/*
 * 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.http.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.annotation.*;
import org.apache.juneau.httppart.*;
import org.apache.juneau.reflect.*;
import org.apache.juneau.svl.*;

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

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

   /** Default value */
   public static final Response 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);
   }

   /**
    * Returns <jk>true</jk> if the specified annotation contains all default values.
    *
    * @param a The annotation to check.
    * @return <jk>true</jk> if the specified annotation contains all default values.
    */
   public static boolean empty(Response a) {
      return a == null || DEFAULT.equals(a);
   }

   //-----------------------------------------------------------------------------------------------------------------
   // 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 TargetedAnnotationTMBuilder<Builder> {

      Class<? extends HttpPartParser> parser = HttpPartParser.Void.class;
      Class<? extends HttpPartSerializer> serializer = HttpPartSerializer.Void.class;
      Header[] headers={};
      Schema schema = SchemaAnnotation.DEFAULT;
      String[] examples={};

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

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

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

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

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

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

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

   }

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

   private static class Impl extends TargetedAnnotationTImpl implements Response {

      private final Class<? extends HttpPartParser> parser;
      private final Class<? extends HttpPartSerializer> serializer;
      private final Header[] headers;
      private final Schema schema;
      private final String[] examples;

      Impl(Builder b) {
         super(b);
         this.examples = copyOf(b.examples);
         this.headers = copyOf(b.headers);
         this.parser = b.parser;
         this.schema = b.schema;
         this.serializer = b.serializer;
         postConstruct();
      }

      @Override /* Response */
      public String[] examples() {
         return examples;
      }

      @Override /* Response */
      public Header[] headers() {
         return headers;
      }

      @Override /* Response */
      public Class<? extends HttpPartParser> parser() {
         return parser;
      }

      @Override /* Response */
      public Schema schema() {
         return schema;
      }

      @Override /* Response */
      public Class<? extends HttpPartSerializer> serializer() {
         return serializer;
      }
   }

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

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

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

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

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

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

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