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.extensions.secman.integration.permissions;
  
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Optional;
  
  import jakarta.inject.Inject;
  import jakarta.inject.Named;
  
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.springframework.stereotype.Service;
  
  import org.apache.causeway.applib.annotation.PriorityPrecedence;
  import org.apache.causeway.applib.services.appfeat.ApplicationFeatureId;
  import org.apache.causeway.commons.internal.assertions._Assert;
  import org.apache.causeway.commons.internal.base._NullSafe;
  import org.apache.causeway.commons.internal.collections._Lists;
  import org.apache.causeway.commons.internal.exceptions._Exceptions;
  import org.apache.causeway.core.config.CausewayConfiguration;
  import org.apache.causeway.core.config.CausewayConfiguration.Extensions.Secman;
  import org.apache.causeway.core.config.CausewayConfiguration.Extensions.Secman.PermissionsEvaluationPolicy;
  import org.apache.causeway.extensions.secman.applib.CausewayModuleExtSecmanApplib;
  import org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionMode;
  import org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionRule;
  import org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionValue;
  import org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionValueSet;
  import org.apache.causeway.extensions.secman.applib.permission.spi.PermissionsEvaluationService;
  
  import lombok.Builder;
  import org.jspecify.annotations.NonNull;
  
  /**
   * @since 2.0 {@index}
   */
  @Service
  @Named(CausewayModuleExtSecmanApplib.NAMESPACE + ".PermissionsEvaluationServiceForSecman")
  @jakarta.annotation.Priority(PriorityPrecedence.MIDPOINT)
  @Qualifier("Secman")
  public class PermissionsEvaluationServiceForSecman
  implements PermissionsEvaluationService {
  
      private static final long serialVersionUID = 1L;
  
      private final @NonNull PermissionsEvaluationPolicy policy; // serializable
  
      /**
       * for testing only
       *
       * @param policy
       * @param applicationFeatureIdTransformer
       */
      @Builder
      private PermissionsEvaluationServiceForSecman(
              final PermissionsEvaluationPolicy policy,
              final ApplicationFeatureIdTransformer applicationFeatureIdTransformer
      ) {
          this.policy = policy;
          this.applicationFeatureIdTransformer = applicationFeatureIdTransformer;
      }
  
      @Inject
      public PermissionsEvaluationServiceForSecman(final CausewayConfiguration causewayConfiguration) {
          this.policy = Optional.ofNullable(
                  causewayConfiguration.getExtensions().getSecman().getPermissionsEvaluationPolicy())
                  .orElseGet(()->new Secman().getPermissionsEvaluationPolicy()); // use config defaults as fallback
          _Assert.assertNotNull(policy);
      }
  
      @Override
      public ApplicationPermissionValueSet.Evaluation evaluate(
              final ApplicationFeatureId targetMemberIdInput,
              final ApplicationPermissionMode mode,
              final Collection<ApplicationPermissionValue> permissionValuesInput) {
  
          final ApplicationFeatureId targetMemberId = applicationFeatureIdTransformer.transform(targetMemberIdInput);
          final Collection<ApplicationPermissionValue> permissionValues = applicationFeatureIdTransformer.transform(permissionValuesInput);
  
          if(_NullSafe.isEmpty(permissionValues)) {
              return null;
          }
  
          final Collection<ApplicationPermissionValue> ordered = ordered(permissionValues);
  
          for (final ApplicationPermissionValue permissionValue : ordered) {
              if(permissionValue.implies(targetMemberId, mode)) {
                  return new ApplicationPermissionValueSet.Evaluation(permissionValue, true);
              } else if(permissionValue.refutes(targetMemberId, mode)) {
                  return new ApplicationPermissionValueSet.Evaluation(permissionValue, false);
              }
          }
          return null;
      }
  
      /**
       * @implSpec
       *     This implementation relies on the fact that the {@link org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionValue}s are
       * passed through in natural order, with the leading part based on the
       * {@link org.apache.causeway.extensions.secman.applib.permission.dom.ApplicationPermissionValue#getRule() rule} and with
       * {@link ApplicationPermissionRule} in turn comparable so that {@link ApplicationPermissionRule#ALLOW allow}
       * is ordered before {@link ApplicationPermissionRule#VETO veto}.
       */
      protected Collection<ApplicationPermissionValue> ordered(
              final Collection<ApplicationPermissionValue> permissionValues) {
          switch (policy) {
          case ALLOW_BEATS_VETO:
              return permissionValues;
          case VETO_BEATS_ALLOW:
              var reversed = _Lists.<ApplicationPermissionValue>newArrayList(permissionValues);
              Collections.reverse(reversed);
              return reversed;
          }
          throw _Exceptions.illegalArgument("PermissionsEvaluationPolicy '%s' not recognised", policy);
      }
  
      @Inject ApplicationFeatureIdTransformer applicationFeatureIdTransformer;
  
  }
  