/**

 * 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, c) {\n"

        + "  var val = v;\n"

        + "  var prop = p;\n"

        + "  var clazz = c;\n"

        + "  return function() {\n"

        + "    if (clazz == null) return val[prop];\n"

        + "    return CLS.prototype.c__Ljava_lang_Object_2Ljava_lang_Class_2Ljava_lang_Object_2(clazz, val[prop]);\n"

        + "  };\n"

        + "}\n"

        + "for (var i = 0; i < arr.length; i += 3) {\n"

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

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

        + "  var c = arr[i + 2];\n"

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

        + "}\n"

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

        + "return a;"

    )

    private static native <T extends Annotation> T create(

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

    );

    private static Object c(Class<? extends Annotation> a, Object v) {

        return create(a, v);

    }

    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 Object[] findProps(Class<?> annoClass) {

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

        Object[] arr = new Object[marr.length * 3];

        int pos = 0;

        for (Method m : marr) {

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

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

            arr[pos++] = m.getReturnType().isAnnotation() ? m.getReturnType() : null;

        }

        return arr;

    }

}