/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (the "License").

 * You may not use this file except in compliance with the License.

 *

 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE

 * or http://www.opensolaris.org/os/licensing.

 * See the License for the specific language governing permissions

 * and limitations under the License.

 *

 * When distributing Covered Code, include this CDDL HEADER in each

 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.

 * If applicable, add the following below this CDDL HEADER, with the

 * fields enclosed by brackets "[]" replaced with your own identifying

 * information: Portions Copyright [yyyy] [name of copyright owner]

 *

 * CDDL HEADER END

 */

/*

 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

package org.opensolaris.os.vp.panel.common.control;

import java.util.*;

import java.util.concurrent.*;

import java.util.regex.Pattern;

import org.opensolaris.os.vp.util.*;

public class Navigator {

    //

    // Static data

    //

    public static final String PATH_SEPARATOR = "/";

    public static final String PARENT_ID = "..";

    //

    // Instance data

    //

    private Thread dispatchThread;

    // Use a thread pool with a single core thread to autmatically handle

    // uncaught exceptions and queued requests

    private ThreadPoolExecutor threadPool;

    {

	ThreadFactory factory =

	    new NamedThreadFactory("Navigator-") {

		@Override

		public Thread newThread(Runnable r) {

		    dispatchThread = super.newThread(r);

		    return dispatchThread;

		}

	    };

	// Unbounded

	BlockingQueue<Runnable> queue = new LinkedBlockingQueue<Runnable>();

	threadPool = new ThreadPoolExecutor(

	    1, 1, 10, TimeUnit.MINUTES, queue, factory);

	threadPool.allowCoreThreadTimeOut(true);

    }

    private StackList<Control> stack = new StackList<Control>();

    private List<NavigationListener> listeners =

	new ArrayList<NavigationListener>();

    private List<NavigationListener> roListeners =

	Collections.unmodifiableList(listeners);

    //

    // Navigator methods

    //

    /**

     * Adds a {@link NavigationListener} to be notified when navigation is

     * stopped and started.

     */

    public void addNavigationListener(NavigationListener l) {

	listeners.add(l);

    }

    /**

     * Runs the given {@code Runnable} asynchronously on this {@code

     * specifically for navigation; the given {@code Runnable} should thus be

     * limited to calling {@link #goTo(Control,Navigable...)} and (briefly)

     * handling any thrown exceptions.

     * <p/>

     * Note: If this method is called when the navigation thread is busy, the

     * given {@code Runnable} will be queued and run when the thread is

     * available.

     *

     * @param	    r

     *		    the {@code Runnable} to run and handle any resulting

     *		    exceptions

     */

    public void asyncExec(Runnable r) {

	threadPool.execute(r);

    }

    /**

     * Runs the given {@link NavRunnable} on this {@code Navigator}'s navigation

     * thread and waits for it to complete.  Any exceptions thrown by {@code r}

     * are thrown here.

     * <p/>

     * See {@link #asyncExec}.

     *

     * @param	    r

     *		    the {@link NavRunnable} to run

     */

    public void asyncExecAndWait(final NavRunnable r)

	throws NavigationAbortedException, InvalidAddressException,

	MissingParameterException, InvalidParameterException {

	if (isDispatchThread()) {

	    r.run();

	    return;

	}

	final boolean[] done = {false};

	final Throwable[] throwable = {null};

	asyncExec(

	    new Runnable() {

		@Override

		public void run() {

		    try {

			r.run();

		    } catch (Throwable t) {

			throwable[0] = t;

		    }

		    synchronized (done) {

			done[0] = true;

			done.notify();

		    }

		}

	    });

	// Sleep until nav thread is done

	synchronized (done) {

	    while (!done[0]) {

		try {

		    done.wait();

		} catch (InterruptedException ignore) {

		}

	    }

	}

	Throwable t = throwable[0];

	if (t != null) {

	    if (t instanceof NavigationAbortedException)

		throw (NavigationAbortedException)t;

	    if (t instanceof InvalidAddressException)

		throw (InvalidAddressException)t;

	    if (t instanceof MissingParameterException)

		throw (MissingParameterException)t;

	    if (t instanceof InvalidParameterException)

		throw (InvalidParameterException)t;

	    if (t instanceof RuntimeException)

		throw (RuntimeException)t;

	    if (t instanceof Error)

		throw (Error)t;

	    // All Throwables should be accounted for

	    assert false;

	}

    }

    /**

     * Notifies all registered {@link NavigationListener}s that a navigation has

     * begun.

     */

    protected void fireNavigationStarted(NavigationEvent e) {

	// Iterate backwards to allow listener removal during iteration

	for (int i = listeners.size() - 1; i >= 0; i--) {

	    listeners.get(i).navigationStarted(e);

	}

    }

    /**

     * Notifies all registered {@link NavigationListener}s that a navigation has

     * stopped.

     */

    protected void fireNavigationStopped(NavigationEvent e) {

	// Iterate backwards to allow listener removal during iteration

	for (int i = listeners.size() - 1; i >= 0; i--) {

	    listeners.get(i).navigationStopped(e);

	}

    }

    public List<NavigationListener> getNavigationListeners() {

	return roListeners;

    }

    /**

     * Gets the current path.  This method is not thread-safe; it is up to

     * callers to ensure the that navigation is not currently modifying this

     * path.

     */

    @SuppressWarnings({"unchecked"})

    public List<Control> getPath() {

	return (List<Control>)stack.clone();

    }

    /**

     * Gets the current path as a {@code String}.  This method is not

     * thread-safe; it is up to callers to ensure the that navigation is not

     * currently modifying this path.

