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package org.apache.juneau.rest;

import java.lang.reflect.Method;

import org.apache.juneau.dto.swagger.*;
import org.apache.juneau.rest.annotation.*;

/**
 * REST resource information provider.
 *
 * <p>
 * Provides localized Swagger documentation and other related information about a REST resource.
 *
 * <ul class='seealso'>
 *    <li class='jf'>{@link RestContext#REST_infoProvider}
 *    <li class='link'>{@doc juneau-rest-server.Swagger}
 * </ul>
 */
public interface RestInfoProvider {

   /**
    * Represents no RestInfoProvider.
    *
    * <p>
    * Used on annotation to indicate that the value should be inherited from the parent class, and
    * ultimately {@link BasicRestInfoProvider} if not specified at any level.
    */
   public interface Null extends RestInfoProvider {}

   /**
    * Returns the localized swagger for the REST resource.
    *
    * <p>
    * This object is made available through the following:
    * <ul class='javatree'>
    *    <li class='jm'>{@link RestRequest#getSwagger()}
    * </ul>
    *
    * @param req The incoming HTTP request.
    * @return
    *    A new {@link Swagger} instance.
    *    <br>Never <jk>null</jk>.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public Swagger getSwagger(RestRequest req) throws Exception;

   /**
    * Returns the localized site name of the REST resource.
    *
    * <p>
    * This object is made available through the following:
    * <ul>
    *    <li class='jm'>{@link RestRequest#getSiteName()}
    *    <li><c>$RI{siteName}</c> variable.
    *    <li><c>$R{siteName}</c> variable.
    * </ul>
    *
    * @param req The current request.
    * @return The localized site name of the REST resource, or <jk>null</jk> if none was found.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public String getSiteName(RestRequest req) throws Exception;

   /**
    * Returns the localized title of the REST resource.
    *
    * <p>
    * This object is made available through the following:
    * <ul>
    *    <li class='jm'>{@link RestRequest#getResourceTitle()}
    *    <li><c>$RI{title}</c> variable.
    *    <li><c>$R{resourceTitle}</c> variable.
    * </ul>
    *
    * @param req The current request.
    * @return The localized title of the REST resource, or <jk>null</jk> if none was found.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public String getTitle(RestRequest req) throws Exception;

   /**
    * Returns the localized description of the REST resource.
    *
    * <p>
    * This object is made available through the following:
    * <ul>
    *    <li class='jm'>{@link RestRequest#getResourceDescription()}
    *    <li><c>$RI{description}</c> variable.
    *    <li><c>$R{resourceDescription}</c> variable.
    * </ul>
    *
    * @param req The current request.
    * @return The localized description of the REST resource, or <jk>null</jk> if none was found.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public String getDescription(RestRequest req) throws Exception;

   /**
    * Returns the localized summary of the specified java method.
    *
    * <p>
    * This object is made available through the following:
    * <ul>
    *    <li class='jm'>{@link RestRequest#getMethodSummary()}
    *    <li><c>$RI{methodSummary}</c> variable.
    *    <li><c>$R{methodSummary}</c> variable.
    * </ul>
    *
    * @param method The Java method annotated with {@link RestMethod @RestMethod}.
    * @param req The current request.
    * @return The localized summary of the method, or <jk>null</jk> if none was found.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public String getMethodSummary(Method method, RestRequest req) throws Exception;

   /**
    * Returns the localized description of the specified java method on this servlet.
    *
    * <p>
    * This object is made available through the following:
    * <ul>
    *    <li class='jm'>{@link RestRequest#getMethodDescription()}
    *    <li><c>$RI{methodDescription}</c> variable.
    *    <li><c>$R{methodDescription}</c> variable.
    * </ul>
    *
    * @param method The Java method annotated with {@link RestMethod @RestMethod}.
    * @param req The current request.
    * @return The localized description of the method, or <jk>null</jk> if none was was found.
    * @throws Exception
    *    Throw a {@link RestException} with a specific HTTP error status or any other exception
    *    to cause a <jsf>SC_INTERNAL_SERVER_ERROR</jsf>.
    */
   public String getMethodDescription(Method method, RestRequest req) throws Exception;
}