package org.mongodb.morphia.query.validation;

import org.mongodb.morphia.mapping.MappedField;
import org.mongodb.morphia.query.FilterOperator;

import java.util.List;

import static java.lang.String.format;
import static org.mongodb.morphia.query.FilterOperator.SIZE;
import static org.mongodb.morphia.query.validation.ValueClassValidator.valueIsClassOrSubclassOf;

Checks if the value can have the FilterOperator.ALL operator applied to it. Since this class does not need state, and the methods can't be static because it implements an interface, it seems to be one of the few places where the Singleton pattern seems appropriate. /**
 * Checks if the value can have the {@code FilterOperator.ALL} operator applied to it.  Since this class does not need state, and the
 * methods can't be static because it implements an interface, it seems to be one of the few places where the Singleton pattern seems
 * appropriate.
 */
public final class SizeOperationValidator extends OperationValidator {
    private static final SizeOperationValidator INSTANCE = new SizeOperationValidator();

    private SizeOperationValidator() {
    }

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

    @Override
    protected FilterOperator getOperator() {
        return SIZE;
    }

    @Override
    protected void validate(final MappedField mappedField, final Object value,
                            final List<ValidationFailure> validationFailures) {
        if (!valueIsClassOrSubclassOf(value, Number.class)) {
            validationFailures.add(new ValidationFailure(format("For a $size operation, value '%s' should be an integer type.  "
                                                                + "Instead it was a: %s", value, value.getClass())));

        }
        if (!CollectionTypeValidator.typeIsIterableOrArrayOrMap(mappedField.getType())) {
            validationFailures.add(new ValidationFailure(format("For a $size operation, field '%s' should be a List or array.  "
                                                                + "Instead it was a: %s",
                                                                mappedField, mappedField.getType())));
        }
    }
}