/**

  * 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.bck2brwsr.emul.reflect;

 import java.lang.annotation.Annotation;

 import java.lang.reflect.Method;

 import java.lang.reflect.Modifier;

 import org.apidesign.bck2brwsr.core.JavaScriptBody;

 /**

  *

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

  */

 public final class AnnotationImpl implements Annotation {

     private final Class<? extends Annotation> type;

     public AnnotationImpl(Class<? extends Annotation> type) {

         this.type = type;

     }

     public Class<? extends Annotation> annotationType() {

         return type;

     }

     @JavaScriptBody(args = { "a", "n", "arr", "values" }, body = ""

         + "function f(v, p) {\n"

         + "  var val = v;\n"

         + "  var prop = p;\n"

         + "  return function() {\n"

         + "    return val[prop];\n"

         + "  };\n"

         + "}\n"

         + "for (var i = 0; i < arr.length; i += 2) {\n"

         + "  var m = arr[i];\n"

         + "  var p = arr[i + 1];\n"

         + "  a[m] = new f(values, p);\n"

         + "}\n"

         + "a['$instOf_' + n] = true;\n"

         + "return a;"

     )

     private static native <T extends Annotation> T create(

         AnnotationImpl a, String n, String[] methodsAndProps, Object values

     );

     public static <T extends Annotation> T create(Class<T> annoClass, Object values) {

         return create(new AnnotationImpl(annoClass), 

             annoClass.getName().replace('.', '_'), 

             findProps(annoClass), values

         );

     }

     public static Annotation[] create(Object anno) {

         String[] names = findNames(anno);

         Annotation[] ret = new Annotation[names.length];

         for (int i = 0; i < names.length; i++) {

             String annoNameSlash = names[i].substring(1, names[i].length() - 1);

             Class<? extends Annotation> annoClass;

             try {

                 annoClass = (Class<? extends Annotation>)Class.forName(annoNameSlash.replace('/', '.'));

             } catch (ClassNotFoundException ex) {

                 throw new IllegalStateException("Can't find annotation class " + annoNameSlash);

             }

             ret[i] = create(

                 new AnnotationImpl(annoClass), 

                 annoNameSlash.replace('/', '_'),

                 findProps(annoClass),

                 findData(anno, names[i])

             );

         }

         return ret;

     }

     @JavaScriptBody(args = "anno", body =

           "var arr = new Array();"

         + "var props = Object.getOwnPropertyNames(anno);\n"

         + "for (var i = 0; i < props.length; i++) {\n"

         + "  var p = props[i];\n"

         + "  arr.push(p);"

         + "}"

         + "return arr;"

     )

     private static native String[] findNames(Object anno);

     @JavaScriptBody(args={ "anno", "p"}, body="return anno[p];")

     private static native Object findData(Object anno, String p);

     private static String[] findProps(Class<?> annoClass) {

         final Method[] marr = MethodImpl.findMethods(annoClass, Modifier.PUBLIC);

         String[] arr = new String[marr.length * 2];

         int pos = 0;

         for (Method m : marr) {

             arr[pos++] = MethodImpl.toSignature(m);

             arr[pos++] = m.getName();

         }

         return arr;

     }

 }