/*
    * Copyright (C) 2015, 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.net.URISyntaxException;
  import java.text.MessageFormat;
  import java.util.Collections;
  import java.util.EnumSet;
  import java.util.HashMap;
  import java.util.Set;
  
  import org.eclipse.jgit.errors.NotSupportedException;
  import org.eclipse.jgit.errors.TransportException;
  import org.eclipse.jgit.internal.JGitText;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.transport.BasePackFetchConnection.FetchConfig;
  import org.eclipse.jgit.transport.resolver.ReceivePackFactory;
  import org.eclipse.jgit.transport.resolver.UploadPackFactory;
  
  /**
   * Protocol for transport between manually-specified repositories in tests.
   * <p>
   * Remote repositories are registered using
   * {@link #register(Object, Repository)}, after which they can be accessed using
   * the returned URI. As this class provides both the client side (the protocol)
   * and the server side, the caller is responsible for setting up and passing the
   * connection context, whatever form that may take.
   * <p>
   * Unlike the other built-in protocols, which are automatically-registered
   * singletons, callers are expected to register/unregister specific protocol
   * instances on demand with
   * {@link org.eclipse.jgit.transport.Transport#register(TransportProtocol)}.
   *
   * @param <C>
   *            the connection type
   * @since 4.0
   */
  public class TestProtocol<C> extends TransportProtocol {
  	private static final String SCHEME = "test"; //$NON-NLS-1$
  
  	private static FetchConfig fetchConfig;
  
  	private class Handle {
  		final C req;
  		final Repository remote;
  
  		Handle(C req, Repository remote) {
  			this.req = req;
  			this.remote = remote;
  		}
  	}
  
  	final UploadPackFactory<C> uploadPackFactory;
  	final ReceivePackFactory<C> receivePackFactory;
  	private final HashMap<URIish, Handle> handles;
  
  	/**
  	 * Constructor for TestProtocol.
  	 *
  	 * @param uploadPackFactory
  	 *            factory for creating
  	 *            {@link org.eclipse.jgit.transport.UploadPack} used by all
  	 *            connections from this protocol instance.
  	 * @param receivePackFactory
  	 *            factory for creating
  	 *            {@link org.eclipse.jgit.transport.ReceivePack} used by all
  	 *            connections from this protocol instance.
  	 */
  	public TestProtocol(UploadPackFactory<C> uploadPackFactory,
  			ReceivePackFactory<C> receivePackFactory) {
  		this.uploadPackFactory = uploadPackFactory;
  		this.receivePackFactory = receivePackFactory;
  		this.handles = new HashMap<>();
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public String getName() {
  		return JGitText.get().transportProtoTest;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public Set<String> getSchemes() {
  		return Collections.singleton(SCHEME);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public Transport open(URIish uri, Repository local, String remoteName)
  			throws NotSupportedException, TransportException {
 		Handle h = handles.get(uri);
 		if (h == null) {
 			throw new NotSupportedException(MessageFormat.format(
 					JGitText.get().URINotSupported, uri));
 		}
 		return new TransportInternal(local, uri, h);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public Set<URIishField> getRequiredFields() {
 		return EnumSet.of(URIishField.HOST, URIishField.PATH);
 	}
 
 	/** {@inheritDoc} */
 	@Override
 	public Set<URIishField> getOptionalFields() {
 		return Collections.emptySet();
 	}
 
 	static void setFetchConfig(FetchConfig c) {
 		fetchConfig = c;
 	}
 
 	/**
 	 * Register a repository connection over the internal test protocol.
 	 *
 	 * @param req
 	 *            connection context. This instance is reused for all connections
 	 *            made using this protocol; if it is stateful and usable only for
 	 *            one connection, the same repository should be registered
 	 *            multiple times.
 	 * @param remote
 	 *            remote repository to connect to.
 	 * @return a URI that can be used to connect to this repository for both fetch
 	 *         and push.
 	 */
 	public synchronized URIish register(C req, Repository remote) {
 		URIish uri;
 		try {
 			int n = handles.size();
 			uri = new URIish(SCHEME + "://test/conn" + n); //$NON-NLS-1$
 		} catch (URISyntaxException e) {
 			throw new IllegalStateException(e);
 		}
 		handles.put(uri, new Handle(req, remote));
 		return uri;
 	}
 
 	private class TransportInternal extends Transport implements PackTransport {
 		private final Handle handle;
 
 		TransportInternal(Repository local, URIish uri, Handle handle) {
 			super(local, uri);
 			this.handle = handle;
 		}
 
 		@Override
 		public FetchConnection openFetch() throws NotSupportedException,
 				TransportException {
 			handle.remote.incrementOpen();
 			return new InternalFetchConnection<C>(this, uploadPackFactory,
 					handle.req, handle.remote) {
 				@Override
 				FetchConfig getFetchConfig() {
 					return fetchConfig != null ? fetchConfig
 							: super.getFetchConfig();
 				}
 			};
 		}
 
 		@Override
 		public PushConnection openPush() throws NotSupportedException,
 				TransportException {
 			handle.remote.incrementOpen();
 			return new InternalPushConnection<>(
 					this, receivePackFactory, handle.req, handle.remote);
 		}
 
 		@Override
 		public void close() {
 			// Resources must be established per-connection.
 		}
 	}
 }