/*******************************************************************************
 * Copyright (c) 2001, 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.sse.ui;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Iterator;

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Preferences;
import org.eclipse.jface.action.IStatusLineManager;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextSelection;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.source.Annotation;
import org.eclipse.jface.text.source.IAnnotationModel;
import org.eclipse.jface.viewers.ISelectionChangedListener;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.SelectionChangedEvent;
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.ui.IEditorActionBarContributor;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IPageLayout;
import org.eclipse.ui.IViewPart;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.editors.text.EditorsUI;
import org.eclipse.ui.part.EditorActionBarContributor;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.eclipse.ui.texteditor.AnnotationPreference;
import org.eclipse.ui.texteditor.IEditorStatusLine;
import org.eclipse.ui.texteditor.ITextEditor;
import org.eclipse.ui.texteditor.MarkerAnnotation;
import org.eclipse.ui.texteditor.TextEditorAction;
import org.eclipse.wst.sse.ui.nls.ResourceHandler;


/**
 * Based on org.eclipse.jdt.internal.ui.javaeditor.GotoAnnotationAction and
 * the org.eclipse.jdt.internal.ui.JavaEditor's gotoError() method. Rewritten
 * based on 3.0M7 version to operate generically.
 *  
 */
public class GotoAnnotationAction extends TextEditorAction {

	/**
	 * Clears the status line on selection changed.
	 */
	protected class StatusLineClearer implements ISelectionChangedListener {
		IStatusLineManager fStatusLineManager = null;

		protected StatusLineClearer(IStatusLineManager mgr) {
			super();
			fStatusLineManager = mgr;
		}

		/*
		 * @see ISelectionChangedListener#selectionChanged(org.eclipse.jface.viewers.SelectionChangedEvent)
		 */
		public void selectionChanged(SelectionChangedEvent event) {
			getTextEditor().getSelectionProvider().removeSelectionChangedListener(StatusLineClearer.this);

			fStatusLineManager.setErrorMessage(null, null);
			fStatusLineManager.setMessage(null, null);
		}
	}

	private boolean fForward;
	private String fLabel;

	private String fPrefix;

	/**
	 * @param prefix
	 * @param editor
	 */
	public GotoAnnotationAction(String prefix, boolean forward) {
		super(ResourceHandler.getResourceBundle(), prefix, null);
		fForward = forward;
		fPrefix = prefix;
		fLabel = ResourceHandler.getResourceBundle().getString(fPrefix);
	}

	/*
	 * This is the default label used for description
	 */
	public String getDefaultLabel() {
		return fLabel;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.action.Action#getDescription()
	 */
	public String getDescription() {
		return getDefaultLabel();
	}

	/**
	 * Returns the annotation closest to the given range respecting the given
	 * direction. If an annotation is found, the annotations current position
	 * is copied into the provided annotation position.
	 * 
	 * @param offset
	 *            the region offset
	 * @param length
	 *            the region length
	 * @param forward
	 *            <code>true</code> for forwards, <code>false</code> for
	 *            backward
	 * @param annotationPosition
	 *            the position of the found annotation
	 * @return the found annotation
	 */
	protected Annotation getNextAnnotation(final int offset, final int length, boolean forward, Position annotationPosition) {
		Annotation nextAnnotation = null;
		Position nextAnnotationPosition = null;
		Annotation containingAnnotation = null;
		Position containingAnnotationPosition = null;
		boolean currentAnnotation = false;

		IDocument document = getTextEditor().getDocumentProvider().getDocument(getTextEditor().getEditorInput());
		int endOfDocument = document.getLength();
		int distance = Integer.MAX_VALUE;

		IAnnotationModel model = getTextEditor().getDocumentProvider().getAnnotationModel(getTextEditor().getEditorInput());
		// external files may not have an annotation model
		if (model != null) {
			Iterator e = model.getAnnotationIterator();
			while (e.hasNext()) {
				Annotation a = (Annotation) e.next();
				if (!isNavigationTarget(a))
					continue;

				Position p = model.getPosition(a);
				if (p == null)
					continue;

				if (forward && p.offset == offset || !forward && p.offset + p.getLength() == offset + length) {
					if (containingAnnotation == null || (forward && p.length >= containingAnnotationPosition.length || !forward && p.length >= containingAnnotationPosition.length)) {
						containingAnnotation = a;
						containingAnnotationPosition = p;
						currentAnnotation = p.length == length;
					}
				} else {
					int currentDistance = 0;

					if (forward) {
						currentDistance = p.getOffset() - offset;
						if (currentDistance < 0) {
							currentDistance = endOfDocument + currentDistance;
						}

						if (currentDistance < distance || currentDistance == distance && p.length < nextAnnotationPosition.length) {
							distance = currentDistance;
							nextAnnotation = a;
							nextAnnotationPosition = p;
						}
					} else {
						currentDistance = offset + length - (p.getOffset() + p.length);
						if (currentDistance < 0)
							currentDistance = endOfDocument + currentDistance;

						if (currentDistance < distance || currentDistance == distance && p.length < nextAnnotationPosition.length) {
							distance = currentDistance;
							nextAnnotation = a;
							nextAnnotationPosition = p;
						}
					}
				}
			}
		}
		if (containingAnnotationPosition != null && (!currentAnnotation || nextAnnotation == null)) {
			annotationPosition.setOffset(containingAnnotationPosition.getOffset());
			annotationPosition.setLength(containingAnnotationPosition.getLength());
			return containingAnnotation;
		}
		if (nextAnnotationPosition != null) {
			annotationPosition.setOffset(nextAnnotationPosition.getOffset());
			annotationPosition.setLength(nextAnnotationPosition.getLength());
		}

