/*******************************************************************************
 * Copyright (c) 2000, 2006 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.jdt.internal.ui.javaeditor;


import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.ISafeRunnable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.core.runtime.jobs.ISchedulingRule;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IFileState;
import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IStorage;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Display;

import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;

import org.eclipse.jface.text.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DefaultLineTracker;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ILineTracker;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.quickassist.IQuickFixableAnnotation;
import org.eclipse.jface.text.source.Annotation;
import org.eclipse.jface.text.source.AnnotationModel;
import org.eclipse.jface.text.source.AnnotationModelEvent;
import org.eclipse.jface.text.source.IAnnotationAccessExtension;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.jface.text.source.IAnnotationModelListener;
import org.eclipse.jface.text.source.IAnnotationModelListenerExtension;
import org.eclipse.jface.text.source.IAnnotationPresentation;
import org.eclipse.jface.text.source.ImageUtilities;

import org.eclipse.ui.IFileEditorInput;
import org.eclipse.ui.IStorageEditorInput;
import org.eclipse.ui.texteditor.AbstractMarkerAnnotationModel;
import org.eclipse.ui.texteditor.AnnotationPreference;
import org.eclipse.ui.texteditor.AnnotationPreferenceLookup;
import org.eclipse.ui.texteditor.IDocumentProvider;
import org.eclipse.ui.texteditor.MarkerAnnotation;
import org.eclipse.ui.texteditor.MarkerUtilities;
import org.eclipse.ui.texteditor.ResourceMarkerAnnotationModel;

import org.eclipse.ui.editors.text.EditorsUI;
import org.eclipse.ui.editors.text.ForwardingDocumentProvider;
import org.eclipse.ui.editors.text.TextFileDocumentProvider;

import org.eclipse.jdt.core.IBuffer;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaModel;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IProblemRequestor;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.WorkingCopyOwner;
import org.eclipse.jdt.core.compiler.CategorizedProblem;
import org.eclipse.jdt.core.compiler.IProblem;

import org.eclipse.jdt.internal.corext.util.JavaModelUtil;

import org.eclipse.jdt.launching.JavaRuntime;

import org.eclipse.jdt.ui.JavaUI;
import org.eclipse.jdt.ui.PreferenceConstants;
import org.eclipse.jdt.ui.text.IJavaPartitions;

import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.JavaPluginImages;
import org.eclipse.jdt.internal.ui.text.correction.JavaCorrectionProcessor;
import org.eclipse.jdt.internal.ui.text.java.IProblemRequestorExtension;
import org.eclipse.jdt.internal.ui.text.spelling.JavaSpellingReconcileStrategy;


public class CompilationUnitDocumentProvider extends TextFileDocumentProvider implements ICompilationUnitDocumentProvider {

		/**
		 * Bundle of all required informations to allow working copy management.
		 */
		static protected class CompilationUnitInfo extends FileInfo {
			public ICompilationUnit fCopy;
		}

		/**
		 * Annotation representing an <code>IProblem</code>.
		 */
		static public class ProblemAnnotation extends Annotation implements IJavaAnnotation, IAnnotationPresentation, IQuickFixableAnnotation {

			public static final String SPELLING_ANNOTATION_TYPE= "org.eclipse.ui.workbench.texteditor.spelling"; //$NON-NLS-1$

			//XXX: To be fully correct these constants should be non-static
			/**
			 * The layer in which task problem annotations are located.
			 */
			private static final int TASK_LAYER;
			/**
			 * The layer in which info problem annotations are located.
			 */
			private static final int INFO_LAYER;
			/**
			 * The layer in which warning problem annotations representing are located.
			 */
			private static final int WARNING_LAYER;
			/**
			 * The layer in which error problem annotations representing are located.
			 */
			private static final int ERROR_LAYER;

			static {
				AnnotationPreferenceLookup lookup= EditorsUI.getAnnotationPreferenceLookup();
				TASK_LAYER= computeLayer("org.eclipse.ui.workbench.texteditor.task", lookup); //$NON-NLS-1$
				INFO_LAYER= computeLayer("org.eclipse.jdt.ui.info", lookup); //$NON-NLS-1$
				WARNING_LAYER= computeLayer("org.eclipse.jdt.ui.warning", lookup); //$NON-NLS-1$
				ERROR_LAYER= computeLayer("org.eclipse.jdt.ui.error", lookup); //$NON-NLS-1$
			}

			private static int computeLayer(String annotationType, AnnotationPreferenceLookup lookup) {
				Annotation annotation= new Annotation(annotationType, false, null);
				AnnotationPreference preference= lookup.getAnnotationPreference(annotation);
				if (preference != null)
					return preference.getPresentationLayer() + 1;
				else
					return IAnnotationAccessExtension.DEFAULT_LAYER + 1;
			}

			private static Image fgQuickFixImage;
			private static Image fgQuickFixErrorImage;
			private static boolean fgQuickFixImagesInitialized= false;

			private ICompilationUnit fCompilationUnit;
			private List fOverlaids;
			private IProblem fProblem;
			private Image fImage;
			private boolean fQuickFixImagesInitialized= false;
			private int fLayer= IAnnotationAccessExtension.DEFAULT_LAYER;
			private boolean fIsQuickFixable;
			private boolean fIsQuickFixableStateSet= false;


			public ProblemAnnotation(IProblem problem, ICompilationUnit cu) {

				fProblem= problem;
				fCompilationUnit= cu;

				if (JavaSpellingReconcileStrategy.SPELLING_PROBLEM_ID == fProblem.getID()) {
					setType(SPELLING_ANNOTATION_TYPE);
					fLayer= WARNING_LAYER;
				} else if (IProblem.Task == fProblem.getID()) {
					setType(JavaMarkerAnnotation.TASK_ANNOTATION_TYPE);
					fLayer= TASK_LAYER;
				} else if (fProblem.isWarning()) {
					setType(JavaMarkerAnnotation.WARNING_ANNOTATION_TYPE);
					fLayer= WARNING_LAYER;
				} else if (fProblem.isError()) {
					setType(JavaMarkerAnnotation.ERROR_ANNOTATION_TYPE);
					fLayer= ERROR_LAYER;
				} else {
					setType(JavaMarkerAnnotation.INFO_ANNOTATION_TYPE);
					fLayer= INFO_LAYER;
				}
			}

