/*
    * #%L
    * wcm.io
    * %%
    * Copyright (C) 2014 wcm.io
    * %%
    * 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%
   */
  package io.wcm.handler.commons.servlets.impl;
  
  import java.io.IOException;
  
  import javax.servlet.RequestDispatcher;
  import javax.servlet.Servlet;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.sling.api.SlingHttpServletRequest;
  import org.apache.sling.api.SlingHttpServletResponse;
  import org.apache.sling.api.request.RequestPathInfo;
  import org.apache.sling.api.servlets.HttpConstants;
  import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
  import org.apache.sling.servlets.annotations.SlingServletResourceTypes;
  import org.jetbrains.annotations.NotNull;
  import org.osgi.service.component.annotations.Component;
  import org.osgi.service.component.annotations.ConfigurationPolicy;
  import org.osgi.service.metatype.annotations.AttributeDefinition;
  import org.osgi.service.metatype.annotations.Designate;
  import org.osgi.service.metatype.annotations.ObjectClassDefinition;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import com.day.cq.wcm.api.NameConstants;
  
  import io.wcm.wcm.commons.contenttype.FileExtension;
  
  /**
   * Virtually maps an *.htx request to a cq:Page resource to a *.html request internally (because components
   * and JSPs are normally only registered to *.html extension). Mapping can be enabled or disabled.
   */
  @Component(service = Servlet.class, configurationPolicy = ConfigurationPolicy.REQUIRE)
  @SlingServletResourceTypes(
      resourceTypes = NameConstants.NT_PAGE,
      methods = HttpConstants.METHOD_GET,
      extensions = FileExtension.HTML_UNCACHED
  )
  @Designate(ocd = HtxPageExtensionMapper.Config.class)
  public class HtxPageExtensionMapper extends SlingSafeMethodsServlet {
    private static final long serialVersionUID = 1L;
  
    @ObjectClassDefinition(name = "wcm.io htx Page Extension Mapper",
        description = "Mapps all *.htx requests on Pages to *.html view.")
    @interface Config {
  
      @AttributeDefinition(name = "Enabled", description = "Enable mapping.")
      boolean enabled() default false;
  
    }
  
    private static final Logger log = LoggerFactory.getLogger(HtxPageExtensionMapper.class);
  
    private boolean enabled;
  
    // ---------- SCR Integration ----------------------------------------------
  
    protected void activate(Config config) {
      // read config
      this.enabled = config.enabled();
    }
  
    @Override
    protected void doGet(@NotNull SlingHttpServletRequest request, @NotNull SlingHttpServletResponse response) throws ServletException, IOException {
  
      // if not enabled: sent http 404
      if (!enabled) {
        response.sendError(HttpServletResponse.SC_NOT_FOUND);
        return;
      }
  
      // rebuild requested url, but use "html" as extension instead of "htx"
      // to allow re-using all component definitions that are registered to "html"
      RequestPathInfo info = request.getRequestPathInfo();
      StringBuilder url = new StringBuilder();
      url.append(info.getResourcePath());
      if (info.getSelectorString() != null) {
        url.append('.').append(info.getSelectorString());
      }
      url.append('.').append(FileExtension.HTML); // use html extension instead of .htx extension
     if (info.getSuffix() != null) {
       url.append('/').append(info.getSuffix());
     }
 
     if (log.isDebugEnabled()) {
       log.debug("Dispatch request {} to {}", request.getRequestURI(), url);
     }
 
     // execute request with *.html extension
     RequestDispatcher requestDispatcher = request.getRequestDispatcher(url.toString());
     if (requestDispatcher != null) {
       requestDispatcher.include(request, response);
     }
     else {
       throw new ServletException("No Request Dispatcher.");
     }
 
   }
 
 }