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// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
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package org.apache.juneau.jsonschema.annotation;

import static java.lang.annotation.RetentionPolicy.*;

import java.lang.annotation.*;

import org.apache.juneau.oapi.*;

/**
 * Swagger items annotation.
 *
 * <p>
 * A limited subset of JSON-Schema's items object.
 *
 * <p>
 * Used to populate the auto-generated Swagger documentation and UI for server-side <ja>@Rest</ja>-annotated classes.
 * <br>Also used to define OpenAPI schema information for POJOs serialized through {@link OpenApiSerializer} and parsed through {@link OpenApiParser}.
 *
 * <h5 class='section'>Examples:</h5>
 * <p class='bcode w800'>
 * 	<jc>// Items have a specific set of enumerated string values</jc>
 * 	<ja>@Query</ja>(
 * 		name=<js>"status"</js>,
 * 		type=<js>"array"</js>,
 * 		collectionFormat=<js>"csv"</js>,
 * 		items=<ja>@Items</ja>(
 * 			type=<js>"string"</js>,
 * 			_enum=<js>"AVAILABLE,PENDING,SOLD"</js>,
 * 			_default=<js>"AVAILABLE"</js>
 *		)
 * 	)
 * </p>
 * <p class='bcode w800'>
 * 	<jc>// Same but defined free-form</jc>
 * 	<ja>@Query</ja>(
 * 		name=<js>"status"</js>,
 * 		type=<js>"array"</js>,
 * 		collectionFormat=<js>"csv"</js>,
 * 		items=<ja>@Items</ja>({
 * 			<js>"type:'string',"</js>,
 * 			<js>"enum:'AVAILABLE,PENDING,SOLD',"</js>,
 * 			<js>"default:'AVAILABLE'"</js>
 *		})
 * 	)
 * </p>
 * <p class='bcode w800'>
 * 	<jc>// An array of arrays, the internal array being of type integer, numbers must be between 0 and 63 (inclusive)</jc>
 * 	<ja>@Query</ja>(
 * 		name=<js>"status"</js>,
 * 		type=<js>"array"</js>,
 * 		collectionFormat=<js>"csv"</js>,
 * 		items=<ja>@Items</ja>(
 * 			type=<js>"array"</js>,
 * 			items=<ja>@SubItems</ja>(
 * 				type=<js>"integer"</js>,
 * 				minimum=<js>"0"</js>,
 * 				maximum=<js>"63"</js>
 * 			)
 *		)
 * 	)
 * </p>
 *
 * <ul class='seealso'>
 * 	<li class='link'>{@doc juneau-rest-server.Swagger}
 * 	<li class='extlink'>{@doc SwaggerItemsObject}
 * </ul>
 */
@Documented
@Retention(RUNTIME)
public @interface Items {

	/**
	 * <mk>type</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String type() default "";

	/**
	 * <mk>format</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String format() default "";

	/**
	 * <mk>collectionFormat</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String collectionFormat() default "";

	/**
	 * <mk>pattern</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String pattern() default "";

	/**
	 * <mk>maximum</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String maximum() default "";

	/**
	 * <mk>minimum</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String minimum() default "";

	/**
	 * <mk>multipleOf</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String multipleOf() default "";

	/**
	 * <mk>maxLength</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	long maxLength() default -1;

	/**
	 * <mk>minLength</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	long minLength() default -1;

	/**
	 * <mk>maxItems</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	long maxItems() default -1;

	/**
	 * <mk>minItems</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	long minItems() default -1;

	/**
	 * <mk>exclusiveMaximum</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	boolean exclusiveMaximum() default false;

	/**
	 * <mk>exclusiveMinimum</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	boolean exclusiveMinimum() default false;

	/**
	 * <mk>uniqueItems</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	boolean uniqueItems() default false;

	/**
	 * <mk>default</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String[] _default() default {};

	/**
	 * <mk>enum</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String[] _enum() default {};

	/**
	 * <mk>$ref</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		The format is a plain-text string.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$L{my.localized.variable}"</js>).
	 * </ul>
	 */
	String $ref() default "";

