add Hungarian id number generator

src/main/java/net/datafaker/idnumbers/HungarianIdNumber.java

@@ -0,0 +1,86 @@
+package net.datafaker.idnumbers;
+
+import net.datafaker.providers.base.BaseProviders;
+import net.datafaker.providers.base.IdNumber;
+import net.datafaker.providers.base.PersonIdNumber;
+
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+
+import static java.lang.Character.getNumericValue;
+import static net.datafaker.idnumbers.Utils.randomGender;
+
+/**
+ * Hungarian personal identification number
+ * <p>
+ * The structure of such number is GYYMMDDXXC, whereas
+ * <ul>
+ *  <li>G indicates century of birth and gender,</li>
+ *  <li>YYMMDD indicates birth year, month and day,</li>
+ *  <li>XX is the serial number, and</li>
+ *  <li>C is a checksum digit.</li>
+ * </ul>
+ * <p>
+ * See <a href="https://en.wikipedia.org/wiki/National_identification_number#Hungary">Hungarian identification number</a>
+ */
+public class HungarianIdNumber implements IdNumberGenerator {
+
+    private static final DateTimeFormatter BIRTHDAY_FORMAT = DateTimeFormatter.ofPattern("yyMMdd");
+
+    @Override
+    public String countryCode() {
+        return "HU";
+    }
+
+    @Override
+    public String generateInvalid(BaseProviders faker) {
+        String validIdNumber = generateValid(faker);
+        String basePart = validIdNumber.substring(0, 9);
+        int validCheckDigit = getNumericValue(validIdNumber.charAt(9));
+        int invalidCheckDigit = (validCheckDigit + 1) % 10;
+        return basePart + invalidCheckDigit;
+    }
+
+    @Override
+    public PersonIdNumber generateValid(BaseProviders faker, IdNumber.IdNumberRequest request) {
+        LocalDate birthday = faker.timeAndDate().birthday();
+        PersonIdNumber.Gender gender = randomGender(faker);
+        int checkDigit;
+        String basePart;
+        do {
+            basePart = basePart(faker, birthday, gender);
+            checkDigit = getCheckDigit(basePart);
+        } while (checkDigit == 10);
+
+        String idNumber = basePart + checkDigit;
+        return new PersonIdNumber(idNumber, birthday, gender);
+    }
+
+    private String basePart(BaseProviders faker, LocalDate birthday, PersonIdNumber.Gender gender) {
+        return firstDigit(birthday.getYear(), gender) +
+            BIRTHDAY_FORMAT.format(birthday) +
+            faker.number().digits(2);
+    }
+
+    static int getCheckDigit(String basePart) {
+        char[] numbers = basePart.toCharArray();
+        int summ = 0;
+        for (int i = 0; i < numbers.length; i++) {
+            summ += getNumericValue(numbers[i]) * (i + 1);
+        }
+
+        return summ % 11;
+    }
+
+    static int firstDigit(int birthYear, PersonIdNumber.Gender gender) {
+        return switch (gender) {
+            case MALE -> isInRange(birthYear) ? 1 : 3;
+            case FEMALE -> isInRange(birthYear) ? 2 : 4;
+        };
+    }
+
+    private static boolean isInRange(int birthYear) {
+        return birthYear >= 1900 && birthYear <= 1999;
+    }
+
+}

src/main/resources/META-INF/services/net.datafaker.idnumbers.IdNumberGenerator

@@ -5,6 +5,7 @@ net.datafaker.idnumbers.ChineseIdNumber
 net.datafaker.idnumbers.EstonianIdNumber
 net.datafaker.idnumbers.FrenchIdNumber
 net.datafaker.idnumbers.GeorgianIdNumber
+net.datafaker.idnumbers.HungarianIdNumber
 net.datafaker.idnumbers.ItalianIdNumber
 net.datafaker.idnumbers.LatvianIdNumber
 net.datafaker.idnumbers.MacedonianIdNumber

src/test/java/net/datafaker/helpers/IdNumberPatterns.java

@@ -10,5 +10,6 @@ public class IdNumberPatterns {
     public static final Pattern FRENCH = Pattern.compile("[12]\\d{2}(1[0-2]|0[1-9])\\d[0-9a-zA-Z]\\d{8}");
     public static final Pattern ITALIAN = Pattern.compile("[A-Z]{6}\\d{2}[ABCDEHLMPRST]\\d{2}[\\dA-Z]{5}");
     public static final Pattern POLISH = Pattern.compile("\\d{11}");
+    public static final Pattern HUNGARIAN = Pattern.compile("[1-4]\\d{9}");
 
