/*******************************************************************************
 * Copyright (c) 2003, 2004 IBM Corporation and others.
 * 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:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.common.componentcore;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.wst.common.componentcore.internal.ComponentResource;
import org.eclipse.wst.common.componentcore.internal.StructureEdit;
import org.eclipse.wst.common.componentcore.internal.impl.ResourceTreeNode;
import org.eclipse.wst.common.componentcore.internal.resources.FlexibleProject;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualComponent;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualFile;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualFolder;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualReference;
import org.eclipse.wst.common.componentcore.internal.resources.VirtualResource;
import org.eclipse.wst.common.componentcore.resources.IFlexibleProject;
import org.eclipse.wst.common.componentcore.resources.IVirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualContainer;
import org.eclipse.wst.common.componentcore.resources.IVirtualFile;
import org.eclipse.wst.common.componentcore.resources.IVirtualFolder;
import org.eclipse.wst.common.componentcore.resources.IVirtualReference;
import org.eclipse.wst.common.componentcore.resources.IVirtualResource;

/**
 * Provides a handle creation factory for the Virtual Path API. Clients may use
 * this class to convert Platform IResource model elements to IVirtualResource
 * model elements.
 * <p>ComponentCore provides a consistent entry point to the IVirtual Path model that
 * allows clients to group resources together in logical collections with a path 
 * structure that varies from their actual source location structures. 
 * </p>
 * 
 * @since 1.0
 */
public class ComponentCore {

	private static final IVirtualResource[] NO_RESOURCES = new VirtualResource[0];

	/**
	 * Return an IFlexibleProject that provides an entry-point to the components
	 * stored within the given project. The returned IFlexibleProject may not contain
	 * any components, which could mean that the supplied IProject is either not 
	 * flexible or empty.  
	 * 
	 * @param aProject A valid, accessible IProject
	 * @return A valid IFlexibleProject 
	 */
	public static IFlexibleProject createFlexibleProject(IProject aProject) {
		return new FlexibleProject(aProject);
	}

	/**
	 * Return an IVirtualComponent with the given name (aComponentName) contained by 
	 * the given project (aProject). Component names should be unique across a project.
	 * 
	 * @param aProject A  valid, accessible project to contain the component
	 * @param aComponentName A name to identify the component within the project. 
	 * @return A handle to an IVirtualComponent that may or may not exist.
	 * @see IVirtualContainer#create(int, IProgressMonitor) 
	 */
	public static IVirtualComponent createComponent(IProject aProject, String aComponentName) {
		return new VirtualComponent(aProject, aComponentName, new Path("/")); //$NON-NLS-1$
	}

	/**
	 * Return an IVirtualFolder with a runtime path specified by aRuntimePath 
	 * contained by aProject, in a component named aComponentName. The resultant
	 * IVirtualFolder may or may not exist. 
	 *   
	 * @param aProject A  valid, accessible project to contain the component
	 * @param aComponentName A name to identify the component within the project. 
	 * @param aRuntimePath The runtime path of the IVirtualFolder to return.
	 * @return An IVirtualFolder contained by the specified component with the given runtime path
	 *  
	 * @see IVirtualContainer#create(int, IProgressMonitor)
	 * @see IVirtualResource#createLink(IPath, int, IProgressMonitor)
	 *  
	 */
	public static IVirtualFolder createFolder(IProject aProject, String aComponentName, IPath aRuntimePath) {
		return new VirtualFolder(aProject, aComponentName, aRuntimePath);
	}
	
	/**
	 * Return an IVirtualFile with a runtime path specified by aRuntimePath 
	 * contained by aProject, in a component named aComponentName. IVirtualFiles 
	 * can only be created as links. Use {@link IVirtualResource#getUnderlyingResource()} or 
	 * {@link IVirtualFile#getUnderlyingFile()} to create a resource with real contents.
	 *   
	 * @param aProject A  valid, accessible project to contain the component
	 * @param aComponentName A name to identify the component within the project. 
	 * @param aRuntimePath The runtime path of the IVirtualFolder to return.
	 * @return An IVirtualFile contained by the specified component with the given runtime path
	 *   
	 * @see IVirtualResource#createLink(IPath, int, IProgressMonitor)
	 *  
	 */
	public static IVirtualFile createFile(IProject aProject, String aComponentName, IPath aRuntimePath) {
		return new VirtualFile(aProject, aComponentName, aRuntimePath);
	}

	/**
	 * Return an IVirtualReference that captures a relationship between aComponent and aReferencedComponent. 
	 * The IVirtualReference will be stored with aComponent and target aReferencedComponent. IVirtualReferences
	 * may span projects. 
	 * @param aComponent A valid, existing IVirtualComponent
	 * @param aReferencedComponent A valid, existing IVirtualComponent
	 * @return An IVirtualReference that captures the relationship between aComponent and aReferencedComponent.
	 * @see IVirtualReference#create(int, IProgressMonitor)
	 */
	public static IVirtualReference createReference(IVirtualComponent aComponent, IVirtualComponent aReferencedComponent) {
		return new VirtualReference(aComponent, aReferencedComponent);		
	} 

	/**
	 * Return an array of IVirtualResources that represent the given IResource. Each IResource could 
	 * be mapped to multiple components, and thus an array of each IVirtualResource that represents
	 * the IResource will be returned. Each IVirtualResource may also map to other existing IResources,
	 * so the mapping is not 1:1.
	 *  
	 * @param aResource An accessible IResource
	 * @return An array of IVirtualResources from the model that represent the IResource.
	 */
	public static IVirtualResource[] createResources(IResource aResource) {
		IProject proj = aResource.getProject();
		StructureEdit se = null;
		List foundResources = new ArrayList();
		try {
			se = StructureEdit.getStructureEditForRead(proj);
			ComponentResource[] resources = se
					.findResourcesBySourcePath(aResource
							.getProjectRelativePath(),aResource.exists() ? ResourceTreeNode.CREATE_NONE:ResourceTreeNode.CREATE_RESOURCE_ALWAYS);
			for (int i = 0; i < resources.length; i++) {
				if (aResource.getType() == IResource.FILE)
					foundResources.add(new VirtualFile(proj, resources[i]
							.getComponent().getName(), resources[i]
							.getRuntimePath()));
				else
					foundResources.add(new VirtualFolder(proj, resources[i]
							.getComponent().getName(), resources[i]
							.getRuntimePath()));
			}
		} catch (UnresolveableURIException e) {
			e.printStackTrace();
		} finally {
			se.dispose();
		}
		if (foundResources.size() > 0)
			return (IVirtualResource[]) foundResources
					.toArray(new VirtualResource[foundResources.size()]);
		return NO_RESOURCES;
	}
}