/*
 * Licensed 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.google.devtools.j2objc.jdt;

import java.lang.annotation.Annotation;
import java.util.Collections;
import java.util.List;

import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.type.NullType;
import javax.lang.model.type.TypeKind;
import javax.lang.model.type.TypeVisitor;
import org.eclipse.jdt.core.dom.IBinding;
import org.eclipse.jdt.core.dom.ITypeBinding;

class JdtNullType extends JdtTypeMirror implements NullType {

  JdtNullType() {
    super(NullTypeBinding.getInstance());
  }

  @Override
  public TypeKind getKind() {
    return TypeKind.NULL;
  }

  @Override
  public <R, P> R accept(TypeVisitor<R, P> v, P p) {
    return v.visitNull(this, p);
  }

  @Override
  public List<? extends AnnotationMirror> getAnnotationMirrors() {
    return Collections.emptyList();
  }

  @Override
  public <A extends Annotation> A getAnnotation(Class<A> annotationType) {
    return null;
  }

  @Override
  @SuppressWarnings("unchecked")
  public <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType) {
    return (A[]) new Annotation[0];
  }

  static class NullTypeBinding extends AbstractTypeBinding {

    private static final NullTypeBinding INSTANCE = new NullTypeBinding();

    public static NullTypeBinding getInstance() {
      return INSTANCE;
    }

    @Override
    public boolean isNullType() {
      return true;
    }

    @Override
    public String getName() {
      return "null";
    }

    @Override
    public String getQualifiedName() {
      return getName();
    }

    @Override
    public String getKey() {
      return "N";
    }

    @Override
    public boolean isAssignmentCompatible(ITypeBinding variableType) {
      return !variableType.isPrimitive();
    }

    @Override
    public boolean isEqualTo(IBinding binding) {
      return binding instanceof ITypeBinding && ((ITypeBinding) binding).isNullType();
    }
  }

}