Copyright (c) 2000, 2017 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.team.internal.core.subscribers;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.resources.mapping.ResourceTraversal;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.team.core.ITeamStatus;
import org.eclipse.team.core.TeamException;
import org.eclipse.team.core.TeamStatus;
import org.eclipse.team.core.mapping.ISynchronizationScope;
import org.eclipse.team.core.subscribers.Subscriber;
import org.eclipse.team.core.synchronize.SyncInfo;
import org.eclipse.team.core.synchronize.SyncInfoSet;
import org.eclipse.team.core.synchronize.SyncInfoTree;
import org.eclipse.team.internal.core.Messages;
import org.eclipse.team.internal.core.TeamPlugin;

An event handler that collects SyncInfo in a SyncInfoTree. /**
 * An event handler that collects {@link SyncInfo} in a {@link SyncInfoTree}.
 */
public class SubscriberSyncInfoEventHandler extends SubscriberEventHandler {

	// The set that receives notification when the resource synchronization state
	// has been calculated by the job.
	private final SyncSetInputFromSubscriber syncSetInput;

	private class SubscriberSyncInfoEvent extends SubscriberEvent {
		private final SyncInfo result;

		public SubscriberSyncInfoEvent(IResource resource, int type, int depth, SyncInfo result) {
			super(resource, type, depth);
			this.result = result;
		}
		public SyncInfo getResult() {
			return result;
		}
	}

	public static ISynchronizationScope createScope(IResource[] roots, Subscriber subscriber) {
		if (roots == null)
			roots = subscriber.roots();
		return new RootResourceSynchronizationScope(roots);
	}

	
Create the event handler for the given subscriber and roots
Params:
subscriber – the subscriber
roots – the roots or null if the roots from the subscriber
should be used./**
	 * Create the event handler for the given subscriber and roots
	 * @param subscriber the subscriber
	 * @param roots the roots or <code>null</code> if the roots from the subscriber
	 * should be used.
	 */
	public SubscriberSyncInfoEventHandler(final Subscriber subscriber, IResource[] roots) {
		super(subscriber, createScope(roots, subscriber));
		this.syncSetInput = new SyncSetInputFromSubscriber(subscriber, this);
	}

	@Override
	protected void handleException(CoreException e, IResource resource, int code, String message) {
		super.handleException(e, resource, code, message);
		syncSetInput.handleError(new TeamStatus(IStatus.ERROR, TeamPlugin.ID, code, message, e, resource));
	}

	@Override
	protected void handleCancel(OperationCanceledException e) {
		super.handleCancel(e);
		syncSetInput.handleError(new TeamStatus(IStatus.ERROR, TeamPlugin.ID, ITeamStatus.SYNC_INFO_SET_CANCELLATION, Messages.SubscriberEventHandler_12, e, ResourcesPlugin.getWorkspace().getRoot()));
	}

	
Return the sync set input that was created by this event handler
Returns:
the sync set input/**
	 * Return the sync set input that was created by this event handler
	 * @return the sync set input
	 */
	public SyncSetInputFromSubscriber getSyncSetInput() {
		return syncSetInput;
	}

	@Override
	protected void handleChange(IResource resource) throws TeamException {
		SyncInfo info = syncSetInput.getSubscriber().getSyncInfo(resource);
		// resource is no longer under the subscriber control
		if (info == null) {
			queueDispatchEvent(
				new SubscriberEvent(resource, SubscriberEvent.REMOVAL, IResource.DEPTH_ZERO));
		} else {
			queueDispatchEvent(
				new SubscriberSyncInfoEvent(resource, SubscriberEvent.CHANGE, IResource.DEPTH_ZERO, info));
		}
	}

