/* 
 * Copyright (c) 2008 Stiftung Deutsches Elektronen-Synchrotron, 
 * Member of the Helmholtz Association, (DESY), HAMBURG, GERMANY.
 *
 * THIS SOFTWARE IS PROVIDED UNDER THIS LICENSE ON AN "../AS IS" BASIS. 
 * WITHOUT WARRANTY OF ANY KIND, EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED 
 * TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE 
 * FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, 
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR 
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE. SHOULD THE SOFTWARE PROVE DEFECTIVE 
 * IN ANY RESPECT, THE USER ASSUMES THE COST OF ANY NECESSARY SERVICING, REPAIR OR 
 * CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL PART OF THIS LICENSE. 
 * NO USE OF ANY SOFTWARE IS AUTHORIZED HEREUNDER EXCEPT UNDER THIS DISCLAIMER.
 * DESY HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, 
 * OR MODIFICATIONS.
 * THE FULL LICENSE SPECIFYING FOR THE SOFTWARE THE REDISTRIBUTION, MODIFICATION, 
 * USAGE AND OTHER RIGHTS AND OBLIGATIONS IS INCLUDED WITH THE DISTRIBUTION OF THIS 
 * PROJECT IN THE FILE LICENSE.HTML. IF THE LICENSE IS NOT INCLUDED YOU MAY FIND A COPY 
 * AT HTTP://WWW.DESY.DE/LEGAL/LICENSE.HTM
 */
package org.csstudio.sds.ui.widgetactionhandler;

import java.util.HashMap;
import java.util.Map;

import org.csstudio.sds.internal.model.logic.ScriptEngine;
import org.csstudio.sds.internal.rules.LogicException;
import org.csstudio.sds.model.AbstractWidgetModel;
import org.csstudio.sds.model.IScript;
import org.csstudio.sds.model.properties.actions.AbstractWidgetActionModel;
import org.csstudio.sds.model.properties.actions.ExecuteScriptActionModel;
import org.csstudio.sds.ui.scripting.RunnableScript;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;

/**
 * Executes a script.
 * 
 * @author Kai Meyer
 */
public final class ExecuteScriptActionHandler implements IWidgetActionHandler {

	private Map<AbstractWidgetModel, ScriptEngine> _engineMap;

	public ExecuteScriptActionHandler() {
		_engineMap = new HashMap<AbstractWidgetModel, ScriptEngine>();
	}

	/**
	 * {@inheritDoc}
	 * 
	 * @required action instanceof ExecuteScriptActionModel
	 */
	@Override
	public void executeAction(final AbstractWidgetModel widget,
			final AbstractWidgetActionModel action) {
		assert action instanceof ExecuteScriptActionModel : "Precondition violated: action instanceof ExecuteScriptActionModel";
		ExecuteScriptActionModel valueAction = (ExecuteScriptActionModel) action;
		IPath scriptPath = valueAction.getScriptPath();
		boolean keepScriptStatus = valueAction.getKeepScriptStatus();

		try {
			IFile file = ResourcesPlugin.getWorkspace().getRoot().getFile(
					scriptPath);
			final ScriptEngine scriptEngine = determineEngine(widget,
					file, keepScriptStatus);
			if (scriptEngine != null) {
				Thread t = new Thread(new Runnable() {
					@Override
					public void run() {
						scriptEngine.processScript();
					}
				});
				t.start();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}

	}

	private ScriptEngine determineEngine(AbstractWidgetModel widget,
			IFile file, boolean keepScriptEngine) throws LogicException,
			CoreException {
		ScriptEngine scriptEngine = null;
		if (keepScriptEngine) {
			if (!_engineMap.containsKey(widget)) {
				IScript script = new RunnableScript(file.getName(), file
						.getContents());
				_engineMap.put(widget, new ScriptEngine(script));
			}
			scriptEngine = _engineMap.get(widget);
		} else {
			IScript script = new RunnableScript(file.getName(), file
					.getContents());
			scriptEngine = new ScriptEngine(script);
		}
		return scriptEngine;
	}

}