	/**
	 * <mk>items</mk> field of the {@doc SwaggerItemsObject}.
	 *
	 * <p>
	 * Describes the type of items in the array.
	 */
	SubItems items() default @SubItems;

	/**
	 * Free-form value for the {@doc SwaggerItemsObject}.
	 *
	 * <p>
	 * This is a {@doc SimpleJson} object that makes up the swagger information for this field.
	 *
	 * <p>
	 * The following are completely equivalent ways of defining the swagger description of an Items object:
	 * <p class='bcode w800'>
	 * 	<jc>// Normal</jc>
	 * 	<ja>@Query</ja>(
	 * 		name=<js>"status"</js>,
	 * 		type=<js>"array"</js>,
	 * 		items=<ja>@Items</ja>(
	 * 			type=<js>"string"</js>,
	 * 			_enum=<js>"AVAILABLE,PENDING,SOLD"</js>,
	 * 			_default=<js>"AVAILABLE"</js>
	 * 		)
	 * 	)
	 * </p>
	 * <p class='bcode w800'>
	 * 	<jc>// Free-form</jc>
	 * 	<ja>@Query</ja>(
	 * 		name=<js>"status"</js>,
	 * 		type=<js>"array"</js>,
	 * 		items=<ja>@Items</ja>({
	 * 			<js>"type: 'string'"</js>,
	 * 			<js>"enum: ['AVAILABLE','PENDING','SOLD'],"</js>,
	 * 			<js>"default: 'AVAILABLE'"</js>
	 * 		})
	 * 	)
	 * </p>
	 * <p class='bcode w800'>
	 * 	<jc>// Free-form as part of parent</jc>
	 * 	<ja>@Query</ja>(
	 * 		name=<js>"status"</js>,
	 * 		api={
	 * 			<js>"type:'array',"</js>,
	 * 			<js>"items: {"</js>,
	 * 				<js>"type: 'string',"</js>,
	 * 				<js>"enum: ['AVAILABLE','PENDING','SOLD'],"</js>,
	 * 				<js>"default: 'AVAILABLE'"</js>,
	 * 			<js>"}"</js>)
	 * 		}
	 * 	)
	 * </p>
	 * <p class='bcode w800'>
	 * 	<jc>// Free-form with variables</jc>
	 * 	<ja>@Query</ja>(
	 * 		name=<js>"status"</js>,
	 * 		type=<js>"array"</js>,
	 * 		items=<ja>@Items</ja>(<js>"$L{statusItemsSwagger}"</js>)
	 * 	)
	 * </p>
	 * <p class='bcode w800'>
	 * 	<mc>// Contents of MyResource.properties</mc>
	 * 	<mk>statusItemsSwagger</mk> = <mv>{ type: "string", enum: ["AVAILABLE","PENDING","SOLD"], default: "AVAILABLE" }</mv>
	 * </p>
	 *
	 * <p>
	 * 	The reasons why you may want to use this field include:
	 * <ul>
	 * 	<li>You want to pull in the entire Swagger JSON definition for this field from an external source such as a properties file.
	 * 	<li>You want to add extra fields to the Swagger documentation that are not officially part of the Swagger specification.
	 * </ul>
	 *
	 * <ul class='notes'>
	 * 	<li>
	 * 		Note that the only swagger field you can't specify using this value is <js>"name"</js> whose value needs to be known during servlet initialization.
	 * 	<li>
	 * 		The format is a {@doc SimpleJson} object.
	 * 	<li>
	 * 		The leading/trailing <c>{ }</c> characters are optional.
	 * 		<br>The following two example are considered equivalent:
	 * 		<p class='bcode w800'>
	 * 	<ja>@Items</ja>(api=<js>"{type: 'string'}"</js>)
	 * 		</p>
	 * 		<p class='bcode w800'>
	 * 	<ja>@Items</ja>(api=<js>"type: 'string'"</js>)
	 * 		</p>
	 * 	<li>
	 * 		Multiple lines are concatenated with newlines so that you can format the value to be readable.
	 * 	<li>
	 * 		Supports {@doc DefaultRestSvlVariables}
	 * 		(e.g. <js>"$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 {};
}