Initial commit: VPN Telegram bot (sanitized defaults)

services/topup_codes.py

@@ -0,0 +1,31 @@
+"""Коды пополнения баланса."""
+
+from __future__ import annotations
+
+import re
+import secrets
+import string
+
+# Без похожих символов O/0, I/1, L
+_CODE_ALPHABET = "".join(
+    c for c in (string.ascii_uppercase + string.digits) if c not in "O0IL1"
+)
+_CODE_RE = re.compile(r"^[A-Z0-9]{4}(?:-[A-Z0-9]{4}){3}$")
+
+
+def normalize_code(raw: str) -> str:
+    """XXXX-XXXX-XXXX-XXXX из произвольного ввода."""
+    cleaned = "".join(ch for ch in (raw or "").upper() if ch.isalnum())
+    if len(cleaned) != 16:
+        return cleaned
+    return "-".join(cleaned[i : i + 4] for i in range(0, 16, 4))
+
+
+def is_valid_code_format(code: str) -> bool:
+    norm = normalize_code(code)
+    return bool(_CODE_RE.fullmatch(norm))
+
+
+def generate_code() -> str:
+    parts = ["".join(secrets.choice(_CODE_ALPHABET) for _ in range(4)) for _ in range(4)]
+    return "-".join(parts)