/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.myfaces.tobago.util;
  
  import javax.faces.application.Application;
  
  public enum FacesVersion {
  
    VERSION_11,
    VERSION_12,
    VERSION_20,
    VERSION_21;
  
    private static FacesVersion currentVersion;
    private static boolean mojarra;
    private static boolean myfaces;
  
    static {
      try {
        currentVersion = VERSION_11;
        Application.class.getMethod("getExpressionFactory");
        currentVersion = VERSION_12;
        Application.class.getMethod("getDefaultValidatorInfo");
        currentVersion = VERSION_20;
        Application.class.getMethod("getExceptionHandler");
        currentVersion = VERSION_21;
      } catch (NoSuchMethodException e) {
        // ignore
      }
  
      mojarra = isAvailable("com.sun.faces.application.ApplicationImpl");
      myfaces = isAvailable("org.apache.myfaces.application.ApplicationImpl");
  
    }
  
    private static boolean isAvailable(String className) {
      try {
        try {
          Class.forName(className, false, Thread.currentThread().getContextClassLoader());
          return true;
        } catch (ClassNotFoundException e) {
          // ignore
          try {
            Class.forName(className, false, FacesVersion.class.getClassLoader());
            return true;
          } catch (ClassNotFoundException e1) {
            // ignore
          }
        }
      } catch (Exception e) {
        // ignore
      }
      return false;
    }
  
    /**
     * Does the JSF is version 1.2 or higher
     * @return Supports 1.2 or higher
     */
    public static boolean supports12() {
      return currentVersion == VERSION_12 || currentVersion == VERSION_20 || currentVersion == VERSION_21;
    }
  
    /**
     * Does the JSF is version 2.0 or higher
     * @return Supports 2.0 or higher
     */
    public static boolean supports20() {
      return currentVersion == VERSION_20 || currentVersion == VERSION_21;
    }
  
    /**
     * Does the JSF is version 2.1 or higher
     * @return Supports 2.1 or higher
     */
    public static boolean supports21() {
      return currentVersion == VERSION_21;
    }
  
    public static boolean isMojarra() {
      return mojarra;
    }
 
   public static boolean isMyfaces() {
     return myfaces;
   }
 }