pickle test 2 from intern

app.py

@@ -1,13 +1,15 @@
 import redis
+import atexit
 from flask import Flask, jsonify
 from flask_apscheduler import APScheduler
 from datetime import datetime, timedelta
-from scanner import update_cache, get_cache_snapshot, get_sensor_summary, get_sensor_details, scan_macs
+from scanner import *
 from config import *
 from ble_redis import *
 import logging
 logging.getLogger('apscheduler').setLevel(logging.ERROR)  
 
+
 app = Flask(__name__)
 scheduler = APScheduler()
 scheduler.init_app(app)
@@ -54,4 +56,6 @@ def hello():
 # --- Run --------------------------------------------------------------
 if __name__ == '__main__':
     # The scheduler runs in its own thread; the main thread serves Flask.
-    app.run(host=bind_ip, port=api_port, debug=False)
+    app.run(host=bind_ip, port=api_port, debug=False)
+    # Register a graceful shutdown hook so the scanner state is persisted
+    atexit.register(save_state)