/**
    * Copyright 2007 Google Inc.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.tonicsystems.jarjar;
  
  import java.io.File;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.util.ArrayList;
  import java.util.List;
  
  class MainUtil
  {
      public static void runMain(Object main, String[] args, String defCommand) throws Exception {
          if (args.length > 0) {
              String command = args[0];
              Method[] methods = main.getClass().getMethods();
              for (int i = 0; i < methods.length; i++) {
                  Method method = methods[i];
                  if (method.getName().equals(command)) {
                      String[] remaining = new String[args.length - 1];
                      System.arraycopy(args, 1, remaining, 0, remaining.length);
                      try {
                          method.invoke(main, bindParameters(method, remaining));
                      } catch (InvocationTargetException e) {
                          Throwable cause = e.getCause();
                          if (cause instanceof IllegalArgumentException) {
                              System.err.println("Syntax error: " + cause.getMessage());
                          } else if (cause instanceof Exception) {
                              throw (Exception) cause;
                          } else {
                              throw e;
                          }
                      }
                      return;
                  }
              }
          }
          if (defCommand != null)
              runMain(main, new String[]{ defCommand }, null);
      }
  
      private static Object[] bindParameters(Method method, String[] args) {
          List<Object> parameters = new ArrayList<Object>();
          Class[] parameterTypes = method.getParameterTypes();
          for (int i = 0, len = parameterTypes.length; i < len; i++) {
              Class type = parameterTypes[i];
              int remaining = Math.max(0, args.length - i);
              if (type.equals(String[].class)) {
                  String[] rest = new String[remaining];
                  System.arraycopy(args, 1, rest, 0, remaining);
                  parameters.add(rest);
              } else if (remaining > 0) {
                  parameters.add(convertParameter(args[i], parameterTypes[i]));
              } else {
                  parameters.add(null);
              }
          }
          return parameters.toArray();
      }
  
      private static Object convertParameter(String arg, Class type) {
          if (type.equals(String.class)) {
              return arg;
          } else if (type.equals(Integer.class)) {
              return Integer.valueOf(arg, 10);
          } else if (type.equals(File.class)) {
              return new File(arg);
          } else {
              throw new UnsupportedOperationException("Unknown type " + type);
          }
      }
  }