package eu.ztsh.wymiana.validation;

import jakarta.validation.ConstraintValidator;
import jakarta.validation.ConstraintValidatorContext;

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
import java.time.format.DateTimeParseException;
import java.util.Arrays;
import java.util.Objects;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

public class AdultValidator implements ConstraintValidator<Adult, String> {

    private final Pattern pattern = Pattern.compile("\\d{11}");
    private final DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyyMMdd");

    @Override
    public boolean isValid(String value, ConstraintValidatorContext context) {
        if (!pattern.matcher(value).matches()) {
            return false;
        }
        var datePart = Arrays.stream(value.substring(0, 6).split("")).map(Integer::parseInt).toArray(Integer[]::new);
        final String prefix;
        if (datePart[2] > 1) {
            datePart[2] = (datePart[2] - 2);
            prefix = "20";
        } else {
            prefix = "19";
        }
        var dateStamp = prefix.concat(Arrays.stream(datePart).map(Objects::toString).collect(Collectors.joining()));
        try {
            return LocalDate.parse(dateStamp, dtf)
                .plusYears(18)
                .isBefore(LocalDate.now(context.getClockProvider().getClock()));
        } catch (DateTimeParseException exception) {
            return false;
        }
    }

}