/*
    * Copyright (C) 2012, 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.io.IOException;
  import java.util.List;
  
  /**
   * {@link org.eclipse.jgit.transport.AdvertiseRefsHook} that delegates to a list
   * of other hooks.
   * <p>
   * Hooks are run in the order passed to the constructor. A hook may inspect or
   * modify the results of the previous hooks in the chain by calling
   * {@link org.eclipse.jgit.transport.UploadPack#getAdvertisedRefs()}, or
   * {@link org.eclipse.jgit.transport.ReceivePack#getAdvertisedRefs()} or
   * {@link org.eclipse.jgit.transport.ReceivePack#getAdvertisedObjects()}.
   */
  public class AdvertiseRefsHookChain implements AdvertiseRefsHook {
  	private final AdvertiseRefsHook[] 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 AdvertiseRefsHook newChain(List<? extends AdvertiseRefsHook> hooks) {
  		AdvertiseRefsHook[] newHooks = new AdvertiseRefsHook[hooks.size()];
  		int i = 0;
  		for (AdvertiseRefsHook hook : hooks)
  			if (hook != AdvertiseRefsHook.DEFAULT)
  				newHooks[i++] = hook;
  		switch (i) {
  		case 0:
  			return AdvertiseRefsHook.DEFAULT;
  		case 1:
  			return newHooks[0];
  		default:
  			return new AdvertiseRefsHookChain(newHooks, i);
  		}
  	}
  
  	/**
  	 * {@inheritDoc}
  	 */
  	@Override
  	public void advertiseRefs(ReceivePack rp)
  			throws IOException {
  		for (int i = 0; i < count; i++)
  			hooks[i].advertiseRefs(rp);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void advertiseRefs(UploadPack rp)
  			throws ServiceMayNotContinueException {
  		for (int i = 0; i < count; i++)
  			hooks[i].advertiseRefs(rp);
  	}
  
  	private AdvertiseRefsHookChain(AdvertiseRefsHook[] hooks, int count) {
  		this.hooks = hooks;
  		this.count = count;
  	}
  }