package org.webslinger.macros;

 import java.io.IOException;

 import java.io.Writer;

 import java.util.ArrayList;

 import java.util.Arrays;

 import java.util.HashMap;

 import java.util.Map;

 import javax.servlet.ServletException;

 import org.apache.bsf.BSFException;

 import org.apache.commons.vfs.FileContent;

 import org.apache.commons.vfs.FileObject;

 import org.webslinger.PathContext;

 import org.webslinger.Webslinger;

 import org.webslinger.WebslingerInvoker;

 import org.webslinger.WebslingerServletContext;

 import org.webslinger.template.TemplateMacro;

 import org.webslinger.template.TemplateManager;

 import org.webslinger.util.GeneratedResult;

 import org.webslinger.util.TTLCachedObject;

 import org.webslinger.util.TTLObject;

 public class FileBasedMacro implements TemplateMacro {

     static {

         TTLObject.setDefaultTTLForClass(ParameterList.class, 1000);

     }

     private final String name;

     private final PathContext pc;

     private final ParameterList parameterList = new ParameterList();

     private final WebslingerServletContext context;

     public FileBasedMacro(WebslingerServletContext context, String name, PathContext pc) {

         this.context = context;

         this.name = name;

         this.pc = pc;

     }

     public String getName() {

         return name;

     }

     public boolean isBlock() {

         try {

             boolean isBlock = "true".equals(pc.getAttribute("macro-is-block"));

             //System.err.println("isBlock(" + pc + "<" + pc.getFile().exists() + ">)=" + isBlock);

             return isBlock;

         } catch (IOException e) {

             // FIXME: log this e.printStackTrace();

             return false;

         }

     }

     public static final TemplateManager.MacroBody MACRO_BODY = new TemplateManager.MacroBody() {

         public boolean render(TemplateManager manager, Object parent, Writer writer, Args args, Map<String, Object> context, Body body) throws IOException, BSFException {

             WebslingerInvoker invoker = ((Webslinger) parent).getInvoker();

             Webslinger old = invoker.popFrame();

             try {

                 return super.render(manager, parent, writer, args, context, body);

             } finally {

                 invoker.pushFrame(old);

             }

         }

     };

     public boolean render(TemplateManager manager, Object parent, Writer writer, Args args, Map<String, Object> context, Body body) throws IOException, BSFException {

         Map<String, Integer> parameters = parameterList.getObject();

         if (args.pList != null) {

             for (Map.Entry<String, Integer> entry: parameters.entrySet()) {

                 Integer index = entry.getValue();

                 if (index.intValue() < args.pList.length) {

                     context.put(entry.getKey(), args.pList[index.intValue()]);

                 }

             }

         } else {

             for (String key: parameters.keySet()) {

                 if (!args.pMap.containsKey(key)) {

                 }

                 context.put(key, args.pMap.get(key));

             }

         }

         manager.pushBody(body);

         try {

             boolean hadCW = context.containsKey("callingWebslinger");

             Object oldCW = (Webslinger) context.get("callingWebslinger");

             try {

                 context.put("callingWebslinger", body.getSource());

                 context.put("templateManager", manager);

                 this.context.getInvoker().run(pc, null, context, "merge", null, writer);

             } finally {

                 if (hadCW) context.put("callingWebslinger", oldCW);

             }

         } catch (ServletException e) {

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

         } finally {

             manager.popBody();

         }

         return true;

     }

     public TemplateMacro newInstance(TemplateManager manager, Object parent, Args args) throws IOException, BSFException {

         return this;

     }

     protected class ParameterList extends TTLCachedObject<Map<String, Integer>> {

         protected long getTimestamp(Map<String, Integer> old) throws IOException {

             FileObject file = pc.getFile();

             return file.exists() ? file.getContent().getLastModifiedTime() : NOT_EXISTANT_TIMESTAMP;

         }

         protected GeneratedResult<Map<String, Integer>> generate(Map<String, Integer> old) throws IOException {

             FileContent fc = pc.getFile().getContent();

             HashMap<String, Integer> parameters = new HashMap<String, Integer>();

             for (int i = 0; ; i++) {

                 String parameterName = (String) fc.getAttribute("macro-parameter-" + i);

                 if (parameterName == null) break;

                 parameters.put(parameterName, i);

             }

             return new GeneratedResult<Map<String, Integer>>(fc.getLastModifiedTime(), parameters);

         }

     }

 }