/*
    * Copyright (C) 2011, Google Inc. and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  
  package org.eclipse.jgit.transport;
  
  import java.util.Collection;
  import java.util.List;
  
  /**
   * {@link org.eclipse.jgit.transport.PreReceiveHook} that delegates to a list of
   * other hooks.
   * <p>
   * Hooks are run in the order passed to the constructor.
   */
  public class PreReceiveHookChain implements PreReceiveHook {
  	private final PreReceiveHook[] hooks;
  	private final int count;
  
  	/**
  	 * Create a new hook chaining the given hooks together.
  	 *
  	 * @param hooks
  	 *            hooks to execute, in order.
  	 * @return a new hook chain of the given hooks.
  	 */
  	public static PreReceiveHook newChain(List<? extends PreReceiveHook> hooks) {
  		PreReceiveHook[] newHooks = new PreReceiveHook[hooks.size()];
  		int i = 0;
  		for (PreReceiveHook hook : hooks)
  			if (hook != PreReceiveHook.NULL)
  				newHooks[i++] = hook;
  		switch (i) {
  		case 0:
  			return PreReceiveHook.NULL;
  		case 1:
  			return newHooks[0];
  		default:
  			return new PreReceiveHookChain(newHooks, i);
  		}
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void onPreReceive(ReceivePack rp,
  			Collection<ReceiveCommand> commands) {
  		for (int i = 0; i < count; i++)
  			hooks[i].onPreReceive(rp, commands);
  	}
  
  	private PreReceiveHookChain(PreReceiveHook[] hooks, int count) {
  		this.hooks = hooks;
  		this.count = count;
  	}
  }