/*
 * 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.
 Remote repositories are registered using 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. 
 Unlike the other built-in protocols, which are automatically-registered singletons, callers are expected to register/unregister specific protocol instances on demand with Transport.register(TransportProtocol). 
Type parameters:
<C> – 
           the connection type
Since:
4.0/**
 * 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.
Params:
uploadPackFactory –  factory for creating UploadPack used by all connections from this protocol instance.
receivePackFactory –  factory for creating ReceivePack used by all connections from this protocol instance./**
	 * 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} /** {@inheritDoc} */
	@Override
	public String getName() {
		return JGitText.get().transportProtoTest;
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public Set<String> getSchemes() {
		return Collections.singleton(SCHEME);
	}

	
{@inheritDoc} /** {@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} /** {@inheritDoc} */
	@Override
	public Set<URIishField> getRequiredFields() {
		return EnumSet.of(URIishField.HOST, URIishField.PATH);
	}

	
{@inheritDoc} /** {@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.
Params:
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.
remote – 
           remote repository to connect to.
Returns:
a URI that can be used to connect to this repository for both fetch
        and push./**
	 * 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.
		}
	}
}