/*
    * Copyright (C) 2018, 2020 Thomas Wolf <thomas.wolf@paranor.ch> 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.internal.transport.sshd;
  
  import static org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile.flag;
  import static org.eclipse.jgit.internal.transport.ssh.OpenSshConfigFile.positive;
  
  import java.io.IOException;
  import java.net.SocketAddress;
  import java.util.Map;
  import java.util.TreeMap;
  
  import org.apache.sshd.client.config.hosts.HostConfigEntry;
  import org.apache.sshd.client.config.hosts.HostConfigEntryResolver;
  import org.apache.sshd.common.AttributeRepository;
  import org.apache.sshd.common.util.net.SshdSocketAddress;
  import org.eclipse.jgit.transport.SshConfigStore;
  import org.eclipse.jgit.transport.SshConstants;
  import org.eclipse.jgit.transport.SshSessionFactory;
  
  /**
   * A bridge between a JGit {@link SshConfigStore} and the Apache MINA sshd
   * {@link HostConfigEntryResolver}.
   */
  public class JGitSshConfig implements HostConfigEntryResolver {
  
  	private final SshConfigStore configFile;
  
  	/**
  	 * Creates a new {@link JGitSshConfig} that will read the config from the
  	 * given {@link SshConfigStore}.
  	 *
  	 * @param store
  	 *            to use
  	 */
  	public JGitSshConfig(SshConfigStore store) {
  		configFile = store;
  	}
  
  	@Override
  	public HostConfigEntry resolveEffectiveHost(String host, int port,
  			SocketAddress localAddress, String username, String proxyJump,
  			AttributeRepository attributes) throws IOException {
  		SshConfigStore.HostConfig entry = configFile == null
  				? SshConfigStore.EMPTY_CONFIG
  				: configFile.lookup(host, port, username);
  		JGitHostConfigEntry config = new JGitHostConfigEntry();
  		// Apache MINA conflates all keys, even multi-valued ones, in one map
  		// and puts multiple values separated by commas in one string. See
  		// the javadoc on HostConfigEntry.
  		Map<String, String> allOptions = new TreeMap<>(
  				String.CASE_INSENSITIVE_ORDER);
  		allOptions.putAll(entry.getOptions());
  		// And what if a value contains a comma??
  		entry.getMultiValuedOptions().entrySet().stream()
  				.forEach(e -> allOptions.put(e.getKey(),
  						String.join(",", e.getValue()))); //$NON-NLS-1$
  		config.setProperties(allOptions);
  		// The following is an extension from JGitHostConfigEntry
  		config.setMultiValuedOptions(entry.getMultiValuedOptions());
  		// Also make sure the underlying properties are set
  		String hostName = entry.getValue(SshConstants.HOST_NAME);
  		if (hostName == null || hostName.isEmpty()) {
  			hostName = host;
  		}
  		config.setHostName(hostName);
  		config.setProperty(SshConstants.HOST_NAME, hostName);
  		config.setHost(SshdSocketAddress.isIPv6Address(hostName) ? "" : hostName); //$NON-NLS-1$
  		String user = username != null && !username.isEmpty() ? username
  				: entry.getValue(SshConstants.USER);
  		if (user == null || user.isEmpty()) {
  			user = SshSessionFactory.getLocalUserName();
  		}
  		config.setUsername(user);
  		config.setProperty(SshConstants.USER, user);
  		int p = port >= 0 ? port : positive(entry.getValue(SshConstants.PORT));
  		config.setPort(p >= 0 ? p : SshConstants.SSH_DEFAULT_PORT);
  		config.setProperty(SshConstants.PORT,
  				Integer.toString(config.getPort()));
  		config.setIdentities(entry.getValues(SshConstants.IDENTITY_FILE));
  		config.setIdentitiesOnly(
  				flag(entry.getValue(SshConstants.IDENTITIES_ONLY)));
  		return config;
  	}
  
  }