bridge: configurable Nextcloud request timeout, dynamic Health metric discovery

Auto-detect which Health metrics the instance actually knows and enable
any that are known but disabled for the user, via GET/PUT configuration.
Also makes the previously hardcoded 10s request timeout configurable via
NC_TIMEOUT_SECONDS to accommodate slower instances.

bridge/server.py

@@ -31,10 +31,58 @@ except KeyError:
 credentials = json.loads(CREDENTIALS_FILE.read_text())
 NC_SERVER = credentials["server"]
 NC_AUTH = (credentials["login_name"], credentials["app_password"])
-ENTRIES_URL = f"{NC_SERVER}/ocs/v2.php/apps/health/api/v2/entries"
+HEALTH_API = f"{NC_SERVER}/ocs/v2.php/apps/health/api/v2"
+ENTRIES_URL = f"{HEALTH_API}/entries"
+CONFIGURATION_URL = f"{HEALTH_API}/configuration"
 # Identifies this bridge in Nextcloud's server logs and admin UI instead of the
 # default "python-requests/x.y.z".
 USER_AGENT = "PrivateHealthBridge"
+# Some instances (cold PHP-FPM, slow DB) need more than a few seconds to answer.
+NC_TIMEOUT_SECONDS = float(os.environ.get("NC_TIMEOUT_SECONDS", "30"))
+# Every metric this bridge can forward; new users only have "stress" enabled
+# by default, so writes would otherwise fail with an "unsupported metric" error.
+WANTED_METRICS = ("weight",)
+# Filled at startup from the server's actual configuration response, since a
+# Health instance may not know a metric yet at all or may just have it
+# disabled for this user.
+supported_metrics: set[str] = set()
+
+
+def discover_supported_metrics() -> None:
+    resp = requests.get(
+        CONFIGURATION_URL,
+        auth=NC_AUTH,
+        headers={"OCS-APIRequest": "true", "Accept": "application/json", "User-Agent": USER_AGENT},
+        params={"format": "json"},
+        timeout=NC_TIMEOUT_SECONDS,
+    )
+    resp.raise_for_status()
+    current = resp.json()["ocs"]["data"]["metrics"]
+
+    unknown = [m for m in WANTED_METRICS if m not in current]
+    if unknown:
+        log.warning("This Health instance doesn't know these metrics yet, skipping them: %s", unknown)
+
+    disabled = [m for m in WANTED_METRICS if m in current and not current[m]["enabled"]]
+    if disabled:
+        log.info("Enabling Health metrics not yet active for this user: %s", disabled)
+        resp = requests.put(
+            CONFIGURATION_URL,
+            json={"metrics": {m: {"enabled": True} for m in disabled}},
+            auth=NC_AUTH,
+            headers={
+                "OCS-APIRequest": "true",
+                "Accept": "application/json",
+                "User-Agent": USER_AGENT,
+            },
+            params={"format": "json"},
+            timeout=NC_TIMEOUT_SECONDS,
+        )
+        if not resp.ok:
+            log.error("Nextcloud rejected configuration update: %s -> %s", resp.status_code, resp.text)
+        resp.raise_for_status()
+
+    supported_metrics.update(m for m in WANTED_METRICS if m not in unknown)
 
 app = Flask(__name__)
 
@@ -80,7 +128,7 @@ def forward_weight_entry(record: dict) -> None:
             "User-Agent": USER_AGENT,
         },
         params={"format": "json"},
-        timeout=10,
+        timeout=NC_TIMEOUT_SECONDS,
     )
     resp.raise_for_status()
 
@@ -112,4 +160,5 @@ def health_connect_webhook():
 
 
 if __name__ == "__main__":
+    discover_supported_metrics()
     app.run(host="0.0.0.0", port=8080)