/*
    * The contents of this file are subject to the terms of the Common Development and
    * Distribution License (the License). You may not use this file except in compliance with the
    * License.
    *
    * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
    * specific language governing permission and limitations under the License.
    *
    * When distributing Covered Software, include this CDDL Header Notice in each file and include
   * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
   * Header, with the fields enclosed by brackets [] replaced by your own identifying
   * information: "Portions copyright [year] [name of copyright owner]".
   *
   * Copyright 2016 ForgeRock AS.
   */
  
  package org.forgerock.json.resource;
  
  import org.forgerock.api.annotations.Create;
  import org.forgerock.api.annotations.Delete;
  import org.forgerock.api.annotations.Patch;
  import org.forgerock.api.annotations.Query;
  import org.forgerock.api.annotations.Read;
  import org.forgerock.api.annotations.RequestHandler;
  import org.forgerock.api.annotations.Update;
  import org.forgerock.api.models.ApiDescription;
  import org.forgerock.http.ApiProducer;
  import org.forgerock.services.context.Context;
  import org.forgerock.services.descriptor.Describable;
  import org.forgerock.util.promise.Promise;
  
  /**
   * Exposes an annotated POJO as an instance {@link org.forgerock.json.resource.RequestHandler} by looking for annotated
   * and/or conventionally-named methods (as per {@link RequestHandler}).
   * {@see org.forgeock.json.resource.annotations}
   */
  class AnnotatedRequestHandler implements org.forgerock.json.resource.RequestHandler,
          Describable<ApiDescription, Request> {
  
      private final AnnotatedMethod createMethod;
      private final AnnotatedMethod readMethod;
      private final AnnotatedMethod updateMethod;
      private final AnnotatedMethod deleteMethod;
      private final AnnotatedMethod patchMethod;
      private final AnnotatedMethod queryMethod;
      private final AnnotatedActionMethods actionMethods;
      private final Describable<ApiDescription, Request> describable;
  
      AnnotatedRequestHandler(Object requestHandler) {
          if (!requestHandler.getClass().isAnnotationPresent(RequestHandler.class)) {
              throw new IllegalArgumentException("RequestHandler missing from class: "
                      + requestHandler.getClass().getName());
          }
          this.createMethod = AnnotatedMethod.findMethod(requestHandler, Create.class, false);
          this.readMethod = AnnotatedMethod.findMethod(requestHandler, Read.class, false);
          this.updateMethod = AnnotatedMethod.findMethod(requestHandler, Update.class, false);
          this.deleteMethod = AnnotatedMethod.findMethod(requestHandler, Delete.class, false);
          this.patchMethod = AnnotatedMethod.findMethod(requestHandler, Patch.class, false);
          this.queryMethod = AnnotatedMethod.findMethod(requestHandler, Query.class, false);
          this.actionMethods = AnnotatedActionMethods.findAll(requestHandler, false);
          this.describable = requestHandler instanceof Describable
                  ? (Describable<ApiDescription, Request>) requestHandler
                  : null;
      }
  
      @Override
      public Promise<ResourceResponse, ResourceException> handleRead(Context context, ReadRequest request) {
          return readMethod.invoke(context, request);
      }
  
      @Override
      public Promise<ResourceResponse, ResourceException> handleUpdate(Context context, UpdateRequest request) {
          return updateMethod.invoke(context, request);
      }
  
      @Override
      public Promise<ResourceResponse, ResourceException> handlePatch(Context context, PatchRequest request) {
          return patchMethod.invoke(context, request);
      }
  
      @Override
      public Promise<QueryResponse, ResourceException> handleQuery(Context context, QueryRequest request,
              QueryResourceHandler handler) {
          return queryMethod.invoke(context, request, handler);
      }
  
      @Override
      public Promise<ActionResponse, ResourceException> handleAction(Context context, ActionRequest request) {
          return actionMethods.invoke(context, request);
      }
  
      @Override
      public Promise<ResourceResponse, ResourceException> handleCreate(Context context, CreateRequest request) {
          return createMethod.invoke(context, request);
      }
  
      @Override
      public Promise<ResourceResponse, ResourceException> handleDelete(Context context, DeleteRequest request) {
          return deleteMethod.invoke(context, request);
     }
 
     @Override
     public ApiDescription api(ApiProducer<ApiDescription> producer) {
         if (describable == null) {
             throw new UnsupportedOperationException(
                     "The provided request handler does not support API Descriptor methods");
         }
         return describable.api(producer);
     }
 
     @Override
     public ApiDescription handleApiRequest(Context context, Request request) {
         if (describable == null) {
             throw new UnsupportedOperationException(
                     "The provided request handler does not support API Descriptor methods");
         }
         return describable.handleApiRequest(context, request);
     }
 
     @Override
     public void addDescriptorListener(Listener listener) {
         if (describable != null) {
             describable.addDescriptorListener(listener);
         }
     }
 
     @Override
     public void removeDescriptorListener(Listener listener) {
         if (describable != null) {
             describable.removeDescriptorListener(listener);
         }
     }
 }