package org.mongodb.morphia.query.validation;

import org.mongodb.morphia.mapping.MappedClass;
import org.mongodb.morphia.mapping.MappedField;

import java.util.List;

import static java.lang.String.format;

Checks the class of the value against the type of the ID for the type.
/**
 * Checks the class of the value against the type of the ID for the type.
 */
public final class EntityTypeAndIdValueValidator implements Validator {
    private static final EntityTypeAndIdValueValidator INSTANCE = new EntityTypeAndIdValueValidator();

    private EntityTypeAndIdValueValidator() {
    }
    //TODO: I think this should be possible with the MappedField, not the type

    
Get the instance.
Returns:
the Singleton instance of this validator/**
     * Get the instance.
     *
     * @return the Singleton instance of this validator
     */
    public static EntityTypeAndIdValueValidator getInstance() {
        return INSTANCE;
    }

    
Checks the class of the value against the type of the ID for the type. Always applies this validation, but there's room to change this to not apply it if, for example, the type is not an entity. 
Params:
mappedClass –        the MappedClass
mappedField –        the MappedField
value –              the value for the query
validationFailures – the list to add any failures to. If validation passes or appliesTo returned false, this list will not change. @return true if the validation was applied./**
     * Checks the class of the {@code value} against the type of the ID for the {@code type}.  Always applies this validation, but there's
     * room to change this to not apply it if, for example, the type is not an entity.
     *
     * @param mappedClass        the MappedClass
     * @param mappedField        the MappedField
     * @param value              the value for the 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 the validation was applied.
     */
    public boolean apply(final MappedClass mappedClass, final MappedField mappedField, final Object value,
                         final List<ValidationFailure> validationFailures) {
        if (appliesTo(mappedClass, mappedField)) {
            Class classOfValue = value.getClass();
            Class classOfIdFieldForType = mappedClass.getMappedIdField().getConcreteType();
            if (!mappedField.getType().equals(classOfValue) && !classOfValue.equals(classOfIdFieldForType)) {
                validationFailures.add(new ValidationFailure(format("The value class needs to match the type of ID for the field. "
                                                                    + "Value was %s and was a %s and the ID of the type was %s",
                                                                    value, classOfValue, classOfIdFieldForType)));
            }
            return true;
        }
        return false;
    }

    private boolean appliesTo(final MappedClass mappedClass, final MappedField mappedField) {
        return mappedField != null && mappedField.equals(mappedClass.getMappedIdField());
    }
}