content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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.apache.causeway.viewer.wicket.ui.errors;
  
  import java.util.List;
  import java.util.Optional;
  
  import org.apache.causeway.applib.exceptions.UnrecoverableException;
  import org.apache.causeway.applib.services.error.ErrorReportingService;
  import org.apache.causeway.applib.services.error.Ticket;
  import org.apache.causeway.applib.services.exceprecog.Recognition;
  import org.apache.causeway.commons.internal.base._Casts;
  import org.apache.causeway.commons.internal.collections._Lists;
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  import org.apache.causeway.core.metamodel.context.MetaModelContext;
  import org.apache.causeway.core.metamodel.spec.feature.ObjectMember;
  import org.apache.causeway.viewer.wicket.model.models.ModelAbstract;
  
  public class ExceptionModel extends ModelAbstract<List<StackTraceDetail>> {
  
      private static final long serialVersionUID = 1L;
  
      private static final String MAIN_MESSAGE_IF_NOT_RECOGNIZED = "Sorry, an unexpected error occurred.";
  
      private List<StackTraceDetail> stackTraceDetailList;
      private List<List<StackTraceDetail>> stackTraceDetailLists;
      private boolean recognized;
      private boolean authorizationCause;
  
      private final String mainMessage;
  
      public static ExceptionModel create(
              final MetaModelContext commonContext,
              final Optional<Recognition> recognition,
              final Exception ex) {
  
          var translationService = commonContext.getTranslationService();
          var recognizedMessage = recognition.map($->$.toMessage(translationService));
  
          return new ExceptionModel(commonContext, recognizedMessage.orElse(null), ex);
      }
  
      /**
       * Three cases: authorization exception, else recognized, else or not recognized.
       */
      private ExceptionModel(
              final MetaModelContext commonContext, final String recognizedMessageIfAny, final Exception ex) {
  
          super();
  
          final ObjectMember.AuthorizationException authorizationException =
                  causalChainOf(ex, ObjectMember.AuthorizationException.class);
  
          if(authorizationException != null) {
              this.authorizationCause = true;
              this.mainMessage = authorizationException.getMessage();
          } else {
              this.authorizationCause = false;
              if(recognizedMessageIfAny != null) {
                  this.recognized = true;
                  this.mainMessage = recognizedMessageIfAny;
              } else {
                  this.recognized =false;
  
                  // see if we can find a NonRecoverableException in the stack trace
  
                  UnrecoverableException nonRecoverableException =
                  _Exceptions.streamCausalChain(ex)
                  .filter(UnrecoverableException.class::isInstance)
                  .map(UnrecoverableException.class::cast)
                  .findFirst()
                  .orElse(null);
  
                  this.mainMessage = nonRecoverableException != null
                          ? nonRecoverableException.getMessage()
                                  : MAIN_MESSAGE_IF_NOT_RECOGNIZED;
              }
          }
          stackTraceDetailList = asStackTrace(ex);
          stackTraceDetailLists = asStackTraces(ex);
      }
  
      @Override
      protected List<StackTraceDetail> load() {
          return stackTraceDetailList;
      }
  
      private static <T extends Exception> T causalChainOf(final Exception ex, final Class<T> exType) {
  
          final List<Throwable> causalChain = _Exceptions.getCausalChain(ex);
          for (Throwable cause : causalChain) {
              if(exType.isAssignableFrom(cause.getClass())) {
                  return _Casts.uncheckedCast(cause);
              }
          }
          return null;
      }
  
      @Override
      public void setObject(final List<StackTraceDetail> stackTraceDetail) {
          if(stackTraceDetail == null) {
              return;
          }
          this.stackTraceDetailList = stackTraceDetail;
      }
  
      private Ticket ticket;
      public Optional<Ticket> getTicket() {
          return Optional.ofNullable(ticket);
      }
  
      /**
       * Optionally called if an {@link ErrorReportingService} has been configured and returns a <tt>non-null</tt> ticket
       * to represent the fact that the error has been recorded.
       */
      public void setTicket(final Ticket ticket) {
          this.ticket = ticket;
      }
  
      public boolean isRecognized() {
          return recognized;
      }
  
      public String getMainMessage() {
          return mainMessage;
      }
  
      /**
       * Whether this was an authorization exception (so UI can suppress information, eg stack trace).
       */
      public boolean isAuthorizationException() {
          return authorizationCause;
      }
  
      public List<StackTraceDetail> getStackTrace() {
          return stackTraceDetailList;
      }
      public List<List<StackTraceDetail>> getStackTraces() {
          return stackTraceDetailLists;
      }
  
      private static List<StackTraceDetail> asStackTrace(final Throwable ex) {
          List<StackTraceDetail> stackTrace = _Lists.newArrayList();
          List<Throwable> causalChain = _Exceptions.getCausalChain(ex);
          boolean firstTime = true;
          for(Throwable cause: causalChain) {
              if(!firstTime) {
                  stackTrace.add(StackTraceDetail.spacer());
                  stackTrace.add(StackTraceDetail.causedBy());
                  stackTrace.add(StackTraceDetail.spacer());
              } else {
                  firstTime = false;
              }
              append(cause, stackTrace);
          }
          return stackTrace;
      }
  
      private static List<List<StackTraceDetail>> asStackTraces(final Throwable ex) {
          List<List<StackTraceDetail>> stackTraces = _Lists.newArrayList();
  
          List<Throwable> causalChain = _Exceptions.getCausalChain(ex);
          for(Throwable cause: causalChain) {
              List<StackTraceDetail> stackTrace = _Lists.newArrayList();
              append(cause, stackTrace);
              stackTraces.add(stackTrace);
          }
          return stackTraces;
      }
  
      private static void append(final Throwable cause, final List<StackTraceDetail> stackTrace) {
          stackTrace.add(StackTraceDetail.exceptionClassName(cause));
          stackTrace.add(StackTraceDetail.exceptionMessage(cause));
          for (StackTraceElement el : cause.getStackTrace()) {
              stackTrace.add(StackTraceDetail.element(el));
          }
      }
  
  }
  