/*******************************************************************************
 * 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.xml.ui.internal.correction;

import java.util.List;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DocumentEvent;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.ICompletionProposalExtension2;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.text.edits.InsertEdit;
import org.eclipse.text.edits.MultiTextEdit;
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.StructuredTextViewer;
import org.eclipse.wst.sse.ui.internal.contentassist.ContentAssistUtils;
import org.eclipse.wst.xml.core.internal.contentmodel.CMAttributeDeclaration;
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 InsertRequiredAttrsQuickAssistProposal implements ICompletionProposal, ICompletionProposalExtension2 {
	private final List fRequiredAttrs;

	/**
	 * @param requiredAttrs
	 */
	public InsertRequiredAttrsQuickAssistProposal(List requiredAttrs) {
		fRequiredAttrs = requiredAttrs;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#apply(org.eclipse.jface.text.IDocument)
	 */
	public void apply(IDocument document) {
		// not implemented?
	}

	/*
	 * (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) {
		IDOMNode node = (IDOMNode) ContentAssistUtils.getNodeAt((StructuredTextViewer) viewer, offset);
		IStructuredDocumentRegion startStructuredDocumentRegion = node.getStartStructuredDocumentRegion();
		int index = startStructuredDocumentRegion.getEndOffset();
		ITextRegion lastRegion = startStructuredDocumentRegion.getLastRegion();
		if (lastRegion.getType() == DOMRegionContext.XML_TAG_CLOSE) {
			index--;
			lastRegion = startStructuredDocumentRegion.getRegionAtCharacterOffset(index - 1);
		}
		else if (lastRegion.getType() == DOMRegionContext.XML_EMPTY_TAG_CLOSE) {
			index = index - 2;
			lastRegion = startStructuredDocumentRegion.getRegionAtCharacterOffset(index - 1);
		}
		MultiTextEdit multiTextEdit = new MultiTextEdit();
		try {
			for (int i = 0; i < fRequiredAttrs.size(); i++) {
				CMAttributeDeclaration attrDecl = (CMAttributeDeclaration) fRequiredAttrs.get(i);
				String requiredAttributeName = attrDecl.getAttrName();
				String defaultValue = attrDecl.getDefaultValue();
				if (defaultValue == null)
					defaultValue = ""; //$NON-NLS-1$
				String nameAndDefaultValue = " "; //$NON-NLS-1$
				if (i == 0 && lastRegion.getLength() > lastRegion.getTextLength())
					nameAndDefaultValue = ""; //$NON-NLS-1$
				nameAndDefaultValue += requiredAttributeName + "=\"" + defaultValue + "\""; //$NON-NLS-1$//$NON-NLS-2$
				multiTextEdit.addChild(new InsertEdit(index, nameAndDefaultValue));
				// BUG3381: MultiTextEdit applies all child TextEdit's basing
				// on offsets
				// in the document before the first TextEdit, not after each
				// child TextEdit. Therefore, do not need to advance the
				// index.
				// index += nameAndDefaultValue.length();
			}
			multiTextEdit.apply(viewer.getDocument());
		}
		catch (BadLocationException e) {
			// log, for now, unless we find there's reasons why we get some
			// here.
			Logger.log(Logger.INFO, e.getMessage());
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.text.contentassist.ICompletionProposal#getAdditionalProposalInfo()
	 */
	public String getAdditionalProposalInfo() {
		return XMLUIMessages.InsertRequiredAttrsQuickAssistProposal_0; //$NON-NLS-1$
	}

	/*
	 * (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.InsertRequiredAttrsQuickAssistProposal_1; //$NON-NLS-1$
	}

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

	/*
	 * (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;
	}
}