/*
 * Copyright (C) 2010, Google Inc.
 * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org> 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.util.Collection;
import java.util.Map;

import org.eclipse.jgit.lib.Ref;

Represent connection for operation on a remote repository.

Currently all operations on remote repository (fetch and push) provide
information about remote refs. Every connection is able to be closed and
should be closed - this is a connection client responsibility.
See Also:
Transport/**
 * Represent connection for operation on a remote repository.
 * <p>
 * Currently all operations on remote repository (fetch and push) provide
 * information about remote refs. Every connection is able to be closed and
 * should be closed - this is a connection client responsibility.
 *
 * @see Transport
 */
public interface Connection extends AutoCloseable {
	
Get the complete map of refs advertised as available for fetching or
pushing.
Returns:
available/advertised refs: map of refname to ref. Never null. Not
        modifiable. The collection can be empty if the remote side has no
        refs (it is an empty/newly created repository)./**
	 * Get the complete map of refs advertised as available for fetching or
	 * pushing.
	 *
	 * @return available/advertised refs: map of refname to ref. Never null. Not
	 *         modifiable. The collection can be empty if the remote side has no
	 *         refs (it is an empty/newly created repository).
	 */
	Map<String, Ref> getRefsMap();

	
Get the complete list of refs advertised as available for fetching or
pushing.

The returned refs may appear in any order. If the caller needs these to
be sorted, they should be copied into a new array or List and then sorted
by the caller as necessary.
Returns:
available/advertised refs. Never null. Not modifiable. The
        collection can be empty if the remote side has no refs (it is an
        empty/newly created repository)./**
	 * Get the complete list of refs advertised as available for fetching or
	 * pushing.
	 * <p>
	 * The returned refs may appear in any order. If the caller needs these to
	 * be sorted, they should be copied into a new array or List and then sorted
	 * by the caller as necessary.
	 *
	 * @return available/advertised refs. Never null. Not modifiable. The
	 *         collection can be empty if the remote side has no refs (it is an
	 *         empty/newly created repository).
	 */
	Collection<Ref> getRefs();

	
Get a single advertised ref by name.

The name supplied should be valid ref name. To get a peeled value for a
ref (aka refs/tags/v1.0^{}) use the base name (without
the ^{} suffix) and look at the peeled object id.
Params:
name – 
           name of the ref to obtain.
Returns:
the requested ref; null if the remote did not advertise this ref./**
	 * Get a single advertised ref by name.
	 * <p>
	 * The name supplied should be valid ref name. To get a peeled value for a
	 * ref (aka <code>refs/tags/v1.0^{}</code>) use the base name (without
	 * the <code>^{}</code> suffix) and look at the peeled object id.
	 *
	 * @param name
	 *            name of the ref to obtain.
	 * @return the requested ref; null if the remote did not advertise this ref.
	 */
	Ref getRef(String name);

	
{@inheritDoc}

Close any resources used by this connection.

If the remote repository is contacted by a network socket this method
must close that network socket, disconnecting the two peers. If the
remote repository is actually local (same system) this method must close
any open file handles used to read the "remote" repository.
 If additional messages were produced by the remote peer, these should still be retained in the connection instance for getMessages(). 
 AutoClosable.close() declares that it throws Exception. Implementers shouldn't throw checked exceptions. This override narrows the signature to prevent them from doing so. /**
	 * {@inheritDoc}
	 * <p>
	 * Close any resources used by this connection.
	 * <p>
	 * If the remote repository is contacted by a network socket this method
	 * must close that network socket, disconnecting the two peers. If the
	 * remote repository is actually local (same system) this method must close
	 * any open file handles used to read the "remote" repository.
	 * <p>
	 * If additional messages were produced by the remote peer, these should
	 * still be retained in the connection instance for {@link #getMessages()}.
	 * <p>
	 * {@code AutoClosable.close()} declares that it throws {@link Exception}.
	 * Implementers shouldn't throw checked exceptions. This override narrows
	 * the signature to prevent them from doing so.
	 */
	@Override
	void close();

	
Get the additional messages, if any, returned by the remote process.

These messages are most likely informational or error messages, sent by
the remote peer, to help the end-user correct any problems that may have
prevented the operation from completing successfully. Application UIs
should try to show these in an appropriate context.
 The message buffer is available after close() has been called. Prior to closing the connection, the message buffer may be empty. 
Returns:
the messages returned by the remote, most likely terminated by a
        newline (LF) character. The empty string is returned if the
        remote produced no additional messages./**
	 * Get the additional messages, if any, returned by the remote process.
	 * <p>
	 * These messages are most likely informational or error messages, sent by
	 * the remote peer, to help the end-user correct any problems that may have
	 * prevented the operation from completing successfully. Application UIs
	 * should try to show these in an appropriate context.
	 * <p>
	 * The message buffer is available after {@link #close()} has been called.
	 * Prior to closing the connection, the message buffer may be empty.
	 *
	 * @return the messages returned by the remote, most likely terminated by a
	 *         newline (LF) character. The empty string is returned if the
	 *         remote produced no additional messages.
	 */
	String getMessages();

	
User agent advertised by the remote server.
Returns:
agent (version of Git) running on the remote server. Null if the
        server does not advertise this version.
Since:
4.0/**
	 * User agent advertised by the remote server.
	 *
	 * @return agent (version of Git) running on the remote server. Null if the
	 *         server does not advertise this version.
	 * @since 4.0
	 */
	String getPeerUserAgent();
}