/******************************************************************************
 * Copyright (c) 2005-2006 BEA Systems, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Konstantin Komissarchik - initial API and implementation
 ******************************************************************************/

package org.eclipse.jst.j2ee.internal.web.classpath;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jdt.core.IClasspathContainer;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jst.common.internal.modulecore.ClasspathContainerVirtualComponent;
import org.eclipse.jst.common.jdt.internal.classpath.FlexibleProjectContainer;
import org.eclipse.jst.j2ee.internal.common.classpath.J2EEComponentClasspathUpdater;
import org.eclipse.jst.j2ee.internal.web.plugin.WebPlugin;
import org.eclipse.osgi.util.NLS;
import org.eclipse.wst.common.componentcore.internal.builder.IDependencyGraph;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualReference;

/**
 * @author <a href="mailto:kosta@bea.com">Konstantin Komissarchik</a>
 */

public final class WebAppLibrariesContainer 
    
    extends FlexibleProjectContainer
    
{
	private WebAppLibrariesStore.RestoreState restoreState;
	
    private static final IPath[] paths 
        = new IPath[] { new Path( "WEB-INF/lib" ),  //$NON-NLS-1$
                        new Path( "WEB-INF/classes" ) }; //$NON-NLS-1$
    
    private static final PathType[] types 
        = new PathType[] { PathType.LIB_DIRECTORY, PathType.CLASSES_DIRECTORY };
    
    public static final String CONTAINER_ID 
        = "org.eclipse.jst.j2ee.internal.web.container"; //$NON-NLS-1$
    
    public WebAppLibrariesContainer( final IPath path,
                                     final IJavaProject jproject )
    {
         super( path, jproject, getProject( path, jproject), paths, types );
         boolean needToVerify = false;
		 if(null != restoreState){
			 synchronized (restoreState) {
				 needToVerify = restoreState.needToVerify;
				 restoreState.needToVerify = false;
			 }
		 }
         if(needToVerify){
        	 Job verifyJob = new Job(Resources.verify){
 				@Override
 				protected IStatus run(IProgressMonitor monitor) {
 			        WebAppLibrariesContainer.this.refresh(false);
 					return Status.OK_STATUS;
 				}
 			};
 			verifyJob.setSystem(true);
 			verifyJob.setRule(ResourcesPlugin.getWorkspace().getRoot());
 			verifyJob.schedule();
         }
    }
    
    public String getDescription()
    {
        if( this.owner.getProject() != this.project )
        {
            return NLS.bind( Resources.labelWithProject, this.project.getName() );
        }
        return Resources.label;
    }
    
    public void install()
    {
        final IJavaProject[] projects = new IJavaProject[] { this.owner };
        final IClasspathContainer[] conts = new IClasspathContainer[] { this };

        try
        {
            JavaCore.setClasspathContainer( path, projects, conts, null );
        }
        catch( JavaModelException e )
        {
            WebPlugin.log( e );
        }
    }
    
    @Override
    public boolean isOutOfDate() {
    	if(IDependencyGraph.INSTANCE.isStale()){
    		//avoid deadlock https://bugs.eclipse.org/bugs/show_bug.cgi?id=334050
    		//if the data is stale, return true and attempt to update again in the near future
    		J2EEComponentClasspathUpdater.getInstance().queueUpdate(owner.getProject());
    		return true;
    	}
    	
    	final List currentEntries = computeClasspathEntries(false);
    	boolean outOfDate  = ! this.entries.equals( currentEntries );
    	if(outOfDate){
    		WebAppLibrariesStore.flush(project.getName());
    	}
    	return outOfDate;
    }
    
    @Override
	public void refresh(boolean forceUpdate){
    	if(IDependencyGraph.INSTANCE.isStale()){
			//avoid deadlock https://bugs.eclipse.org/bugs/show_bug.cgi?id=334050
			//if the data is stale abort and attempt to update again in the near future
			J2EEComponentClasspathUpdater.getInstance().queueUpdate(owner.getProject());
			return;
		}
		
    	if(forceUpdate || isOutOfDate()){
    		refresh();
    	}
    }
    
    @Override
	public void refresh()
    {
    	if(IDependencyGraph.INSTANCE.isStale()){
			//avoid deadlock https://bugs.eclipse.org/bugs/show_bug.cgi?id=335645
			//if the data is stale abort and attempt to update again in the near future
			J2EEComponentClasspathUpdater.getInstance().queueUpdate(owner.getProject());
			return;
		}
    	
        ( new WebAppLibrariesContainer( this.path, this.owner ) ).install();
    }
    
    private static Map<String, Object> referenceOptions = new HashMap<String, Object>();
    static {
    	referenceOptions.put("GET_JAVA_REFS", Boolean.FALSE); //$NON-NLS-1$
    }
    
    protected List <IVirtualReference>consumedReferences;
    
    @Override
    protected IVirtualReference[] computeReferences(IVirtualComponent vc) {
    	IVirtualReference [] baseRefs = ((VirtualComponent)vc).getReferences(referenceOptions);
    	List <IVirtualReference> refs = new ArrayList <IVirtualReference>();
    	for(IVirtualReference ref: baseRefs){
    		if(ref.getDependencyType() == IVirtualReference.DEPENDENCY_TYPE_USES){
    			refs.add(ref);
    		} else {
    			if (ref.getRuntimePath().equals(paths[0].makeAbsolute())){
    				if(consumedReferences == null){
    					consumedReferences = new ArrayList<IVirtualReference>();
    				}
    				consumedReferences.add(ref);
    			}
    		}
    	}
    	return refs.toArray(new IVirtualReference[refs.size()]);
    }
    
    @Override
    protected List computeClasspathEntries() {
    	return computeClasspathEntries(true);
    }
    
    protected List computeClasspathEntries(boolean useRestoreState) {
    	if(useRestoreState){
	    	restoreState = WebAppLibrariesStore.getRestoreState(project.getName());
	    	if(restoreState != null){
	    		return restoreState.paths;
	    	}
    	}
    	
    	List <IPath>entries = super.computeClasspathEntries();
    	if(consumedReferences != null){
	    	for(IVirtualReference ref:consumedReferences){
	    		if(ref.getReferencedComponent() instanceof ClasspathContainerVirtualComponent){
	    			ClasspathContainerVirtualComponent cpvc = (ClasspathContainerVirtualComponent)ref.getReferencedComponent();
	    			if(cpvc != null){
	    				IClasspathContainer container = cpvc.getClasspathContainer();
	    				if(container != null){
			    			IClasspathEntry [] newEntries = container.getClasspathEntries();
			    			for(IClasspathEntry entry:newEntries){
			    				IPath entryPath = entry.getPath();
			    				if(!entries.contains(entryPath)){
			    					entries.add(entryPath);
			    				}
			    			}
	    				}
	    			}
	    		}
	    	}
    	}
    	WebAppLibrariesStore.saveState(project.getName(), entries);
    	return entries;
    }
    
    private static final IProject getProject( final IPath path,
                                              final IJavaProject jproject )
    {
        if( path.segmentCount() == 1 )
        {
            return jproject.getProject();
        }
        final String name = path.segment( 1 );
        return ResourcesPlugin.getWorkspace().getRoot().getProject( name );
    }
    
    private static final class Resources
    
        extends NLS
        
    {
        public static String label;
        public static String labelWithProject;
        public static String verify;
        
        static
        {
            initializeMessages( WebAppLibrariesContainer.class.getName(), 
                                Resources.class );
        }
    }
    
}