/*
    * Copyright (C) 2012 The Guava Authors
    *
    * 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.common.reflect;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.AccessibleObject;
  import java.lang.reflect.Constructor;
  import java.lang.reflect.Field;
  import java.lang.reflect.Member;
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  
  import javax.annotation.Nullable;
  
  /**
   * Represents either a {@link Field}, a {@link Method} or a {@link Constructor}.
   * Provides convenience methods such as {@link #isPublic} and {@link #isPackagePrivate}.
   * 
   * @author Ben Yu
   */
  class Element extends AccessibleObject implements Member {
  
    private final AccessibleObject accessibleObject;
    private final Member member;
  
    <M extends AccessibleObject & Member> Element(M member) {
      checkNotNull(member);
      this.accessibleObject = member;
      this.member = member;
    }
  
    public TypeToken<?> getOwnerType() {
      return TypeToken.of(getDeclaringClass());
    }
  
    @Override public final boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
      return accessibleObject.isAnnotationPresent(annotationClass);
    }
  
    @Override public final <A extends Annotation> A getAnnotation(Class<A> annotationClass) {
      return accessibleObject.getAnnotation(annotationClass);
    }
  
    @Override public final Annotation[] getAnnotations() {
      return accessibleObject.getAnnotations();
    }
  
    @Override public final Annotation[] getDeclaredAnnotations() {
      return accessibleObject.getDeclaredAnnotations();
    }
  
    @Override public final void setAccessible(boolean flag) throws SecurityException {
      accessibleObject.setAccessible(flag);
    }
  
    @Override public final boolean isAccessible() {
      return accessibleObject.isAccessible();
    }
  
    @Override public Class<?> getDeclaringClass() {
      return member.getDeclaringClass();
    }
  
    @Override public final String getName() {
      return member.getName();
    }
  
    @Override public final int getModifiers() {
      return member.getModifiers();
    }
  
    @Override public final boolean isSynthetic() {
      return member.isSynthetic();
    }
  
    /** Returns true if the element is public. */
    public final boolean isPublic() {
      return Modifier.isPublic(getModifiers());
    }
  
    /** Returns true if the element is protected. */
    public final boolean isProtected() {
      return Modifier.isProtected(getModifiers());
   }
 
   /** Returns true if the element is package-private. */
   public final boolean isPackagePrivate() {
     return !isPrivate() && !isPublic() && !isProtected();
   }
 
   /** Returns true if the element is private. */
   public final boolean isPrivate() {
     return Modifier.isPrivate(getModifiers());
   }
 
   /** Returns true if the element is static. */
   public final boolean isStatic() {
     return Modifier.isStatic(getModifiers());
   }
 
   /**
    * Returns {@code true} if this method is final, per {@code Modifier.isFinal(getModifiers())}.
    * 
    * <p>Note that a method may still be effectively "final", or non-overridable when it has no
    * {@code final} keyword. For example, it could be private, or it could be declared by a final
    * class. To tell whether a method is overridable, use {@link Invokable#isOverridable}.
    */
   public final boolean isFinal() {
     return Modifier.isFinal(getModifiers());
   }
 
   /** Returns true if the method is abstract. */
   public final boolean isAbstract() {
     return Modifier.isAbstract(getModifiers());
   }
 
   /** Returns true if the element is native. */
   public final boolean isNative() {
     return Modifier.isNative(getModifiers());
   }
 
   /** Returns true if the method is synchronized. */
   public final boolean isSynchronized() {
     return Modifier.isSynchronized(getModifiers());
   }
 
   /** Returns true if the field is volatile. */
   final boolean isVolatile() {
     return Modifier.isVolatile(getModifiers());
   }
 
   /** Returns true if the field is transient. */
   final boolean isTransient() {
     return Modifier.isTransient(getModifiers());
   }
 
   @Override public boolean equals(@Nullable Object obj) {
     if (obj instanceof Element) {
       Element that = (Element) obj;
       return getOwnerType().equals(that.getOwnerType()) && member.equals(that.member);
     }
     return false;
   }
 
   @Override public int hashCode() {
     return member.hashCode();
   }
 
   @Override public String toString() {
     return member.toString();
   }
 }