/*
 * Copyright 2017-2020 original authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.micronaut.validation.validator.constraints;

import io.micronaut.core.annotation.AnnotationValue;

import edu.umd.cs.findbugs.annotations.NonNull;
import edu.umd.cs.findbugs.annotations.Nullable;
import javax.validation.constraints.Digits;
import java.math.BigDecimal;

Abstract Digits validator implementation. 
Author:
graemerocher
Type parameters:
<T> – The target type
Since:
1.2/**
 * Abstract {@link Digits} validator implementation.
 * @param <T> The target type
 *
 * @author graemerocher
 * @since 1.2
 */
@FunctionalInterface
public interface DigitsValidator<T> extends ConstraintValidator<Digits, T> {
    @Override
    default boolean isValid(@Nullable T value, @NonNull AnnotationValue<Digits> annotationMetadata, @NonNull ConstraintValidatorContext context) {
        if (value == null) {
            // null valid according to spec
            return true;
        }
        final int intMax = annotationMetadata.get("integer", int.class).orElse(0);

        if (intMax < 0) {
            throw new IllegalArgumentException("The length of the integer part cannot be negative.");
        }

        final int fracMax = annotationMetadata.get("fraction", int.class).orElse(0);
        if (fracMax < 0) {
            throw new IllegalArgumentException("The length of the fraction part cannot be negative.");
        }

        BigDecimal bigDecimal;
        try {
            bigDecimal = getBigDecimal(value);
        } catch (NumberFormatException e) {
            return false;
        }

        int intLen = bigDecimal.precision() - bigDecimal.scale();
        int fracLen = bigDecimal.scale() < 0 ? 0 : bigDecimal.scale();

        return intMax >= intLen && fracMax >= fracLen;
    }

    
Resolve a big decimal for the given value.
Params:
value – The value
Returns:
The big decimal/**
     * Resolve a big decimal for the given value.
     * @param value The value
     * @return The big decimal
     */
    BigDecimal getBigDecimal(@NonNull T value);
}