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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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package org.apache.juneau.http.annotation;

import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.*;

import org.apache.juneau.jsonschema.annotation.ExternalDocs;

/**
 * Swagger tag annotation.
 *
 * <p>
 * Allows adding meta data to a single tag that is used by the {@doc SwaggerOperationObject}.
 * It is not mandatory to have a Tag Object per tag used there.
 *
 * <p>
 * Used to populate the auto-generated Swagger documentation and UI for server-side <ja>@Rest</ja>-annotated classes.
 *
 * <h5 class='section'>Examples:</h5>
 * <p class='bcode w800'>
 *    <jc>// A response object thats a hex-encoded string</jc>
 *    <ja>@Rest</ja>(
 *       swagger={
 *          tags={
 *             <ja>@Tag</ja>(
 *                name=<js>"utility"</js>,
 *                description=<js>"Utility methods"</js>
 *             )
 *          }
 *       }
 *    )
 * </p>
 * <p class='bcode w800'>
 *    <jc>// Free-form</jc>
 *    <ja>@Rest</ja>(
 *       swagger={
 *          tags={
 *             <ja>@Tag</ja>({
 *                <js>"name:'utility',"</js>,
 *                <js>"description:'Utility methods'"</js>
 *             })
 *          }
 *       }
 *    )
 * </p>
 *
 * <ul class='seealso'>
 *    <li class='link'>{@doc juneau-rest-server.Swagger}
 *    <li class='extlink'>{@doc SwaggerTagObject}
 * </ul>
 */
@Documented
@Retention(RUNTIME)
public @interface Tag {

   /**
    * <mk>name</mk> field of the {@doc SwaggerTagObject}.
    *
    * <ul class='notes'>
    *    <li>
    *       The format is plain text.
    * </ul>
    */
   String name() default "";

   /**
    * <mk>description</mk> field of the {@doc SwaggerTagObject}.
    *
    * <ul class='notes'>
    *    <li>
    *       The format is a {@doc SimpleJson} object.
    *       <br>Multiple lines are concatenated with newlines.
    *    <li>
    *       Supports {@doc DefaultRestSvlVariables}
    *       (e.g. <js>"$L{my.localized.variable}"</js>).
    * </ul>
    */
   String[] description() default {};

   /**
    * <mk>externalDocs</mk> field of the {@doc SwaggerTagObject}.
    *
    * <ul class='notes'>
    *    <li>
    *       The format is a {@doc SimpleJson} object.
    *       <br>Multiple lines are concatenated with newlines.
    *    <li>
    *       Supports {@doc DefaultRestSvlVariables}
    *       (e.g. <js>"$L{my.localized.variable}"</js>).
    * </ul>
    */
   ExternalDocs externalDocs() default @ExternalDocs;

   /**
    * Free-form value for the {@doc SwaggerTagObject}.
    *
    * <p>
    * This is a {@doc SimpleJson} object that makes up the swagger information for this Tag object.
    *
    * <p>
    * The following are completely equivalent ways of defining the swagger description of the resource tags:
    * <p class='bcode w800'>
    *    <jc>// Normal</jc>
    *    <ja>@Rest</ja>(
    *       tags={
    *          <ja>@Tag</ja>(
    *             name=<js>"pet"</js>,
    *             description=<js>"Everything about your Pets"</js>,
    *             externalDocs=<ja>@ExternalDocs</ja>(
    *                description="<js>Find out more"</js>,
    *                url=<js>"http://juneau.apache.org"</js>
    *             }
    *          )
    *       }
    *    )
    * </p>
    * <p class='bcode w800'>
    *    <jc>// Free-form</jc>
    *    <ja>@Rest</ja>(
    *       tags={
    *          <ja>@Tag</ja>(
    *             name=<js>"pet"</js>,
    *             api={
    *                <js>"name: 'pet',"</js>,
    *                <js>"description: 'Everything about your Pets',"</js>,
    *                <js>"externalDocs: {"</js>,
    *                   <js>"description: 'Find out more',"</js>,
    *                   <js>"url: 'http://juneau.apache.org'"</js>
    *                <js>"}"</js>
    *             }
    *          )
    *       }
    *    )
    * </p>
    * <p class='bcode w800'>
    *    <jc>// Free-form with variables</jc>
    *    <ja>@Rest</ja>(
    *       tags={
    *          <ja>@Tag</ja>(
    *             name=<js>"pet"</js>,
    *             api=<js>"$L{petTagSwagger}"</js>
    *          )
    *       }
    *    )
    * </p>
    * <p class='bcode w800'>
    *    <mc>// Contents of MyResource.properties</mc>
    *    <mk>petTagSwagger</mk> = <mv>{ name: "pet", description: "Everything about your Pets", externalDocs: { description: "Find out more", url: "http://juneau.apache.org" } }</mv>
    * </p>
    *
    * <p>
    *    The reasons why you may want to use this field include:
    * <ul>
    *    <li>You want to pull in the entire Swagger JSON definition for this body from an external source such as a properties file.
    *    <li>You want to add extra fields to the Swagger documentation that are not officially part of the Swagger specification.
    * </ul>
    *
    * <ul class='notes'>
    *    <li>
    *       The format is a {@doc SimpleJson} object.
    *    <li>
    *       The leading/trailing <c>{ }</c> characters are optional.
    *       <br>The following two example are considered equivalent:
    *       <p class='bcode w800'>
    *    <ja>@Tag</ja>(api=<js>"{description: 'Everything about your Pets'}"</js>)
    *       </p>
    *       <p class='bcode w800'>
    *    <ja>@Tag</ja>(api=<js>"description: 'Everything about your Pets'"</js>)
    *       </p>
    *    <li>
    *       Multiple lines are concatenated with newlines so that you can format the value to be readable:
    *    <li>
    *       Supports {@doc DefaultRestSvlVariables}
    *       (e.g. <js>"$L{my.localized.variable}"</js>).
    *    <li>
    *       Values defined in this field supersede values pulled from the Swagger JSON file and are superseded by individual values defined on this annotation.
    * </ul>
    */
   String[] value() default {};
}