     */

    public String getPathString() {

	return getPathString(stack);

    }

    /**

     * Navigates to the {@link Control} identified by the given path.

     *

     * @param	    relativeTo

     *		    a {@link Control} within the navigation stack to which

     *		    {@code path} is relative, or {@code null} if {@code path} is

     *		    absolute

     *

     * @param	    path

     *		    the path (relative to {@code relativeTo}), or unspecified to

     *

     *

     * @exception   NavigationAbortedException

     *		    if the navigation is vetoed

     *

     * @exception   InvalidAddressException

     *		    if {@code path} does not refer to a valid address

     *

     * @exception   MissingParameterException

     *		    if some {@link Control} in the process of navigation could

     *		    not be {@link Control#start started} due to a missing

     *		    intialization parameter

     *

     * @exception   InvalidParameterException

     *		    if some {@link Control} in the process of navigation could

     *		    not be {@link Control#start started} due to an invalid

     *		    intialization parameter

     *

     * @exception   IllegalArgumentException

     *		    if {@code relativeTo} is not in the navigation stack

     */

    public Control goTo(Control relativeTo, Navigable... path)

	throws NavigationAbortedException, InvalidAddressException,

	MissingParameterException, InvalidParameterException {

	assert isDispatchThread();

	synchronized (stack) {

	    // Last absolute path

	    StackList<Navigable> laPath = new StackList<Navigable>();

	    laPath.addAll(stack);

	    while (true) {

		// Current absolute path

		StackList<Navigable> caPath = new StackList<Navigable>();

		if (relativeTo != null) {

		    caPath.addAll(laPath);

		    try {

			// Remove path elements until relativeTo is at the top

			while (!((HasControl)caPath.peek()).getControl().

			    equals(relativeTo)) {

			    caPath.pop();

			}

		    } catch (EmptyStackException e) {

			throw new IllegalArgumentException(String.format(

			    "Control not in navigation path: %s (%s)",

			    relativeTo.getClass().getName(),

			    relativeTo.getId()));

		    }

		}

		    CollectionUtil.addAll(caPath, path);

		    // Remove unnecessary ".." segments

		    normalize(caPath);

		}

		List<Navigable> rPath = getRelativePath(laPath, caPath);

		if (rPath.isEmpty()) {

		    break;

		}

			}

			laPath.pop();

		    } else {

			}

			PendingControl pair =

			laPath.push(pair);

		    }

		}

		}

	    }

	    // The original Control, before navigation

	    @SuppressWarnings({"unchecked"})

	    if (!rPath.isEmpty()) {

		NavigationEvent event = new NavigationEvent(this,

		    Collections.unmodifiableList(rPath));

		fireNavigationStarted(event);

		try {

		    for (PendingControl pend : rPath) {

			if (pend.getId().equals(PARENT_ID)) {

			    curControl.stop();

			    stack.pop();

			} else {

			    Control newControl = pend.getControl();

			    newControl.start(this, pend.getParameters());

			    stack.push(newControl);

			}

			if (System.getProperty("vpanels.debug.navigator") !=

			    null) {

			    System.out.printf("%s\n", getPathString());

			}

		    }

		} finally {

		    fireNavigationStopped(event);

		}

	    }

	    return orig;

	}

    }

    /**

     * Asynchronously navigates to the {@link Control} identified by the

     * given path.  A wrapper around {@link #goTo(Control,Navigable...)}

     * that is run asynchronously using {@link #asyncExec}.

     */

    public void goToAsync(final Control relativeTo, final Navigable... path) {

	asyncExec(

	    new Runnable() {

		@Override

		public void run() {

		    try {

			goTo(relativeTo, path);

		    } catch (NavigationException ignore) {

		    }

		}

	    });

    }

    /**

     * Asynchronously navigates to the {@link Control} identified by the given

     * path, returning only when navigation is complete.  A wrapper around

     * {@link #goTo(Control,Navigable...)} that is run asynchronously using

     * {@link #asyncExecAndWait}.

     */

    public void goToAsyncAndWait(

	final Control relativeTo, final Navigable... path)

	throws NavigationAbortedException, InvalidAddressException,

	MissingParameterException, InvalidParameterException {

	asyncExecAndWait(

	    new NavRunnable() {

		@Override

		public void run()

		    throws NavigationAbortedException, InvalidAddressException,

		    MissingParameterException, InvalidParameterException {

		    goTo(relativeTo, path);

		}

	    });

    }

    /**

     * Shortcut for:

     * <p>

     *	 <code>

     *	   {@link #goTo(Control,Navigable...) goTo}(relativeTo,

     *	   new {@link SimpleNavigable#SimpleNavigable(String,Map)

     *	   SimpleNavigable}(id, {@link Navigable.Util#toMap

     *	   Navigable.Util.toMap}(parameters)));

     *	 </code>

     * </p>

     */

    public Control goTo(Control relativeTo, String id,

	String... parameters) throws NavigationAbortedException,

	InvalidAddressException, MissingParameterException,

	InvalidParameterException {

	return goTo(relativeTo,

	    new SimpleNavigable(id, Navigable.Util.toMap(parameters)));

    }

    /**

     * A wrapper around {@link #goTo(Control,String,String...)}

     * that is run asynchronously using {@link #asyncExec}.

     */

    public void goToAsync(final Control relativeTo, final String id,

	final String... parameters) {

	    asyncExec(

		new Runnable() {

		    @Override

		    public void run() {

			try {

			    goTo(relativeTo, id, parameters);

			} catch (NavigationException ignore) {

			}

		    }

		});

    }

    /**

     * A wrapper around {@link #goTo(Control,String,String...)}

     * that is run asynchronously using {@link #asyncExecAndWait}.