content: package act.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 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 act.app.ActionContext;
  import org.osgl.http.H;
  import org.osgl.util.E;
  import org.osgl.util.S;
  
  /**
   * Map the {@link org.osgl.http.H.Session} and {@link org.osgl.http.H.Cookie} to/from
   * {@link org.osgl.http.H.Response}/{@link org.osgl.http.H.Request}
   */
  public interface SessionMapper {
  
      void serializeSession(H.Cookie sessionCookie, ActionContext context);
  
      void serializeFlash(H.Cookie flashCookie, ActionContext context);
  
      String deserializeSession(ActionContext context);
  
      String deserializeFlash(ActionContext context);
  
      /**
       * The default session mapper, do the mapping by adding/reading cookie information
       * directly to response/request
       */
      class DefaultSessionMapper implements SessionMapper {
  
          public static SessionMapper INSTANCE = new DefaultSessionMapper();
  
          @Override
          public void serializeSession(H.Cookie sessionCookie, ActionContext context) {
              context.resp().addCookie(sessionCookie);
          }
  
          @Override
          public void serializeFlash(H.Cookie flashCookie, ActionContext context) {
              context.resp().addCookie(flashCookie);
          }
  
          @Override
          public String deserializeSession(ActionContext context) {
              H.Cookie sessionCookie = context.req().cookie(context.config().sessionCookieName());
              return null == sessionCookie ? null : sessionCookie.value();
          }
  
          @Override
          public String deserializeFlash(ActionContext context) {
              H.Cookie flashCookie = context.req().cookie(context.config().flashCookieName());
              return null == flashCookie ? null : flashCookie.value();
          }
  
          public static  SessionMapper wrap(final SessionMapper theMapper) {
              if (null == theMapper) {
                  return INSTANCE;
              }
              if (DefaultSessionMapper.class.equals(theMapper.getClass())) {
                  return theMapper;
              }
              return new SessionMapper() {
                  @Override
                  public void serializeSession(H.Cookie sessionCookie, ActionContext context) {
                      theMapper.serializeSession(sessionCookie, context);
                      INSTANCE.serializeSession(sessionCookie, context);
                  }
  
                  @Override
                  public void serializeFlash(H.Cookie flashCookie, ActionContext context) {
                      theMapper.serializeFlash(flashCookie, context);
                      INSTANCE.serializeFlash(flashCookie, context);
                  }
  
                  @Override
                  public String deserializeSession(ActionContext context) {
                      String s = theMapper.deserializeSession(context);
                      return S.blank(s) ? INSTANCE.deserializeSession(context) : s;
                  }
  
                  @Override
                  public String deserializeFlash(ActionContext context) {
                      String s = theMapper.deserializeFlash(context);
                      return S.blank(s) ? INSTANCE.deserializeFlash(context) : s;
                  }
              };
          }
      }
  
      /**
       * The header session mapper do mapping through write/read the header of response/request
       */
      class HeaderSessionMapper implements SessionMapper {
  
          public static final String DEF_HEADER_PREFIX = "X-Act-";
  
          private String headerPrefix;
  
          public HeaderSessionMapper(String headerPrefix) {
              E.illegalArgumentIf(S.blank(headerPrefix));
              this.headerPrefix = headerPrefix;
          }
  
          public HeaderSessionMapper() {
              this(DEF_HEADER_PREFIX);
          }
  
          @Override
          public void serializeSession(H.Cookie sessionCookie, ActionContext context) {
              context.resp().header(sessionHeaderName(), sessionCookie.value());
          }
  
          @Override
          public void serializeFlash(H.Cookie flashCookie, ActionContext context) {
              context.resp().header(flashHeaderName(), flashCookie.value());
          }
  
          @Override
          public String deserializeSession(ActionContext context) {
              return context.req().header(sessionHeaderName());
          }
  
          @Override
          public String deserializeFlash(ActionContext context) {
              return context.req().header(flashHeaderName());
          }
  
          private String sessionHeaderName() {
              return headerPrefix + "Session";
          }
  
          private String flashHeaderName() {
              return headerPrefix + "Flash";
          }
      }
  
  }
  