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

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

import java.io.*;
import java.lang.annotation.*;
import org.apache.juneau.annotation.*;
import org.apache.juneau.http.annotation.*;

/**
 * Annotation applied to Java methods on REST proxy interface classes.
 *
 * <p>
 * Note that this annotation is optional if you do not need to override any of the values.
 *
 * <h5 class='section'>See Also:</h5><ul>
 *    <li class='link'><a class="doclink" href="../../../../../index.html#jrc.Proxies">REST Proxies</a>
 * </ul>
 */
@Documented
@Target(METHOD)
@Retention(RUNTIME)
@Inherited
@AnnotationGroup(RemoteOp.class)
public @interface RemoteOp {

   /**
    * REST service path.
    *
    * <p>
    * If you do not specify a path, then the path is inferred from the Java method name.
    *
    * <h5 class='figure'>Example:</h5>
    * <p class='bjava'>
    *    <ja>@RemotePost</ja>
    *    <jk>public void</jk> postPet(...);
    * </p>
    *
    * <p>
    * Note that you can also use {@link #value()} to specify the method name and path in shortened form.
    *
    * <ul class='values'>
    *    <li>An absolute URL.
    *    <li>A relative URL interpreted as relative to the root URL defined on the <c>RestClient</c> and/or {@link Remote#path()}.
    *    <li>No path.
    * </ul>
    *
    * @return The annotation value.
    */
   String path() default "";

   /**
    * Defines the HTTP method to use for REST calls.
    *
    * <p>
    * If not specified, then the method is inferred from the Java method name.
    *
    * <h5 class='figure'>Example:</h5>
    * <p class='bjava'>
    *    <ja>@RemotePost</ja>
    *    <jk>public void</jk> postPet(...);
    * </p>
    *
    * <br>If the method cannot be inferred, then the default is <js>"GET"</js>.
    *
    * <p>
    * Note that you can also use {@link #value()} to specify the method name and path in shortened form.
    *
    * @return The annotation value.
    */
   String method() default "";

   /**
    * The value the remote method returns.
    *
    * <ul class='values'>
    *    <li>
    *       {@link RemoteReturn#BODY} (default) - The body of the HTTP response converted to a POJO.
    *       <br>The return type on the Java method can be any of the following:
    *       <ul class='spaced-list'>
    *          <li>
    *             <jk>void</jk> - Don't parse any response.  Note that the method will still throw an exception if an
    *             error HTTP status is returned.
    *          <li>
    *             Any parsable POJO - The body of the response will be converted to the POJO using the parser defined
    *             on the <c>RestClient</c>.
    *          <li>
    *             Any POJO annotated with the {@link Response @Response} annotation.
    *             This allows for response beans to be used which also allows for OpenAPI-based parsing and validation.
    *          <li>
    *             <c>HttpResponse</c> - Returns the raw <c>HttpResponse</c> returned by the inner
    *             <c>HttpClient</c>.
    *          <li>
    *             {@link Reader} - Returns access to the raw reader of the response.
    *          <li>
    *             {@link InputStream} - Returns access to the raw input stream of the response.
    *       </ul>
    *    <li>
    *       {@link RemoteReturn#STATUS} - The HTTP status code on the response.
    *       <br>The return type on the Java method can be any of the following:
    *       <ul>
    *          <li><jk>int</jk>/<c>Integer</c> - The HTTP response code.
    *          <li><jk>boolean</jk>/<c>Boolean</c> - <jk>true</jk> if the response code is <c>&lt;400</c>
    *       </ul>
    * </ul>
    *
    * @return The annotation value.
    */
   RemoteReturn returns() default RemoteReturn.BODY;

   /**
    * REST method name and path.
    *
    * <p>
    * Can be used to provide a shortened combined form for the {@link #method()} and {@link #path()} values.
    *
    * <p>
    * The following examples are considered equivalent.
    * <p class='bjava'>
    *    <jc>// Normal form</jc>
    *    <ja>@RemoteOp</ja>(method=<jsf>PUT</jsf>, path=<js>"/{propertyName}"</js>)
    *
    *    <jc>// Shortened form</jc>
    *    <ja>@RemoteOp</ja>(<js>"PUT /{propertyName}"</js>)
    * </p>
    *
    * <h5 class='section'>Notes:</h5><ul>
    *    <li class='note'>
    *       The path portion is optional.
    * </ul>
    *
    * @return The annotation value.
    */
   String value() default "";
}