/*******************************************************************************
 * 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.contentassist;

import java.util.HashMap;

import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Position;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
import org.eclipse.jface.text.contentassist.IContextInformationValidator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.wst.sse.core.text.IStructuredDocument;
import org.eclipse.wst.sse.core.text.IStructuredDocumentRegion;
import org.eclipse.wst.sse.core.text.ITextRegion;
import org.eclipse.wst.sse.core.text.ITextRegionList;
import org.eclipse.wst.xml.core.document.IDOMNode;
import org.eclipse.wst.xml.core.internal.regions.DOMRegionContext;


/**
 * Responsible for the presentation of the context info popup. This includes
 * text style, and when the window should close.
 * 
 * @author pavery
 */
public class AttributeContextInformationPresenter implements IContextInformationPresenter, IContextInformationValidator {
	private int fDocumentPosition = -1;

	private IContextInformation fInfo = null;
	private ContextInfoModelUtil fModelUtil = null;
	private ITextViewer fViewer = null;

	/**
	 * @see org.eclipse.jface.text.contentassist.IContextInformationValidator#install(org.eclipse.jface.text.contentassist.IContextInformation,
	 *      org.eclipse.jface.text.ITextViewer, int)
	 */
	public void install(IContextInformation info, ITextViewer viewer, int documentPosition) {
		fInfo = info;
		fViewer = viewer;
		fDocumentPosition = documentPosition;
		fModelUtil = new ContextInfoModelUtil((IStructuredDocument) fViewer.getDocument());
	}

	/**
	 * @see org.eclipse.jface.text.contentassist.IContextInformationValidator#isContextInformationValid(int)
	 */
	public boolean isContextInformationValid(int documentPosition) {
		// determine whether or not this context info should still be
		// showing...
		// if cursor still within the element it's valid...
		IStructuredDocumentRegion startRegion = fModelUtil.getXMLNode(fDocumentPosition).getStartStructuredDocumentRegion();
		int start = startRegion.getStartOffset();
		int end = startRegion.getEndOffset();
		return documentPosition < end && documentPosition > start + 1;
	}

	/**
	 * @see org.eclipse.jface.text.contentassist.IContextInformationPresenter#updatePresentation(int,
	 *      org.eclipse.jface.text.TextPresentation)
	 */
	public boolean updatePresentation(int documentPosition, TextPresentation presentation) {
		presentation.clear();

		if (!(fInfo instanceof AttributeContextInformation))
			return false;

		// iterate existing attributes from current node
		IDOMNode xmlNode = fModelUtil.getXMLNode(documentPosition);
		IStructuredDocumentRegion sdRegion = xmlNode.getFirstStructuredDocumentRegion();
		ITextRegionList regions = sdRegion.getRegions();
		ITextRegion r = null;
		String attrName = ""; //$NON-NLS-1$
		Object temp = null;
		Position p = null;
		HashMap map = ((AttributeContextInformation) fInfo).getAttr2RangeMap();

		// so we can add ranges in order
		StyleRange[] sorted = new StyleRange[fInfo.getInformationDisplayString().length()];
		for (int i = 0; i < regions.size(); i++) {
			r = regions.get(i);
			if (r.getType() == DOMRegionContext.XML_TAG_ATTRIBUTE_NAME) {
				attrName = sdRegion.getText(r);
				temp = map.get(attrName);
				if (temp != null) {
					p = (Position) temp;
					sorted[p.offset] = new StyleRange(p.offset, p.length, null, null, SWT.BOLD);
				}
			}
		}
		// style ranges need to be added in order
		StyleRange sr = null;
		for (int i = 0; i < sorted.length; i++) {
			sr = sorted[i];
			if (sr != null)
				presentation.addStyleRange(sr);
		}
		return true;
	}
}