/*
    * Grapht, an open source dependency injector.
    * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
    * Copyright 2010-2014 Regents of the University of Minnesota
    *
    * This program 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 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; if not, write to the Free Software Foundation, Inc., 51
   * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  package org.grouplens.grapht.context;
  
  import org.apache.commons.lang3.tuple.Pair;
  import org.grouplens.grapht.reflect.InjectionPoint;
  import org.grouplens.grapht.reflect.QualifierMatcher;
  import org.grouplens.grapht.reflect.Satisfaction;
  
  /**
   * Utilities for context matching.
   *
   * @author <a href="http://www.grouplens.org">GroupLens Research</a>
   */
  public final class ContextElements {
      private ContextElements() {}
  
      /**
       * Match priority constants.
       */
      public static enum MatchPriority {
          TYPE,
          INVERTED,
          ANY
      }
  
      public static ContextElementMatcher matchAny() {
          return AnyMatcher.INSTANCE;
      }
  
      public static ContextElementMatcher matchType(Class<?> type) {
          return new TypeElementMatcher(type);
      }
  
      public static ContextElementMatcher matchType(Class<?> type,  QualifierMatcher qual) {
          return new TypeElementMatcher(type, qual);
      }
  
      public static ContextElementMatcher invertMatch(ContextElementMatcher matcher) {
          return new InvertedMatcher(matcher);
      }
  
      private static enum AnyMatcher implements ContextElementMatcher {
          INSTANCE;
  
          @Override
          public MatchElement apply(Pair<Satisfaction, InjectionPoint> n) {
              return MatchElementImpl.ANY;
          }
  
  
          @Override
          public String toString() {
              return "{Object}";
          }
      }
  
      private static class InvertedMatcher implements ContextElementMatcher {
          private static final long serialVersionUID = 1L;
  
          private final ContextElementMatcher delegate;
  
          public InvertedMatcher(ContextElementMatcher base) {
              delegate = base;
          }
  
          @Override
          public MatchElement apply(Pair<Satisfaction, InjectionPoint> elem) {
              MatchElement result = delegate.apply(elem);
              if (result == null) {
                  return MatchElementImpl.INVERTED;
              } else {
                  return null;
              }
          }
  
          @Override
          public String toString() {
              return "!" + delegate.toString();
          }
      }
  
     private static enum MatchElementImpl implements MatchElement {
         ANY(MatchPriority.ANY),
         INVERTED(MatchPriority.INVERTED);
 
         private final MatchPriority priority;
 
         private MatchElementImpl(MatchPriority p) {
             priority = p;
         }
 
         @Override
         public MatchPriority getPriority() {
             return priority;
         }
 
         @Override
         public Integer getTypeDistance() {
             return null;
         }
     }
 }