package org.sample;

import java.util.Locale;
import java.util.ResourceBundle;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.MessageInterpolator;
import javax.validation.Validation;
import javax.validation.Validator;
import javax.validation.ValidatorFactory;

import org.hibernate.validator.engine.MessageInterpolatorContext;

import com.javaconcurrencyinpractice.annotations.ThreadSafe;

@ThreadSafe
public final class BeanValidator {
	
	private static final BeanValidator instance = new BeanValidator();
	private final ValidatorFactory validatorFactory;
	
	public static BeanValidator getInstance() {
		return instance;
	}

	private BeanValidator() {
		MessageInterpolator messageInterpolator = new ExtendedResourceBundleMessageInterpolator();
		validatorFactory = Validation.byDefaultProvider().configure().messageInterpolator(messageInterpolator).buildValidatorFactory();
	}

	private ValidatorFactory getValidatorFactory() {
		return validatorFactory;
	}
	
	public Validator getValidator() {
		return getValidatorFactory().getValidator();
	}

	/**
	 * Validates a value (property) as indicated by annotations on the domain class
	 * 
	 * @param clazz
	 * @param propertyName
	 * @param newValue
	 * @param groups
	 * @return <constraintViolations> the validation errors
	 */
	public Set<?> validateValue(Class<? extends Object> clazz, String propertyName, Object newValue, Class<?>... groups) {
		return getValidator().validateValue(clazz, propertyName, newValue, groups);
	}

	/**
	 * bean The object to validate
	 * groups
	 */
	public Set<ConstraintViolation<Object>> validateBean(Object bean, Class<?>... groups) {
		return getValidator().validate(bean, groups);
	}
	
	public String getValidationMessage(ConstraintViolation<Object> constraintViolation, Locale locale) {
		
		MessageInterpolatorContext ctx = new ExtendedMessageInterpolatorContext(constraintViolation.getConstraintDescriptor(), constraintViolation.getLeafBean(), constraintViolation);
		ResourceBundle validationMessageResourceBundle = ResourceBundle.getBundle("ValidationMessages", locale, Thread.currentThread().getContextClassLoader());
		MessageInterpolator msgInterpolator = new ExtendedResourceBundleMessageInterpolator(validationMessageResourceBundle);
		String violationMessage = msgInterpolator.interpolate(constraintViolation.getMessageTemplate(), ctx);

		return violationMessage;
	}

}