Copyright (c) 2000, 2016 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
    Terry Parker  - [performance] Low hit rates in JavaModel caches - https://bugs.eclipse.org/421165
/*******************************************************************************
 * Copyright (c) 2000, 2016 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
 *     Terry Parker <tparker@google.com> - [performance] Low hit rates in JavaModel caches - https://bugs.eclipse.org/421165
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import java.io.File;
import java.util.ArrayList;
import java.util.Map;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IFolder;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.Assert;
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.jdt.core.*;
import org.eclipse.jdt.internal.compiler.util.SuffixConstants;
import org.eclipse.jdt.internal.core.util.MementoTokenizer;
import org.eclipse.jdt.internal.core.util.Messages;

Implementation of IJavaModel. The Java Model maintains a cache of active IJavaProjects in a workspace. A Java Model is specific to a workspace. To retrieve a workspace's model, use the #getJavaModel() method. 
See Also:
IJavaModel/**
 * Implementation of {@link IJavaModel}. The Java Model maintains a cache of active
 * {@link IJavaProject}s in a workspace. A Java Model is specific to a workspace.
 * To retrieve a workspace's model, use the
 * {@link IJavaElement#getJavaModel() #getJavaModel()} method.
 *
 * @see IJavaModel
 */
@SuppressWarnings({"rawtypes", "unchecked"})
public class JavaModel extends Openable implements IJavaModel {

Constructs a new Java Model on the given workspace.
Note that only one instance of JavaModel handle should ever be created.
One should only indirect through JavaModelManager#getJavaModel() to get
access to it.
Throws:
Error – if called more than once/**
 * Constructs a new Java Model on the given workspace.
 * Note that only one instance of JavaModel handle should ever be created.
 * One should only indirect through JavaModelManager#getJavaModel() to get
 * access to it.
 *
 * @exception Error if called more than once
 */
protected JavaModel() throws Error {
	super(null);
}
@Override
protected boolean buildStructure(OpenableElementInfo info, IProgressMonitor pm, Map newElements, IResource underlyingResource)	/*throws JavaModelException*/ {

	// determine my children
	IProject[] projects = ResourcesPlugin.getWorkspace().getRoot().getProjects();
	int length = projects.length;
	IJavaElement[] children = new IJavaElement[length];
	int index = 0;
	for (int i = 0; i < length; i++) {
		IProject project = projects[i];
		if (JavaProject.hasJavaNature(project)) {
			children[index++] = getJavaProject(project);
		}
	}
	if (index < length)
		System.arraycopy(children, 0, children = new IJavaElement[index], 0, index);
	info.setChildren(children);

	newElements.put(this, info);

	return true;
}
/*
 * @see IJavaModel
 */
@Override
public boolean contains(IResource resource) {
	switch (resource.getType()) {
		case IResource.ROOT:
		case IResource.PROJECT:
			return true;
	}
	// file or folder
	IJavaProject[] projects;
	try {
		projects = getJavaProjects();
	} catch (JavaModelException e) {
		return false;
	}
	for (int i = 0, length = projects.length; i < length; i++) {
		JavaProject project = (JavaProject)projects[i];
		if (!project.contains(resource)) {
			return false;
		}
	}
	return true;
}
See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public void copy(IJavaElement[] elements, IJavaElement[] containers, IJavaElement[] siblings, String[] renamings, boolean force, IProgressMonitor monitor) throws JavaModelException {
	if (elements != null && elements.length > 0 && elements[0] != null && elements[0].getElementType() < IJavaElement.TYPE) {
		runOperation(new CopyResourceElementsOperation(elements, containers, force), elements, siblings, renamings, monitor);
	} else {
		runOperation(new CopyElementsOperation(elements, containers, force), elements, siblings, renamings, monitor);
	}
}
Returns a new element info for this element.
/**
 * Returns a new element info for this element.
 */
@Override
protected Object createElementInfo() {
	return new JavaModelInfo();
}

See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public void delete(IJavaElement[] elements, boolean force, IProgressMonitor monitor) throws JavaModelException {
	if (elements != null && elements.length > 0 && elements[0] != null && elements[0].getElementType() < IJavaElement.TYPE) {
		new DeleteResourceElementsOperation(elements, force).runOperation(monitor);
	} else {
		new DeleteElementsOperation(elements, force).runOperation(monitor);
	}
}
@Override
public boolean equals(Object o) {
	if (!(o instanceof JavaModel)) return false;
	return super.equals(o);
}
See Also:
IJavaElement/**
 * @see IJavaElement
 */
@Override
public int getElementType() {
	return JAVA_MODEL;
}

