From 5df3f2bf292592c438bc35f40e5498c16c7d005a Mon Sep 17 00:00:00 2001
From: Jan <jdolkowski@soldevelo.com>
Date: Tue, 31 Oct 2023 14:05:25 +0100
Subject: [PATCH] OM-10: add worker number validation (#9)

Co-authored-by: Jan <j.dolkowski@soldevelo.com>
---
 msystems/utils.py | 57 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 msystems/utils.py

diff --git a/msystems/utils.py b/msystems/utils.py
new file mode 100644
index 0000000..bf316ef
--- /dev/null
+++ b/msystems/utils.py
@@ -0,0 +1,57 @@
+from django.utils.translation import gettext as _
+from insuree.apps import InsureeConfig
+
+ZERO_CHAR = '0'
+ONE_CHAR = '1'
+TWO_CHAR = '2'
+THREE_CHAR = '3'
+NINE_CHAR = '9'
+ZERO_NINE_STR = '09'
+
+
+def generate_error_return(instance_name_str, checksum_return=False):
+    if checksum_return:
+        return [{"errorCode": InsureeConfig.validation_code_invalid_insuree_number_checksum,
+                 "message": _(f"{instance_name_str}_national_id_checksum_not_valid")}]
+    else:
+        return [{"errorCode": InsureeConfig.validation_code_invalid_insuree_number_exception,
+                 "message": _(f"{instance_name_str}_national_id_not_valid")}]
+
+
+def is_valid(idn):
+    """
+    A function for validating Moldovan national identification numbers (IDs).
+    Can be specified as an insuree number validator in apps.py config with the key: "insuree_number_validator"
+    Example: "insuree_number_validator": IdentifierValidator().is_valid_resident_identifier
+    """
+    if idn is None or len(idn) != 13 or not idn.strip():
+        return False
+    crc = 0
+    for i in range(12):
+        if not (ZERO_CHAR <= idn[i] <= NINE_CHAR):
+            return False
+        crc += (ord(idn[i]) - ord(ZERO_CHAR)) * (7 if i % 3 == 0 else (3 if i % 3 == 1 else 1))
+    if not (ZERO_CHAR <= idn[12] <= NINE_CHAR):
+        return False
+    return crc % 10 == (ord(idn[12]) - ord(ZERO_CHAR))
+
+
+def is_valid_resident_identifier(idnp):
+    if not is_valid(idnp):
+        return generate_error_return("resident")
+    if not (idnp[0] == TWO_CHAR or idnp.startswith(ZERO_NINE_STR)):
+        return generate_error_return("resident", checksum_return=True)
+
+
+def is_valid_organization_identifier(idno):
+    if not is_valid(idno):
+        return generate_error_return("organization")
+    if not idno[0] == ONE_CHAR:
+        return generate_error_return("organization", checksum_return=True)
+
+
+def is_valid_vehicle_identifier(idnv):
+    if not is_valid(idnv):
+        return generate_error_return("vehicle")
+    if not idnv[0] == THREE_CHAR:
+        return generate_error_return("vehicle", checksum_return=True)