	@Override
	protected void collectAll(
			IResource resource,
			int depth,
			IProgressMonitor monitor) {

		monitor.beginTask(null, IProgressMonitor.UNKNOWN);
		try {

			// Create a monitor that will handle preemption and dispatch if required
			IProgressMonitor collectionMonitor = new SubProgressMonitor(monitor, IProgressMonitor.UNKNOWN) {
				boolean dispatching = false;
				@Override
				public void subTask(String name) {
					dispatch();
					super.subTask(name);
				}
				private void dispatch() {
					if (dispatching) return;
					try {
						dispatching = true;
						handlePreemptiveEvents(this);
						handlePendingDispatch(this);
					} finally {
						dispatching = false;
					}
				}
				@Override
				public void worked(int work) {
					dispatch();
					super.worked(work);
				}
			};

			// Create a sync set that queues up resources and errors for dispatch
			SyncInfoSet collectionSet = new SyncInfoSet() {
				@Override
				public void add(SyncInfo info) {
					super.add(info);
					queueDispatchEvent(
							new SubscriberSyncInfoEvent(info.getLocal(), SubscriberEvent.CHANGE, IResource.DEPTH_ZERO, info));
				}
				@Override
				public void addError(ITeamStatus status) {
					if (status instanceof TeamStatus) {
						TeamStatus ts = (TeamStatus) status;
						IResource resource = ts.getResource();
						if (resource != null && !resource.getProject().isAccessible()) {
							// The project was closed while we were collecting sync info.
							// The close delta will cause us to clean up properly
							return;
						}
					}
					super.addError(status);
					TeamPlugin.getPlugin().getLog().log(status);
					syncSetInput.handleError(status);
				}
				@Override
				public void remove(IResource resource) {
					super.remove(resource);
					queueDispatchEvent(
							new SubscriberEvent(resource, SubscriberEvent.REMOVAL, IResource.DEPTH_ZERO));
				}
			};

			syncSetInput.getSubscriber().collectOutOfSync(new IResource[] { resource }, depth, collectionSet, collectionMonitor);

		} finally {
			monitor.done();
		}
	}

	@Override
	protected void dispatchEvents(SubscriberEvent[] events, IProgressMonitor monitor) {
		// this will batch the following set changes until endInput is called.
		SubscriberSyncInfoSet syncSet = syncSetInput.getSyncSet();
		try {
			syncSet.beginInput();
			for (SubscriberEvent event : events) {
				switch (event.getType()) {
					case SubscriberEvent.CHANGE :
						if (event instanceof SubscriberSyncInfoEvent) {
							SubscriberSyncInfoEvent se = (SubscriberSyncInfoEvent) event;
							syncSetInput.collect(se.getResult(), monitor);
						}
						break;
					case SubscriberEvent.REMOVAL :
						syncSet.remove(event.getResource(), event.getDepth());
						break;
				}
			}
		} finally {
			syncSet.endInput(monitor);
		}
	}

	
Initialize all resources for the subscriber associated with the set. This
will basically recalculate all synchronization information for the
subscriber.

This method is synchronized with the queueEvent method to ensure that the
two events queued by this method are back-to-back.
Params:
roots – 
           the new roots or null if the roots from the
           subscriber should be used./**
	 * Initialize all resources for the subscriber associated with the set. This
	 * will basically recalculate all synchronization information for the
	 * subscriber.
	 * <p>
	 * This method is synchronized with the queueEvent method to ensure that the
	 * two events queued by this method are back-to-back.
	 *
	 * @param roots
	 *            the new roots or <code>null</code> if the roots from the
	 *            subscriber should be used.
	 */
	public void reset(IResource[] roots) {
		RootResourceSynchronizationScope scope = (RootResourceSynchronizationScope)getScope();
		if (roots == null)
			roots = getSubscriber().roots();
		scope.setRoots(roots);
	}

	@Override
	protected synchronized void reset(ResourceTraversal[] oldTraversals, ResourceTraversal[] newTraversals) {
		// First, reset the sync set input to clear the sync set
		run(monitor -> syncSetInput.reset(monitor), false /* keep ordering the same */);
		// Then, prime the set from the subscriber
		super.reset(oldTraversals, newTraversals);
	}
}