			/*
			 * @see org.eclipse.jface.text.source.IAnnotationPresentation#getLayer()
			 */
			public int getLayer() {
				return fLayer;
			}

			private void initializeImages() {
				// http://bugs.eclipse.org/bugs/show_bug.cgi?id=18936
				if (!fQuickFixImagesInitialized) {
					if (!isQuickFixableStateSet())
						setQuickFixable(isProblem() && indicateQuixFixableProblems() && JavaCorrectionProcessor.hasCorrections(this)); // no light bulb for tasks
					if (isQuickFixable()) {
						if (!fgQuickFixImagesInitialized) {
							fgQuickFixImage= JavaPluginImages.get(JavaPluginImages.IMG_OBJS_FIXABLE_PROBLEM);
							fgQuickFixErrorImage= JavaPluginImages.get(JavaPluginImages.IMG_OBJS_FIXABLE_ERROR);
							fgQuickFixImagesInitialized= true;
						}
						if (JavaMarkerAnnotation.ERROR_ANNOTATION_TYPE.equals(getType()))
							fImage= fgQuickFixErrorImage;
						else
							fImage= fgQuickFixImage;
					}
					fQuickFixImagesInitialized= true;
				}
			}

			private boolean indicateQuixFixableProblems() {
				return PreferenceConstants.getPreferenceStore().getBoolean(PreferenceConstants.EDITOR_CORRECTION_INDICATION);
			}

			/*
			 * @see Annotation#paint
			 */
			public void paint(GC gc, Canvas canvas, Rectangle r) {
				initializeImages();
				if (fImage != null)
					ImageUtilities.drawImage(fImage, gc, canvas, r, SWT.CENTER, SWT.TOP);
			}

			/*
			 * @see IJavaAnnotation#getImage(Display)
			 */
			public Image getImage(Display display) {
				initializeImages();
				return fImage;
			}

			/*
			 * @see IJavaAnnotation#getMessage()
			 */
			public String getText() {
				return fProblem.getMessage();
			}

			/*
			 * @see IJavaAnnotation#getArguments()
			 */
			public String[] getArguments() {
				return isProblem() ? fProblem.getArguments() : null;
			}

			/*
			 * @see IJavaAnnotation#getId()
			 */
			public int getId() {
				return fProblem.getID();
			}

			/*
			 * @see IJavaAnnotation#isProblem()
			 */
			public boolean isProblem() {
				String type= getType();
				return  JavaMarkerAnnotation.WARNING_ANNOTATION_TYPE.equals(type)  ||
							JavaMarkerAnnotation.ERROR_ANNOTATION_TYPE.equals(type) ||
							SPELLING_ANNOTATION_TYPE.equals(type);
			}

			/*
			 * @see IJavaAnnotation#hasOverlay()
			 */
			public boolean hasOverlay() {
				return false;
			}

			/*
			 * @see org.eclipse.jdt.internal.ui.javaeditor.IJavaAnnotation#getOverlay()
			 */
			public IJavaAnnotation getOverlay() {
				return null;
			}

			/*
			 * @see IJavaAnnotation#addOverlaid(IJavaAnnotation)
			 */
			public void addOverlaid(IJavaAnnotation annotation) {
				if (fOverlaids == null)
					fOverlaids= new ArrayList(1);
				fOverlaids.add(annotation);
			}

			/*
			 * @see IJavaAnnotation#removeOverlaid(IJavaAnnotation)
			 */
			public void removeOverlaid(IJavaAnnotation annotation) {
				if (fOverlaids != null) {
					fOverlaids.remove(annotation);
					if (fOverlaids.size() == 0)
						fOverlaids= null;
				}
			}

			/*
			 * @see IJavaAnnotation#getOverlaidIterator()
			 */
			public Iterator getOverlaidIterator() {
				if (fOverlaids != null)
					return fOverlaids.iterator();
				return null;
			}

			/*
			 * @see org.eclipse.jdt.internal.ui.javaeditor.IJavaAnnotation#getCompilationUnit()
			 */
			public ICompilationUnit getCompilationUnit() {
				return fCompilationUnit;
			}

			/*
			 * @see org.eclipse.jdt.internal.ui.javaeditor.IJavaAnnotation#getMarkerType()
			 */
			public String getMarkerType() {
				if (fProblem instanceof CategorizedProblem)
					return ((CategorizedProblem) fProblem).getMarkerType();
				return null;
			}

			/*
			 * @see org.eclipse.jface.text.quickassist.IQuickFixableAnnotation#setQuickFixable(boolean)
			 * @since 3.2
			 */
			public void setQuickFixable(boolean state) {
				fIsQuickFixable= state;
				fIsQuickFixableStateSet= true;
			}

