/*******************************************************************************
 * Copyright (c) 2001, 2011 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.internal.search;

import java.text.MessageFormat;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IWorkspace;
import org.eclipse.core.resources.IWorkspaceRunnable;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.ISchedulingRule;
import org.eclipse.wst.sse.core.internal.provisional.text.IStructuredDocument;
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.core.internal.provisional.text.ITextRegionList;
import org.eclipse.wst.sse.ui.internal.Logger;
import org.eclipse.wst.sse.ui.internal.SSEUIMessages;
import org.eclipse.wst.sse.ui.internal.SSEUIPlugin;

/**
 * Basic ISearchQuery that finds matches of region type and region text.
 * 
 * @author pavery
 */
public class OccurrencesSearchQuery extends BasicSearchQuery {

	/**
	 * We need a runnable so that the search markers show up in the live
	 * document.
	 */
	private class FindRegions implements IWorkspaceRunnable {

		private IStructuredDocument fFindRegionsDocument = null;
		private String fMatchName = null;
		private String fMatchRegionType = null;

		public FindRegions(IStructuredDocument document, String matchText, String matchRegionType) {

			this.fFindRegionsDocument = document;
			this.fMatchName = matchText;
			this.fMatchRegionType = matchRegionType;
		}

		private void findOccurrences(IProgressMonitor monitor) {

			if (!isCanceled(monitor)) {

				int matchStart = -1;
				int matchEnd = -1;
				String findRegionText = ""; //$NON-NLS-1$

				ITextRegion r = null;
				ITextRegionList regions = null;
				IStructuredDocumentRegion current = this.fFindRegionsDocument.getFirstStructuredDocumentRegion();

				// this is the main loop that iterates the document
				while (current != null && !isCanceled(monitor)) {
					regions = current.getRegions();
					for (int i = 0; i < regions.size() && !isCanceled(monitor); i++) {

						r = regions.get(i);

						// maybe this is the equals check where some valid
						// matches are failing (like searching on end tag)
						if (r.getType().equals(this.fMatchRegionType) && current.getText(r).equals(this.fMatchName)) {

							findRegionText = current.getText(r);

							// region found
							matchStart = current.getStartOffset(r);
							matchEnd = matchStart + findRegionText.trim().length();

							addMatch(this.fFindRegionsDocument, matchStart, matchEnd);
						}
					}
					current = current.getNext();
				}
			}
		}

		private boolean isCanceled(IProgressMonitor monitor) {
			return monitor != null && monitor.isCanceled();
		}

		public void run(IProgressMonitor monitor) throws CoreException {

			try {
				findOccurrences(monitor);
			} catch (Exception e) {
				Logger.logException(e);
			}
		}
	}// end inner class FindRegions


	private IStructuredDocument fDocument = null;
	private String fRegionText = null;
	private String fRegionType = null;

	public OccurrencesSearchQuery(IFile file, IStructuredDocument document, String regionText, String regionType) {
		super(file);
		super.setResult(new OccurrencesSearchResult(this));
		this.fDocument = document;
		this.fRegionText = regionText;
		this.fRegionType = regionType;
	}

	/**
	 * <p><i>Note: </i>Some investigation needs to be put into how to do this safely</p>
	 * 
	 * @see org.eclipse.wst.sse.ui.internal.search.BasicSearchQuery#canRunInBackground()
	 */
	public boolean canRunInBackground() {
		return false;
	}
	
	/**
	 * <p>The label format is:<br/>
	 * searchText - # occurrences in file</p>
	 * 
	 * @see org.eclipse.wst.sse.ui.internal.search.BasicSearchQuery#getLabel()
	 */
	public String getLabel() {
		String label = SSEUIMessages.OccurrencesSearchQuery_0; //$NON-NLS-1$
		String[] args = {getSearchText(), "" + super.getMatchCount(), getFilename()};
		return MessageFormat.format(label, args);
	}

	/**
	 * This query looks for all occurrences of the selected string
	 * 
	 * @see org.eclipse.wst.sse.ui.internal.search.BasicSearchQuery#doQuery()
	 */
	protected IStatus doQuery(IProgressMonitor monitor) {
		IStatus status = Status.OK_STATUS;
		FindRegions findRegions = new FindRegions(this.fDocument, this.fRegionText, this.fRegionType);
		try {
			// BUG158846 - deadlock if lock up entire workspace, so only lock
			// up the file we are searching on
			ISchedulingRule markerRule = ResourcesPlugin.getWorkspace().getRuleFactory().markerRule(getFile());
			ResourcesPlugin.getWorkspace().run(findRegions, markerRule, IWorkspace.AVOID_UPDATE, monitor);
		} catch (CoreException e) {
			status = new Status(IStatus.ERROR, SSEUIPlugin.ID, IStatus.OK, "", null); //$NON-NLS-1$
		}
		return status;
	}

	protected String getSearchText() {
		return this.fRegionText;
	}
	
	private String getFilename() {
		String filename = SSEUIMessages.OccurrencesSearchQuery_2; //$NON-NLS-1$ "file"
		if (getFile() != null)
			filename = getFile().getName().toString();
		return filename;
	}
}