/*
 * 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.uon.annotation;

import static java.lang.annotation.ElementType.*;
import static java.lang.annotation.RetentionPolicy.*;
import static org.apache.juneau.commons.utils.CollectionUtils.*;

import java.lang.annotation.*;
import java.lang.reflect.*;

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

/**
 * Utility classes and methods for the {@link Uon @Uon} annotation.
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/UonBasics">UON Basics</a>
 * </ul>
 */
public class UonAnnotation {
   /**
    * Applies targeted {@link Uon} annotations to a {@link org.apache.juneau.Context.Builder}.
    */
   public static class Apply extends AnnotationApplier<Uon,Context.Builder> {

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

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

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

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

   /**
    * 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 AppliedAnnotationObject.BuilderTMF {

      private String[] description = {};

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

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

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

      @Override /* Overridden from AppliedAnnotationObject.Builder */
      public Builder on(String...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderT */
      public Builder on(Class<?>...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedOnClassAnnotationObject.Builder */
      public Builder onClass(Class<?>...value) {
         super.onClass(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderM */
      public Builder on(Method...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderMF */
      public Builder on(Field...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderT */
      public Builder on(ClassInfo...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderT */
      public Builder onClass(ClassInfo...value) {
         super.onClass(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderTMF */
      public Builder on(FieldInfo...value) {
         super.on(value);
         return this;
      }

      @Override /* Overridden from AppliedAnnotationObject.BuilderTMF */
      public Builder on(MethodInfo...value) {
         super.on(value);
         return this;
      }

   }

   private static class Object extends AppliedOnClassAnnotationObject implements Uon {

      private final String[] description;

      Object(UonAnnotation.Builder b) {
         super(b);
         this.description = copyOf(b.description);
      }

      @Override /* Overridden from annotation */
      public String[] description() {
         return description;
      }
   }

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

   /**
    * 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 Uon copy(Uon a, VarResolverSession r) {
      return create().on(r.resolve(a.on())).onClass(a.onClass()).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);
   }
}