/*
 * Licensed 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 io.methvin.watchservice;

import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.ProviderMismatchException;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.nio.file.Watchable;
import java.util.Arrays;

public class WatchablePath implements Watchable {

  private final Path file;

  public WatchablePath(Path file) {
    if (file == null) {
      throw new NullPointerException("file must not be null");
    }
    this.file = file;
  }

  public Path getFile() {
    return file;
  }

  @Override
  public WatchKey register(
      WatchService watcher, WatchEvent.Kind<?>[] events, WatchEvent.Modifier... modifiers)
      throws IOException {
    if (watcher == null) {
      throw new NullPointerException();
    }
    if (!(watcher instanceof AbstractWatchService)) {
      throw new ProviderMismatchException();
    }
    return ((AbstractWatchService) watcher).register(this, Arrays.asList(events));
  }

  private static final WatchEvent.Modifier[] NO_MODIFIERS = new WatchEvent.Modifier[0];

  @Override
  public final WatchKey register(WatchService watcher, WatchEvent.Kind<?>... events)
      throws IOException {
    if (!file.toFile().exists()) {
      throw new RuntimeException("Directory to watch doesn't exist: " + file);
    }
    return register(watcher, events, NO_MODIFIERS);
  }

  @Override
  public String toString() {
    return "Path{" + "file=" + file + '}';
  }
}
