/*
    * 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.cli;
  
  import java.lang.reflect.InvocationTargetException;
  import java.util.Collection;
  import java.util.Map;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  import org.mycore.common.MCRException;
  import org.mycore.datamodel.common.MCRActiveLinkException;
  
  /**
   * Shows details about an exception that occured during command processing
   * 
   * @author Frank L\u00FCtzenkirchen
   */
  public class MCRCLIExceptionHandler {
  
      private static final Logger LOGGER = LogManager.getLogger(MCRCLIExceptionHandler.class);
  
      public static void handleException(InvocationTargetException ex) {
          handleException(ex.getTargetException());
      }
  
      public static void handleException(ExceptionInInitializerError ex) {
          handleException(ex.getCause());
      }
  
      public static void handleException(MCRActiveLinkException ex) {
          showActiveLinks(ex);
          showException(ex);
      }
  
      private static void showActiveLinks(MCRActiveLinkException activeLinks) {
          MCRCommandLineInterface
              .output("There are links active preventing the commit of work, see error message for details.");
          MCRCommandLineInterface.output("The following links where affected:");
  
          Map<String, Collection<String>> links = activeLinks.getActiveLinks();
  
          for (String curDest : links.keySet()) {
              LOGGER.debug("Current Destination: {}", curDest);
              Collection<String> sources = links.get(curDest);
              for (String source : sources) {
                  MCRCommandLineInterface.output(source + " ==> " + curDest);
              }
          }
      }
  
      public static void handleException(Throwable ex) {
          showException(ex);
      }
  
      private static void showException(Throwable ex) {
          MCRCommandLineInterface.output("");
          MCRCommandLineInterface.output("Exception occured: " + ex.getClass().getName());
          MCRCommandLineInterface.output("Exception message: " + ex.getLocalizedMessage());
          MCRCommandLineInterface.output("");
          showStackTrace(ex);
          showCauseOf(ex);
      }
  
      private static void showStackTrace(Throwable ex) {
          String trace = MCRException.getStackTraceAsString(ex);
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug(trace);
          } else {
              MCRCommandLineInterface.output(trace);
          }
      }
  
      private static void showCauseOf(Throwable ex) {
          ex = ex.getCause();
          if (ex == null) {
              return;
          }
  
          MCRCommandLineInterface.output("");
          MCRCommandLineInterface.output("This exception was caused by:");
          handleException(ex);
      }
 }