refactor: make blink_led non-blocking in the state machine

tests/test_wecker.py

@@ -32,15 +32,6 @@ def test_set_led(mock_gpio):
     mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.HIGH)
 
 
-@patch("wecker.time.sleep")
-def test_blink_led(mock_sleep, mock_gpio):
-    wecker.blink_led(2)
-    # 2 blinks = 4 sleep calls, 2 set_led(True), 2 set_led(False)
-    assert mock_sleep.call_count == 4
-    # GPIO output called 4 times total (on, off, on, off)
-    assert mock_gpio.output.call_count == 4
-
-
 @patch("wecker.time.time")
 def test_run_alarm_start_to_wait(mock_time, mock_gpio, mock_pygame):
     # Mock pygame.mixer.get_init() to return True so music plays
@@ -59,33 +50,30 @@ def test_state_machine_evaluation(mock_gpio, mock_pygame):
     assert clock.state == wecker.STATE_WAIT_BEFORE_BLINK
 
     # Wait 3 seconds -> blinking
-    with patch("wecker.blink_led"):
+    with patch("wecker.random.randint", return_value=3):
         clock.update(103.1, False)
     assert clock.state == wecker.STATE_BLINKING
+    assert clock.target_blinks == 3
 
-    with patch("wecker.blink_led"):
-        clock.update(103.2, False)
+    # Advance time past the blink sequence (3 blinks * 2 phases * 0.3s = 1.8s)
+    clock.update(105.0, False)
     assert clock.state == wecker.STATE_WAIT_FOR_INPUT
-    assert clock.target_blinks >= 1
-
-    # Set the user presses to be correct
-    clock.target_blinks = 3
 
     # Press 1
-    clock.update(104.0, True)
-    clock.update(104.1, False)
+    clock.update(105.5, True)
+    clock.update(105.6, False)
     # Press 2
-    clock.update(104.5, True)
-    clock.update(104.6, False)
+    clock.update(106.0, True)
+    clock.update(106.1, False)
     # Press 3
-    clock.update(105.0, True)
-    clock.update(105.1, False)
+    clock.update(106.5, True)
+    clock.update(106.6, False)
 
     assert clock.user_presses == 3
 
     # Wait 3 seconds to evaluate
-    clock.update(108.2, False)  # Triggers state change
-    keep_running = clock.update(108.3, False)  # Triggers evaluation
+    clock.update(109.7, False)  # Triggers state change
+    keep_running = clock.update(109.8, False)  # Triggers evaluation
 
     # It should evaluate, see it's correct, and return False (stop running)
     assert clock.state == wecker.STATE_EVALUATING
@@ -111,19 +99,38 @@ def test_state_machine_incorrect(mock_gpio, mock_pygame):
     assert clock.state == wecker.STATE_WAIT_BEFORE_RETRY
 
 
-@patch("wecker.time.time")
-def test_blinking_updates_time_correctly(mock_time, mock_gpio, mock_pygame):
+def test_blinking_is_non_blocking(mock_gpio, mock_pygame):
+    clock = wecker.AlarmClock()
+    clock.state = wecker.STATE_BLINKING
+    clock.target_blinks = 2
+
+    # Start of blinking: LED on
+    clock.update(100.0, False)
+    assert clock.state == wecker.STATE_BLINKING
+    mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.LOW)
+
+    # Mid-blink: LED toggles based on elapsed time
+    clock.update(100.3, False)
+    mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.HIGH)
+
+    # After sequence completes (2 blinks * 2 phases * 0.3s = 1.2s)
+    clock.update(101.2, False)
+    assert clock.state == wecker.STATE_WAIT_FOR_INPUT
+    mock_gpio.output.assert_called_with(wecker.LED_PIN, mock_gpio.HIGH)
+
+
+def test_blinking_updates_time_correctly(mock_gpio, mock_pygame):
     clock = wecker.AlarmClock()
     clock.state = wecker.STATE_BLINKING
     clock.target_blinks = 4
 
-    mock_time.return_value = 200.0
-
-    with patch("wecker.blink_led"):
+    # Start blinking, then advance to the end of the sequence.
+    # 4 blinks * 2 phases * 0.3s = 2.4s
     clock.update(100.0, False)
+    clock.update(102.4, False)
 
     assert clock.state == wecker.STATE_WAIT_FOR_INPUT
-    assert clock.last_interaction_time == 200.0
+    assert clock.last_interaction_time == 102.4
 
 
 def test_setup_uses_env_music_file(mock_gpio, mock_pygame, monkeypatch):

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)
+            # 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 = (
-                time.time()
-            )  # Use time.time() to account for blocking blink_led
+                    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)