From 6f59874d9ed22783310805be1d7aa4d3f0adb0e7 Mon Sep 17 00:00:00 2001
From: Serhii Lozytskyi <42421616+lozik4@users.noreply.github.com>
Date: Mon, 29 Jan 2024 19:10:26 +0200
Subject: [PATCH] Add support for birthday and gender to  `uk_UA` `ssn` method
 (#1983)

* feat(ssn)Add support uk_Ua ssn method birthday and gender optional params

* Fix unit test name capitalization

---------

Co-authored-by: Flavio Curella <89607+fcurella@users.noreply.github.com>
---
 faker/providers/ssn/uk_UA/__init__.py | 77 +++++++++++++++++----------
 tests/providers/test_ssn.py           | 28 ++++++++++
 2 files changed, 78 insertions(+), 27 deletions(-)

diff --git a/faker/providers/ssn/uk_UA/__init__.py b/faker/providers/ssn/uk_UA/__init__.py
index 4848d6113a..e647be2da1 100644
--- a/faker/providers/ssn/uk_UA/__init__.py
+++ b/faker/providers/ssn/uk_UA/__init__.py
@@ -1,36 +1,59 @@
-from datetime import date
+import random
 
+from datetime import date, datetime
+from typing import Optional
+
+from ....typing import SexLiteral
 from .. import Provider as SsnProvider
 
 
+def select_gender(gender: SexLiteral) -> int:
+    """Choose an even number for Female and odd number for Male."""
+    gender = 0 if gender.lower() == "f" else 1
+    return random.choice(range(gender, 10, 2))
+
+
+def calculate_day_count(birthday: date) -> int:
+    """Calculate the day count from reference date '31 December 1899'."""
+    ref_date = date(1899, 12, 31)
+    return (birthday - ref_date).days
+
+
+def calculate_check_sum(val: str) -> int:
+    """Calculate checksum using INN calculation method."""
+    weights = [-1, 5, 7, 9, 4, 6, 10, 5, 7]
+    checksum = sum(int(v) * w for v, w in zip(val, weights))
+
+    return checksum % 11 % 10
+
+
 class Provider(SsnProvider):
-    def ssn(self) -> str:
+    def ssn(self, birthday: Optional[str] = None, gender: Optional[SexLiteral] = None) -> str:
         """
         Ukrainian "Реєстраційний номер облікової картки платника податків"
         also known as "Ідентифікаційний номер фізичної особи".
+        @params: birthday: "DD-MM-YYYY" format, default random date
+        @params: gender: "M" or "F" default: random gender
+
+        :sample:
+        :sample: birthday='22-06-1990', gender='F'
         """
-        digits = []
-
-        # Number of days between 1899-12-31 and a birth date
-        for digit in str((self.generator.date_object() - date(1899, 12, 31)).days):
-            digits.append(int(digit))
-
-        # Person's sequence number
-        for _ in range(4):
-            digits.append(self.random_int(0, 9))
-
-        checksum = (
-            digits[0] * -1
-            + digits[1] * 5
-            + digits[2] * 7
-            + digits[3] * 9
-            + digits[4] * 4
-            + digits[5] * 6
-            + digits[6] * 10
-            + digits[7] * 5
-            + digits[8] * 7
-        )
-        # Remainder of a checksum divided by 11 or 1 if it equals to 10
-        digits.append(checksum % 11 % 10)
-
-        return "".join(str(digit) for digit in digits)
+
+        try:
+            # generate day of birthday date object
+            if birthday:
+                dob = datetime.strptime(birthday, "%d-%m-%Y").date()
+            else:
+                dob = self.generator.date_object()
+        except Exception:
+            raise ValueError("Birthday format must be DD-MM-YYYY")
+
+        if gender and gender not in ("M", "F"):
+            raise ValueError('Gender must be "m" or "f" or None')
+
+        day_count = calculate_day_count(dob)
+        people_num = self.random_number(3, fix_len=True)
+        gender_ = select_gender(gender) if gender else random.randint(0, 1)
+        ssn_without_checksum = f"{day_count}{people_num}{gender_}"
+        checksum = calculate_check_sum(ssn_without_checksum)
+        return f"{ssn_without_checksum}{checksum}"
diff --git a/tests/providers/test_ssn.py b/tests/providers/test_ssn.py
index b41f08d206..a4955c326b 100644
--- a/tests/providers/test_ssn.py
+++ b/tests/providers/test_ssn.py
@@ -34,6 +34,7 @@
 from faker.providers.ssn.pt_BR import checksum as pt_checksum
 from faker.providers.ssn.ro_RO import ssn_checksum as ro_ssn_checksum
 from faker.providers.ssn.ro_RO import vat_checksum as ro_vat_checksum
+from faker.providers.ssn.uk_UA import Provider as uk_Provider
 from faker.providers.ssn.zh_TW import checksum as tw_checksum
 from faker.utils.checksums import luhn_checksum
 
@@ -1364,3 +1365,30 @@ def test_gender(self):
     def test_checksum(self):
         for sample in self.samples:
             assert tw_checksum(sample) % 10 == 0
+
+
+class TestUkUA(unittest.TestCase):
+    def setUp(self):
+        self.fake = Faker("uk_Ua")
+        Faker.seed(0)
+        self.provider = uk_Provider
+
+    def test_ssn_len(self):
+        assert len(self.fake.ssn()) == 10
+
+    def test_start_ssn(self):
+        assert self.fake.ssn("21-06-1994")[:5] == "34505"
+
+    def test_ssn_gender(self):
+        m = self.fake.ssn(gender="M")
+        w = self.fake.ssn(gender="F")
+        assert int(m[8]) % 2 != 0, "Must be odd for men"
+        assert int(w[8]) % 2 == 0, "Must be even for women"
+
+    def test_incorrect_birthday(self):
+        with pytest.raises(ValueError):
+            self.fake.ssn(birthday="1994-06-01")
+
+    def test_incorrect_gender(self):
+        with pytest.raises(ValueError):
+            self.fake.ssn(gender="f")