package org.mongodb.morphia.query.validation;

import java.util.List;

Provides validation based on the Value in the query
/**
 * Provides validation based on the Value in the query
 */
public abstract class ValueValidator implements Validator {
    
Applied validation for the given field.  If the value does not match the correct type, the validation is not applied and this method
returns false.  If the value is to be validated, then the validate method is called to see if the value and type are compatible.
Errors are appended to the validationFailures list.
Params:
type –               the Class of the field being queried
value –              the non-null value being used for a query
validationFailures – the list to add any failures to. If validation passes or appliesTo returned false, this list will not change.
Returns:
true if validation was applied, false if this validation doesn't apply to this field type./**
     * Applied validation for the given field.  If the value does not match the correct type, the validation is not applied and this method
     * returns false.  If the value is to be validated, then the validate method is called to see if the value and type are compatible.
     * Errors are appended to the validationFailures list.
     *
     * @param type               the Class of the field being queried
     * @param value              the non-null value being used for a query
     * @param validationFailures the list to add any failures to. If validation passes or {@code appliesTo} returned false, this list will
     *                           not change.
     * @return true if validation was applied, false if this validation doesn't apply to this field type.
     */
    public boolean apply(final Class<?> type, final Object value, final List<ValidationFailure> validationFailures) {
        if (getRequiredValueType().isAssignableFrom(value.getClass())) {
            validate(type, value, validationFailures);
            return true;
        }
        return false;
    }

    
Used by apply to figure out whether to apply the validation or simply return. 
Returns:
the class the value should be in order to go ahead and perform validation/**
     * Used by {@code apply} to figure out whether to apply the validation or simply return.
     *
     * @return the class the value should be in order to go ahead and perform validation
     */
    protected abstract Class<?> getRequiredValueType();

    protected abstract void validate(final Class<?> type, final Object value, final List<ValidationFailure> validationFailures);
}