/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.elasticsearch.watcher;

import java.nio.file.Path;

/**
 * Callback interface that file changes File Watcher is using to notify listeners about changes.
 */
public interface FileChangesListener {
    /**
     * Called for every file found in the watched directory during initialization
     */
    default void onFileInit(Path file) {}

    /**
     * Called for every subdirectory found in the watched directory during initialization
     */
    default void onDirectoryInit(Path file) {}

    /**
     * Called for every new file found in the watched directory
     */
    default void onFileCreated(Path file) {}

    /**
     * Called for every file that disappeared in the watched directory
     */
    default void onFileDeleted(Path file) {}

    /**
     * Called for every file that was changed in the watched directory
     */
    default void onFileChanged(Path file) {}

    /**
     * Called for every new subdirectory found in the watched directory
     */
    default void onDirectoryCreated(Path file) {}

    /**
     * Called for every file that disappeared in the watched directory
     */
    default void onDirectoryDeleted(Path file) {}
}