 }

src/test/java/net/datafaker/idnumbers/HungarianIdNumberTest.java

@@ -0,0 +1,34 @@
+package net.datafaker.idnumbers;
+
+import org.junit.jupiter.api.Test;
+
+import static net.datafaker.providers.base.PersonIdNumber.Gender.FEMALE;
+import static net.datafaker.providers.base.PersonIdNumber.Gender.MALE;
+import static org.assertj.core.api.Assertions.assertThat;
+
+class HungarianIdNumberTest {
+
+    @Test
+    void firstDigit() {
+        assertThat(HungarianIdNumber.firstDigit(1899, MALE)).isEqualTo(3);
+        assertThat(HungarianIdNumber.firstDigit(1900, MALE)).isEqualTo(1);
+        assertThat(HungarianIdNumber.firstDigit(1901, MALE)).isEqualTo(1);
+        assertThat(HungarianIdNumber.firstDigit(1899, FEMALE)).isEqualTo(4);
+        assertThat(HungarianIdNumber.firstDigit(1900, FEMALE)).isEqualTo(2);
+        assertThat(HungarianIdNumber.firstDigit(1901, FEMALE)).isEqualTo(2);
+        assertThat(HungarianIdNumber.firstDigit(1999, MALE)).isEqualTo(1);
+        assertThat(HungarianIdNumber.firstDigit(2000, MALE)).isEqualTo(3);
+        assertThat(HungarianIdNumber.firstDigit(1999, FEMALE)).isEqualTo(2);
+        assertThat(HungarianIdNumber.firstDigit(2000, FEMALE)).isEqualTo(4);
+    }
+
+    @Test
+    void checkDigit() {
+        assertThat(HungarianIdNumber.getCheckDigit("807159215")).isEqualTo(3);
+        assertThat(HungarianIdNumber.getCheckDigit("100000000")).isEqualTo(1);
+        assertThat(HungarianIdNumber.getCheckDigit("010000000")).isEqualTo(2);
+        assertThat(HungarianIdNumber.getCheckDigit("001000000")).isEqualTo(3);
+        assertThat(HungarianIdNumber.getCheckDigit("000000001")).isEqualTo(9);
+        assertThat(HungarianIdNumber.getCheckDigit("170010103")).isEqualTo(10);
+    }
+}

src/test/java/net/datafaker/providers/base/IdNumberTest.java

@@ -34,6 +34,7 @@ class IdNumberTest extends BaseFakerTest<BaseFaker> {
     private static final Faker UKRAINIAN = new Faker(new Locale("uk", "UA"));
     private static final Faker FRENCH = new Faker(new Locale("fr", "FR"));
     private static final Faker ITALIAN = new Faker(new Locale("it", "IT"));
+    private static final Faker HUNGARIAN = new Faker(new Locale("hu", "HU"));
 
     @Test
     void testValid() {
@@ -235,6 +236,16 @@ void italianIdNumber() {
         assertThatPin(ITALIAN.idNumber().valid()).matches(IdNumberPatterns.ITALIAN);
     }
 
+    @RepeatedTest(100)
+    void hungarianIdNumber_valid() {
+        assertThatPin(HUNGARIAN.idNumber().valid()).matches(IdNumberPatterns.HUNGARIAN);
+    }
+
+    @RepeatedTest(100)
+    void hungarianIdNumber_invalid() {
+        assertThatPin(HUNGARIAN.idNumber().invalid()).matches(IdNumberPatterns.HUNGARIAN);
+    }
+
     private static AbstractStringAssert<?> assertThatPin(String pin) {
         return assertThat(pin)
             .as(() -> "PIN: %s".formatted(pin));