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

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.resources.IResource;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.wst.sse.core.internal.provisional.text.ITextRegion;
import org.eclipse.wst.xml.core.internal.provisional.document.IDOMNode;
import org.eclipse.wst.xml.ui.internal.XMLUIPlugin;
import org.eclipse.wst.xml.ui.internal.preferences.XMLUIPreferenceNames;
import org.eclipse.wst.xml.ui.internal.templates.TemplateContextTypeIdsXML;

public class XMLContentAssistProcessor extends AbstractContentAssistProcessor implements IPropertyChangeListener {

	protected IPreferenceStore fPreferenceStore = null;
	protected IResource fResource = null;
	private XMLTemplateCompletionProcessor fTemplateProcessor = null;
	private List fTemplateContexts = new ArrayList();

	public XMLContentAssistProcessor() {
		super();
	}
	
	protected void addAttributeNameProposals(ContentAssistRequest contentAssistRequest) {
		addTemplates(contentAssistRequest, TemplateContextTypeIdsXML.ATTRIBUTE);
		super.addAttributeNameProposals(contentAssistRequest);
	}
	
	protected void addAttributeValueProposals(ContentAssistRequest contentAssistRequest) {
		addTemplates(contentAssistRequest, TemplateContextTypeIdsXML.ATTRIBUTE_VALUE);
		super.addAttributeValueProposals(contentAssistRequest);
	}
	
	protected void addEmptyDocumentProposals(ContentAssistRequest contentAssistRequest) {
		addTemplates(contentAssistRequest, TemplateContextTypeIdsXML.NEW);
		super.addEmptyDocumentProposals(contentAssistRequest);
	}
	
	protected void addTagInsertionProposals(ContentAssistRequest contentAssistRequest, int childPosition) {
		addTemplates(contentAssistRequest, TemplateContextTypeIdsXML.TAG);
		super.addTagInsertionProposals(contentAssistRequest, childPosition);
	}
	
	/**
	 * Adds templates to the list of proposals
	 * 
	 * @param contentAssistRequest
	 * @param context
	 */
	private void addTemplates(ContentAssistRequest contentAssistRequest, String context) {
		addTemplates(contentAssistRequest, context, contentAssistRequest.getReplacementBeginPosition());
	}
	
	/**
	 * Adds templates to the list of proposals
	 * 
	 * @param contentAssistRequest
	 * @param context
	 * @param startOffset
	 */
	private void addTemplates(ContentAssistRequest contentAssistRequest, String context, int startOffset) {
		if (contentAssistRequest == null)
			return;
		
		// if already adding template proposals for a certain context type, do
		// not add again
		if (!fTemplateContexts.contains(context)) {
			fTemplateContexts.add(context);
			boolean useProposalList = !contentAssistRequest.shouldSeparate();

			if (getTemplateCompletionProcessor() != null) {
				getTemplateCompletionProcessor().setContextType(context);
				ICompletionProposal[] proposals = getTemplateCompletionProcessor().computeCompletionProposals(fTextViewer, startOffset);
				for (int i = 0; i < proposals.length; ++i) {
					if (useProposalList)
						contentAssistRequest.addProposal(proposals[i]);
					else
						contentAssistRequest.addMacro(proposals[i]);
				}
			}
		}
	}
	
	protected ContentAssistRequest computeCompletionProposals(int documentPosition, String matchString, ITextRegion completionRegion, IDOMNode treeNode, IDOMNode xmlnode) {
		ContentAssistRequest request = super.computeCompletionProposals(documentPosition, matchString, completionRegion, treeNode, xmlnode);
		// bug115927 use original document position for all/any region templates
		addTemplates(request, TemplateContextTypeIdsXML.ALL, documentPosition);
		return request;
	}
	
	/* (non-Javadoc)
	 * @see org.eclipse.wst.xml.ui.contentassist.AbstractContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer, int)
	 */
	public ICompletionProposal[] computeCompletionProposals(ITextViewer textViewer, int documentPosition) {
		fTemplateContexts.clear();
		return super.computeCompletionProposals(textViewer, documentPosition);
	}

	protected IPreferenceStore getPreferenceStore() {
		if (fPreferenceStore == null)
			fPreferenceStore = XMLUIPlugin.getDefault().getPreferenceStore();
		return fPreferenceStore;
	}

	private XMLTemplateCompletionProcessor getTemplateCompletionProcessor() {
		if (fTemplateProcessor == null) {
			fTemplateProcessor = new XMLTemplateCompletionProcessor();
		}
		return fTemplateProcessor;
	}

	protected void init() {
		getPreferenceStore().addPropertyChangeListener(this);
		reinit();
	}

	public void propertyChange(PropertyChangeEvent event) {
		String property = event.getProperty();

		if (property.compareTo(XMLUIPreferenceNames.AUTO_PROPOSE) == 0 || property.compareTo(XMLUIPreferenceNames.AUTO_PROPOSE_CODE) == 0) {
			reinit();
		}
	}

	protected void reinit() {
		String key = XMLUIPreferenceNames.AUTO_PROPOSE;
		boolean doAuto = getPreferenceStore().getBoolean(key);
		if (doAuto) {
			key = XMLUIPreferenceNames.AUTO_PROPOSE_CODE;
			completionProposalAutoActivationCharacters = getPreferenceStore().getString(key).toCharArray();
		} else {
			completionProposalAutoActivationCharacters = null;
		}
	}

	public void release() {
		super.release();
		getPreferenceStore().removePropertyChangeListener(this);
	}
}