/**

  * Back 2 Browser Bytecode Translator

  * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

  *

  * This program is free software: you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation, version 2 of the License.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program. Look for COPYING file in the top folder.

  * If not, see http://opensource.org/licenses/GPL-2.0.

  */

 package org.apidesign.vm4brwsr;

 import java.io.ByteArrayInputStream;

 import java.io.IOException;

 import org.apidesign.bck2brwsr.core.JavaScriptBody;

 /**

  *

  * @author Jaroslav Tulach <jtulach@netbeans.org>

  */

 class VMLazy extends ByteCodeToJavaScript {

     private final Object loader;

     private VMLazy(Object loader, Appendable out) {

         super(out);

         this.loader = loader;

     }

     static void init() {

     }

     @JavaScriptBody(args={"res", "args" }, body = "return args[0](res.toString());")

     private static native byte[] read(String res, Object[] args);

     static Object load(Object loader, String name, Object[] arguments) 

     throws IOException, ClassNotFoundException {

         String res = name.replace('.', '/') + ".class";

         byte[] arr = read(res, arguments);

         if (arr == null) {

             throw new ClassNotFoundException(name);

         }

         String code = toJavaScript(loader, arr);

         return applyCode(loader, name, code);

     }

     @JavaScriptBody(args = {"loader", "name", "script" }, body =

         "try {\n" +

         "  new Function(script)(loader, name);\n" +

         "} catch (ex) {\n" +

         "  throw 'Cannot compile ' + ex + ' script:\\\\n' + script;\n" +

         "}\n" +

         "return vm[name](false);\n"

     )

     private static native Object applyCode(Object loader, String name, String script);

     private static String toJavaScript(Object loader, byte[] is) throws IOException {

         StringBuilder sb = new StringBuilder();

         sb.append("var loader = arguments[0];\n");

         sb.append("var vm = loader.vm;\n");

         new VMLazy(loader, sb).compile(new ByteArrayInputStream(is));

         return sb.toString().toString();

     }

     @JavaScriptBody(args = { "self", "n" }, 

         body=

           "var cls = n.replace__Ljava_lang_String_2CC(n,'/','_').toString();"

         + "var loader = self.fld_loader;"

         + "var vm = loader.vm;"

         + "if (vm[cls]) return false;"

         + "vm[cls] = function() {"

         + "  return loader.loadClass(n,cls);"

         + "};"

         + "return true;"

     )

     @Override

     protected boolean requireReference(String internalClassName) {

         throw new UnsupportedOperationException();

     }

     @Override

     protected void requireScript(String resourcePath) {

     }

     @Override

     String assignClass(String className) {

         return "vm[arguments[1]]=";

     }

     @Override

     String accessClass(String classOperation) {

         return "vm." + classOperation;

     }

 }