/*******************************************************************************
 * Copyright (c) 2001, 2015 IBM Corporation and others.
 * All rights reserved. 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/
package org.eclipse.wst.xml.ui.internal.correction;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.ITextViewerExtension;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension2;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.link.LinkedModeModel;
import org.eclipse.jface.text.link.LinkedModeUI;
import org.eclipse.jface.text.link.LinkedPosition;
import org.eclipse.jface.text.link.LinkedPositionGroup;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.ui.texteditor.link.EditorLinkedModeUI;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.sse.ui.internal.contentassist.ContentAssistUtils;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;
import org.eclipse.wst.xml.ui.internal.Logger;
import org.eclipse.wst.xml.ui.internal.XMLUIMessages;
import org.eclipse.wst.xml.ui.internal.editor.XMLEditorPluginImageHelper;
import org.eclipse.wst.xml.ui.internal.editor.XMLEditorPluginImages;

public class RenameInFileQuickAssistProposal implements ICompletionProposal, ICompletionProposalExtension2 {
	protected IRegion fSelectedRegion; // initialized by apply()

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#apply(org.eclipse.jface.text.IDocument)
	 */
	public void apply(IDocument document) {
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension2#apply(org.eclipse.jface.text.ITextViewer,
	 *      char, int, int)
	 */
	public void apply(ITextViewer viewer, char trigger, int stateMask, int offset) {
		IDocument document = viewer.getDocument();
		Point originalRange = viewer.getSelectedRange();
		LinkedPositionGroup group = new LinkedPositionGroup();
		try {
				IDOMNode node = (IDOMNode) ContentAssistUtils.getNodeAt(viewer, offset);
				IStructuredDocumentRegion startStructuredDocumentRegion = node.getStartStructuredDocumentRegion();
				ITextRegion region = (startStructuredDocumentRegion == null) ? null : startStructuredDocumentRegion.getRegionAtCharacterOffset(offset);
				if (region != null) {
					group.addPosition(new LinkedPosition(document, startStructuredDocumentRegion.getStartOffset() + region.getStart(), region.getTextLength(), 0));

					if ((region.getType() == DOMRegionContext.XML_TAG_NAME) && (node.getEndStructuredDocumentRegion() != null)) {
						region = node.getEndStructuredDocumentRegion().getRegions().get(1);
						if (region != null) {
							group.addPosition(new LinkedPosition(document, node.getEndStructuredDocumentRegion().getStartOffset() + region.getStart(), region.getTextLength(), 1));
						}
					}
				}
				else {
					IStructuredDocumentRegion endStructuredDocumentRegion = node.getEndStructuredDocumentRegion();
					region = (endStructuredDocumentRegion == null) ? null : endStructuredDocumentRegion.getRegionAtCharacterOffset(offset);
					if (region != null) {
						if ((region.getType() == DOMRegionContext.XML_TAG_NAME) && (node.getStartStructuredDocumentRegion() != null)) {
							ITextRegion startTagNameRegion = node.getStartStructuredDocumentRegion().getRegions().get(1);
							if (region != null) {
								group.addPosition(new LinkedPosition(document, node.getStartStructuredDocumentRegion().getStartOffset() + startTagNameRegion.getStart(), startTagNameRegion.getTextLength(), 0));
								group.addPosition(new LinkedPosition(document, endStructuredDocumentRegion.getStartOffset() + region.getStart(), region.getTextLength(), 1));
							}
						}
						else {
							group.addPosition(new LinkedPosition(document, endStructuredDocumentRegion.getStartOffset() + region.getStart(), region.getTextLength(), 0));
						}
					}
				}

				// TODO CompletionProposalPopup#insertProposal() calls
				// IRewriteTarget.beginCompoundChange()
				// which disables redraw in ITextViewer. Workaround for now.
				if(viewer instanceof ITextViewerExtension)
					((ITextViewerExtension) viewer).setRedraw(true);

			LinkedModeModel linkedModeModel = new LinkedModeModel();
			linkedModeModel.addGroup(group);
			linkedModeModel.forceInstall();

			LinkedModeUI ui = new EditorLinkedModeUI(linkedModeModel, viewer);
			ui.setExitPosition(viewer, offset, 0, LinkedPositionGroup.NO_STOP);
			ui.enter();
			/*
			 * Keep the cursor at the original offset and restore the original
			 * selection instead of the entire first matching region
			 */
			viewer.setSelectedRange(originalRange.x, originalRange.y);
			fSelectedRegion = ui.getSelectedRegion();
		}
		catch (BadLocationException e) {
			// log for now, unless find reason not to
			Logger.log(Logger.INFO, e.getMessage());
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getAdditionalProposalInfo()
	 */
	public String getAdditionalProposalInfo() {
		return XMLUIMessages.RenameInFileQuickAssistProposal_0;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getContextInformation()
	 */
	public IContextInformation getContextInformation() {
		return null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getDisplayString()
	 */
	public String getDisplayString() {
		return XMLUIMessages.RenameInFileQuickAssistProposal_1;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getImage()
	 */
	public Image getImage() {
		return XMLEditorPluginImageHelper.getInstance().getImage(XMLEditorPluginImages.IMG_OBJ_LOCAL_VARIABLE);
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getSelection(org.eclipse.jface.text.IDocument)
	 */
	public Point getSelection(IDocument document) {
		return null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension2#selected(org.eclipse.jface.text.ITextViewer,
	 *      boolean)
	 */
	public void selected(ITextViewer viewer, boolean smartToggle) {
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension2#unselected(org.eclipse.jface.text.ITextViewer)
	 */
	public void unselected(ITextViewer viewer) {
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposalExtension2#validate(org.eclipse.jface.text.IDocument,
	 *      int, org.eclipse.jface.text.DocumentEvent)
	 */
	public boolean validate(IDocument document, int offset, DocumentEvent event) {
		return false;
	}

}