			/*
			 * @see org.eclipse.jface.text.quickassist.IQuickFixableAnnotation#isQuickFixableStateSet()
			 * @since 3.2
			 */
			public boolean isQuickFixableStateSet() {
				return fIsQuickFixableStateSet;
			}

			/*
			 * @see org.eclipse.jface.text.quickassist.IQuickFixableAnnotation#isQuickFixable()
			 * @since 3.2
			 */
			public boolean isQuickFixable() {
				Assert.isTrue(isQuickFixableStateSet());
				return fIsQuickFixable;
			}
		}

		/**
		 * Internal structure for mapping positions to some value.
		 * The reason for this specific structure is that positions can
		 * change over time. Thus a lookup is based on value and not
		 * on hash value.
		 */
		protected static class ReverseMap {

			static class Entry {
				Position fPosition;
				Object fValue;
			}

			private List fList= new ArrayList(2);
			private int fAnchor= 0;

			public ReverseMap() {
			}

			public Object get(Position position) {

				Entry entry;

				// behind anchor
				int length= fList.size();
				for (int i= fAnchor; i < length; i++) {
					entry= (Entry) fList.get(i);
					if (entry.fPosition.equals(position)) {
						fAnchor= i;
						return entry.fValue;
					}
				}

				// before anchor
				for (int i= 0; i < fAnchor; i++) {
					entry= (Entry) fList.get(i);
					if (entry.fPosition.equals(position)) {
						fAnchor= i;
						return entry.fValue;
					}
				}

				return null;
			}

			private int getIndex(Position position) {
				Entry entry;
				int length= fList.size();
				for (int i= 0; i < length; i++) {
					entry= (Entry) fList.get(i);
					if (entry.fPosition.equals(position))
						return i;
				}
				return -1;
			}

			public void put(Position position,  Object value) {
				int index= getIndex(position);
				if (index == -1) {
					Entry entry= new Entry();
					entry.fPosition= position;
					entry.fValue= value;
					fList.add(entry);
				} else {
					Entry entry= (Entry) fList.get(index);
					entry.fValue= value;
				}
			}

			public void remove(Position position) {
				int index= getIndex(position);
				if (index > -1)
					fList.remove(index);
			}

			public void clear() {
				fList.clear();
			}
		}

		/**
		 * Annotation model dealing with java marker annotations and temporary problems.
		 * Also acts as problem requester for its compilation unit. Initially inactive. Must explicitly be
		 * activated.
		 */
		protected static class CompilationUnitAnnotationModel extends ResourceMarkerAnnotationModel implements IProblemRequestor, IProblemRequestorExtension {

			private static class ProblemRequestorState {
				boolean fInsideReportingSequence= false;
				List fReportedProblems;
			}

			private ThreadLocal fProblemRequestorState= new ThreadLocal();
			private int fStateCount= 0;

			private ICompilationUnit fCompilationUnit;
			private List fGeneratedAnnotations;
			private IProgressMonitor fProgressMonitor;
			private boolean fIsActive= false;
			private boolean fIsHandlingTemporaryProblems;

			private ReverseMap fReverseMap= new ReverseMap();
			private List fPreviouslyOverlaid= null;
			private List fCurrentlyOverlaid= new ArrayList();


			public CompilationUnitAnnotationModel(IResource resource) {
				super(resource);
			}

			public void setCompilationUnit(ICompilationUnit unit)  {
				fCompilationUnit= unit;
			}

			protected MarkerAnnotation createMarkerAnnotation(IMarker marker) {
				String markerType= MarkerUtilities.getMarkerType(marker);
				if (markerType != null && markerType.startsWith(JavaMarkerAnnotation.JAVA_MARKER_TYPE_PREFIX))
					return new JavaMarkerAnnotation(marker);
				return super.createMarkerAnnotation(marker);
			}

			/*
			 * @see org.eclipse.jface.text.source.AnnotationModel#createAnnotationModelEvent()
			 */
			protected AnnotationModelEvent createAnnotationModelEvent() {
				return new CompilationUnitAnnotationModelEvent(this, getResource());
			}

			protected Position createPositionFromProblem(IProblem problem) {
				int start= problem.getSourceStart();
				if (start < 0)
					return null;

				int length= problem.getSourceEnd() - problem.getSourceStart() + 1;
				if (length < 0)
					return null;

				return new Position(start, length);
			}

			/*
			 * @see IProblemRequestor#beginReporting()
			 */
			public void beginReporting() {
				ProblemRequestorState state= (ProblemRequestorState) fProblemRequestorState.get();
				if (state == null)
					internalBeginReporting(false);
			}

			/*
			 * @see org.eclipse.jdt.internal.ui.text.java.IProblemRequestorExtension#beginReportingSequence()
			 */
			public void beginReportingSequence() {
				ProblemRequestorState state= (ProblemRequestorState) fProblemRequestorState.get();
				if (state == null)
					internalBeginReporting(true);
			}

			/**
			 * Sets up the infrastructure necessary for problem reporting.
			 *
			 * @param insideReportingSequence <code>true</code> if this method
			 *            call is issued from inside a reporting sequence
			 */
			private void internalBeginReporting(boolean insideReportingSequence) {
				if (fCompilationUnit != null && fCompilationUnit.getJavaProject().isOnClasspath(fCompilationUnit)) {
					ProblemRequestorState state= new ProblemRequestorState();
					state.fInsideReportingSequence= insideReportingSequence;
					state.fReportedProblems= new ArrayList();
					synchronized (getLockObject()) {
						fProblemRequestorState.set(state);
						++fStateCount;
					}
				}
			}

