package org.webslinger;

 import java.io.ByteArrayOutputStream;

 import java.io.IOException;

 import java.io.StringReader;

 import java.io.StringWriter;

 import java.util.HashMap;

 import java.util.Map;

 import javax.servlet.RequestDispatcher;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import org.webslinger.collections.CollectionUtil;

 import org.webslinger.io.IOUtil;

 import org.webslinger.json.JSON;

 import org.webslinger.json.JSONWriter;

 public final class WebslingerRequestDispatcher implements RequestDispatcher {

     private final WebslingerServletContext sc;

     private final PathContext pc;

     private final Map<String, Object> context;

     protected WebslingerRequestDispatcher(WebslingerServletContext sc, PathContext pc, Map<String, Object> context) {

         this.sc = sc;

         this.pc = pc;

         this.context = context;

     }

     public PathContext getPathContext() {

         return pc;

     }

     public Map<String, Object> getContext() {

         return context;

     }

     public void forward(ServletRequest request, ServletResponse response) throws IOException, ServletException {

         if (!"text/x-json".equals(request.getContentType())) {

             run(request, response, "forward", null);

             return;

         }

         if (!(request instanceof HttpServletRequest)) new Exception("dispatcher: not http request").printStackTrace();

         ByteArrayOutputStream baos = new ByteArrayOutputStream();

         IOUtil.copy(request.getInputStream(), true, baos, true);

         Map<String, Object> result = new HashMap<String, Object>();

         try {

             Object value = new JSON(new StringReader(baos.toString())).allowResolve(true).JSONValue();

             if (!(value instanceof Map)) {

                 ((HttpServletResponse) response).sendError(500);

                 return;

             }

             StringWriter savedOutput = new StringWriter();

             HttpServletResponse tmpResponse = sc.alterPaths(pc, (HttpServletRequest) request, (HttpServletResponse) response, savedOutput);

             Map<String, Object> inMap = (Map<String, Object>) value;

             Map<String, Object> context = (Map<String, Object>) inMap.get("context");

             context.putAll(getContext());

             Object payload = inMap.get("payload");

             context.put("RequestPath", request.getAttribute("RequestPath"));

             Object eventResult = sc.run(pc, sc.alterPaths(pc, (HttpServletRequest) request), (HttpServletResponse) tmpResponse, context, "json", payload);

             if (eventResult != null) {

                 result.put("result", eventResult);

             } else {

                 result.put("result", savedOutput.toString());

             }

         } catch (Throwable t) {

             result.put("error", CollectionUtil.toMap("type", "exception", "exc", t.getMessage()));

         } finally {

             result.put("hub", sc.getInvoker().getJSONHub());

         }

         response.setContentType("text/x-json");

         new JSONWriter(response.getWriter()).write(result);

     }

     public void include(ServletRequest request, ServletResponse response) throws IOException, ServletException {

         run(request, response, "include", null);

     }

     public void comet(CometEventType eventType, ServletRequest request, ServletResponse response) throws IOException, ServletException {

         run(request, response, "comet", eventType);

     }

     protected void run(ServletRequest request, ServletResponse response, String command, Object payload) throws IOException, ServletException {

         if (!(request instanceof HttpServletRequest)) new Exception("dispatcher: not http request").printStackTrace();

         //response.flushBuffer();

         //System.err.println("include(" + pc + ", " + request + ", " + response + ")");

         response = sc.alterPaths(pc, (HttpServletRequest) request, (HttpServletResponse) response);

         HashMap<String, Object> context = new HashMap<String, Object>(this.context);

         context.put("RequestPath", request.getAttribute("RequestPath"));

         sc.run(pc, sc.alterPaths(pc, (HttpServletRequest) request), (HttpServletResponse) response, context, command, payload);

     }

 }