/*
    * Copyright (C) 2016, 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.internal.ketch;
  
  import java.util.Collection;
  import java.util.Map;
  
  import org.eclipse.jgit.annotations.Nullable;
  import org.eclipse.jgit.lib.Ref;
  import org.eclipse.jgit.lib.Repository;
  import org.eclipse.jgit.transport.ReceiveCommand;
  
  /**
   * A push request sending objects to a replica, and its result.
   * <p>
   * Implementors of {@link org.eclipse.jgit.internal.ketch.KetchReplica} must
   * populate the command result fields, {@link #setRefs(Map)}, and call one of
   * {@link #setException(Repository, Throwable)} or {@link #done(Repository)} to
   * finish processing.
   */
  public class ReplicaPushRequest {
  	private final KetchReplica replica;
  	private final Collection<ReceiveCommand> commands;
  	private Map<String, Ref> refs;
  	private Throwable exception;
  	private boolean notified;
  
  	/**
  	 * Construct a new push request for a replica.
  	 *
  	 * @param replica
  	 *            the replica being pushed to.
  	 * @param commands
  	 *            commands to be executed.
  	 */
  	public ReplicaPushRequest(KetchReplica replica,
  			Collection<ReceiveCommand> commands) {
  		this.replica = replica;
  		this.commands = commands;
  	}
  
  	/**
  	 * Get commands to be executed, and their results.
  	 *
  	 * @return commands to be executed, and their results.
  	 */
  	public Collection<ReceiveCommand> getCommands() {
  		return commands;
  	}
  
  	/**
  	 * Get remote references, usually from the advertisement.
  	 *
  	 * @return remote references, usually from the advertisement.
  	 */
  	@Nullable
  	public Map<String, Ref> getRefs() {
  		return refs;
  	}
  
  	/**
  	 * Set references observed from the replica.
  	 *
  	 * @param refs
  	 *            references observed from the replica.
  	 */
  	public void setRefs(Map<String, Ref> refs) {
  		this.refs = refs;
  	}
  
  	/**
  	 * Get exception thrown, if any.
  	 *
  	 * @return exception thrown, if any.
  	 */
  	@Nullable
  	public Throwable getException() {
  		return exception;
  	}
  
  	/**
  	 * Mark the request as crashing with a communication error.
  	 * <p>
  	 * This method may take significant time acquiring the leader lock and
  	 * updating the Ketch state machine with the failure.
  	 *
  	 * @param repo
  	 *            local repository reference used by the push attempt.
  	 * @param err
  	 *            exception thrown during communication.
  	 */
 	public void setException(@Nullable Repository repo, Throwable err) {
 		if (KetchReplica.log.isErrorEnabled()) {
 			KetchReplica.log.error(describe("failed"), err); //$NON-NLS-1$
 		}
 		if (!notified) {
 			notified = true;
 			exception = err;
 			replica.afterPush(repo, this);
 		}
 	}
 
 	/**
 	 * Mark the request as completed without exception.
 	 * <p>
 	 * This method may take significant time acquiring the leader lock and
 	 * updating the Ketch state machine with results from this replica.
 	 *
 	 * @param repo
 	 *            local repository reference used by the push attempt.
 	 */
 	public void done(Repository repo) {
 		if (KetchReplica.log.isDebugEnabled()) {
 			KetchReplica.log.debug(describe("completed")); //$NON-NLS-1$
 		}
 		if (!notified) {
 			notified = true;
 			replica.afterPush(repo, this);
 		}
 	}
 
 	private String describe(String heading) {
 		StringBuilder b = new StringBuilder();
 		b.append("push to "); //$NON-NLS-1$
 		b.append(replica.describeForLog());
 		b.append(' ').append(heading).append(":\n"); //$NON-NLS-1$
 		for (ReceiveCommand cmd : commands) {
 			b.append(String.format(
 					"  %-12s %-12s %s %s", //$NON-NLS-1$
 					LeaderSnapshot.str(cmd.getOldId()),
 					LeaderSnapshot.str(cmd.getNewId()),
 					cmd.getRefName(),
 					cmd.getResult()));
 			if (cmd.getMessage() != null) {
 				b.append(' ').append(cmd.getMessage());
 			}
 			b.append('\n');
 		}
 		return b.toString();
 	}
 }