/*
    * Copyright 2011 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 1.0 (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/ecl1.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.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.ErrorLevel;
  import org.kuali.rice.krad.datadictionary.validation.ValidationUtils;
  import org.kuali.rice.krad.datadictionary.validation.constraint.Constraint;
  import org.kuali.rice.krad.datadictionary.validation.constraint.MustOccurConstraint;
  import org.kuali.rice.krad.datadictionary.validation.constraint.PrerequisiteConstraint;
  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;
  
  import java.util.List;
  
  /**
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org) 
   */
  public class MustOccurConstraintProcessor extends BasePrerequisiteConstraintProcessor<MustOccurConstraint> {
  
  	private static final String CONSTRAINT_NAME = "must occur constraint";
  	
  	/**
  	 * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#process(DictionaryValidationResult, Object, org.kuali.rice.krad.datadictionary.validation.capability.Constrainable, org.kuali.rice.krad.datadictionary.validation.AttributeValueReader)
  	 */
  	@Override
  	public ProcessorResult process(DictionaryValidationResult result,
  			Object value, MustOccurConstraint constraint, AttributeValueReader attributeValueReader)
  			throws AttributeValidationException {
  
  		if (ValidationUtils.isNullOrEmpty(value))
  			return new ProcessorResult(result.addSkipped(attributeValueReader, CONSTRAINT_NAME));
  		
  
  		ConstraintValidationResult constraintValidationResult = new ConstraintValidationResult(CONSTRAINT_NAME);
  				
  		if (!processMustOccurConstraint(constraintValidationResult, constraint, attributeValueReader)) {
  			// If the processing of this constraint was not successful then it's an error
  		    if (attributeValueReader.getAttributeName() == null){
  		        constraintValidationResult.setAttributeName(attributeValueReader.getPath());
  		    } else{
  		        constraintValidationResult.setAttributeName(attributeValueReader.getAttributeName());
  		        constraintValidationResult.setAttributePath(attributeValueReader.getPath());
  		    }
  			constraintValidationResult.setError(RiceKeyConstants.ERROR_OCCURS);
  		} 
  
  		// Store the label key (if one exists) for this constraint on the constraint validation result so it can be shown later
  		constraintValidationResult.setConstraintLabelKey(constraint.getLabelKey());
  		// Add it to the DictionaryValidationResult object
  		result.addConstraintValidationResult(attributeValueReader, constraintValidationResult);
  
  		return new ProcessorResult(constraintValidationResult);
  
  	}
  	
  	@Override 
  	public String getName() {
  		return CONSTRAINT_NAME;
  	}
  
  	/**
  	 * @see org.kuali.rice.krad.datadictionary.validation.processor.ConstraintProcessor#getConstraintType()
  	 */
  	@Override
  	public Class<? extends Constraint> getConstraintType() {
  		return MustOccurConstraint.class;
  	}
  	
      protected boolean processMustOccurConstraint(ConstraintValidationResult topLevelResult, MustOccurConstraint constraint, AttributeValueReader attributeValueReader) throws AttributeValidationException {
  
          boolean isSuccessful = false;
          int trueCount = 0;
          
          List<PrerequisiteConstraint> prerequisiteConstraints = constraint.getPrerequisiteConstraints();
          if (prerequisiteConstraints != null) {
  	        for (PrerequisiteConstraint prerequisiteConstraint : prerequisiteConstraints) {
  	        	ConstraintValidationResult constraintValidationResult = processPrerequisiteConstraint(prerequisiteConstraint, attributeValueReader);
  	        	// Add the result of each prerequisite constraint validation to the top level result object as a child
  	        	topLevelResult.addChild(constraintValidationResult);
  	            trueCount += (constraintValidationResult.getStatus().getLevel() <= ErrorLevel.WARN.getLevel()) ? 1 : 0;
  	        }
         }
 
         List<MustOccurConstraint> mustOccurConstraints = constraint.getMustOccurConstraints();
         if (mustOccurConstraints != null) {
 	        for (MustOccurConstraint mustOccurConstraint : mustOccurConstraints) {
 	        	// Create a new constraint validation result for this must occur constraint and make it child of the top-level constraint, 
 	        	// then pass it in to the recursive call so that prerequisite constraints can be placed under it
 	        	ConstraintValidationResult constraintValidationResult = new ConstraintValidationResult(CONSTRAINT_NAME);
 	        	topLevelResult.addChild(constraintValidationResult);
 	            trueCount += (processMustOccurConstraint(constraintValidationResult, mustOccurConstraint, attributeValueReader)) ? 1 : 0;
 	        }
         }
 
         int minimum = constraint.getMin() != null ? constraint.getMin().intValue() : 0;
         int maximum = constraint.getMax() != null ? constraint.getMax().intValue() : 0;
         
         isSuccessful = (trueCount >= minimum && trueCount <= maximum) ? true : false;
 
         return isSuccessful;
     }
 
 }