content: package act.controller.captcha;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2018 ActFramework
   * %%
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  
  import static org.osgl.http.H.Format.JPG;
  import static org.osgl.http.H.Header.Names.CACHE_CONTROL;
  
  import act.app.event.SysEventId;
  import act.controller.Controller;
  import act.controller.annotation.UrlContext;
  import act.controller.captcha.render.CaptchaImageRender;
  import act.crypto.AppCrypto;
  import act.handler.NonBlock;
  import act.util.JsonView;
  import act.util.SubClassFinder;
  import org.osgl.Lang;
  import org.osgl.http.H;
  import org.osgl.mvc.annotation.GetAction;
  import org.osgl.mvc.result.Result;
  import org.osgl.util.Img;
  import org.osgl.util.Output;
  
  import javax.inject.Inject;
  
  @UrlContext("captcha")
  public class CaptchaService extends Controller.Util {
  
      @Inject
      private AppCrypto crypto;
  
      @Inject
      private CaptchaManager pluginManager;
  
      @SubClassFinder(callOn = SysEventId.POST_START)
      public void foundSessionGenerator(CaptchaSessionGenerator generator) {
          pluginManager.registerGenerator(generator);
      }
  
      @SubClassFinder(callOn = SysEventId.POST_START)
      public void foundImageRender(CaptchaImageRender render) {
          pluginManager.registerImageGenerator(render);
      }
  
      @GetAction()
      @NonBlock
      @JsonView
      public CaptchaSession randomSession(H.Response resp) {
          resp.addHeader(CACHE_CONTROL, "no-store");
          return pluginManager.randomGenerator().generate();
      }
  
      @GetAction("{encrypted}")
      public Result renderMedia(String encrypted) {
          try {
              final String text = crypto.decrypt(encrypted);
              return renderBinary(new Lang.Visitor<Output>() {
                  @Override
                  public void visit(Output output) throws Lang.Break {
                      CaptchaImageRender imageRender = pluginManager.randomImageRender();
                      Img.source(imageRender.render(text)).writeTo(Output.Adaptors.asOutputStream(output), JPG.contentType());
                  }
              }).contentType(JPG);
          } catch (Exception e) {
              throw notFound();
          }
      }
  
  }
  