			/*
			 * @see IProblemRequestor#acceptProblem(IProblem)
			 */
			public void acceptProblem(IProblem problem) {
				if (fIsHandlingTemporaryProblems) {
					ProblemRequestorState state= (ProblemRequestorState) fProblemRequestorState.get();
					if (state != null)
						state.fReportedProblems.add(problem);
				}
			}

			/*
			 * @see IProblemRequestor#endReporting()
			 */
			public void endReporting() {
				ProblemRequestorState state= (ProblemRequestorState) fProblemRequestorState.get();
				if (state != null && !state.fInsideReportingSequence)
					internalEndReporting(state);
			}

			/*
			 * @see org.eclipse.jdt.internal.ui.text.java.IProblemRequestorExtension#endReportingSequence()
			 */
			public void endReportingSequence() {
				ProblemRequestorState state= (ProblemRequestorState) fProblemRequestorState.get();
				if (state != null && state.fInsideReportingSequence)
					internalEndReporting(state);
			}

			private void internalEndReporting(ProblemRequestorState state) {
				int stateCount= 0;
				synchronized(getLockObject()) {
					-- fStateCount;
					stateCount= fStateCount;
					fProblemRequestorState.set(null);
				}

				if (stateCount == 0 && fIsHandlingTemporaryProblems)
					reportProblems(state.fReportedProblems);
			}

			/**
			 * Signals the end of problem reporting.
			 */
			private void reportProblems(List reportedProblems) {
				if (fProgressMonitor != null && fProgressMonitor.isCanceled())
					return;

				boolean temporaryProblemsChanged= false;

				synchronized (getLockObject()) {

					boolean isCanceled= false;

					fPreviouslyOverlaid= fCurrentlyOverlaid;
					fCurrentlyOverlaid= new ArrayList();

					if (fGeneratedAnnotations.size() > 0) {
						temporaryProblemsChanged= true;
						removeAnnotations(fGeneratedAnnotations, false, true);
						fGeneratedAnnotations.clear();
					}

					if (reportedProblems != null && reportedProblems.size() > 0) {

						Iterator e= reportedProblems.iterator();
						while (e.hasNext()) {

							if (fProgressMonitor != null && fProgressMonitor.isCanceled()) {
								isCanceled= true;
								break;
							}

							IProblem problem= (IProblem) e.next();
							Position position= createPositionFromProblem(problem);
							if (position != null) {

								try {
									ProblemAnnotation annotation= new ProblemAnnotation(problem, fCompilationUnit);
									overlayMarkers(position, annotation);
									addAnnotation(annotation, position, false);
									fGeneratedAnnotations.add(annotation);

									temporaryProblemsChanged= true;
								} catch (BadLocationException x) {
									// ignore invalid position
								}
							}
						}
					}

					removeMarkerOverlays(isCanceled);
					fPreviouslyOverlaid= null;
				}

				if (temporaryProblemsChanged)
					fireModelChanged();
			}

			private void removeMarkerOverlays(boolean isCanceled) {
				if (isCanceled) {
					fCurrentlyOverlaid.addAll(fPreviouslyOverlaid);
				} else if (fPreviouslyOverlaid != null) {
					Iterator e= fPreviouslyOverlaid.iterator();
					while (e.hasNext()) {
						JavaMarkerAnnotation annotation= (JavaMarkerAnnotation) e.next();
						annotation.setOverlay(null);
					}
				}
			}

			/**
			 * Overlays value with problem annotation.
			 * @param problemAnnotation
			 */
			private void setOverlay(Object value, ProblemAnnotation problemAnnotation) {
				if (value instanceof  JavaMarkerAnnotation) {
					JavaMarkerAnnotation annotation= (JavaMarkerAnnotation) value;
					if (annotation.isProblem()) {
						annotation.setOverlay(problemAnnotation);
						fPreviouslyOverlaid.remove(annotation);
						fCurrentlyOverlaid.add(annotation);
					}
				} else {
				}
			}

			private void  overlayMarkers(Position position, ProblemAnnotation problemAnnotation) {
				Object value= getAnnotations(position);
				if (value instanceof List) {
					List list= (List) value;
					for (Iterator e = list.iterator(); e.hasNext();)
						setOverlay(e.next(), problemAnnotation);
				} else {
					setOverlay(value, problemAnnotation);
				}
			}

			/**
			 * Tells this annotation model to collect temporary problems from now on.
			 */
			private void startCollectingProblems() {
				fGeneratedAnnotations= new ArrayList();
			}

			/**
			 * Tells this annotation model to no longer collect temporary problems.
			 */
			private void stopCollectingProblems() {
				if (fGeneratedAnnotations != null)
					removeAnnotations(fGeneratedAnnotations, true, true);
				fGeneratedAnnotations= null;
			}

			/*
			 * @see IProblemRequestor#isActive()
			 */
			public boolean isActive() {
				return fIsActive;
			}

			/*
			 * @see IProblemRequestorExtension#setProgressMonitor(IProgressMonitor)
			 */
			public void setProgressMonitor(IProgressMonitor monitor) {
				fProgressMonitor= monitor;
			}

			/*
			 * @see IProblemRequestorExtension#setIsActive(boolean)
			 */
			public void setIsActive(boolean isActive) {
				fIsActive= isActive;
			}

			/*
			 * @see IProblemRequestorExtension#setIsHandlingTemporaryProblems(boolean)
			 * @since 3.1
			 */
			public void setIsHandlingTemporaryProblems(boolean enable) {
				if (fIsHandlingTemporaryProblems != enable) {
					fIsHandlingTemporaryProblems= enable;
					if (fIsHandlingTemporaryProblems)
						startCollectingProblems();
					else
						stopCollectingProblems();
				}

