feat(webhook): is_repo_enabled reads .pr-review.json:enabled

pilot/webhook_server.py

@@ -34,14 +34,16 @@ Env:
                        (optional) request-body cap, default 10 MiB
 """
 
+import base64
 import hashlib
 import hmac
 import json
 import os
 import threading
+import urllib.parse
 from http.server import BaseHTTPRequestHandler, ThreadingHTTPServer
 
-from ai_review import review_pr
+from ai_review import gitea_get, review_pr
 
 try:
     import feedback_harvest  # optional — absent in CI-step pod, present in
@@ -109,6 +111,31 @@ def _labels_have_ai_review(labels) -> bool:
     return _labels_have(labels, AI_REVIEW_LABEL)
 
 
+def is_repo_enabled(api: str, repo: str, ref: str, token: str) -> bool:
+    """True iff `.pr-review.json` on `ref` has `"enabled": true`.
+
+    Reads from the given ref (typically the PR's base ref). False on any
+    failure: 404, parse error, missing file, missing `enabled`, wrong type.
+    The bool-coerce of `.get("enabled") is True` rejects the common
+    gotchas (`null`, `1`, `"yes"`, missing field all yield False).
+    """
+    code, raw = gitea_get(
+        api, repo,
+        "contents/.pr-review.json?ref=" + urllib.parse.quote(ref, safe=""),
+        token,
+    )
+    if code != 200:
+        return False
+    try:
+        data = json.loads(raw)
+        content_b64 = data.get("content", "").replace("\n", "")
+        decoded = base64.b64decode(content_b64).decode("utf-8", errors="replace")
+        cfg = json.loads(decoded)
+    except (json.JSONDecodeError, ValueError):
+        return False
+    return isinstance(cfg, dict) and cfg.get("enabled") is True
+
+
 def _verify_signature(raw_body: bytes, headers) -> bool:
     if not WEBHOOK_SECRET:
         return False  # refuse to run without a configured secret

tests/pilot/test_webhook_server.py

@@ -1,4 +1,5 @@
 """Unit tests for the webhook receiver's gating, dedupe and limits. No network."""
+import base64
 import os
 import sys
 import threading
@@ -134,3 +135,35 @@ def test_missing_label_is_ignored(monkeypatch):
 def test_review_slots_bound_matches_config():
     assert ws.MAX_CONCURRENT >= 1
     assert ws._review_slots._value <= ws.MAX_CONCURRENT
+
+
+# ---------------------------------------------------------------------------
+# is_repo_enabled — reads `.pr-review.json` from the PR base ref and parses
+# its `enabled` flag. False on any failure (404, parse error, missing field).
+# ---------------------------------------------------------------------------
+
+
+def test_is_repo_enabled_returns_false_when_404(monkeypatch):
+    monkeypatch.setattr(
+        "webhook_server.gitea_get",
+        lambda *a, **kw: (404, b'{"message":"not found"}'),
+    )
+    assert ws.is_repo_enabled("api", "owner/repo", "main", "tok") is False
+
+
+def test_is_repo_enabled_returns_true_when_enabled(monkeypatch):
+    body = b'{"content":"' + base64.b64encode(b'{"enabled": true}').decode().encode() + b'"}'
+    monkeypatch.setattr("webhook_server.gitea_get", lambda *a, **kw: (200, body))
+    assert ws.is_repo_enabled("api", "owner/repo", "main", "tok") is True
+
+
+def test_is_repo_enabled_returns_false_when_disabled(monkeypatch):
+    body = b'{"content":"' + base64.b64encode(b'{"enabled": false}').decode().encode() + b'"}'
+    monkeypatch.setattr("webhook_server.gitea_get", lambda *a, **kw: (200, body))
+    assert ws.is_repo_enabled("api", "owner/repo", "main", "tok") is False
+
+
+def test_is_repo_enabled_returns_false_when_field_missing(monkeypatch):
+    body = b'{"content":"' + base64.b64encode(b'{}').decode().encode() + b'"}'
+    monkeypatch.setattr("webhook_server.gitea_get", lambda *a, **kw: (200, body))
+    assert ws.is_repo_enabled("api", "owner/repo", "main", "tok") is False