/*
 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA
 */
package org.infinispan.configuration.cache;

import org.infinispan.config.ConfigurationException;
import org.infinispan.configuration.cache.InterceptorConfiguration.Position;
import org.infinispan.interceptors.base.CommandInterceptor;

/**
 * This builder defines details of a specific custom interceptor.
 */
public class InterceptorConfigurationBuilder extends AbstractCustomInterceptorsConfigurationChildBuilder<InterceptorConfiguration> {

   private Class<? extends CommandInterceptor> after;
   private Class<? extends CommandInterceptor> before;
   private CommandInterceptor interceptor;
   private int index = -1;
   private Position position = null;
   
   InterceptorConfigurationBuilder(CustomInterceptorsConfigurationBuilder builder) {
      super(builder);
   }

   /**
    * Dictates that the custom interceptor appears immediately <i>after</i> the specified interceptor. If the specified
    * interceptor is not found in the interceptor chain, a {@link ConfigurationException} will be thrown when the
    * cache starts.
    * 
    * @param after the class of the interceptor to look for
    */
   public InterceptorConfigurationBuilder after(Class<? extends CommandInterceptor> after) {
      this.after = after;
      return this;
   }

   /**
    * Dictates that the custom interceptor appears immediately <i>before</i> the specified interceptor. If the specified
    * interceptor is not found in the interceptor chain, a {@link ConfigurationException} will be thrown when the
    * cache starts.
    *
    * @param before the class of the interceptor to look for
    */
   public InterceptorConfigurationBuilder before(Class<? extends CommandInterceptor> before) {
      this.before = before;
      return this;
   }

   /**
    * An instance of the new custom interceptor to add to the configuration.
    * @param interceptor an instance of {@link CommandInterceptor}
    */
   public InterceptorConfigurationBuilder interceptor(CommandInterceptor interceptor) {
      this.interceptor = interceptor;
      return this;
   }

   /**
    * Specifies a position in the interceptor chain to place the new interceptor.  The index starts at 0 and goes up to
    * the number of interceptors in a given configuration.  A {@link ConfigurationException} is thrown if the index is 
    * less than 0 or greater than the maximum number of interceptors in the chain.
    * 
    * @param i positional index in the interceptor chain to place the new interceptor.
    */
   public InterceptorConfigurationBuilder index(int i) {
      if (i < 0) throw new IllegalArgumentException("Index cannot be negative");
      this.index = i;
      return this;
   }

   /**
    * Specifies a position, denoted by the {@link Position} enumeration, where to place the new interceptor.
    *
    * @param p position to place the new interceptor
    */
   public InterceptorConfigurationBuilder position(Position p) {
      this.position = p;
      return this;
   }

   @Override
   void validate() {
      // Make sure more than one 'position' isn't picked.
      int positions = 0;

      if (before != null) positions++;
      if (after != null) positions++;
      if (position != null) positions++;
      if (index > -1) positions++;

      switch (positions) {
         case 0:
            position = Position.OTHER_THAN_FIRST_OR_LAST;
            break;
         case 1:
            break;
         default:
            throw new ConfigurationException("You can only specify the position of a custom interceptor once.");
      }
   }

   @Override
   InterceptorConfiguration create() {
      return new InterceptorConfiguration(after, before, interceptor, index, position);
   }
   
   @Override
   public InterceptorConfigurationBuilder read(InterceptorConfiguration template) {
      this.after = template.after();
      this.before = template.before();
      this.index = template.index();
      this.interceptor = template.interceptor();
      this.position = template.position();
      
      return this;
   }

   @Override
   public String toString() {
      return "InterceptorConfigurationBuilder{" +
            "after=" + after +
            ", before=" + before +
            ", interceptor=" + interceptor +
            ", index=" + index +
            ", position=" + position +
            '}';
   }

}