package org.kuali.student.r2.common.validator;
   
   import org.slf4j.Logger;
   import org.slf4j.LoggerFactory;
   
   import java.util.ArrayList;
   import java.util.HashMap;
   import java.util.List;
   import java.util.Map;
  
  /**
   * ValidatorFactory provides a mechanism to 
   *  
   * 
   * @author Kuali Rice Team (kuali-rice@googlegroups.com)
   *
   */
  
  // This class is a special case, this class/equivelent doesn't exist in R2 
  //packages and is a common and has methods used in both R1 and R2 packages, 
  //this class was duplicated to R2 and modified to work with R2 services
  //BaseAbstractValidator, BaseAbstractValidator, Validator, ValidatorFactory
  
  public class ValidatorFactory {
  	private static final Logger LOG = LoggerFactory.getLogger(ValidatorFactory.class);
  	private volatile Map<String,Validator> customValidators = null; 
  	private DefaultValidatorImpl defaultValidator = new DefaultValidatorImpl();
  	
  	private List<Validator> validatorList = new ArrayList<Validator>();
  	
  	public ValidatorFactory(){
  		defaultValidator.setValidatorFactory(this);
  	}
  	
  	/**
  	 * Updated to fix double check lock not working
  	 * @return
  	 */
  	public Map<String,Validator> getCustomValidators(){
  		Map<String,Validator> result = customValidators;
  	    if(result == null) {
  	    	synchronized (this) {
  	    		result = customValidators;
  	    		if(result == null){
  	    	        result = new HashMap<String, Validator>();
  	    	        for(Validator validator: validatorList){
  	    	            String validatorName = validator.getClass().getName();
  	    	            result.put(validatorName, validator);
  	    	        }
  	    			customValidators = result;
  	    		}
  			}
  	    }
  	    return result;
  	}
  	
  	
  	public Validator getValidator(String customValidator) {
  	
  		LOG.info("Retrieving validatior: {}", customValidator);
  	    
  	    Validator v = getCustomValidators().get(customValidator); 
  	    
  	    if(v != null && v instanceof BaseAbstractValidator) {
  	        BaseAbstractValidator bv = (BaseAbstractValidator)v;
  	        bv.setValidatorFactory(this);
  	        return bv;
  	    } else {
  	       return v;
  	    }
  	}
  	
  	public Validator getValidator(){
  		return defaultValidator;
  	}
  	
  	public DefaultValidatorImpl getDefaultValidator() {
  		return defaultValidator;
  	}
  
  	public void setDefaultValidator(DefaultValidatorImpl defaultValidator) {
  		this.defaultValidator = defaultValidator;
  		this.defaultValidator.setValidatorFactory(this);
  	}
  
      public void setValidatorList(List<Validator> validatorList) {
          this.validatorList = validatorList;
      }
  }