/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.util;
  
  import java.lang.reflect.Constructor;
  import java.lang.reflect.InvocationTargetException;
  
  import ch.qos.logback.classic.ClassicConstants;
  import ch.qos.logback.classic.LoggerContext;
  import ch.qos.logback.classic.selector.ContextJNDISelector;
  import ch.qos.logback.classic.selector.ContextSelector;
  import ch.qos.logback.classic.selector.DefaultContextSelector;
  import ch.qos.logback.core.util.Loader;
  import ch.qos.logback.core.util.OptionHelper;
  
  /**
   * Holds the context selector for use in the current environment.
   * 
   * @author Ceki Gülcü
   * @since 0.9.19
   */
  public class ContextSelectorStaticBinder {
  
    static ContextSelectorStaticBinder singleton = new ContextSelectorStaticBinder();
  
    ContextSelector contextSelector;
    Object key;
    
    public static ContextSelectorStaticBinder getSingleton() {
      return singleton;
    }
  
    /**
     * FOR INTERNAL USE. This method is intended for use by  StaticLoggerBinder.
     *  
     * @param defaultLoggerContext
     * @throws ClassNotFoundException
     * @throws NoSuchMethodException
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws InvocationTargetException
     */
    public void init(LoggerContext defaultLoggerContext, Object key) throws ClassNotFoundException,
        NoSuchMethodException, InstantiationException, IllegalAccessException,
        InvocationTargetException  {
      if(this.key == null) {
        this.key = key;
      } else if (this.key != key) {
        throw new IllegalAccessException("Only certain classes can access this method.");
      }
      
      
      String contextSelectorStr = OptionHelper
          .getSystemProperty(ClassicConstants.LOGBACK_CONTEXT_SELECTOR);
      if (contextSelectorStr == null) {
        contextSelector = new DefaultContextSelector(defaultLoggerContext);
      } else if (contextSelectorStr.equals("JNDI")) {
        // if jndi is specified, let's use the appropriate class
        contextSelector = new ContextJNDISelector(defaultLoggerContext);
      } else {
        contextSelector = dynamicalContextSelector(defaultLoggerContext,
            contextSelectorStr);
      }
    }
    
    /**
     * Instantiate the context selector class designated by the user. The selector
     * must have a constructor taking a LoggerContext instance as an argument.
     * 
     * @param defaultLoggerContext
     * @param contextSelectorStr
     * @return an instance of the designated context selector class
     * @throws ClassNotFoundException
     * @throws SecurityException
     * @throws NoSuchMethodException
     * @throws IllegalArgumentException
     * @throws InstantiationException
     * @throws IllegalAccessException
     * @throws InvocationTargetException
     */
    static ContextSelector dynamicalContextSelector(
        LoggerContext defaultLoggerContext, String contextSelectorStr)
        throws ClassNotFoundException, SecurityException, NoSuchMethodException,
        IllegalArgumentException, InstantiationException, IllegalAccessException,
        InvocationTargetException {
      Class<?> contextSelectorClass = Loader.loadClass(contextSelectorStr);
      Constructor cons = contextSelectorClass
          .getConstructor(new Class[] { LoggerContext.class });
     return (ContextSelector) cons.newInstance(defaultLoggerContext);
   }
   
   public ContextSelector getContextSelector() {
     return contextSelector;
   }
 
 }