Create config.py

config.py

@@ -0,0 +1,31 @@
+import os
+import json
+from functools import lru_cache
+from google.cloud import firestore
+from google.oauth2 import service_account
+
+@lru_cache(maxsize=1)
+def get_db() -> firestore.Client:
+    """
+    Creates a Firestore client using one of:
+      1) Emulator (FIRESTORE_EMULATOR_HOST)
+      2) FIREBASE_CREDENTIALS_JSON (stringified service account JSON)
+      3) ADC (GOOGLE_APPLICATION_CREDENTIALS)
+    """
+    # Prefer explicit project envs; otherwise pull from SA JSON
+    proj = os.getenv("GOOGLE_CLOUD_PROJECT") or os.getenv("FIREBASE_PROJECT_ID")
+
+    # 1) Emulator
+    if os.getenv("FIRESTORE_EMULATOR_HOST"):
+        return firestore.Client(project=proj or "local-dev")
+
+    # 2) Service account JSON in env
+    creds_env = os.getenv("FIREBASE_CREDENTIALS_JSON")
+    if creds_env:
+        info = json.loads(creds_env)
+        creds = service_account.Credentials.from_service_account_info(info)
+        project_id = proj or info.get("project_id") or "unknown-project"
+        return firestore.Client(project=project_id, credentials=creds)
+
+    # 3) ADC fallback
+    return firestore.Client(project=proj or None)