/**

  * 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.ide.editor;

 import java.lang.reflect.Method;

 import java.util.HashMap;

 import java.util.Map;

 /**

  * JNI Helper.

  * To facilitate lookup of methods by name and signature, instead of manually parsing signatures,

  * constructs the map of all methods and uses Class.getName() to generate almost-correct signatures.

  */

 class JNIHelper {

     static Method method(String clazz, String method, String signature) {

         final Map<String, Method> methods = methodMap(JNIHelper.clazz(clazz));

         return methods.get(methodKey(method, signature));

     }

     static Class<?> clazz(String clazz) {

         try {

             return Class.forName(clazz);

         } catch (ClassNotFoundException e) {

             throw new IllegalArgumentException(e);

         }

     }

     static Map<String, Method> methodMap(final Class<?> clazz) {

         final Map<String, Method> map = new HashMap<String, Method>();

         final Method[] methods = clazz.getDeclaredMethods();

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

             final Method method = methods[i];

             map.put(methodKey(method.getName(), signature(method)), method);

         }

         return map;

     }

     static String methodKey(String method, String signature) {

         return method + '@' + signature;

     }

     static String signature(final Method method) {

         final Class<?>[] parameterTypes = method.getParameterTypes();

         final StringBuilder b = new StringBuilder();

         for (int j = 0; j < parameterTypes.length; j++) {

             b.append(signature(parameterTypes[j]));

         }

         return b.toString();

     }

     static String signature(final Class<?> clazz) {

         if (clazz == boolean.class) return "Z";

         else if (clazz == byte.class) return "B";

         else if (clazz == char.class) return "C";

         else if (clazz == double.class) return "D";

         else if (clazz == float.class) return "F";

         else if (clazz == int.class) return "I";

         else if (clazz == long.class) return "J";

         else if (clazz == short.class) return "S";

         else if (clazz == void.class) return "V";

         else if (clazz.isArray()) return clazz.getName().replace('.','/');

         else return "L" + clazz.getName().replace('.','/') + ";";

     }

 }