/*
 * 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.juneau.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
import static org.apache.juneau.internal.ArrayUtils.*;

import java.lang.annotation.*;

import org.apache.juneau.*;
import org.apache.juneau.reflect.*;
import org.apache.juneau.svl.*;

/**
 * Utility classes and methods for the {@link Marshalled @Marshalled} annotation.
 *
 * <h5 class='section'>See Also:</h5><ul>
 * </ul>
 */
public class MarshalledAnnotation {

   //-----------------------------------------------------------------------------------------------------------------
   // Static
   //-----------------------------------------------------------------------------------------------------------------

   /** Default value */
   public static final Marshalled DEFAULT = create().build();

   /**
    * Instantiates a new builder for this class.
    *
    * @return A new builder object.
    */
   public static Builder create() {
      return new Builder();
   }

   /**
    * Instantiates a new builder for this class.
    *
    * @param on The targets this annotation applies to.
    * @return A new builder object.
    */
   public static Builder create(Class<?>...on) {
      return create().on(on);
   }

   /**
    * Instantiates a new builder for this class.
    *
    * @param on The targets this annotation applies to.
    * @return A new builder object.
    */
   public static Builder create(String...on) {
      return create().on(on);
   }

   /**
    * Creates a copy of the specified annotation.
    *
    * @param a The annotation to copy.s
    * @param r The var resolver for resolving any variables.
    * @return A copy of the specified annotation.
    */
   public static Marshalled copy(Marshalled a, VarResolverSession r) {
      return
         create()
         .example(r.resolve(a.example()))
         .implClass(a.implClass())
         .on(r.resolve(a.on()))
         .onClass(a.onClass())
         .build();
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Builder
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Builder class.
    *
    * <h5 class='section'>See Also:</h5><ul>
    *    <li class='jm'>{@link org.apache.juneau.BeanContext.Builder#annotations(Annotation...)}
    * </ul>
    */
   public static class Builder extends TargetedAnnotationTBuilder<Builder> {

      Class<?> implClass=void.class;
      String example="";

      /**
       * Constructor.
       */
      protected Builder() {
         super(Marshalled.class);
      }

      /**
       * Instantiates a new {@link Marshalled @Marshalled} object initialized with this builder.
       *
       * @return A new {@link Marshalled @Marshalled} object.
       */
      public Marshalled build() {
         return new Impl(this);
      }

      /**
       * Sets the {@link Marshalled#example()} property on this annotation.
       *
       * @param value The new value for this property.
       * @return This object.
       */
      public Builder example(String value) {
         this.example = value;
         return this;
      }

      /**
       * Sets the {@link Marshalled#implClass()} property on this annotation.
       *
       * @param value The new value for this property.
       * @return This object.
       */
      public Builder implClass(Class<?> value) {
         this.implClass = value;
         return this;
      }

   }

   //-----------------------------------------------------------------------------------------------------------------
   // Implementation
   //-----------------------------------------------------------------------------------------------------------------

   private static class Impl extends TargetedAnnotationTImpl implements Marshalled {

      private final Class<?> implClass;
      private final String example;

      Impl(Builder b) {
         super(b);
         this.example = b.example;
         this.implClass = b.implClass;
         postConstruct();
      }

      @Override /* Marshalled */
      public String example() {
         return example;
      }

      @Override /* Marshalled */
      public Class<?> implClass() {
         return implClass;
      }
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Appliers
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * Applies targeted {@link Marshalled} annotations to a {@link org.apache.juneau.BeanContext.Builder}.
    */
   public static class Applier extends AnnotationApplier<Marshalled,BeanContext.Builder> {

      /**
       * Constructor.
       *
       * @param vr The resolver for resolving values in annotations.
       */
      public Applier(VarResolverSession vr) {
         super(Marshalled.class, BeanContext.Builder.class, vr);
      }

      @Override
      public void apply(AnnotationInfo<Marshalled> ai, BeanContext.Builder b) {
         Marshalled a = ai.inner();
         if (isEmptyArray(a.on(), a.onClass()))
            return;
         b.annotations(copy(a, vr()));
      }
   }

   //-----------------------------------------------------------------------------------------------------------------
   // Other
   //-----------------------------------------------------------------------------------------------------------------

   /**
    * A collection of {@link Marshalled @Marshalled annotations}.
    */
   @Documented
   @Target({METHOD,TYPE})
   @Retention(RUNTIME)
   @Inherited
   public static @interface Array {

      /**
       * The child annotations.
       *
       * @return The annotation value.
       */
      Marshalled[] value();
   }
}