at |path|.
    // If |exclusive| is true, it fails if the |path| already exists.
    // If |exclusive| is false, it succeeds if the |path| already exists or
    // it has successfully created a new file at |path|.
    //
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void createFile(const WebURL& path, bool exclusive, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Creates a directory at a given |path|.
    // If the |path| doesn't exist, it creates a new directory at |path|.
    // If |exclusive| is true, it fails if the |path| already exists.
    // If |exclusive| is false, it succeeds if the |path| already exists or it has successfully created a new directory at |path|.
    //
    // WebFileSystemCallbacks::didSucceed() must be called when
    // the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void createDirectory(const WebURL& path, bool exclusive, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Checks if a file exists at a given |path|.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void fileExists(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Checks if a directory exists at a given |path|.
    // WebFileSystemCallbacks::didSucceed() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void directoryExists(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Reads directory entries of a given directory at |path| and returns a callbacks ID which can be used to wait for additional results.
    // WebFileSystemCallbacks::didReadDirectory() must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual int readDirectory(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); return 0; }

    // Creates a WebFileWriter that can be used to write to the given file.
    // WebFileSystemCallbacks::didCreateFileWriter() must be called with the created WebFileWriter when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void createFileWriter(const WebURL& path, WebFileWriterClient*, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Creates a snapshot file for a given file specified by |path|. It returns the metadata of the created snapshot file.
    // The returned metadata should include a local platform path to the snapshot image.
    // In local filesystem cases the backend may simply return the metadata of the file itself (as well as readMetadata does), while in
    // remote filesystem case the backend may download the file into a temporary snapshot file and return the metadata of the temporary file.
    // The returned metadata is used to create a File object for the |path|.
    // The snapshot file is supposed to be deleted when the last reference to a blink::File referring to it's path is dropped.
    // WebFileSystemCallbacks::didCreateSnapshotFile() with the metadata of the snapshot file must be called when the operation is completed successfully.
    // WebFileSystemCallbacks::didFail() must be called otherwise.
    virtual void createSnapshotFileAndReadMetadata(const WebURL& path, WebFileSystemCallbacks) { BLINK_ASSERT_NOT_REACHED(); }

    // Waits for additional results returned for the method call and returns true if possible.
    // Returns false if there is no running method call corresponding for the given ID.
    // |callbacksId| must be the value returned by the original method call.
    virtual bool waitForAdditionalResult(int callbacksId) { BLINK_ASSERT_NOT_REACHED(); return false; }

protected:
    virtual ~WebFileSystem() { }
};

} // namespace blink

#endif