			}

			private Object getAnnotations(Position position) {
				synchronized (getLockObject()) {
					return fReverseMap.get(position);
				}
			}

			/*
			 * @see AnnotationModel#addAnnotation(Annotation, Position, boolean)
			 */
			protected void addAnnotation(Annotation annotation, Position position, boolean fireModelChanged) throws BadLocationException {
				super.addAnnotation(annotation, position, fireModelChanged);

				synchronized (getLockObject()) {
					Object cached= fReverseMap.get(position);
					if (cached == null)
						fReverseMap.put(position, annotation);
					else if (cached instanceof List) {
						List list= (List) cached;
						list.add(annotation);
					} else if (cached instanceof Annotation) {
						List list= new ArrayList(2);
						list.add(cached);
						list.add(annotation);
						fReverseMap.put(position, list);
					}
				}
			}

			/*
			 * @see AnnotationModel#removeAllAnnotations(boolean)
			 */
			protected void removeAllAnnotations(boolean fireModelChanged) {
				super.removeAllAnnotations(fireModelChanged);
				synchronized (getLockObject()) {
					fReverseMap.clear();
				}
			}

			/*
			 * @see AnnotationModel#removeAnnotation(Annotation, boolean)
			 */
			protected void removeAnnotation(Annotation annotation, boolean fireModelChanged) {
				Position position= getPosition(annotation);
				synchronized (getLockObject()) {
					Object cached= fReverseMap.get(position);
					if (cached instanceof List) {
						List list= (List) cached;
						list.remove(annotation);
						if (list.size() == 1) {
							fReverseMap.put(position, list.get(0));
							list.clear();
						}
					} else if (cached instanceof Annotation) {
						fReverseMap.remove(position);
					}
				}
				super.removeAnnotation(annotation, fireModelChanged);
			}
		}


		protected static class GlobalAnnotationModelListener implements IAnnotationModelListener, IAnnotationModelListenerExtension {

			private ListenerList fListenerList;

			public GlobalAnnotationModelListener() {
				fListenerList= new ListenerList(ListenerList.IDENTITY);
			}

			/**
			 * @see IAnnotationModelListener#modelChanged(IAnnotationModel)
			 */
			public void modelChanged(IAnnotationModel model) {
				Object[] listeners= fListenerList.getListeners();
				for (int i= 0; i < listeners.length; i++) {
					((IAnnotationModelListener) listeners[i]).modelChanged(model);
				}
			}

			/**
			 * @see IAnnotationModelListenerExtension#modelChanged(AnnotationModelEvent)
			 */
			public void modelChanged(AnnotationModelEvent event) {
				Object[] listeners= fListenerList.getListeners();
				for (int i= 0; i < listeners.length; i++) {
					Object curr= listeners[i];
					if (curr instanceof IAnnotationModelListenerExtension) {
						((IAnnotationModelListenerExtension) curr).modelChanged(event);
					}
				}
			}

			public void addListener(IAnnotationModelListener listener) {
				fListenerList.add(listener);
			}

			public void removeListener(IAnnotationModelListener listener) {
				fListenerList.remove(listener);
			}
		}

	/** Preference key for temporary problems */
	private final static String HANDLE_TEMPORARY_PROBLEMS= PreferenceConstants.EDITOR_EVALUTE_TEMPORARY_PROBLEMS;


	/** Indicates whether the save has been initialized by this provider */
	private boolean fIsAboutToSave= false;
	/** The save policy used by this provider */
	private ISavePolicy fSavePolicy;
	/** Internal property changed listener */
	private IPropertyChangeListener fPropertyListener;
	/** Annotation model listener added to all created CU annotation models */
	private GlobalAnnotationModelListener fGlobalAnnotationModelListener;
	/**
	 * Element information of all connected elements with a fake CU but no file info.
	 * @since 3.2
	 */
	private final Map fFakeCUMapForMissingInfo= new HashMap();


	/**
	 * Constructor
	 */
	public CompilationUnitDocumentProvider() {

		IDocumentProvider provider= new TextFileDocumentProvider();
		provider= new ForwardingDocumentProvider(IJavaPartitions.JAVA_PARTITIONING, new JavaDocumentSetupParticipant(), provider);
		setParentDocumentProvider(provider);

		fGlobalAnnotationModelListener= new GlobalAnnotationModelListener();
		fPropertyListener= new IPropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent event) {
				if (HANDLE_TEMPORARY_PROBLEMS.equals(event.getProperty()))
					enableHandlingTemporaryProblems();
			}
		};
		JavaPlugin.getDefault().getPreferenceStore().addPropertyChangeListener(fPropertyListener);
	}

	/**
	 * Creates a compilation unit from the given file.
	 *
	 * @param file the file from which to create the compilation unit
	 */
	protected ICompilationUnit createCompilationUnit(IFile file) {
		Object element= JavaCore.create(file);
		if (element instanceof ICompilationUnit)
			return (ICompilationUnit) element;
		return null;
	}

	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createEmptyFileInfo()
	 */
	protected FileInfo createEmptyFileInfo() {
		return new CompilationUnitInfo();
	}

	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createAnnotationModel(org.eclipse.core.resources.IFile)
	 */
	protected IAnnotationModel createAnnotationModel(IFile file) {
		return new CompilationUnitAnnotationModel(file);
	}

