/**
    * Copyright By Grandsoft Company Limited.  
    * 2014年4月25日 下午4:32:15
    */
   package gboat2.base.view.components;
   
   import gboat2.base.bridge.util.BundleUtil;
   import gboat2.base.view.GboatViewUtil;
   
  import java.io.Writer;
  import java.util.HashSet;
  import java.util.Set;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.struts2.JSPRuntime;
  import org.apache.struts2.ServletActionContext;
  import org.apache.struts2.StrutsConstants;
  import org.apache.struts2.components.Component;
  import org.apache.struts2.components.Include;
  import org.apache.struts2.views.annotations.StrutsTag;
  import org.apache.struts2.views.annotations.StrutsTagAttribute;
  import org.osgi.framework.Bundle;
  
  import com.opensymphony.xwork2.ActionContext;
  import com.opensymphony.xwork2.ActionInvocation;
  import com.opensymphony.xwork2.inject.Inject;
  import com.opensymphony.xwork2.util.ValueStack;
  import com.opensymphony.xwork2.util.logging.Logger;
  import com.opensymphony.xwork2.util.logging.LoggerFactory;
  
  /**
   * JSP 页面标签，设置页面级全局参数
   * @author <a href="mailto:[email protected]">何明旺</a>
   * @since 3.0
   * @date 2014年4月25日
   */
  @StrutsTag(
          name="page",
          tldTagClass="gboat2.base.view.jsp.PageTag",
          description="JSP 页面标签，处理页面继承和设置页面全局参数")
  public class Page extends Component{
      
      private static final Logger LOG = LoggerFactory.getLogger(Page.class);
      
      protected HttpServletRequest request;
      protected HttpServletResponse response;
      protected Set<String> requestAttrNames = new HashSet<String>();
  
      protected String extend;
      protected String encoding;
      protected String readonly;
      
      public Page(ValueStack stack, HttpServletRequest request, HttpServletResponse response) {
          super(stack);
          this.request = request;
          this.response = response;
      }
  
      protected void evaluateParams() {
          request.setAttribute("contextPath", request.getContextPath());
          addParameterWithRequest("readonly", readonly, Boolean.class, GboatViewUtil.PAGE_READONLY_KEY);
          if (extend != null) {
              addParameter("extend", findString(extend));
          }
      }
  
      protected void addParameterWithRequest(String fieldName, String expr, Class<?> valueType, String attrName) {
          Object obj = request.getAttribute(attrName); // 从 request 中获取
          
          if (obj == null && expr != null) {
              obj = findValue(expr, valueType);
              request.setAttribute(attrName, obj);
              requestAttrNames.add(attrName);
          }
  
          if (obj != null) {
              addParameter(fieldName, obj);
          }
      } 
    
      @Override
      public boolean end(Writer writer, String body) {
          evaluateParams();
          if (extend != null) {
              String page = findString(extend);
              page = Include.getContextRelativePath(request, page);
              
              ActionContext actionContext = ServletActionContext.getContext();
              ActionInvocation invocation = actionContext.getActionInvocation();
              
              Bundle bundle = BundleUtil.getBundleForRequestJsp(page, invocation);
              if(bundle != null && !page.startsWith("/" + bundle.getSymbolicName() + "/")) {
                  page = "/" + bundle.getSymbolicName() + page;
              }
              /*
              // 使用 struts2-convention-plugin 的 ConventionsService 对路径 进行转换处理
              Container container = actionContext.getContainer();
             ConventionsService conventionsService = container.getInstance(ConventionsService.class,
                   container.getInstance(String.class, ConventionConstants.CONVENTION_CONVENTIONS_SERVICE));
             page = (conventionsService.determineResultPath(invocation.getAction().getClass()) + "/" + page).replaceAll("/+", "/");
            */
    
             try {
                 // 编译、执行 JSP
                 JSPRuntime.handle(page, false, invocation, bundle);
             } catch (Exception e1) {
                 LOG.error("解析继承的 JSP 文件[#0] 发生错误。", e1, page);
             }
         }
         
         // 调用父类中的实现
         boolean result = super.end(writer, body);
         
         // 将当前标签设置在 request 中的 Attribute 全部移除
         for (String key : requestAttrNames) {
             request.removeAttribute(key);
         }
         
         return result;
     }
 
     @StrutsTagAttribute(description="继承页面（父页面）")
     public void setExtend(String extend) {
         this.extend = extend;
     }
 
     @Inject(StrutsConstants.STRUTS_I18N_ENCODING)
     @StrutsTagAttribute(description = "父页面的字符编码，如：UTF-8。如果不指定，则默认为 struts.xml 中常量“struts.i18n.encoding” 设置的值")
     public void setEncoding(String encoding) {
         this.encoding = encoding;
     }
    
     @StrutsTagAttribute(description="页面中的表单元素是否为不可编辑（适用于 查看、打印 等页面）", type="Boolean", defaultValue="false")
     public void setReadonly(String readonly) {
         this.readonly = readonly;
     }
 }