initial scaffold

app/services.py

@@ -0,0 +1,55 @@
+"""
+Placeholder for NL43 TCP connector.
+Implement TCP session management, command serialization, and DOD/DRD parsing here,
+then call persist_snapshot to store the latest values.
+"""
+
+from dataclasses import dataclass
+from datetime import datetime
+from typing import Optional
+
+from app.database import get_db_session
+from app.models import NL43Status
+
+
+@dataclass
+class NL43Snapshot:
+    unit_id: str
+    measurement_state: str = "unknown"
+    lp: Optional[str] = None
+    leq: Optional[str] = None
+    lmax: Optional[str] = None
+    lmin: Optional[str] = None
+    lpeak: Optional[str] = None
+    battery_level: Optional[str] = None
+    power_source: Optional[str] = None
+    sd_remaining_mb: Optional[str] = None
+    sd_free_ratio: Optional[str] = None
+    raw_payload: Optional[str] = None
+
+
+def persist_snapshot(s: NL43Snapshot):
+    """Persist the latest snapshot for API/dashboard use."""
+    db = get_db_session()
+    try:
+        row = db.query(NL43Status).filter_by(unit_id=s.unit_id).first()
+        if not row:
+            row = NL43Status(unit_id=s.unit_id)
+            db.add(row)
+
+        row.last_seen = datetime.utcnow()
+        row.measurement_state = s.measurement_state
+        row.lp = s.lp
+        row.leq = s.leq
+        row.lmax = s.lmax
+        row.lmin = s.lmin
+        row.lpeak = s.lpeak
+        row.battery_level = s.battery_level
+        row.power_source = s.power_source
+        row.sd_remaining_mb = s.sd_remaining_mb
+        row.sd_free_ratio = s.sd_free_ratio
+        row.raw_payload = s.raw_payload
+
+        db.commit()
+    finally:
+        db.close()