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.persistence.querydsl.metamodel.facets;
  
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Optional;
  import java.util.function.BiConsumer;
  import java.util.function.Function;
  import java.util.stream.Collectors;
  
  import org.apache.causeway.applib.annotation.DomainObject;
  import org.apache.causeway.applib.annotation.Property;
  import org.apache.causeway.commons.collections.Can;
  import org.apache.causeway.core.metamodel.consent.InteractionInitiatedBy;
  import org.apache.causeway.core.metamodel.facetapi.FacetAbstract;
  import org.apache.causeway.core.metamodel.facetapi.FacetHolder;
  import org.apache.causeway.core.metamodel.facets.object.autocomplete.AutoCompleteFacet;
  import org.apache.causeway.core.metamodel.object.ManagedObject;
  import org.apache.causeway.core.metamodel.object.MmVisibilityUtils;
  import org.apache.causeway.core.metamodel.object.PackedManagedObject;
  import org.apache.causeway.persistence.querydsl.applib.services.support.QueryDslSupport;
  
  import org.jspecify.annotations.Nullable;
  
  import com.querydsl.core.types.Predicate;
  import com.querydsl.core.types.dsl.PathBuilder;
  
  public class AutoCompleteUsingQueryDslFacet extends FacetAbstract implements AutoCompleteFacet {
  
      private final Class<?> entity;
  
      private final Optional<Object> additionalPredicateRepositoryIfAny;
      private final Optional<Method> autoCompletePredicateMethodIfAny;
      private final Optional<Integer> limitResultsIfAny;
      private final Optional<Integer> minLengthIfAny;
  
      private final List<AutoCompleteGeneratedDslQuery.SearchableProperty> searchableProperties = new ArrayList<>();
  
      private final QueryDslSupport queryDslSupport;
      private final Optional<AutoCompleteFacet> previousAutoCompleteFacetIfAny;
  
      /**
       * Remains empty until properties are added using {@link #addSearchableProperty(String, Property.QueryDslAutoCompletePolicy)}.
       */
      private Optional<AutoCompleteGeneratedDslQuery> autoCompleteGeneratedDslQueryIfAny;
  
      public AutoCompleteUsingQueryDslFacet(
              final Class<?> entity,
              final FacetHolder facetHolder,
              final @Nullable Object additionalPredicateRepository,
              final @Nullable Method additionalPredicateMethod,
              final @Nullable Integer limit,
              final @Nullable Integer minLength,
              final QueryDslSupport queryDslSupport
      ) {
          super(AutoCompleteFacet.class, facetHolder);
  
          this.entity = entity;
          this.additionalPredicateRepositoryIfAny = Optional.ofNullable(additionalPredicateRepository);
          this.autoCompletePredicateMethodIfAny = Optional.ofNullable(additionalPredicateMethod);
          this.limitResultsIfAny = Optional.ofNullable(limit);
          this.minLengthIfAny = Optional.ofNullable(minLength);
          this.queryDslSupport = queryDslSupport;
  
          // in case no searchable properties are provided, we keep track of any previous implementation, to delegate to if required
          this.previousAutoCompleteFacetIfAny = Optional.ofNullable(facetHolder.getFacet(AutoCompleteFacet.class));
  
          // this remains empty until at least one searchableProperty is added.
          autoCompleteGeneratedDslQueryIfAny = Optional.empty();
      }
  
      @Override
      public Can<ManagedObject> execute(
              final String search,
              final InteractionInitiatedBy interactionInitiatedBy
      ){
  
          if (autoCompleteGeneratedDslQueryIfAny.isEmpty()) {
              return previousAutoCompleteFacetIfAny
                      .map(previousFacet -> previousFacet.execute(search, interactionInitiatedBy))
                      .orElse(Can.empty());
          }
  
          List<?> results = autoComplete(search);
          if(!results.isEmpty()){
              // Transform results to list managed objects, then filter out any that are not visible (eg due to ApplicationTenancyEvaluator)
              return ((PackedManagedObject) getObjectManager().adapt(results)).unpack()
                      .filter(MmVisibilityUtils.filterOn(interactionInitiatedBy));
          }
          return Can.empty();
      }
  
      public <T> List<T> autoComplete(
              final String search
      ) {
          return autoComplete(search,null);
      }
  
      public <T> List<T> autoComplete(
              final String search,
              final Function<PathBuilder<T>, Predicate> additionalExpression
      ){
          return autoCompleteGeneratedDslQueryIfAny
                  .map(query -> query.autoComplete(search, additionalExpression))
                  .orElse(Collections.emptyList());
      }
  
      public <T> List<T> executeQuery(
              final String search
      ) {
          return executeQuery(search,null);
      }
  
      public <T> List<T> executeQuery(
              final String search,
              final Function<PathBuilder<T>, Predicate> additionalExpression
      ){
          return autoCompleteGeneratedDslQueryIfAny
                  .map(query -> query.executeQuery(search, additionalExpression))
                  .orElse(Collections.emptyList());
      }
  
      @Override
      public int getMinLength() {
          return minLengthIfAny.orElse(DomainObject.QueryDslAutoCompleteConstants.MIN_LENGTH);
      }
  
      public int getLimitResults() {
          return limitResultsIfAny.orElse(DomainObject.QueryDslAutoCompleteConstants.LIMIT_RESULTS);
      }
  
      @Override
      public void visitAttributes(final BiConsumer<String, Object> visitor) {
          super.visitAttributes(visitor);
          visitor.accept("entity", entity.getName());
          visitor.accept("searchableProperties", searchableProperties
                  .stream()
                  .map(AutoCompleteGeneratedDslQuery.SearchableProperty::toString)
                  .collect(Collectors.joining(",")));
          visitor.accept("minLength", getMinLength());
          visitor.accept("limitResults", getLimitResults());
      }
  
      public void addSearchableProperty(
              final String propertyId,
              final Property.QueryDslAutoCompletePolicy queryDslAutoCompletePolicy
      ) {
          searchableProperties.add(new AutoCompleteGeneratedDslQuery.SearchableProperty(propertyId, queryDslAutoCompletePolicy));
  
          // replace the dsl query
          this.autoCompleteGeneratedDslQueryIfAny =
                  Optional.of(
                      AutoCompleteGeneratedDslQuery
                      .builder()
                      .queryDslSupport(queryDslSupport)
                      .entity(entity)
                      .searchableProperties(searchableProperties)
                      .repository(additionalPredicateRepositoryIfAny.orElse(null))
                      .predicateMethod(autoCompletePredicateMethodIfAny.orElse(null))
                      .limitResults(limitResultsIfAny.orElse(DomainObject.QueryDslAutoCompleteConstants.LIMIT_RESULTS))
                      .minLength(minLengthIfAny.orElse(DomainObject.QueryDslAutoCompleteConstants.MIN_LENGTH))
                      .build()
                  );
      }
  }
  