/*
    * Copyright (C) 2018, Thomas Wolf <thomas.wolf@paranor.ch>
    * and other copyright owners as documented in the project's IP log.
    *
    * This program and the accompanying materials are made available
    * under the terms of the Eclipse Distribution License v1.0 which
    * accompanies this distribution, is reproduced below, and is
    * available at http://www.eclipse.org/org/documents/edl-v10.php
    *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or
   * without modification, are permitted provided that the following
   * conditions are met:
   *
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   *
   * - Redistributions in binary form must reproduce the above
   *   copyright notice, this list of conditions and the following
   *   disclaimer in the documentation and/or other materials provided
   *   with the distribution.
   *
   * - Neither the name of the Eclipse Foundation, Inc. nor the
   *   names of its contributors may be used to endorse or promote
   *   products derived from this software without specific prior
   *   written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
   * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
   * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
   * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  package org.eclipse.jgit.internal.transport.sshd;
  
  import java.io.IOException;
  import java.net.URISyntaxException;
  import java.security.GeneralSecurityException;
  import java.util.Arrays;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.apache.sshd.common.NamedResource;
  import org.apache.sshd.common.session.SessionContext;
  import org.eclipse.jgit.annotations.NonNull;
  import org.eclipse.jgit.transport.CredentialsProvider;
  import org.eclipse.jgit.transport.URIish;
  import org.eclipse.jgit.transport.sshd.KeyPasswordProvider;
  
  /**
   * A bridge from sshd's {@link RepeatingFilePasswordProvider} to our
   * {@link KeyPasswordProvider} API.
   */
  public class PasswordProviderWrapper implements RepeatingFilePasswordProvider {
  
  	private final KeyPasswordProvider delegate;
  
  	private Map<String, AtomicInteger> counts = new ConcurrentHashMap<>();
  
  	/**
  	 * @param delegate
  	 */
  	public PasswordProviderWrapper(@NonNull KeyPasswordProvider delegate) {
  		this.delegate = delegate;
  	}
  
  	@Override
  	public void setAttempts(int numberOfPasswordPrompts) {
  		delegate.setAttempts(numberOfPasswordPrompts);
  	}
  
  	@Override
  	public int getAttempts() {
  		return delegate.getAttempts();
  	}
  
  	@Override
  	public String getPassword(SessionContext session, NamedResource resource,
  			int attemptIndex) throws IOException {
  		String key = resource.getName();
  		int attempt = counts
  				.computeIfAbsent(key, k -> new AtomicInteger()).get();
  		char[] passphrase = delegate.getPassphrase(toUri(key), attempt);
  		if (passphrase == null) {
  			return null;
  		}
  		try {
  			return new String(passphrase);
  		} finally {
 			Arrays.fill(passphrase, '\000');
 		}
 	}
 
 	@Override
 	public ResourceDecodeResult handleDecodeAttemptResult(
 			SessionContext session, NamedResource resource, int retryIndex,
 			String password, Exception err)
 			throws IOException, GeneralSecurityException {
 		String key = resource.getName();
 		AtomicInteger count = counts.get(key);
 		int numberOfAttempts = count == null ? 0 : count.incrementAndGet();
 		ResourceDecodeResult result = null;
 		try {
 			if (delegate.keyLoaded(toUri(key), numberOfAttempts, err)) {
 				result = ResourceDecodeResult.RETRY;
 			} else {
 				result = ResourceDecodeResult.TERMINATE;
 			}
 		} finally {
 			if (result != ResourceDecodeResult.RETRY) {
 				counts.remove(key);
 			}
 		}
 		return result;
 	}
 
 	/**
 	 * Creates a {@link URIish} from a given string. The
 	 * {@link CredentialsProvider} uses uris as resource identifications.
 	 *
 	 * @param resourceKey
 	 *            to convert
 	 * @return the uri
 	 */
 	private URIish toUri(String resourceKey) {
 		try {
 			return new URIish(resourceKey);
 		} catch (URISyntaxException e) {
 			return new URIish().setPath(resourceKey); // Doesn't check!!
 		}
 	}
 
 }