		return nextAnnotation;
	}

	private IStatusLineManager getStatusLineManager() {
		// The original JavaEditor M7 implementation made use of an adapter,
		// but that approach
		// fails with a MultiPageEditorSite
		AbstractUIPlugin plugin = (AbstractUIPlugin) Platform.getPlugin(PlatformUI.PLUGIN_ID);
		IWorkbenchWindow window = plugin.getWorkbench().getActiveWorkbenchWindow();
		if (window == null)
			return null;
		IWorkbenchPage page = window.getActivePage();
		if (page == null)
			return null;
		IEditorPart editor = page.getActiveEditor();
		if (editor == null)
			return null;
		IEditorActionBarContributor contributor = editor.getEditorSite().getActionBarContributor();
		if (contributor instanceof EditorActionBarContributor) {
			return ((EditorActionBarContributor) contributor).getActionBars().getStatusLineManager();
		}
		return null;
	}

	public String getText() {
		return getDefaultLabel();
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.action.Action#getToolTipText()
	 */
	public String getToolTipText() {
		return getDefaultLabel();
	}

	/**
	 * Jumps to the error next according to the given direction based off
	 * JavaEditor#gotoAnnotation()
	 * 
	 * @param forward
	 *            is the direction
	 */
	public void gotoAnnotation(boolean forward) {
		ITextSelection selection = (ITextSelection) getTextEditor().getSelectionProvider().getSelection();
		Position position = new Position(0, 0);
		if (false /* delayed - see bug 18316 */) {
			getNextAnnotation(selection.getOffset(), selection.getLength(), forward, position);
			getTextEditor().selectAndReveal(position.getOffset(), position.getLength());
		} else /* no delay - see bug 18316 */{
			Annotation annotation = getNextAnnotation(selection.getOffset(), selection.getLength(), forward, position);
			IEditorStatusLine editorStatusLine = (IEditorStatusLine) getTextEditor().getAdapter(IEditorStatusLine.class);
			if (editorStatusLine != null) {
				editorStatusLine.setMessage(true, null, null);
				editorStatusLine.setMessage(false, null, null);
			} else {
				IStatusLineManager mgr = getStatusLineManager();
				if (mgr != null) {
					mgr.setErrorMessage(null);
					mgr.setMessage(null, null);
				}
			}
			if (annotation != null) {
				updateAnnotationViews(annotation);
				getTextEditor().selectAndReveal(position.getOffset(), position.getLength());
				if (editorStatusLine != null) {
					editorStatusLine.setMessage(true, null, null);
					editorStatusLine.setMessage(false, annotation.getText(), null);
				} else {
					IStatusLineManager mgr = getStatusLineManager();
					if (mgr != null) {
						mgr.setErrorMessage(null);
						mgr.setMessage(null, annotation.getText());
					}
					getTextEditor().getSelectionProvider().addSelectionChangedListener(new StatusLineClearer(mgr));
				}
			}
		}
	}

	/**
	 * Returns whether the given annotation is configured as a target for the
	 * "Go to Next/Previous Annotation" actions
	 * 
	 * @param annotation
	 *            the annotation
	 * @return <code>true</code> if this is a target, <code>false</code>
	 *         otherwise
	 * @since 3.0
	 */
	protected boolean isNavigationTarget(Annotation annotation) {
		Preferences preferences = Platform.getPlugin(EditorsUI.PLUGIN_ID).getPluginPreferences();
		AnnotationPreference preference = EditorsUI.getAnnotationPreferenceLookup().getAnnotationPreference(annotation);
		//	See bug 41689
		//	String key= forward ? preference.getIsGoToNextNavigationTargetKey()
		// : preference.getIsGoToPreviousNavigationTargetKey();
		String key = preference == null ? null : preference.getIsGoToNextNavigationTargetKey();
		return (key != null && preferences.getBoolean(key));
	}

	public void run() {
		gotoAnnotation(fForward);
	}

	public void setEditor(ITextEditor editor) {
		super.setEditor(editor);
		update();
	}

	/**
	 * Updates the annotation views that show the given annotation.
	 * 
	 * @param annotation
	 *            the annotation
	 */
	protected void updateAnnotationViews(Annotation annotation) {
		IMarker marker = null;
		if (annotation instanceof MarkerAnnotation)
			marker = ((MarkerAnnotation) annotation).getMarker();

		if (marker != null) {
			try {
				IWorkbenchWindow window = PlatformUI.getWorkbench().getActiveWorkbenchWindow();
				if (window != null) {
					IWorkbenchPage page = window.getActivePage();
					if (page != null) {
						IViewPart view = null;
						if (marker.isSubtypeOf(IMarker.PROBLEM)) {
							view = page.findView(IPageLayout.ID_PROBLEM_VIEW);
						} else if (marker.isSubtypeOf(IMarker.TASK)) {
							view = page.findView(IPageLayout.ID_TASK_LIST);
						} else if (marker.isSubtypeOf(IMarker.BOOKMARK)) {
							view = page.findView(IPageLayout.ID_BOOKMARKS);
						}
						// If the view isn't open on this perspective, don't
						// interact with it
						if (view != null) {
							Method method = view.getClass().getMethod("setSelection", new Class[]{IStructuredSelection.class, boolean.class}); //$NON-NLS-1$
							if (method != null) {
								method.invoke(view, new Object[]{new StructuredSelection(marker), Boolean.TRUE});
								page.bringToTop(view);
							}
						}
					}
				}
			}
			// ignore exceptions, don't update any of the lists, just set
			// statusline
			catch (CoreException x) {
				//
			} catch (NoSuchMethodException x) {
				//
			} catch (IllegalAccessException x) {
				//
			} catch (InvocationTargetException x) {
				//
			}
		}
	}
}