/*
 * @see JavaElement
 */
@Override
public IJavaElement getHandleFromMemento(String token, MementoTokenizer memento, WorkingCopyOwner owner) {
	switch (token.charAt(0)) {
		case JEM_JAVAPROJECT:
			if (!memento.hasMoreTokens()) return this;
			String projectName = memento.nextToken();
			JavaElement project = (JavaElement)getJavaProject(projectName);
			return project.getHandleFromMemento(memento, owner);
	}
	return null;
}
See Also:
getHandleMemento.getHandleMemento(StringBuffer)/**
 * @see JavaElement#getHandleMemento(StringBuffer)
 */
@Override
protected void getHandleMemento(StringBuffer buff) {
	buff.append(getElementName());
}
Returns the char that marks the start of this handles
contribution to a memento.
/**
 * Returns the <code>char</code> that marks the start of this handles
 * contribution to a memento.
 */
@Override
protected char getHandleMementoDelimiter(){
	Assert.isTrue(false, "Should not be called"); //$NON-NLS-1$
	return 0;
}
See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public IJavaProject getJavaProject(String projectName) {
	return new JavaProject(ResourcesPlugin.getWorkspace().getRoot().getProject(projectName), this);
}
Returns the active Java project associated with the specified
resource, or null if no Java project yet exists
for the resource.
Throws:
IllegalArgumentException – if the given resource
is not one of an IProject, IFolder, or IFile./**
 * Returns the active Java project associated with the specified
 * resource, or <code>null</code> if no Java project yet exists
 * for the resource.
 *
 * @exception IllegalArgumentException if the given resource
 * is not one of an IProject, IFolder, or IFile.
 */
public IJavaProject getJavaProject(IResource resource) {
	switch(resource.getType()){
		case IResource.FOLDER:
			return new JavaProject(((IFolder)resource).getProject(), this);
		case IResource.FILE:
			return new JavaProject(((IFile)resource).getProject(), this);
		case IResource.PROJECT:
			return new JavaProject((IProject)resource, this);
		default:
			throw new IllegalArgumentException(Messages.element_invalidResourceForProject);
	}
}
See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public IJavaProject[] getJavaProjects() throws JavaModelException {
	ArrayList list = getChildrenOfType(JAVA_PROJECT);
	IJavaProject[] array= new IJavaProject[list.size()];
	list.toArray(array);
	return array;

}
See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public Object[] getNonJavaResources() throws JavaModelException {
		return ((JavaModelInfo) getElementInfo()).getNonJavaResources();
}

/*
 * @see IJavaElement
 */
@Override
public IPath getPath() {
	return Path.ROOT;
}
/*
 * @see IJavaElement
 */
@Override
public IResource resource(PackageFragmentRoot root) {
	return ResourcesPlugin.getWorkspace().getRoot();
}
See Also:
IOpenable/**
 * @see IOpenable
 */
@Override
public IResource getUnderlyingResource() {
	return null;
}
Returns the workbench associated with this object.
/**
 * Returns the workbench associated with this object.
 */
@Override
public IWorkspace getWorkspace() {
	return ResourcesPlugin.getWorkspace();
}

See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public void move(IJavaElement[] elements, IJavaElement[] containers, IJavaElement[] siblings, String[] renamings, boolean force, IProgressMonitor monitor) throws JavaModelException {
	if (elements != null && elements.length > 0 && elements[0] != null && elements[0].getElementType() < IJavaElement.TYPE) {
		runOperation(new MoveResourceElementsOperation(elements, containers, force), elements, siblings, renamings, monitor);
	} else {
		runOperation(new MoveElementsOperation(elements, containers, force), elements, siblings, renamings, monitor);
	}
}

See Also:
refreshExternalArchives.refreshExternalArchives(IJavaElement[], IProgressMonitor)/**
 * @see IJavaModel#refreshExternalArchives(IJavaElement[], IProgressMonitor)
 */
@Override
public void refreshExternalArchives(IJavaElement[] elementsScope, IProgressMonitor monitor) throws JavaModelException {
	if (elementsScope == null){
		elementsScope = new IJavaElement[] { this };
	}
	JavaModelManager.getJavaModelManager().getDeltaProcessor().checkExternalArchiveChanges(elementsScope, monitor);
}

See Also:
IJavaModel/**
 * @see IJavaModel
 */
@Override
public void rename(IJavaElement[] elements, IJavaElement[] destinations, String[] renamings, boolean force, IProgressMonitor monitor) throws JavaModelException {
	MultiOperation op;
	if (elements != null && elements.length > 0 && elements[0] != null && elements[0].getElementType() < IJavaElement.TYPE) {
		op = new RenameResourceElementsOperation(elements, destinations, renamings, force);
	} else {
		op = new RenameElementsOperation(elements, destinations, renamings, force);
	}

	op.runOperation(monitor);
}
Configures and runs the MultiOperation.
/**
 * Configures and runs the <code>MultiOperation</code>.
 */
protected void runOperation(MultiOperation op, IJavaElement[] elements, IJavaElement[] siblings, String[] renamings, IProgressMonitor monitor) throws JavaModelException {
	op.setRenamings(renamings);
	if (siblings != null) {
		for (int i = 0; i < elements.length; i++) {
			op.setInsertBefore(elements[i], siblings[i]);
		}
	}
	op.runOperation(monitor);
}
@private
Debugging purposes/**
 * @private Debugging purposes
 */
@Override
protected void toStringInfo(int tab, StringBuffer buffer, Object info, boolean showResolvedInfo) {
	buffer.append(tabString(tab));
	buffer.append("Java Model"); //$NON-NLS-1$
	if (info == null) {
		buffer.append(" (not open)"); //$NON-NLS-1$
	}
}

