/*
    * Copyright (C) 2009, Google Inc.
    * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> 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.util;
  
  import java.net.Authenticator;
  import java.net.PasswordAuthentication;
  import java.util.Collection;
  import java.util.concurrent.CopyOnWriteArrayList;
  
  /**
   * Abstract authenticator which remembers prior authentications.
   */
  public abstract class CachedAuthenticator extends Authenticator {
  	private static final Collection<CachedAuthentication> cached = new CopyOnWriteArrayList<>();
  
  	/**
  	 * Add a cached authentication for future use.
  	 *
  	 * @param ca
  	 *            the information we should remember.
  	 */
  	public static void add(CachedAuthentication ca) {
  		cached.add(ca);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	protected final PasswordAuthentication getPasswordAuthentication() {
  		final String host = getRequestingHost();
  		final int port = getRequestingPort();
  		for (CachedAuthentication ca : cached) {
  			if (ca.host.equals(host) && ca.port == port)
  				return ca.toPasswordAuthentication();
  		}
  		PasswordAuthentication pa = promptPasswordAuthentication();
  		if (pa != null) {
  			CachedAuthentication ca = new CachedAuthentication(host, port, pa
  					.getUserName(), new String(pa.getPassword()));
  			add(ca);
  			return ca.toPasswordAuthentication();
  		}
  		return null;
  	}
  
  	/**
  	 * Prompt for and request authentication from the end-user.
  	 *
  	 * @return the authentication data; null if the user canceled the request
  	 *         and does not want to continue.
  	 */
  	protected abstract PasswordAuthentication promptPasswordAuthentication();
  
  	/** Authentication data to remember and reuse. */
  	public static class CachedAuthentication {
  		final String host;
  
  		final int port;
  
  		final String user;
  
  		final String pass;
  
  		/**
  		 * Create a new cached authentication.
  		 *
  		 * @param aHost
  		 *            system this is for.
  		 * @param aPort
  		 *            port number of the service.
  		 * @param aUser
  		 *            username at the service.
  		 * @param aPass
  		 *            password at the service.
  		 */
  		public CachedAuthentication(final String aHost, final int aPort,
  				final String aUser, final String aPass) {
  			host = aHost;
  			port = aPort;
  			user = aUser;
  			pass = aPass;
  		}
  
  		PasswordAuthentication toPasswordAuthentication() {
  			return new PasswordAuthentication(user, pass.toCharArray());
  		}
  	}
  }