/*******************************************************************************
 * Copyright (c) 2003, 2005 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.internal.resources;

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

import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFolder;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.jobs.ISchedulingRule;
import org.eclipse.wst.common.componentcore.ComponentCore;
import org.eclipse.wst.common.componentcore.internal.ComponentResource;
import org.eclipse.wst.common.componentcore.internal.StructureEdit;
import org.eclipse.wst.common.componentcore.internal.WorkbenchComponent;
import org.eclipse.wst.common.componentcore.internal.impl.ModuleURIUtil;
import org.eclipse.wst.common.componentcore.internal.impl.ResourceTreeNode;
import org.eclipse.wst.common.componentcore.internal.impl.ResourceTreeRoot;
import org.eclipse.wst.common.componentcore.internal.impl.WorkbenchComponentImpl;
import org.eclipse.wst.common.componentcore.resources.IVirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualContainer;
import org.eclipse.wst.common.componentcore.resources.IVirtualResource;

public abstract class VirtualResource implements IVirtualResource {

	protected static final IResource[] NO_RESOURCES = null;
	private final IProject componentProject;
	private final IPath runtimePath;
	private int hashCode;
	private String toString;
	private static final String EMPTY_STRING = ""; //$NON-NLS-1$
	private IVirtualComponent component;
	private String resourceType;
	
	private final ResourceTimestampMappings mapping = new ResourceTimestampMappings();


	protected VirtualResource(IProject aComponentProject, IPath aRuntimePath) {
		componentProject = aComponentProject;
		runtimePath = aRuntimePath;
	}

	public void delete(int updateFlags, IProgressMonitor monitor) throws CoreException {

		if ((updateFlags & IVirtualResource.IGNORE_UNDERLYING_RESOURCE) == 0) {
			doDeleteRealResources(updateFlags, monitor);
		}

		doDeleteMetaModel(updateFlags, monitor);
	}

	protected void doDeleteMetaModel(int updateFlags, IProgressMonitor monitor) {
		StructureEdit moduleCore = null;
		try {
			moduleCore = StructureEdit.getStructureEditForWrite(getProject());
			WorkbenchComponent aComponent = moduleCore.getComponent();
			ComponentResource[] resources = aComponent.findResourcesByRuntimePath(getRuntimePath());
			aComponent.getResources().removeAll(Arrays.asList(resources));
		} finally {
			if (moduleCore != null) {
				moduleCore.saveIfNecessary(monitor);
				moduleCore.dispose();
			}
		}
	}


	protected abstract void doDeleteRealResources(int updateFlags, IProgressMonitor monitor) throws CoreException;

	public boolean exists() {
		// verify all underlying resources exist for the virtual resource to exist
		IResource[] resources = getUnderlyingResources();
		if (resources==null || resources.length==0)
			return false;
		for (int i=0; i<resources.length; i++) {
			if (resources[i]==null || !resources[i].exists())
				return false;
		}
		return true;
	}

	public String getFileExtension() {
		String name = getName();
		int dot = name.lastIndexOf('.');
		if (dot == -1)
			return null;
		if (dot == name.length() - 1)
			return EMPTY_STRING;
		return name.substring(dot + 1);
	}

	public IPath getWorkspaceRelativePath() {
		return getProject().getFullPath().append(getProjectRelativePath());
	}

	public IPath getRuntimePath() {
		return runtimePath;
	}

	public IPath[] getProjectRelativePaths() {
 
		WorkbenchComponent aComponent = getReadOnlyComponent();
		if (aComponent != null) {
			ResourceTreeRoot root = ResourceTreeRoot.getDeployResourceTreeRoot(aComponent);
			// still need some sort of loop here to search subpieces of the runtime path.
			ComponentResource[] componentResources = null;

			if (root != null) {
				IPath[] estimatedPaths = null;
				IPath searchPath = null;
				do {
					searchPath = (searchPath == null) ? getRuntimePath() : searchPath.removeLastSegments(1);
					componentResources = root.findModuleResources(searchPath, ResourceTreeNode.CREATE_NONE);
					estimatedPaths = findBestMatches(componentResources);
				} while (estimatedPaths.length==0 && canSearchContinue(componentResources, searchPath));
				if (estimatedPaths==null || estimatedPaths.length==0)
					return new IPath[] {getRuntimePath()};
				return estimatedPaths;
			}
		} 
 
		return new IPath[] {getRuntimePath()};
	}

	public IPath getProjectRelativePath() { 
		if (getRuntimePath().equals(new Path("/"))) { 
			WorkbenchComponent aComponent = getReadOnlyComponent();
			if (aComponent != null) {
				if (((WorkbenchComponentImpl) aComponent).getDefaultSourceRoot() != null)
					return ((WorkbenchComponentImpl) aComponent).getDefaultSourceRoot();
			} 
		}
		return getProjectRelativePaths()[0];
	}
	
	private boolean canSearchContinue(ComponentResource[] componentResources, IPath searchPath) {
		return (searchPath.segmentCount() > 0);
	}

