/*
 * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
 * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 or - as soon they will be approved by the European
 * Commission - subsequent versions of the EUPL (the "Licence"); You may not use this work except in
 * compliance with the Licence. You may obtain a copy of the Licence at:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the Licence
 * is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
 * or implied. See the Licence for the specific language governing permissions and limitations under
 * the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text file for details on the
 * various modules and licenses. The "NOTICE" text file is part of the distribution. Any derivative
 * works that you distribute must include a readable copy of the "NOTICE" text file.
*/

package at.gv.egiz.eaaf.core.impl.idp.controller;

import java.io.IOException;

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

import org.apache.commons.text.StringEscapeUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;

import at.gv.egiz.eaaf.core.api.IRequest;
import at.gv.egiz.eaaf.core.api.IRequestStorage;
import at.gv.egiz.eaaf.core.api.IStatusMessenger;
import at.gv.egiz.eaaf.core.api.data.EaafConstants;
import at.gv.egiz.eaaf.core.api.idp.process.ProcessEngine;
import at.gv.egiz.eaaf.core.exceptions.EaafException;
import at.gv.egiz.eaaf.core.exceptions.EaafIllegalStateException;
import at.gv.egiz.eaaf.core.impl.utils.TransactionIdUtils;

/**
 * Servlet that resumes a suspended process (in case of asynchronous tasks).
 *
 * @author tknall
 *
 */
public abstract class AbstractProcessEngineSignalController extends AbstractController {
  private static final Logger log =
      LoggerFactory.getLogger(AbstractProcessEngineSignalController.class);

  @Autowired(required = true)
  protected ProcessEngine processEngine;
  @Autowired(required = true)
  protected IRequestStorage requestStorage;

  protected void signalProcessManagement(final HttpServletRequest req,
      final HttpServletResponse resp) throws IOException, EaafException {
    final String pendingRequestID = StringEscapeUtils.escapeHtml4(getPendingRequestId(req));
    IRequest pendingReq = null;
    try {
      if (pendingRequestID == null) {
        throw new EaafException(IStatusMessenger.CODES_INTERNAL_ERROR_AUTH_NOPENDIGREQID, null);

      }

      pendingReq = requestStorage.getPendingRequest(pendingRequestID);
      if (pendingReq == null) {
        log.info("No PendingRequest with Id: " + pendingRequestID
            + " Maybe, a transaction timeout occure.");
        throw new EaafException(IStatusMessenger.CODES_INTERNAL_ERROR_AUTH_TIMEOUT,
            new Object[] { pendingRequestID });

      }

      // change pending-request ID
      requestStorage.changePendingRequestID(pendingReq);

      // process instance is mandatory
      if (pendingReq.getProcessInstanceId() == null) {
        throw new EaafIllegalStateException(
            new Object[] { "MOA session does not provide process instance id." });

      }

      // wake up next task
      processEngine.signal(pendingReq);

    } catch (final Exception ex) {
      handleError(null, ex, req, resp, pendingReq);

    } finally {
      // MOASessionDBUtils.closeSession();
      TransactionIdUtils.removeAllLoggingVariables();

    }

  }

  /**
   * Retrieves the current pending-request id from the HttpServletRequest
   * parameter
   *
   * <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(final HttpServletRequest request) {
    return StringEscapeUtils
        .escapeHtml4(request.getParameter(EaafConstants.PARAM_HTTP_TARGET_PENDINGREQUESTID));

  }

}