	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createFileInfo(java.lang.Object)
	 */
	protected FileInfo createFileInfo(Object element) throws CoreException {
		ICompilationUnit original= null;
		if (element instanceof IFileEditorInput) {
			IFileEditorInput input= (IFileEditorInput) element;
			original= createCompilationUnit(input.getFile());
			if (original == null)
				return null;
		}
		
		FileInfo info= super.createFileInfo(element);
		if (!(info instanceof CompilationUnitInfo))
			return null;
		
		if (original == null)
			original= createFakeCompiltationUnit(element, false);
		if (original == null)
			return null;

		CompilationUnitInfo cuInfo= (CompilationUnitInfo) info;
		setUpSynchronization(cuInfo);

		IProblemRequestor requestor= cuInfo.fModel instanceof IProblemRequestor ? (IProblemRequestor) cuInfo.fModel : null;
		if (requestor instanceof IProblemRequestorExtension) {
			IProblemRequestorExtension extension= (IProblemRequestorExtension) requestor;
			extension.setIsActive(false);
			extension.setIsHandlingTemporaryProblems(isHandlingTemporaryProblems());
		}

		if (JavaModelUtil.isPrimary(original))
			original.becomeWorkingCopy(requestor, getProgressMonitor());
		cuInfo.fCopy= original;

		if (cuInfo.fModel instanceof CompilationUnitAnnotationModel)   {
			CompilationUnitAnnotationModel model= (CompilationUnitAnnotationModel) cuInfo.fModel;
			model.setCompilationUnit(cuInfo.fCopy);
		}

		if (cuInfo.fModel != null)
			cuInfo.fModel.addAnnotationModelListener(fGlobalAnnotationModelListener);

		return cuInfo;
	}
	
	/**
	 * Creates a fake compilation unit.
	 *
	 * @param element the element
	 * @param setContents tells whether to read and set the contents to the new CU
	 * @since 3.2
	 */
	private ICompilationUnit createFakeCompiltationUnit(Object element, boolean setContents) {
		if (!(element instanceof IStorageEditorInput))
			return null;
		
		final IStorageEditorInput sei= (IStorageEditorInput)element;
		
		try {
			final IStorage storage= sei.getStorage();
			final IPath storagePath= storage.getFullPath();
			if (storage.getName() == null || storagePath == null)
				return null;
			
			final IPath documentPath;
			if (storage instanceof IFileState)
				documentPath= storagePath.append(Long.toString(((IFileState)storage).getModificationTime()));
			else
				documentPath= storagePath;
			
			WorkingCopyOwner woc= new WorkingCopyOwner() {
				/*
				 * @see org.eclipse.jdt.core.WorkingCopyOwner#createBuffer(org.eclipse.jdt.core.ICompilationUnit)
				 * @since 3.2
				 */
				public IBuffer createBuffer(ICompilationUnit workingCopy) {
					return new DocumentAdapter(workingCopy, documentPath);
				}
			};

			IClasspathEntry[] cpEntries= null;
			IJavaProject jp= findJavaProject(storagePath);
			if (jp != null)
				cpEntries= jp.getResolvedClasspath(true);
			
			if (cpEntries == null || cpEntries.length == 0)
				cpEntries= new IClasspathEntry[] { JavaRuntime.getDefaultJREContainerEntry() };

			final ICompilationUnit cu= woc.newWorkingCopy(storage.getName(), cpEntries, null, getProgressMonitor());
			if (setContents) {
				int READER_CHUNK_SIZE= 2048;
				int BUFFER_SIZE= 8 * READER_CHUNK_SIZE;
				Reader in= new BufferedReader(new InputStreamReader(storage.getContents()));
				StringBuffer buffer= new StringBuffer(BUFFER_SIZE);
				char[] readBuffer= new char[READER_CHUNK_SIZE];
				int n;
				try {
					n= in.read(readBuffer);
					while (n > 0) {
						buffer.append(readBuffer, 0, n);
						n= in.read(readBuffer);
					}
				} catch (IOException e) {
					JavaPlugin.log(e);
				}
				cu.getBuffer().setContents(buffer.toString());
			}
			
			if (!isModifiable(element))
				JavaModelUtil.reconcile(cu);
			
			return cu;
		} catch (CoreException ex) {
			return null;
		}
	}
	
	/**
	 * Fuzzy search for Java project in the workspace that matches
	 * the given path.
	 * 
	 * @param path the path to match
	 * @return the matching Java project or <code>null</code>
	 * @since 3.2
	 */
	private IJavaProject findJavaProject(IPath path) {
		if (path == null)
			return null;

		String[] pathSegments= path.segments();
		IJavaModel model= JavaCore.create(JavaPlugin.getWorkspace().getRoot());
		IJavaProject[] projects;
		try {
			projects= model.getJavaProjects();
		} catch (JavaModelException e) {
			return null; // ignore - use default JRE
		}
		for (int i= 0; i < projects.length; i++) {
			IPath projectPath= projects[i].getProject().getFullPath();
			String projectSegment= projectPath.segments()[0];
			for (int j= 0; j < pathSegments.length; j++)
				if (projectSegment.equals(pathSegments[j]))
					return projects[i];
		}
		return null;
	}

    /*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#disposeFileInfo(java.lang.Object, org.eclipse.ui.editors.text.TextFileDocumentProvider.FileInfo)
	 */
	protected void disposeFileInfo(Object element, FileInfo info) {
		if (info instanceof CompilationUnitInfo) {
			CompilationUnitInfo cuInfo= (CompilationUnitInfo) info;

			try  {
			    cuInfo.fCopy.discardWorkingCopy();
			} catch (JavaModelException x)  {
			    handleCoreException(x, x.getMessage());
			}

			if (cuInfo.fModel != null)
				cuInfo.fModel.removeAnnotationModelListener(fGlobalAnnotationModelListener);
		}
		super.disposeFileInfo(element, info);
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#connect(java.lang.Object)
	 * @since 3.2
	 */
	public void connect(Object element) throws CoreException {
		super.connect(element);
		if (getFileInfo(element) != null)
			return;

