06/15 Phase 3 codes

app/services/contact.py

@@ -0,0 +1,48 @@
+"""Contact masking.
+
+Phone numbers and email addresses in listing bodies / messages are masked
+for low-trust senders to push communication through the in-site channel.
+Unmasked only once sender reaches TrustTier.trusted or verified_email=True.
+
+Masking is a display-layer concern: raw body stored as-is; masked on render.
+For the *sending* side we heuristic-flag high-contact-density messages so
+moderators can spot scraping attempts.
+"""
+import re
+from app.models.enums import TrustTier
+
+# patterns
+_PHONE_RE = re.compile(
+    r"(\+?1[\s\-.]?)?"
+    r"(\(?\d{3}\)?[\s\-.])"
+    r"\d{3}[\s\-.]\d{4}"
+)
+_EMAIL_RE = re.compile(r"[A-Za-z0-9._%+\-]+@[A-Za-z0-9.\-]+\.[A-Za-z]{2,}")
+_URL_RE   = re.compile(r"https?://\S+|www\.\S+", re.I)
+
+
+def contact_revealed(user) -> bool:
+    """True when this user's contact info may be shown unmasked."""
+    if user is None:
+        return False
+    return (user.email_verified and
+            user.trust_tier in (TrustTier.trusted, TrustTier.verified))
+
+
+def mask_body(text: str, reveal: bool = False) -> str:
+    """Optionally mask phones, emails, and URLs in a block of text."""
+    if reveal or not text:
+        return text
+    text = _PHONE_RE.sub("[phone hidden]", text)
+    text = _EMAIL_RE.sub("[email hidden]", text)
+    text = _URL_RE.sub("[link hidden]", text)
+    return text
+
+
+def contact_density(text: str) -> int:
+    """Count how many contact signals appear in text (for heuristic flagging)."""
+    if not text:
+        return 0
+    return (len(_PHONE_RE.findall(text))
+            + len(_EMAIL_RE.findall(text))
+            + len(_URL_RE.findall(text)))