content: /*
   * Copyright 2016-2020 Andres Almiray
   *
   * This file is part of Java Trove Examples
   *
   * Java Trove Examples is free software: you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation, either version 3 of the License, or
   * (at your option) any later version.
   *
   * Java Trove Examples is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with Java Trove Examples. If not, see <http://www.gnu.org/licenses/>.
   */
  package org.kordamp.javatrove.todo02.servlet;
  
  import com.fasterxml.jackson.databind.ObjectMapper;
  import com.github.mustachejava.DefaultMustacheFactory;
  import com.github.mustachejava.Mustache;
  import com.github.mustachejava.MustacheFactory;
  import org.kordamp.javatrove.todo02.routes.Route;
  
  import javax.inject.Inject;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  
  /**
   * @author Andres Almiray
   */
  public abstract class AbstractRoute implements Route {
      @Inject private ObjectMapper objectMapper;
  
      @Override
      public void handle(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
          ModelAndView modelAndView = doHandle(req, resp);
          resp.setStatus(200);
          if (shouldReturnHtml(req)) {
              resp.setContentType("text/html");
              MustacheFactory mf = new DefaultMustacheFactory("templates");
              Mustache mustache = mf.api(modelAndView.getViewName());
              mustache.execute(resp.getWriter(), modelAndView.getModel()).flush();
          } else {
              resp.setContentType("application/json");
              resp.getWriter().write(objectMapper.writeValueAsString(modelAndView.getModel()));
          }
      }
  
      protected abstract ModelAndView doHandle(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException;
  
      private boolean shouldReturnHtml(HttpServletRequest request) {
          String accept = request.getHeader("Accept");
          return accept != null && accept.contains("text/html");
      }
  }
  