/*-
    * Copyright (C) 2019, Salesforce. 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.lib.internal;
  
  import java.net.URISyntaxException;
  import java.nio.file.Path;
  import java.text.MessageFormat;
  
  import org.bouncycastle.openpgp.PGPException;
  import org.bouncycastle.util.encoders.Hex;
  import org.eclipse.jgit.api.errors.CanceledException;
  import org.eclipse.jgit.errors.UnsupportedCredentialItem;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.transport.CredentialItem.CharArrayType;
  import org.eclipse.jgit.transport.CredentialItem.InformationalMessage;
  import org.eclipse.jgit.transport.CredentialsProvider;
  import org.eclipse.jgit.transport.URIish;
  
  /**
   * Prompts for a passphrase and caches it until {@link #clear() cleared}.
   * <p>
   * Implements {@link AutoCloseable} so it can be used within a
   * try-with-resources block.
   * </p>
   */
  class BouncyCastleGpgKeyPassphrasePrompt implements AutoCloseable {
  
  	private CharArrayType passphrase;
  
  	private CredentialsProvider credentialsProvider;
  
  	public BouncyCastleGpgKeyPassphrasePrompt(
  			CredentialsProvider credentialsProvider) {
  		this.credentialsProvider = credentialsProvider;
  	}
  
  	/**
  	 * Clears any cached passphrase
  	 */
  	public void clear() {
  		if (passphrase != null) {
  			passphrase.clear();
  			passphrase = null;
  		}
  	}
  
  	@Override
  	public void close() {
  		clear();
  	}
  
  	private URIish createURI(Path keyLocation) throws URISyntaxException {
  		return new URIish(keyLocation.toUri().toString());
  	}
  
  	/**
  	 * Prompts use for a passphrase unless one was cached from a previous
  	 * prompt.
  	 *
  	 * @param keyFingerprint
  	 *            the fingerprint to show to the user during prompting
  	 * @param keyLocation
  	 *            the location the key was loaded from
  	 * @return the passphrase (maybe <code>null</code>)
  	 * @throws PGPException
  	 * @throws CanceledException
  	 *             in case passphrase was not entered by user
  	 * @throws URISyntaxException
  	 * @throws UnsupportedCredentialItem
  	 */
  	public char[] getPassphrase(byte[] keyFingerprint, Path keyLocation)
  			throws PGPException, CanceledException, UnsupportedCredentialItem,
  			URISyntaxException {
  		if (passphrase == null) {
  			passphrase = new CharArrayType(JGitText.get().credentialPassphrase,
  					true);
  		}
  
  		if (credentialsProvider == null) {
  			throw new PGPException(JGitText.get().gpgNoCredentialsProvider);
  		}
  
  		if (passphrase.getValue() == null
  				&& !credentialsProvider.get(createURI(keyLocation),
  						new InformationalMessage(
  								MessageFormat.format(JGitText.get().gpgKeyInfo,
  										Hex.toHexString(keyFingerprint))),
  						passphrase)) {
  			throw new CanceledException(JGitText.get().gpgSigningCancelled);
  		}
  		return passphrase.getValue();
  	}
 
 }