/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.frontend.servlets;
  
  import static org.mycore.access.MCRAccessManager.PERMISSION_WRITE;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.jdom2.Attribute;
  import org.jdom2.Document;
  import org.jdom2.Element;
  import org.mycore.access.MCRAccessManager;
  import org.mycore.datamodel.metadata.MCRDerivate;
  import org.mycore.datamodel.metadata.MCRMetadataManager;
  import org.mycore.datamodel.metadata.MCRObjectID;
  import org.mycore.frontend.MCRFrontendUtil;
  
  import jakarta.servlet.http.HttpServletResponse;
  
  /**
   * @author shermann
   */
  public class MCRDisplayHideDerivateServlet extends MCRServlet {
      private static final long serialVersionUID = 1L;
  
      private static final Logger LOGGER = LogManager.getLogger(MCRDisplayHideDerivateServlet.class);
  
      @Override
      protected void doGetPost(MCRServletJob job) throws Exception {
          String derivate = job.getRequest().getParameter("derivate");
  
          if (derivate == null || (!derivate.contains("_derivate_"))) {
              LOGGER.error("Cannot toogle display attribute. No derivate id provided.");
              job.getResponse().sendError(HttpServletResponse.SC_BAD_REQUEST, "You must provide a proper derivate id");
              return;
          }
  
          if (!MCRAccessManager.checkPermission(MCRObjectID.getInstance(derivate), PERMISSION_WRITE)) {
              job.getResponse().sendError(HttpServletResponse.SC_FORBIDDEN, "You have to be logged in.");
              return;
          }
  
          LOGGER.info("Toggling display attribute of {}", derivate);
          MCRDerivate obj = MCRMetadataManager.retrieveMCRDerivate(MCRObjectID.getInstance(derivate));
          toggleDisplay(obj);
  
          String url = MCRFrontendUtil.getBaseURL() + "receive/" + getParentHref(obj);
          job.getResponse().sendRedirect(job.getResponse().encodeRedirectURL(url));
      }
  
      private String getParentHref(MCRDerivate obj) {
          return obj.getDerivate().getMetaLink().getXLinkHref();
      }
  
      /**
       * Toggles the display attribute value of the derivate element.
       */
      private void toggleDisplay(MCRDerivate derObj) throws Exception {
          Document xml = derObj.createXML();
          Element derivateNode = xml.getRootElement().getChild("derivate");
  
          Attribute displayAttr = derivateNode.getAttribute("display");
  
          if (displayAttr == null) {
              /* the attributs is not existing, user wants to hide derivate */
              displayAttr = new Attribute("display", "false");
              derivateNode.setAttribute(displayAttr);
          } else {
              /* attribute exists, thus toggle the attribute value */
              String oldVal = displayAttr.getValue();
              String newVal = oldVal.equals(String.valueOf(true)) ? String.valueOf(false) : String.valueOf(true);
              displayAttr.setValue(newVal);
              LOGGER.info("Setting display attribute of derivate with id {} to {}", derObj.getId(), newVal);
          }
          MCRDerivate updated = new MCRDerivate(xml);
          MCRMetadataManager.update(updated);
      }
  }