/*
 * Copyright (C) 2016, Google Inc.
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package org.eclipse.jgit.internal.ketch;

import static java.util.concurrent.TimeUnit.MILLISECONDS;
import static java.util.concurrent.TimeUnit.SECONDS;
import static org.eclipse.jgit.internal.ketch.Proposal.State.EXECUTED;
import static org.eclipse.jgit.internal.ketch.Proposal.State.QUEUED;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_OTHER_REASON;

import java.io.IOException;
import java.util.Collection;

import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.transport.PreReceiveHook;
import org.eclipse.jgit.transport.ProgressSpinner;
import org.eclipse.jgit.transport.ReceiveCommand;
import org.eclipse.jgit.transport.ReceivePack;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

PreReceiveHook for handling push traffic in a Ketch system.
 Install an instance on ReceivePack to capture the commands and other connection state and relay them through the KetchLeader, allowing the leader to gain consensus about the new reference state. /**
 * PreReceiveHook for handling push traffic in a Ketch system.
 * <p>
 * Install an instance on {@link org.eclipse.jgit.transport.ReceivePack} to
 * capture the commands and other connection state and relay them through the
 * {@link org.eclipse.jgit.internal.ketch.KetchLeader}, allowing the leader to
 * gain consensus about the new reference state.
 */
public class KetchPreReceive implements PreReceiveHook {
	private static final Logger log = LoggerFactory.getLogger(KetchPreReceive.class);

	private final KetchLeader leader;

	
Construct a hook executing updates through a KetchLeader. 
Params:
leader – 
           leader for this repository./**
	 * Construct a hook executing updates through a
	 * {@link org.eclipse.jgit.internal.ketch.KetchLeader}.
	 *
	 * @param leader
	 *            leader for this repository.
	 */
	public KetchPreReceive(KetchLeader leader) {
		this.leader = leader;
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	public void onPreReceive(ReceivePack rp, Collection<ReceiveCommand> cmds) {
		cmds = ReceiveCommand.filter(cmds, NOT_ATTEMPTED);
		if (cmds.isEmpty()) {
			return;
		}

		try {
			Proposal proposal = new Proposal(rp.getRevWalk(), cmds)
				.setPushCertificate(rp.getPushCertificate())
				.setAuthor(rp.getRefLogIdent())
				.setMessage("push"); //$NON-NLS-1$
			leader.queueProposal(proposal);
			if (proposal.isDone()) {
				// This failed fast, e.g. conflict or bad precondition.
				return;
			}

			ProgressSpinner spinner = new ProgressSpinner(
					rp.getMessageOutputStream());
			if (proposal.getState() == QUEUED) {
				waitForQueue(proposal, spinner);
			}
			if (!proposal.isDone()) {
				waitForPropose(proposal, spinner);
			}
		} catch (IOException | InterruptedException e) {
			String msg = JGitText.get().transactionAborted;
			for (ReceiveCommand cmd : cmds) {
				if (cmd.getResult() == NOT_ATTEMPTED) {
					cmd.setResult(REJECTED_OTHER_REASON, msg);
				}
			}
			log.error(msg, e);
		}
	}

	private void waitForQueue(Proposal proposal, ProgressSpinner spinner)
			throws InterruptedException {
		spinner.beginTask(KetchText.get().waitingForQueue, 1, SECONDS);
		while (!proposal.awaitStateChange(QUEUED, 250, MILLISECONDS)) {
			spinner.update();
		}
		switch (proposal.getState()) {
		case RUNNING:
		default:
			spinner.endTask(KetchText.get().starting);
			break;

		case EXECUTED:
			spinner.endTask(KetchText.get().accepted);
			break;

		case ABORTED:
			spinner.endTask(KetchText.get().failed);
			break;
		}
	}

	private void waitForPropose(Proposal proposal, ProgressSpinner spinner)
			throws InterruptedException {
		spinner.beginTask(KetchText.get().proposingUpdates, 2, SECONDS);
		while (!proposal.await(250, MILLISECONDS)) {
			spinner.update();
		}
		spinner.endTask(proposal.getState() == EXECUTED
				? KetchText.get().accepted
				: KetchText.get().failed);
	}
}