Add centralized constants module and .env configuration support

app/whois.py

@@ -9,22 +9,23 @@ import os
 import re
 from typing import Iterable
 
-from .ip_utils import ip_version, parse_ip
-
-# WHOIS Cache file path
-_WHOIS_CACHE_PATH = os.path.join(
-    os.path.dirname(os.path.dirname(os.path.abspath(__file__))
-                    ), "data", "whois_cache.json"
+from .constants import (
+    SUBNET_THRESHOLD,
+    WHOIS_CACHE_PATH,
+    WHOIS_PORT,
+    WHOIS_SERVER,
+    WHOIS_TIMEOUT,
 )
+from .ip_utils import ip_version, parse_ip
 
 _whois_cache: dict[str, str] = {}
 
 
 def load_whois_cache() -> None:
     global _whois_cache
-    if not _whois_cache and os.path.exists(_WHOIS_CACHE_PATH):
+    if not _whois_cache and os.path.exists(WHOIS_CACHE_PATH):
         try:
-            with open(_WHOIS_CACHE_PATH, "r", encoding="utf-8") as f:
+            with open(WHOIS_CACHE_PATH, "r", encoding="utf-8") as f:
                 _whois_cache = json.load(f)
         except Exception:
             _whois_cache = {}
@@ -32,9 +33,9 @@ def load_whois_cache() -> None:
 
 def save_whois_cache() -> None:
     if _whois_cache:
-        os.makedirs(os.path.dirname(_WHOIS_CACHE_PATH), exist_ok=True)
+        os.makedirs(os.path.dirname(WHOIS_CACHE_PATH), exist_ok=True)
         try:
-            with open(_WHOIS_CACHE_PATH, "w", encoding="utf-8") as f:
+            with open(WHOIS_CACHE_PATH, "w", encoding="utf-8") as f:
                 json.dump(_whois_cache, f, indent=2)
         except Exception:
             pass
@@ -53,8 +54,8 @@ def query_whois_subnet(ip: str) -> str | None:
     import socket
     try:
         s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        s.settimeout(3.0)
-        s.connect(("whois.radb.net", 43))
+        s.settimeout(WHOIS_TIMEOUT)
+        s.connect((WHOIS_SERVER, WHOIS_PORT))
         s.sendall(f"{ip}\r\n".encode())
         res = ""
         while True:
@@ -89,7 +90,8 @@ def query_whois_subnet(ip: str) -> str | None:
     return subnet_str
 
 
-def consolidate_by_subnet(ips: Iterable[str], threshold: int = 3) -> set[str]:
+def consolidate_by_subnet(ips: Iterable[str],
+                          threshold: int = SUBNET_THRESHOLD) -> set[str]:
     """Group IPs by WHOIS subnet; if >= threshold IPs in a subnet, block the subnet.
 
     Otherwise, block individual IPs.
@@ -124,7 +126,3 @@ def consolidate_by_subnet(ips: Iterable[str], threshold: int = 3) -> set[str]:
                     f"{ip}/32" if ip_version(ip) == 4 else f"{ip}/128")
 
     return blocked_targets
-
-
-# Re-export path for backward compat
-WHOIS_CACHE_PATH = _WHOIS_CACHE_PATH