refactor: make blink_led non-blocking in the state machine

wecker.py

@@ -96,11 +96,7 @@ STATE_WAIT_FOR_INPUT = 3
 STATE_EVALUATING = 4
 STATE_WAIT_BEFORE_RETRY = 5
 
-state = STATE_RINGING
-target_blinks = 0
-user_presses = 0
-last_interaction_time = 0
-button_was_pressed = False
+BLINK_INTERVAL = 0.3
 
 
 def set_led(on):
@@ -112,15 +108,6 @@ def set_led(on):
             GPIO.output(LED_PIN, GPIO.HIGH)
 
 
-def blink_led(times):
-    """Blinks the LED a specific number of times (blocking)"""
-    for _ in range(times):
-        set_led(True)
-        time.sleep(0.3)  # LED on for 300ms
-        set_led(False)
-        time.sleep(0.3)  # LED off for 300ms
-
-
 class AlarmClock:
     def __init__(self):
         self.state = STATE_RINGING
@@ -128,6 +115,9 @@ class AlarmClock:
         self.user_presses = 0
         self.last_interaction_time = 0
         self.button_was_pressed = False
+        self._blink_phase: int = 0
+        self._blink_phases: int = 0
+        self._blink_next_toggle: float | None = None
 
     def update(self, now, is_pressed):
         button_just_pressed = False
@@ -150,19 +140,38 @@ class AlarmClock:
                 self.target_blinks = random.randint(1, 7)
                 logging.info(f"Blinking {self.target_blinks} times...")
                 self.state = STATE_BLINKING
+                self._blink_phase = 0
+                self._blink_phases = self.target_blinks * 2
+                self._blink_next_toggle = now + BLINK_INTERVAL
+                set_led(True)
 
         elif self.state == STATE_BLINKING:
-            # Move the blink_led out of the update loop for testability,
-            # or just call it directly. Here we call it.
-            blink_led(self.target_blinks)
-            logging.info("Blinking finished. Waiting for input...")
-            self.state = STATE_WAIT_FOR_INPUT
-            self.user_presses = 0
-            self.last_interaction_time = (
-                time.time()
-            )  # Use time.time() to account for blocking blink_led
-            if "GPIO" in globals() and hasattr(GPIO, "input"):
-                self.button_was_pressed = GPIO.input(BUTTON_PIN) == GPIO.LOW
+            # Non-blocking blink: toggle the LED at fixed intervals so the main
+            # loop keeps sampling the button and can be interrupted.
+            if self._blink_next_toggle is None:
+                # Safety for direct state assignment (e.g. tests).
+                self._blink_phase = 0
+                self._blink_phases = self.target_blinks * 2
+                self._blink_next_toggle = now + BLINK_INTERVAL
+                set_led(True)
+
+            while now >= self._blink_next_toggle:
+                self._blink_phase += 1
+                self._blink_next_toggle += BLINK_INTERVAL
+                if self._blink_phase >= self._blink_phases:
+                    set_led(False)
+                    self._blink_phase = 0
+                    self._blink_phases = 0
+                    self._blink_next_toggle = None
+                    logging.info("Blinking finished. Waiting for input...")
+                    self.state = STATE_WAIT_FOR_INPUT
+                    self.user_presses = 0
+                    self.last_interaction_time = now
+                    if "GPIO" in globals() and hasattr(GPIO, "input"):
+                        self.button_was_pressed = GPIO.input(BUTTON_PIN) == GPIO.LOW
+                    break
+                else:
+                    set_led(self._blink_phase % 2 == 0)
 
         elif self.state == STATE_WAIT_FOR_INPUT:
             set_led(is_pressed)