package org.kuali.student.r2.common.criteria;
   
   import java.io.Serializable;
   import java.util.ArrayList;
   import java.util.List;
   
   import org.kuali.rice.core.api.criteria.Predicate;
   import org.kuali.rice.core.api.mo.ModelBuilder;
   import org.kuali.rice.core.framework.persistence.jpa.criteria.Criteria;
  
  public class LookupCustomizer<T> {
      
      private List<PredicateTransform> additionalTransforms;
      private List<PredicateTransform> predicateTransforms;
      private final Transform<T, T> resultTransform;
  
      private LookupCustomizer(Builder<T> builder) {
          this.additionalTransforms = builder.getAdditionalTransforms();
          this.predicateTransforms = builder.getPredicateTransforms();
          this.resultTransform = builder.getResultTransform() != null ? builder.getResultTransform() : IndentityTransform.<T, T>getInstance();
      }
      
      public Predicate applyAdditionalTransforms(Predicate predicate, Criteria criteria) {
          for (PredicateTransform transform : additionalTransforms){
              predicate = transform.apply(predicate, criteria);
          }
          return predicate;
      }
  
      public Predicate applyPredicateTransforms(Predicate predicate, Criteria criteria) {
          for (PredicateTransform transform : predicateTransforms){
              predicate = transform.apply(predicate, criteria);
          }
          return predicate;
      }
  
      public T applyResultTransforms(Object o) {
          return null;
      }
      
      public List<PredicateTransform> getAdditionalTransforms() {
          return additionalTransforms;
      }
  
      public void setAdditionalTransforms(List<PredicateTransform> additionalTransforms) {
          this.additionalTransforms = additionalTransforms;
      }
  
      public List<PredicateTransform> getPredicateTransforms() {
          return predicateTransforms;
      }
  
      public void setPredicateTransforms(List<PredicateTransform> predicateTransforms) {
          this.predicateTransforms = predicateTransforms;
      }
  
      public Transform<T, T> getResultTransform() {
          return resultTransform;
      }
      
      public static final class Builder<T> implements ModelBuilder, Serializable {
  
          private List<PredicateTransform> additionalTransforms;
          private List<PredicateTransform> predicateTransforms;
          private Transform<T, T> resultTransform;
  
          private Builder() {
  
          }
  
          public static <T> Builder<T> create() {
              return new Builder<T>();
          }
  
          public List<PredicateTransform> getAdditionalTransforms() {
              return additionalTransforms;
          }
  
          public void setAdditionalTransforms(List<PredicateTransform> additionalTransforms) {
              this.additionalTransforms = additionalTransforms;
          }
  
          public List<PredicateTransform> getPredicateTransforms() {
              return predicateTransforms;
          }
  
          public void setPredicateTransforms(List<PredicateTransform> predicateTransforms) {
              this.predicateTransforms = predicateTransforms;
          }
  
          public Transform<T, T> getResultTransform() {
              return resultTransform;
          }
  
          public void setResultTransform(final Transform<T, T> resultTransform) {
              this.resultTransform = resultTransform;
          }
  
          @Override
         public LookupCustomizer<T> build() {
             if (additionalTransforms == null){
                 additionalTransforms = new ArrayList<LookupCustomizer.PredicateTransform>();
             }
             if (predicateTransforms == null){
                 predicateTransforms = new ArrayList<LookupCustomizer.PredicateTransform>();
             }
             return new LookupCustomizer<T>(this);
         }
     }
 
     public interface PredicateTransform {
         Predicate apply(Predicate input, Criteria criteria);
     }
     
     public interface Transform<P, R> {
         R apply(P input);
     }
 
     /**
      * f: x -> x.  This function just returns the passed in parameter.
      *
      * @param <I> the type the function acts on.
      */
     private static final class IndentityTransform<I> implements Transform<I, I> {
 
         @SuppressWarnings("unchecked")
         private static final Transform INSTANCE = new IndentityTransform();
 
         @SuppressWarnings("unchecked")
         public static <P, R> Transform<P, R> getInstance() {
             return INSTANCE;
         }
 
         @Override
         public I apply(final I input) {
             return input;
         }
     }
 
 }