feat: last connected tag uid available at /api/v1/last_tag_uid

- Reset the app idle timer when interacting with the webapp, so that the
  device does not turn off while the web ui is used.

- Handle denying put/post while playback is active centrally in the
  before_request handler, so that it does not need to be copy/pasted
  into every request handler.

Signed-off-by: Matthias Blankertz <matthias@blankertz.org>

software/src/app.py

@@ -63,6 +63,7 @@ class PlayerApp:
         self._onIdle()
 
     def __del__(self):
+        print("app __del__")
         if self.mp3file is not None:
             self.mp3file.close()
             self.mp3file = None
@@ -116,6 +117,10 @@ class PlayerApp:
             # Check again in a minute
             self.timer_manager.schedule(time.ticks_ms() + self.idle_timeout_ms, self.onIdleTimeout)
 
+    def reset_idle_timeout(self):
+        if not self.playing:
+            self.timer_manager.schedule(time.ticks_ms() + self.idle_timeout_ms, self.onIdleTimeout)
+
     def is_playing(self) -> bool:
         return self.playing
 
@@ -186,3 +191,6 @@ class PlayerApp:
         self.timer_manager.cancel(self.onIdleTimeout)
         self.leds.set_state(self.leds.PLAYING)
         self.playing = True
+
+    def get_nfc(self):
+        return self.nfc

software/src/webserver.py

@@ -11,13 +11,22 @@ webapp = Microdot()
 server = None
 config = None
 app = None
+nfc = None
 
 
 def start_webserver(config_, app_):
-    global server, config, app
+    global server, config, app, nfc
     server = asyncio.create_task(webapp.start_server(port=80))
     config = config_
     app = app_
+    nfc = app.get_nfc()
+
+
+@webapp.before_request
+async def before_request_handler(request):
+    if request.method in ['PUT', 'POST'] and app.is_playing():
+        return "Cannot write to device while playback is active", 503
+    app.reset_idle_timeout()
 
 
 @webapp.route('/')
@@ -52,10 +61,14 @@ async def config_get(request):
 
 @webapp.route('/api/v1/config', methods=['PUT'])
 async def config_put(request):
-    if app.is_playing():
-        return 503
     try:
         config.set_config(request.json)
     except ValueError as ex:
         return str(ex), 400
     return '', 204
+
+
+@webapp.route('/api/v1/last_tag_uid', methods=['GET'])
+async def last_tag_uid_get(request):
+    tag, _ = nfc.get_last_uid()
+    return "No tag present" if tag is None else tag