/**
    * Copyright 2005-2014 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 2.0 (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.opensource.org/licenses/ecl2.php
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.kuali.rice.krad.datadictionary.validation.processor;
  
  import org.kuali.rice.core.api.uif.DataType;
  import org.kuali.rice.core.api.util.RiceKeyConstants;
  import org.kuali.rice.krad.datadictionary.exception.AttributeValidationException;
  import org.kuali.rice.krad.datadictionary.validation.AttributeValueReader;
  import org.kuali.rice.krad.datadictionary.validation.ValidationUtils;
  import org.kuali.rice.krad.datadictionary.validation.ValidationUtils.Result;
  import org.kuali.rice.krad.datadictionary.validation.constraint.Constraint;
  import org.kuali.rice.krad.datadictionary.validation.constraint.LengthConstraint;
  import org.kuali.rice.krad.datadictionary.validation.result.ConstraintValidationResult;
  import org.kuali.rice.krad.datadictionary.validation.result.DictionaryValidationResult;
  import org.kuali.rice.krad.datadictionary.validation.result.ProcessorResult;
  
  /**
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  public class LengthConstraintProcessor extends MandatoryElementConstraintProcessor<LengthConstraint> {
  
      private static final String MIN_LENGTH_KEY = "validation.minLengthConditional";
      private static final String MAX_LENGTH_KEY = "validation.maxLengthConditional";
      private static final String RANGE_KEY = "validation.lengthRange";
  
      private static final String CONSTRAINT_NAME = "length constraint";
  
      /**
       * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#process(org.kuali.rice.krad.datadictionary.validation.result.DictionaryValidationResult,
       *      Object, org.kuali.rice.krad.datadictionary.validation.constraint.Constraint,
       *      org.kuali.rice.krad.datadictionary.validation.AttributeValueReader)
       */
      @Override
      public ProcessorResult process(DictionaryValidationResult result, Object value, LengthConstraint constraint,
              AttributeValueReader attributeValueReader) throws AttributeValidationException {
  
          // To accommodate the needs of other processors, the ConstraintProcessor.process() method returns a list of ConstraintValidationResult objects
          // but since a definition that is length constrained only constrains a single field, there is effectively always a single constraint
          // being imposed
          return new ProcessorResult(processSingleLengthConstraint(result, value, constraint, attributeValueReader));
      }
  
      @Override
      public String getName() {
          return CONSTRAINT_NAME;
      }
  
      /**
       * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#getConstraintType()
       */
      @Override
      public Class<? extends Constraint> getConstraintType() {
          return LengthConstraint.class;
      }
  
      protected ConstraintValidationResult processSingleLengthConstraint(DictionaryValidationResult result, Object value,
              LengthConstraint constraint,
              AttributeValueReader attributeValueReader) throws AttributeValidationException {
          // Can't process any range constraints on null values
          if (ValidationUtils.isNullOrEmpty(value)) {
              return result.addSkipped(attributeValueReader, CONSTRAINT_NAME);
          }
  
          DataType dataType = constraint.getDataType();
          Object typedValue = value;
  
          if (dataType != null) {
              typedValue = ValidationUtils.convertToDataType(value, dataType, dateTimeService);
          }
  
          // The only thing that can have a length constraint currently is a string.
          if (typedValue instanceof String) {
              return validateLength(result, (String) typedValue, constraint, attributeValueReader);
          }
  
          return result.addSkipped(attributeValueReader, CONSTRAINT_NAME);
      }
  
      protected ConstraintValidationResult validateLength(DictionaryValidationResult result, String value,
              LengthConstraint constraint, AttributeValueReader attributeValueReader) throws IllegalArgumentException {
          Integer valueLength = Integer.valueOf(value.length());
  
          Integer maxLength = constraint.getMaxLength();
          Integer minLength = constraint.getMinLength();
  
          Result lessThanMax = ValidationUtils.isLessThanOrEqual(valueLength, maxLength);
         Result greaterThanMin = ValidationUtils.isGreaterThanOrEqual(valueLength, minLength);
 
         // It's okay for one end of the range to be undefined - that's not an error. It's only an error if one of them is invalid 
         if (lessThanMax != Result.INVALID && greaterThanMin != Result.INVALID) {
             // Of course, if they're both undefined then we didn't actually have a real constraint
             if (lessThanMax == Result.UNDEFINED && greaterThanMin == Result.UNDEFINED) {
                 return result.addNoConstraint(attributeValueReader, CONSTRAINT_NAME);
             }
 
             // In this case, we've succeeded
             return result.addSuccess(attributeValueReader, CONSTRAINT_NAME);
         }
 
         String maxErrorParameter = maxLength != null ? maxLength.toString() : null;
         String minErrorParameter = minLength != null ? minLength.toString() : null;
 
         // If both comparisons happened then if either comparison failed we can show the end user the expected range on both sides.
         if (lessThanMax != Result.UNDEFINED && greaterThanMin != Result.UNDEFINED) {
             return result.addError(RANGE_KEY, attributeValueReader, CONSTRAINT_NAME,
                     RiceKeyConstants.ERROR_OUT_OF_RANGE, minErrorParameter, maxErrorParameter);
         }
         // If it's the max comparison that fails, then just tell the end user what the max can be
         else if (lessThanMax == Result.INVALID) {
             return result.addError(MAX_LENGTH_KEY, attributeValueReader, CONSTRAINT_NAME,
                     RiceKeyConstants.ERROR_INCLUSIVE_MAX, maxErrorParameter);
         }
         // Otherwise, just tell them what the min can be
         else {
             return result.addError(MIN_LENGTH_KEY, attributeValueReader, CONSTRAINT_NAME,
                     RiceKeyConstants.ERROR_EXCLUSIVE_MIN, minErrorParameter);
         }
 
     }
 
 }