		CompilationUnitInfo info= (CompilationUnitInfo)fFakeCUMapForMissingInfo.get(element);
		if (info == null) {
			ICompilationUnit cu= createFakeCompiltationUnit(element, true);
			if (cu == null)
				return;
			info= new CompilationUnitInfo();
			info.fCopy= cu;
			info.fElement= element;
			info.fModel= new AnnotationModel();
			fFakeCUMapForMissingInfo.put(element, info);
		}
		info.fCount++;
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#getAnnotationModel(java.lang.Object)
	 * @since 3.2
	 */
	public IAnnotationModel getAnnotationModel(Object element) {
		IAnnotationModel model= super.getAnnotationModel(element);
		if (model != null)
			return model;
		
		FileInfo info= (FileInfo)fFakeCUMapForMissingInfo.get(element);
		if (info != null) {
			if (info.fModel != null)
				return info.fModel;
			if (info.fTextFileBuffer != null)
				return info.fTextFileBuffer.getAnnotationModel();
		}
		
		return null;
	}
	
	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#disconnect(java.lang.Object)
	 * @since 3.2
	 */
	public void disconnect(Object element) {
		CompilationUnitInfo info= (CompilationUnitInfo)fFakeCUMapForMissingInfo.get(element);
		if (info != null)  {
			if (info.fCount == 1) {
				fFakeCUMapForMissingInfo.remove(element);
				info.fModel= null;
				// Destroy and unregister fake working copy
				try {
					info.fCopy.discardWorkingCopy();
				} catch (JavaModelException ex) {
					handleCoreException(ex, ex.getMessage());
				}
			} else
				info.fCount--;
		}
		super.disconnect(element);
	}
	

	/**
	 * Creates and returns a new sub-progress monitor for the
	 * given parent monitor.
	 *
	 * @param monitor the parent progress monitor
	 * @param ticks the number of work ticks allocated from the parent monitor
	 * @return the new sub-progress monitor
	 */
	private IProgressMonitor getSubProgressMonitor(IProgressMonitor monitor, int ticks) {
		if (monitor != null)
			return new SubProgressMonitor(monitor, ticks, SubProgressMonitor.PREPEND_MAIN_LABEL_TO_SUBTASK);

		return new NullProgressMonitor();
	}

	protected void commitWorkingCopy(IProgressMonitor monitor, Object element, final CompilationUnitInfo info, boolean overwrite) throws CoreException {

		if (monitor == null)
			monitor= new NullProgressMonitor();

		monitor.beginTask("", 100); //$NON-NLS-1$

		try {
			final IProgressMonitor subMonitor1= getSubProgressMonitor(monitor, 50);

			try {
				SafeRunner.run(new ISafeRunnable() {
					public void run() {
						try {
							info.fCopy.reconcile(ICompilationUnit.NO_AST, false, null, subMonitor1);
						} catch (JavaModelException ex) {
							handleException(ex);
						} catch (OperationCanceledException ex) {
							// do not log this
						}
					}
					public void handleException(Throwable ex) {
						IStatus status= new Status(IStatus.ERROR, JavaUI.ID_PLUGIN, IStatus.OK, "Error in JDT Core during reconcile while saving", ex);  //$NON-NLS-1$
						JavaPlugin.getDefault().getLog().log(status);
					}
				});
			} finally {
				subMonitor1.done();
			}

			IDocument document= info.fTextFileBuffer.getDocument();
			IResource resource= info.fCopy.getResource();

			Assert.isTrue(resource instanceof IFile);

			boolean isSynchronized= resource.isSynchronized(IResource.DEPTH_ZERO);
			
			/* https://bugs.eclipse.org/bugs/show_bug.cgi?id=98327
			 * Make sure file gets save in commit() if the underlying file has been deleted */
			if (!isSynchronized && isDeleted(element))
				info.fTextFileBuffer.setDirty(true);

			if (!resource.exists()) {
				// underlying resource has been deleted, just recreate file, ignore the rest
				IProgressMonitor subMonitor2= getSubProgressMonitor(monitor, 50);
				try {
					createFileFromDocument(subMonitor2, (IFile) resource, document);
				} finally {
					subMonitor2.done();
				}
				return;
			}

			if (fSavePolicy != null)
				fSavePolicy.preSave(info.fCopy);

			IProgressMonitor subMonitor3= getSubProgressMonitor(monitor, 50);
			try {
				fIsAboutToSave= true;
				info.fCopy.commitWorkingCopy(isSynchronized || overwrite, subMonitor3);
			} catch (CoreException x) {
				// inform about the failure
				fireElementStateChangeFailed(element);
				throw x;
			} catch (RuntimeException x) {
				// inform about the failure
				fireElementStateChangeFailed(element);
				throw x;
			} finally {
				fIsAboutToSave= false;
				subMonitor3.done();
			}

