register and sign in pages

backend/users/mobile.py

@@ -0,0 +1,29 @@
+"""Maldives mobile number normalisation.
+
+Everything past the serializer layer deals in E.164 (`+960XXXXXXX`) so a
+number is stored and looked up exactly one way.
+"""
+
+import re
+
+from django.core.exceptions import ValidationError
+
+COUNTRY_CODE = "960"
+LOCAL_LENGTH = 7
+# Maldives mobile prefixes are 7xx and 9xx.
+LOCAL_RE = re.compile(r"^[79]\d{6}$")
+
+
+def normalize_mobile(value: str) -> str:
+    """Return `value` as +960XXXXXXX, or raise ValidationError."""
+    digits = re.sub(r"[\s()-]", "", str(value or "")).lstrip("+")
+
+    if digits.startswith("00" + COUNTRY_CODE):
+        digits = digits[len("00" + COUNTRY_CODE) :]
+    elif digits.startswith(COUNTRY_CODE) and len(digits) > LOCAL_LENGTH:
+        digits = digits[len(COUNTRY_CODE) :]
+
+    if not LOCAL_RE.match(digits):
+        raise ValidationError("Enter a valid Maldives mobile number.")
+
+    return f"+{COUNTRY_CODE}{digits}"