	private IPath[] findBestMatches(ComponentResource[] theComponentResources) {
		List result = new ArrayList();
		int currentMatchLength = 0;
		int bestMatchLength = -1;
		IPath estimatedPath = null;
		IPath currentPath = null;
		final IPath aRuntimePath = getRuntimePath();
		for (int i = 0; i < theComponentResources.length; i++) {
			currentPath = theComponentResources[i].getRuntimePath();
			if (currentPath.isPrefixOf(aRuntimePath)) {
				if (currentPath.segmentCount() == aRuntimePath.segmentCount()) {
					result.add(theComponentResources[i].getSourcePath());
					continue;
				}	
				currentMatchLength = currentPath.matchingFirstSegments(aRuntimePath);
				if (currentMatchLength == currentPath.segmentCount() && currentMatchLength > bestMatchLength) {
					bestMatchLength = currentMatchLength;
					IPath sourcePath = theComponentResources[i].getSourcePath();
					IPath subpath = aRuntimePath.removeFirstSegments(currentMatchLength);
					estimatedPath = sourcePath.append(subpath);
				}
			}
		}
		if (result.size()>0)
			return (IPath[]) result.toArray(new IPath[result.size()]);
		if (estimatedPath == null)
			return new IPath[] {};
		return new IPath[] {estimatedPath};
	}

	public String getName() {
		if (getRuntimePath().segmentCount()>0)
			return getRuntimePath().lastSegment();
		return getRuntimePath().toString();
	}

	public IVirtualComponent getComponent() {
		if (component == null)
			component = ComponentCore.createComponent(getProject());
		return component;
	}
    
	//returns null if the folder is already the root folder
	public IVirtualContainer getParent() {
		if (getRuntimePath().segmentCount() >= 1)
			return ComponentCore.createFolder(getProject(), getRuntimePath().removeLastSegments(1));
		return null;
	}

	public IProject getProject() {
		return componentProject;
	}

	public boolean isAccessible() {
		throw new UnsupportedOperationException("Method not supported"); //$NON-NLS-1$
		// return false;
	}

	public Object getAdapter(Class adapter) {
		throw new UnsupportedOperationException("Method not supported"); //$NON-NLS-1$
		// return null;
	}

	public boolean contains(ISchedulingRule rule) {
		throw new UnsupportedOperationException("Method not supported"); //$NON-NLS-1$
		// return false;
	}

	public boolean isConflicting(ISchedulingRule rule) {
		throw new UnsupportedOperationException("Method not supported"); //$NON-NLS-1$
		// return false;
	}

	public String toString() {
		if (toString == null)
			toString = "[" + ModuleURIUtil.getHandleString(getComponent()) + ":" + getRuntimePath() + "]"; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
		return toString;
	}

	public int hashCode() {
		if (hashCode == 0)
			hashCode = toString().hashCode();
		return hashCode;
	}

	public boolean equals(Object anOther) {
		return hashCode() == ((anOther != null && anOther instanceof VirtualResource) ? anOther.hashCode() : 0);
	}

	public void setResourceType(String aResourceType) {
		resourceType = aResourceType; 
		WorkbenchComponent aComponent = getReadOnlyComponent();
		ComponentResource[] resources = aComponent.findResourcesByRuntimePath(getRuntimePath());
		for (int i = 0; i < resources.length; i++) {
			resources[i].setResourceType(aResourceType);
		}
		 
	}

	// TODO Fetch the resource type from the model.
	public String getResourceType() {
		if (null == resourceType) { 
			WorkbenchComponent aComponent = getReadOnlyComponent();
			ComponentResource[] resources = aComponent.findResourcesByRuntimePath(getRuntimePath());
			for (int i = 0; i < resources.length; i++) {
				resourceType = resources[i].getResourceType();
				return resourceType;
			}
			 
		}
		resourceType = ""; //$NON-NLS-1$
		return resourceType;
	}


	protected void createResource(IContainer resource, int updateFlags, IProgressMonitor monitor) throws CoreException {

		if (resource.exists())
			return;
		if (!resource.getParent().exists())
			createResource(resource.getParent(), updateFlags, monitor);
		if (!resource.exists() && resource.getType() == IResource.FOLDER) {
			((IFolder) resource).create(updateFlags, true, monitor);
		}
	}

	protected boolean isPotentalMatch(IPath aRuntimePath) {
		return aRuntimePath.isPrefixOf(getRuntimePath());
	}

	/* (non-Javadoc)
	 * @see org.eclipse.wst.common.componentcore.resources.IVirtualResource#removeLink(org.eclipse.core.runtime.IPath, int, org.eclipse.core.runtime.IProgressMonitor)
	 */
	public void removeLink(IPath aProjectRelativeLocation, int updateFlags, IProgressMonitor monitor) throws CoreException {
		StructureEdit moduleCore = null;
		try {
			moduleCore = StructureEdit.getStructureEditForWrite(getProject());
			WorkbenchComponent component = moduleCore.getComponent();
			ResourceTreeRoot root = ResourceTreeRoot.getDeployResourceTreeRoot(component);
			ComponentResource[] resources = root.findModuleResources(getRuntimePath(), ResourceTreeNode.CREATE_NONE);
			if (resources.length > 0) {
				for (int resourceIndx = 0; resourceIndx < resources.length; resourceIndx++) {
					if (aProjectRelativeLocation.makeAbsolute().equals(resources[resourceIndx].getSourcePath())) {
						component.getResources().remove(resources[resourceIndx]);
					}
				}
			}
		} finally {
			if (moduleCore != null) {
				moduleCore.saveIfNecessary(monitor);
				moduleCore.dispose();
			}
		}
	}
	
	protected final WorkbenchComponent getReadOnlyComponent() {
		if(!mapping.hasChanged(getProject()) && mapping.hasCacheData(getProject()))
			return (WorkbenchComponent) mapping.getData(getProject());
		
		StructureEdit moduleCore = null;
		WorkbenchComponent component = null;
		try {
			moduleCore = StructureEdit.getStructureEditForRead(getProject());
			component = moduleCore.getComponent();
			mapping.mark(getProject(), component);
		} finally {
			if (moduleCore != null) { 
				moduleCore.dispose();
			}
		}
		return component;
		
			
	}
}