			// If here, the dirty state of the editor will change to "not dirty".
			// Thus, the state changing flag will be reset.
			if (info.fModel instanceof AbstractMarkerAnnotationModel) {
				AbstractMarkerAnnotationModel model= (AbstractMarkerAnnotationModel) info.fModel;
				model.updateMarkers(document);
			}

			if (fSavePolicy != null) {
				ICompilationUnit unit= fSavePolicy.postSave(info.fCopy);
				if (unit != null && info.fModel instanceof AbstractMarkerAnnotationModel) {
					IResource r= unit.getResource();
					IMarker[] markers= r.findMarkers(IMarker.MARKER, true, IResource.DEPTH_ZERO);
					if (markers != null && markers.length > 0) {
						AbstractMarkerAnnotationModel model= (AbstractMarkerAnnotationModel) info.fModel;
						for (int i= 0; i < markers.length; i++)
							model.updateMarker(document, markers[i], null);
					}
				}
			}
		} finally {
			monitor.done();
		}
	}

	/*
	 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider#createSaveOperation(java.lang.Object, org.eclipse.jface.text.IDocument, boolean)
	 */
	protected DocumentProviderOperation createSaveOperation(final Object element, final IDocument document, final boolean overwrite) throws CoreException {
		final FileInfo info= getFileInfo(element);
		if (info instanceof CompilationUnitInfo) {
			
			// Delegate handling of non-primary CUs
			ICompilationUnit cu= ((CompilationUnitInfo)info).fCopy;
			if (cu != null && !JavaModelUtil.isPrimary(cu))
				return super.createSaveOperation(element, document, overwrite);

			if (info.fTextFileBuffer.getDocument() != document) {
				// the info exists, but not for the given document
				// -> saveAs was executed with a target that is already open
				// in another editor
				// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=85519
				Status status= new Status(IStatus.WARNING, EditorsUI.PLUGIN_ID, IStatus.ERROR, JavaEditorMessages.CompilationUnitDocumentProvider_saveAsTargetOpenInEditor, null);
				throw new CoreException(status);
			}

			return new DocumentProviderOperation() {
				/*
				 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider.DocumentProviderOperation#execute(org.eclipse.core.runtime.IProgressMonitor)
				 */
				protected void execute(IProgressMonitor monitor) throws CoreException {
					commitWorkingCopy(monitor, element, (CompilationUnitInfo) info, overwrite);
				}
				/*
				 * @see org.eclipse.ui.editors.text.TextFileDocumentProvider.DocumentProviderOperation#getSchedulingRule()
				 */
				public ISchedulingRule getSchedulingRule() {
					if (info.fElement instanceof IFileEditorInput) {
						IFile file= ((IFileEditorInput) info.fElement).getFile();
						return computeSchedulingRule(file);
					} else
						return null;
				}
			};
		}
		return null;
	}

	/**
	 * Returns the preference whether handling temporary problems is enabled.
	 */
	protected boolean isHandlingTemporaryProblems() {
		IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
		return store.getBoolean(HANDLE_TEMPORARY_PROBLEMS);
	}

		/**
		 * Switches the state of problem acceptance according to the value in the preference store.
		 */
		protected void enableHandlingTemporaryProblems() {
			boolean enable= isHandlingTemporaryProblems();
			for (Iterator iter= getFileInfosIterator(); iter.hasNext();) {
				FileInfo info= (FileInfo) iter.next();
				if (info.fModel instanceof IProblemRequestorExtension) {
					IProblemRequestorExtension  extension= (IProblemRequestorExtension) info.fModel;
					extension.setIsHandlingTemporaryProblems(enable);
				}
			}
		}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#setSavePolicy(org.eclipse.jdt.internal.ui.javaeditor.ISavePolicy)
	 */
	public void setSavePolicy(ISavePolicy savePolicy) {
		fSavePolicy= savePolicy;
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#addGlobalAnnotationModelListener(org.eclipse.jface.text.source.IAnnotationModelListener)
	 */
	public void addGlobalAnnotationModelListener(IAnnotationModelListener listener) {
		fGlobalAnnotationModelListener.addListener(listener);
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#removeGlobalAnnotationModelListener(org.eclipse.jface.text.source.IAnnotationModelListener)
	 */
	public void removeGlobalAnnotationModelListener(IAnnotationModelListener listener) {
		fGlobalAnnotationModelListener.removeListener(listener);
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#getWorkingCopy(java.lang.Object)
	 */
	public ICompilationUnit getWorkingCopy(Object element) {
		FileInfo fileInfo= getFileInfo(element);
		if (fileInfo instanceof CompilationUnitInfo) {
			CompilationUnitInfo info= (CompilationUnitInfo)fileInfo;
			return info.fCopy;
		}
		CompilationUnitInfo cuInfo= (CompilationUnitInfo)fFakeCUMapForMissingInfo.get(element);
		if (cuInfo != null)
			return cuInfo.fCopy;
		
		return null;
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#shutdown()
	 */
	public void shutdown() {
		JavaPlugin.getDefault().getPreferenceStore().removePropertyChangeListener(fPropertyListener);
		Iterator e= getConnectedElementsIterator();
		while (e.hasNext())
			disconnect(e.next());
		fFakeCUMapForMissingInfo.clear();
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#saveDocumentContent(org.eclipse.core.runtime.IProgressMonitor, java.lang.Object, org.eclipse.jface.text.IDocument, boolean)
	 */
	public void saveDocumentContent(IProgressMonitor monitor, Object element, IDocument document, boolean overwrite) throws CoreException {
		if (!fIsAboutToSave)
			return;
		super.saveDocument(monitor, element, document, overwrite);
	}

	/*
	 * @see org.eclipse.jdt.internal.ui.javaeditor.ICompilationUnitDocumentProvider#createLineTracker(java.lang.Object)
	 */
	public ILineTracker createLineTracker(Object element) {
		return new DefaultLineTracker();
	}

}
