implemented

backend/validation.py

@@ -1,7 +1,19 @@
 """Validation utilities for user profile fields."""
+import json
+from pathlib import Path
+
 from email_validator import validate_email, EmailNotValidError
 from bech32 import bech32_decode
 
+# Load validation rules from shared constants
+_constants_path = Path(__file__).parent.parent / "shared" / "constants.json"
+with open(_constants_path) as f:
+    _constants = json.load(f)
+
+TELEGRAM_RULES = _constants["validation"]["telegram"]
+SIGNAL_RULES = _constants["validation"]["signal"]
+NPUB_RULES = _constants["validation"]["nostrNpub"]
+
 
 def validate_contact_email(value: str | None) -> str | None:
     """
@@ -24,22 +36,25 @@ def validate_telegram(value: str | None) -> str | None:
     """
     Validate Telegram handle.
     
-    Must start with @ if provided, with 1-32 characters after @.
+    Must start with @ if provided, with characters after @ within max length.
     Returns None if valid, error message if invalid.
     Empty/None values are valid (field is optional).
     """
     if not value:
         return None
     
-    if not value.startswith("@"):
-        return "Telegram handle must start with @"
+    prefix = TELEGRAM_RULES["mustStartWith"]
+    max_len = TELEGRAM_RULES["maxLengthAfterAt"]
+    
+    if not value.startswith(prefix):
+        return f"Telegram handle must start with {prefix}"
     
     handle = value[1:]
     if not handle:
-        return "Telegram handle must have at least one character after @"
+        return f"Telegram handle must have at least one character after {prefix}"
     
-    if len(handle) > 32:
-        return "Telegram handle must be at most 32 characters (after @)"
+    if len(handle) > max_len:
+        return f"Telegram handle must be at most {max_len} characters (after {prefix})"
     
     return None
 
@@ -48,19 +63,21 @@ def validate_signal(value: str | None) -> str | None:
     """
     Validate Signal username.
     
-    Any non-empty string is valid.
+    Any non-empty string within max length is valid.
     Returns None if valid, error message if invalid.
     Empty/None values are valid (field is optional).
     """
     if not value:
         return None
     
+    max_len = SIGNAL_RULES["maxLength"]
+    
     # Signal usernames are fairly permissive, just check it's not empty
     if len(value.strip()) == 0:
         return "Signal username cannot be empty"
     
-    if len(value) > 64:
-        return "Signal username must be at most 64 characters"
+    if len(value) > max_len:
+        return f"Signal username must be at most {max_len} characters"
     
     return None
 
@@ -76,8 +93,11 @@ def validate_nostr_npub(value: str | None) -> str | None:
     if not value:
         return None
     
-    if not value.startswith("npub1"):
-        return "Nostr npub must start with 'npub1'"
+    prefix = NPUB_RULES["prefix"]
+    expected_words = NPUB_RULES["bech32Words"]
+    
+    if not value.startswith(prefix):
+        return f"Nostr npub must start with '{prefix}'"
     
     # Decode bech32 to validate checksum
     hrp, data = bech32_decode(value)
@@ -90,7 +110,7 @@ def validate_nostr_npub(value: str | None) -> str | None:
     
     # npub should decode to 32 bytes (256 bits) for a public key
     # In bech32, each character encodes 5 bits, so 32 bytes = 52 characters of data
-    if len(data) != 52:
+    if len(data) != expected_words:
         return "Invalid Nostr npub: incorrect length"
     
     return None