Helper method - for the provided IPath, returns: 

If the path corresponds to an internal file or folder, the IResource for that resource 
If the path corresponds to an external folder linked through ExternalFoldersManager, the IFolder for that folder 
If the path corresponds to an external library archive, the File for that archive 
Can return null if checkResourceExistence is true
and the entity referred to by the path does not exist on the file system

Internal items must be referred to using container-relative paths.
/**
 * Helper method - for the provided {@link IPath}, returns:
 * <ul>
 * <li>If the path corresponds to an internal file or folder, the {@link IResource} for that resource
 * <li>If the path corresponds to an external folder linked through {@link ExternalFoldersManager},
 * the {@link IFolder} for that folder
 * <li>If the path corresponds to an external library archive, the {@link File} for that archive
 * <li>Can return <code>null</code> if <code>checkResourceExistence</code> is <code>true</code>
 * and the entity referred to by the path does not exist on the file system
 * </ul>
 * Internal items must be referred to using container-relative paths.
 */
public static Object getTarget(IPath path, boolean checkResourceExistence) {
	Object target = getWorkspaceTarget(path); // Implicitly checks resource existence
	if (target != null)
		return target;
	return getExternalTarget(path, checkResourceExistence);
}

Helper method - returns the IResource corresponding to the provided IPath, or null if no such resource exists.
/**
 * Helper method - returns the {@link IResource} corresponding to the provided {@link IPath},
 * or <code>null</code> if no such resource exists.
 */
public static IResource getWorkspaceTarget(IPath path) {
	if (path == null || path.getDevice() != null)
		return null;
	IWorkspace workspace = ResourcesPlugin.getWorkspace();
	if (workspace == null)
		return null;
	return workspace.getRoot().findMember(path);
}

Helper method - returns either the linked IFolder or the File corresponding to the provided IPath. If checkResourceExistence is false,
then the IFolder or File object is always returned, otherwise null is returned
if it does not exist on the file system.
/**
 * Helper method - returns either the linked {@link IFolder} or the {@link File} corresponding
 * to the provided {@link IPath}. If <code>checkResourceExistence</code> is <code>false</code>,
 * then the IFolder or File object is always returned, otherwise <code>null</code> is returned
 * if it does not exist on the file system.
 */
public static Object getExternalTarget(IPath path, boolean checkResourceExistence) {
	if (path == null)
		return null;
	ExternalFoldersManager externalFoldersManager = JavaModelManager.getExternalManager();
	Object linkedFolder = externalFoldersManager.getFolder(path);
	if (linkedFolder != null) {
		if (checkResourceExistence) {
			// check if external folder is present
			File externalFile = new File(path.toOSString());
			if (!externalFile.isDirectory()) {
				return null;
			}
		}
		return linkedFolder;
	}
	File externalFile = new File(path.toOSString());
	if (!checkResourceExistence) {
		return externalFile;
	} else if (isExternalFile(path)) {
		return externalFile;
	}
	return null;
}

Helper method - returns whether an object is a file (i.e., it returns true to File.isFile(). /**
 * Helper method - returns whether an object is a file (i.e., it returns <code>true</code>
 * to {@link File#isFile()}.
 */
public static boolean isFile(Object target) {
	if (target instanceof File) {
		IPath path = Path.fromOSString(((File) target).getPath());
		return isExternalFile(path);
	}
	return false;
}

public static boolean isJimage(File file) {
	return JavaModelManager.isJrt(file.getPath());
}
public static boolean isJmod(File file) {
	IPath path = Path.fromOSString(file.getPath());
	if (path.getFileExtension().equalsIgnoreCase(SuffixConstants.EXTENSION_jmod)) {
		return true;
	}
	return false;
}

Returns whether the provided path is an external file, checking and updating the
JavaModelManager's external file cache.
/**
 * Returns whether the provided path is an external file, checking and updating the
 * JavaModelManager's external file cache.
 */
static private boolean isExternalFile(IPath path) {
	if (JavaModelManager.getJavaModelManager().isExternalFile(path)) {
		return true;
	}
	if (JavaModelManager.ZIP_ACCESS_VERBOSE) {
		System.out.println("(" + Thread.currentThread() + ") [JavaModel.isExternalFile(...)] Checking existence of " + path.toString()); //$NON-NLS-1$ //$NON-NLS-2$
	}
	boolean isFile = path.toFile().isFile();
	if (isFile) {
		JavaModelManager.getJavaModelManager().addExternalFile(path);
	}
	return isFile;
}

Helper method - returns the File item if target is a file (i.e., the target
returns true to File.isFile(). Otherwise returns null.
/**
 * Helper method - returns the {@link File} item if <code>target</code> is a file (i.e., the target
 * returns <code>true</code> to {@link File#isFile()}. Otherwise returns <code>null</code>.
 */
public static File getFile(Object target) {
	return isFile(target) ? (File) target : null;
}

@Override
protected IStatus validateExistence(IResource underlyingResource) {
	// Java model always exists
	return JavaModelStatus.VERIFIED_OK;
}
}