api/src/main/java/io/mifos/portfolio/api/v1/validation/CheckValidLossProvisionList.java

/*
 * Copyright 2017 Kuelap, Inc.
 *
 * 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
 *
 *    http://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.mifos.portfolio.api.v1.validation;

import io.mifos.individuallending.api.v1.domain.product.LossProvisionStep;

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * @author Myrle Krantz
 */
public class CheckValidLossProvisionList implements ConstraintValidator<ValidLossProvisionList, List<LossProvisionStep>> {
  @Override
  public void initialize(ValidLossProvisionList constraintAnnotation) {

  }

  @Override
  public boolean isValid(
      final List<LossProvisionStep> value,
      final ConstraintValidatorContext context) {
    if (value == null) return false;
    final Map<Integer, Long> configurationsPerDay = value.stream()
        .collect(Collectors.groupingBy(LossProvisionStep::getDaysLate, Collectors.counting()));
    final boolean moreThanOneConfigurationForAtLeastOneDay = configurationsPerDay.values().stream()
        .anyMatch(x -> x > 1);
    return !moreThanOneConfigurationForAtLeastOneDay;
  }
}