/**
   The contents of this file are subject to the Mozilla Public License Version 1.1 
   (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.mozilla.org/MPL/ 
   Software distributed under the License is distributed on an "AS IS" basis, 
   WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the 
   specific language governing rights and limitations under the License. 
   
   The Original Code is "PredicatePrimitiveTypeRule.java".  Description: 
  "PrimitiveTypeRule that validates using predicates" 
  
  The Initial Developer of the Original Code is University Health Network. Copyright (C) 
  2012.  All Rights Reserved. 
  
  Contributor(s): ______________________________________. 
  
  Alternatively, the contents of this file may be used under the terms of the 
  GNU General Public License (the "GPL"), in which case the provisions of the GPL are 
  applicable instead of those above.  If you wish to allow use of your version of this 
  file only under the terms of the GPL and not to allow others to use your version 
  of this file under the MPL, indicate your decision by deleting  the provisions above 
  and replace  them with the notice and other provisions required by the GPL License.  
  If you do not delete the provisions above, a recipient may use your version of 
  this file under either the MPL or the GPL. 
   */
  package ca.uhn.hl7v2.validation.builder;
  
  import java.util.regex.Pattern;
  
  import ca.uhn.hl7v2.validation.ValidationException;
  import ca.uhn.hl7v2.validation.impl.AbstractPrimitiveTypeRule;
  
  /**
   * Abstract base class for PrimitiveTypeRules that validate using predicates
   * 
   * @author Christian Ohr
   */
  @SuppressWarnings("serial")
  public class PredicatePrimitiveTypeRule extends AbstractPrimitiveTypeRule implements
  		PredicateRuleSupport<String> {
   
      private static final Pattern LEADING_WHITESPACE = Pattern.compile("^\\s+");
      private static final Pattern TRAILING_WHITESPACE = Pattern.compile("\\s+$");
  
      
      public enum Trimmer {
  
          LEFT {
              @Override public String trim(String source) { return trimPattern(LEADING_WHITESPACE, source); }            
          },
          RIGHT {
              @Override public String trim(String source) { return trimPattern(TRAILING_WHITESPACE, source); }            
          },                
          NONE {
              @Override public String trim(String source) { return source; }            
          },
          ALL {
              @Override public String trim(String source) { return source == null ? null : source.trim(); }                        
          };
  
          /**
           * Trims a string
           * @param source the string to be trimmed
           * @return the trimmed string
           */
          public abstract String trim(String source);
          
          protected String trimPattern(Pattern pattern, String source) {
              if (source == null || pattern == null) 
                  return source;
              return pattern.matcher(source).replaceAll("");
          }
      }
  
  	private final Predicate predicate;
  	private final Trimmer trimmer;
  
      /**
       * Creates a new primitive rule without trimming
       * @param predicate predicate to be used
       */
  	public PredicatePrimitiveTypeRule(Predicate predicate) {
  		this(predicate, Trimmer.NONE);
  	}
  
      /**
       * Creates a new primitive rule
       * @param predicate predicate to be used
       * @param trimmer trimming behavior
       */
  	public PredicatePrimitiveTypeRule(Predicate predicate, Trimmer trimmer) {
  		this.predicate = predicate;
  		this.trimmer = trimmer;
          setDescription("Primitive value '%s' requires to be " + predicate.getDescription());
  	}
  
  	public Predicate getPredicate() {
  		return predicate;
  	}
 
 	public String correct(String value) {
 	    return trimmer.trim(value);
 	}
 
 	public boolean test(String value) {
 		try {
 			return getPredicate().evaluate(value);
 		} catch (ValidationException e) {
 			return false;
 		}
 	}
 
 	public ValidationException[] apply(String value) {
 		try {
 			return result(getPredicate().evaluate(correct(value)), value);
 		} catch (ValidationException e) {
 			return failed(e);
 		}
 	}
 
 	@Override
 	public String toString() {
 		return getDescription();
 	}
 
 }