/*
 * Copyright (C) 2010 Mathieu Baudier <mbaudier@argeo.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.argeo.slc.core.execution;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.argeo.slc.execution.ExecutionFlowDescriptor;
import org.argeo.slc.execution.ExecutionStep;
import org.argeo.slc.process.RealizedFlow;

/** Thread of a single execution */
public class ExecutionThread extends Thread {
	public final static String SYSPROP_EXECUTION_AUTO_UPGRADE = "slc.execution.autoupgrade";

	private final static Log log = LogFactory.getLog(ExecutionThread.class);

	private final RealizedFlow realizedFlow;
	private final ProcessThread processThread;

	public ExecutionThread(ProcessThread processThread,
			RealizedFlow realizedFlow) {
		super(processThread.getProcessThreadGroup(), "Flow "
				+ realizedFlow.getFlowDescriptor().getName());
		this.realizedFlow = realizedFlow;
		this.processThread = processThread;
	}

	public void run() {
		if (getContextClassLoader() != null) {
			if (log.isTraceEnabled())
				log.trace("Context class loader set to "
						+ getContextClassLoader());
		}

		// Retrieve execution flow descriptor
		ExecutionFlowDescriptor executionFlowDescriptor = realizedFlow
				.getFlowDescriptor();
		String flowName = executionFlowDescriptor.getName();

		dispatchAddStep(new ExecutionStep(realizedFlow.getModuleName(),
				ExecutionStep.PHASE_START, "Flow " + flowName));

		try {
			String autoUpgrade = System
					.getProperty(SYSPROP_EXECUTION_AUTO_UPGRADE);
			if (autoUpgrade != null && autoUpgrade.equals("true"))
				processThread.getExecutionModulesManager().upgrade(
						realizedFlow.getModuleNameVersion());

			// START FLOW
			processThread.getExecutionModulesManager().execute(realizedFlow);
			// END FLOW
		} catch (Exception e) {
			// TODO: re-throw exception ?
			String msg = "Execution of flow " + flowName + " failed.";
			log.error(msg, e);
			dispatchAddStep(new ExecutionStep(realizedFlow.getModuleName(),
					ExecutionStep.ERROR, msg + " " + e.getMessage()));
			processThread.notifyError();
		} finally {
			processThread.flowCompleted();
			dispatchAddStep(new ExecutionStep(realizedFlow.getModuleName(),
					ExecutionStep.PHASE_END, "Flow " + flowName));
		}
	}

	private void dispatchAddStep(ExecutionStep step) {
		processThread.getProcessThreadGroup().dispatchAddStep(step);
	}

	public RealizedFlow getRealizedFlow() {
		return realizedFlow;
	}

}