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 com.datastax.oss.driver.internal.mapper.processor.util;
  
  import com.datastax.oss.driver.api.core.data.GettableByName;
  import com.datastax.oss.driver.api.core.data.SettableByName;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.CompletableFuture;
  import java.util.concurrent.CompletionStage;
  import javax.lang.model.element.Element;
  import javax.lang.model.element.TypeElement;
  import javax.lang.model.type.DeclaredType;
  import javax.lang.model.type.TypeMirror;
  import javax.lang.model.util.Elements;
  import javax.lang.model.util.Types;
  
  /**
   * Utility methods to work with existing classes in the context of an annotation processing round.
   *
   * <p>Similar to {@link Types} and {@link Elements}, but for classes that are known at compile time,
   * e.g. they belong to the JDK or one of the processor's dependencies.
   */
  public class Classes {
  
    private final Types typeUtils;
    private final Elements elementUtils;
  
    private final TypeMirror settableByNameType;
    private final TypeMirror gettableByNameType;
    private final TypeElement listElement;
    private final TypeElement setElement;
    private final TypeElement mapElement;
    private final TypeElement completionStageElement;
    private final TypeElement completableFutureElement;
  
    public Classes(Types typeUtils, Elements elementUtils) {
      this.typeUtils = typeUtils;
      this.elementUtils = elementUtils;
  
      this.settableByNameType =
          typeUtils.erasure(elementUtils.getTypeElement(SettableByName.class.getName()).asType());
      this.gettableByNameType =
          typeUtils.erasure(elementUtils.getTypeElement(GettableByName.class.getName()).asType());
      this.listElement = elementUtils.getTypeElement(List.class.getCanonicalName());
      this.setElement = elementUtils.getTypeElement(Set.class.getCanonicalName());
      this.mapElement = elementUtils.getTypeElement(Map.class.getCanonicalName());
      this.completionStageElement =
          elementUtils.getTypeElement(CompletionStage.class.getCanonicalName());
      this.completableFutureElement =
          elementUtils.getTypeElement(CompletableFuture.class.getCanonicalName());
    }
  
    /** Whether an element is the {@link TypeElement} for the given class. */
    public boolean isSame(Element element, Class<?> javaClass) {
      return element.equals(elementUtils.getTypeElement(javaClass.getName()));
    }
  
    /**
     * Whether a type mirror is the {@link DeclaredType} for the given class.
     *
     * <p>Note that this only intended for non-parameterized classes, e.g. {@code String}. If the type
     * mirror is {@code List<String>}, it won't match {@code List.class}.
     */
    public boolean isSame(TypeMirror mirror, Class<?> javaClass) {
      return typeUtils.isSameType(mirror, elementUtils.getTypeElement(javaClass.getName()).asType());
    }
  
    public boolean implementsSettableByName(TypeMirror mirror) {
      return typeUtils.isAssignable(mirror, settableByNameType);
    }
  
    public boolean implementsGettableByName(TypeMirror mirror) {
      return typeUtils.isAssignable(mirror, gettableByNameType);
    }
  
    /** Whether a type mirror is a parameterized {@code java.util.List}. */
    public boolean isList(DeclaredType declaredType) {
      return declaredType.asElement().equals(listElement);
    }
  
    /** Whether a type mirror is a parameterized {@code java.util.Set}. */
    public boolean isSet(DeclaredType declaredType) {
      return declaredType.asElement().equals(setElement);
    }
  
    /** Whether a type mirror is a parameterized {@code java.util.Map}. */
    public boolean isMap(DeclaredType declaredType) {
      return declaredType.asElement().equals(mapElement);
    }
  
    /**
     * Whether a type mirror is a parameterized Java 8 future ({@code CompletionStage or
     * CompletableFuture}.
     */
    public boolean isFuture(DeclaredType declaredType) {
      return declaredType.asElement().equals(completionStageElement)
          || declaredType.asElement().equals(completableFutureElement);
    }
  }
  