/*
 * 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 java.lang.annotation.*;

import org.apache.juneau.annotation.*;
import org.apache.juneau.httppart.*;
import org.apache.juneau.oapi.*;

/**
 * REST response annotation.
 *
 * <p>
 * Identifies an interface to use to interact with HTTP parts of an HTTP response through a bean.
 *
 * <p>
 * Can be used in the following locations:
 *  <ul>
 *    <li>Exception classes thrown from server-side <ja>@RestOp</ja>-annotated methods.
 *    <li>Return type classes of server-side <ja>@RestOp</ja>-annotated methods.
 *    <li>Arguments and argument-types of server-side <ja>@RestOp</ja>-annotated methods.
 *    <li>Return type classes of server-side <ja>@RemoteOp</ja>-annotated methods.
 *    <li>Client-side <ja>@RemoteOp</ja>-annotated methods.
 *    <li>Return type interfaces of client-side <ja>@RemoteOp</ja>-annotated methods.
 * </ul>
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/Response">@Response</a>
 *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanSwagger2">juneau-bean-swagger-v2</a>
 *    <li class='extlink'><a class="doclink" href="https://swagger.io/specification/v2#responseObject">Swagger Response Object</a>
 * </ul>
 */
@Documented
@Target({PARAMETER,TYPE,METHOD})
@Retention(RUNTIME)
@Inherited
@Repeatable(ResponseAnnotation.Array.class)
@ContextApply(ResponseAnnotation.Applier.class)
public @interface Response {

    /**
     * Optional description for the exposed API.
     *
     * @return The annotation value.
     * @since 9.2.0
     */
    String[] description() default {};

   /**
    * Serialized examples of the body of a response.
    *
    * <p>
    * This is a <a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanSwagger2">juneau-bean-swagger-v2</a> object whose keys are media types and values are string representations of that value.
    *
    * <p class='bjava'>
    *    <jc>// A JSON representation of a PetCreate object.</jc>
    *    <ja>@Response</ja>(
    *       examples={
    *          <js>"'application/json':'{name:\\'Doggie\\',species:\\'Dog\\'}',"</js>,
    *          <js>"'text/uon':'(name:Doggie,species=Dog)'"</js>
    *       }
    *    )
    * </p>
    *
    * <h5 class='section'>Used for:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       Server-side generated Swagger documentation.
    * </ul>
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>
    *       The format is a <a class="doclink" href="https://juneau.apache.org/docs/topics/JuneauBeanSwagger2">juneau-bean-swagger-v2</a> object with string keys (media type) and string values (example for that media type) .
    *    <li class='note'>
    *       The leading/trailing <c>{ }</c> characters are optional.
    *    <li class='note'>
    *       Multiple lines are concatenated with newlines so that you can format the value to be readable:
    *    <li class='note'>
    *       Supports <a class="doclink" href="https://juneau.apache.org/docs/topics/RestServerSvlVariables">SVL Variables</a> (e.g. <js>"$L{my.localized.variable}"</js>) for the swagger generator.
    *    <li class='note'>
    *       Resolution of variables is delayed until request time and occurs before parsing.
    *       <br>This allows you to, for example, pull in a JSON construct from a properties file based on the locale of the HTTP request.
    * </ul>
    *
    * @return The annotation value.
    */
   String[] examples() default {};

   /**
    * <mk>headers</mk> field of the <a class="doclink" href="https://swagger.io/specification/v2#responseObject">Swagger Response Object</a>.
    *
    * <h5 class='section'>Used for:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       Server-side generated Swagger documentation.
    * </ul>
    *
    * @return The annotation value.
    */
   Header[] headers() default {};

   /**
    * Dynamically apply this annotation to the specified classes.
    *
    * <h5 class='section'>See Also:</h5><ul>
    *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
    * </ul>
    *
    * @return The annotation value.
    */
   String[] on() default {};

   /**
    * Dynamically apply this annotation to the specified classes.
    *
    * <p>
    * Identical to {@link #on()} except allows you to specify class objects instead of a strings.
    *
    * <h5 class='section'>See Also:</h5><ul>
    *    <li class='link'><a class="doclink" href="https://juneau.apache.org/docs/topics/DynamicallyAppliedAnnotations">Dynamically Applied Annotations</a>
    * </ul>
    *
    * @return The annotation value.
    */
   Class<?>[] onClass() default {};

   /**
    * Specifies the {@link HttpPartParser} class used for parsing strings to values.
    *
    * <p>
    * Overrides for this part the part parser defined on the REST resource which by default is {@link OpenApiParser}.
    *
    * @return The annotation value.
    */
   Class<? extends HttpPartParser> parser() default HttpPartParser.Void.class;

   /**
    * <mk>schema</mk> field of the <a class="doclink" href="https://swagger.io/specification/v2#responseObject">Swagger Response Object</a>.
    *
    * <h5 class='section'>Used for:</h5>
    * <ul class='spaced-list'>
    *    <li>
    *       Server-side schema-based serializing and serializing validation.
    *    <li>
    *       Server-side generated Swagger documentation.
    * </ul>
    *
    * @return The annotation value.
    */
   Schema schema() default @Schema;

   /**
    * Specifies the {@link HttpPartSerializer} class used for serializing values to strings.
    *
    * <p>
    * Overrides for this part the part serializer defined on the REST resource which by default is {@link OpenApiSerializer}.
    *
    * @return The annotation value.
    */
   Class<? extends HttpPartSerializer> serializer() default HttpPartSerializer.Void.class;
}