package org.webslinger.types;

 import java.io.IOException;

 import java.io.Writer;

 import java.util.Collection;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Map;

 import java.util.Vector;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import org.apache.bsf.BSFException;

 import org.apache.commons.vfs.FileObject;

 import org.webslinger.PathContext;

 import org.webslinger.TypeHandler;

 import org.webslinger.Webslinger;

 import org.webslinger.WebslingerInvoker;

 import org.webslinger.WebslingerServletContext;

 import org.webslinger.bsf.LanguageEngine;

 import org.webslinger.bsf.LanguageManager;

 import org.webslinger.commons.vfs.VFSUtil;

 import org.webslinger.template.TemplateMacro;

 import org.webslinger.template.TemplateManager;

 import org.webslinger.macros.ContentMacro;

 import org.webslinger.macros.ContentPathMacro;

 import org.webslinger.macros.FileBasedMacro;

 import org.webslinger.macros.MergeMacro;

 import org.webslinger.macros.SectionMacro;

 public class template extends TypeHandler {

     public static final String DEFAULT_LANGUAGE = "velocity";

     private static final String[] paramNames = new String[5];

     private static final Class[] paramTypes = new Class[5];

     static {

         paramNames[0] ="writer";

         paramTypes[0] = Writer.class;

         paramNames[1] ="context";

         paramTypes[1] = Map.class;

         paramNames[2] ="webslinger";

         paramTypes[2] = Webslinger.class;

         paramNames[3] = "request";

         paramTypes[3] = HttpServletRequest.class;

         paramNames[4] = "response";

         paramTypes[4] = HttpServletResponse.class;

     }

     protected TemplateManager templateManager;

     protected event eventHandler;

     protected HashSet<String> extensions = new HashSet<String>();

     protected HashSet<String> loadedMacros = new HashSet<String>();

     protected void scanForMacros() throws BSFException, IOException {

         FileObject macroDir = getContext().getFile("/WEB-INF/Macros");

         VFSUtil.refresh(macroDir);

         HashSet<String> fileNames = new HashSet<String>();

         if (macroDir.exists()) {

             FileObject[] children = macroDir.getChildren();

             for (FileObject child: macroDir.getChildren()) {

                 String baseName = child.getName().getBaseName();

                 int period = baseName.lastIndexOf('.');

                 if (period == -1) continue;

                 String ext = baseName.substring(period);

                 if (extensions.contains(ext)) fileNames.add(baseName.substring(0, period));

             }

         }

         fileNames.removeAll(templateManager.getMacroNames());

         synchronized (this) {

             for (String loadedMacroName: loadedMacros) {

                 if (fileNames.remove(loadedMacroName)) continue;

                 undeclareBean(loadedMacroName);

             }

             for (String name: fileNames) {

                 declareBean(name, new FileBasedMacro(getContext(), name, getContext().resolve("/WEB-INF/Macros/" + name)), TemplateMacro.class);

                 loadedMacros.add(name);

             }

         }

     }

     protected void undeclareBean(String name) throws BSFException {

         templateManager.undeclareBean(name);

         eventHandler.undeclareBean(name);

     }

     protected <T> void declareBean(String name, T bean, Class<T> type) throws BSFException {

         templateManager.declareBean(name, bean, type);

         eventHandler.declareBean(name, bean, type);

     }

     public TemplateMacro findMacro(String name) throws IOException {

         if (templateManager == null) throw new InternalError("template type not initialized");

         return (TemplateMacro) templateManager.lookupBean(name);

     }

     public void init(WebslingerServletContext context, String type) throws IOException {

         super.init(context, type);

         eventHandler = (event) context.getTypeHandler("event");

         for (String extension: context.getContainer().getExtensionList()) {

             extensions.add(extension);

         }

         try {

             templateManager = new TemplateManager(context.getVFSDelegate(), logger);

             templateManager.setClassLoader(context.getClassLoader());

             declareBean("MacroBody", FileBasedMacro.MACRO_BODY, TemplateMacro.class);

             scanForMacros();

         } catch (BSFException e) {

             throw (IOException) new IOException(e.getMessage()).initCause(e);

         }

     }

     public Object run(Webslinger webslinger) throws IOException, ServletException {

         //System.err.println(this + ".run(" + pc + ", " + request + ", " + response + ", " + initObject + ")");

         //System.err.println("E.servletPath[" + request.getServletPath() + "]");

         try {

             ServletRequest request = webslinger.getRequest();

             ServletResponse response = webslinger.getResponse();

             response.flushBuffer();

             Object[] params = new Object[5];

             params[0] = response.getWriter();

             params[1] = webslinger.getContext();

             params[2] = webslinger;

             params[3] = webslinger.getRequest();

             params[4] = webslinger.getResponse();

             String language = (String) webslinger.getAttribute("template-language");

             if (language == null) language = DEFAULT_LANGUAGE;

             templateManager.apply(language, "top", 0, 0, webslinger, paramNames, params, paramTypes);

             return null;

         } catch (BSFException e) {

             throw (IOException) new IOException(e.getMessage()).initCause(e);

         }

     }

 }