package at.gv.egovernment.moa.id.auth.servlet;

import java.io.IOException;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringEscapeUtils;
import org.springframework.beans.factory.annotation.Autowired;

import at.gv.egovernment.moa.id.advancedlogging.TransactionIDUtils;
import at.gv.egovernment.moa.id.auth.exception.MOAIllegalStateException;
import at.gv.egovernment.moa.id.commons.MOAIDAuthConstants;
import at.gv.egovernment.moa.id.commons.api.IRequest;
import at.gv.egovernment.moa.id.commons.api.exceptions.MOAIDException;
import at.gv.egovernment.moa.id.process.ProcessEngine;
import at.gv.egovernment.moa.logging.Logger;

/**
 * Servlet that resumes a suspended process (in case of asynchronous tasks).
 * 
 * @author tknall
 * 
 */
public abstract class AbstractProcessEngineSignalController extends AbstractController {
		
	@Autowired protected ProcessEngine processEngine;
	
	protected void signalProcessManagement(HttpServletRequest req, HttpServletResponse resp) throws IOException {
		String pendingRequestID = StringEscapeUtils.escapeHtml(getPendingRequestId(req));
		IRequest pendingReq = null;
		try {	
			if (pendingRequestID == null) {
				throw new MOAIllegalStateException("process.03", new Object[]{"Unable to determine MOA pending-request id."});
				
			}
			
			pendingReq = requestStorage.getPendingRequest(pendingRequestID);
			if (pendingReq == null) {
				Logger.info("No PendingRequest with Id: " + pendingRequestID + " Maybe, a transaction timeout occure.");
				throw new MOAIDException("auth.28", new Object[]{pendingRequestID});
				
			}
			
			//change pending-request ID
			requestStorage.changePendingRequestID(pendingReq);
			pendingRequestID = pendingReq.getRequestID();
			
			//add transactionID and unique sessionID to Logger
			TransactionIDUtils.setSessionId(pendingReq.getUniqueSessionIdentifier());
			TransactionIDUtils.setTransactionId(pendingReq.getUniqueTransactionIdentifier());
			
			// process instance is mandatory
			if (pendingReq.getProcessInstanceId() == null) {
				throw new MOAIllegalStateException("process.03", new Object[]{"MOA session does not provide process instance id."});
				
			}

			// wake up next task
			processEngine.signal(pendingReq);
			
		} catch (Exception ex) {
			handleError(null, ex, req, resp, pendingReq);
			
		} finally {
			//MOASessionDBUtils.closeSession();
			TransactionIDUtils.removeTransactionId();
			TransactionIDUtils.removeSessionId();
			
		}
		
		
	}
	
	/**
	 * Retrieves the current pending-request id from the HttpServletRequest parameter
	 * {@link MOAIDAuthConstants#PARAM_TARGET_PENDINGREQUESTID}.
	 * <p/>
	 * Note that this class/method can be overwritten by modules providing their own strategy of retrieving the
	 * respective pending-request id.
	 * 
	 * @param request
	 *            The unterlying HttpServletRequest.
	 * @return The current pending-request id.
	 */
	public String getPendingRequestId(HttpServletRequest request) {
		return StringEscapeUtils.escapeHtml(request.getParameter(MOAIDAuthConstants.PARAM_TARGET_PENDINGREQUESTID));
		
	}

}