feat: add state machine for agent activity detection

Made-with: Cursor

tests/test_state.py

@@ -0,0 +1,75 @@
+import pytest
+from cursor_flasher.state import FlasherState, StateMachine
+
+
+class TestStateMachine:
+    def test_initial_state_is_idle(self):
+        sm = StateMachine()
+        assert sm.state == FlasherState.IDLE
+
+    def test_idle_to_agent_working(self):
+        sm = StateMachine()
+        changed = sm.update(agent_working=True, approval_needed=False)
+        assert sm.state == FlasherState.AGENT_WORKING
+        assert changed is True
+
+    def test_agent_working_to_waiting(self):
+        sm = StateMachine()
+        sm.update(agent_working=True, approval_needed=False)
+        changed = sm.update(agent_working=False, approval_needed=False)
+        assert sm.state == FlasherState.WAITING_FOR_USER
+        assert changed is True
+
+    def test_approval_needed_triggers_waiting(self):
+        sm = StateMachine()
+        sm.update(agent_working=True, approval_needed=False)
+        changed = sm.update(agent_working=False, approval_needed=True)
+        assert sm.state == FlasherState.WAITING_FOR_USER
+        assert changed is True
+
+    def test_idle_does_not_jump_to_waiting(self):
+        sm = StateMachine()
+        changed = sm.update(agent_working=False, approval_needed=False)
+        assert sm.state == FlasherState.IDLE
+        assert changed is False
+
+    def test_waiting_to_user_interacting(self):
+        sm = StateMachine()
+        sm.update(agent_working=True, approval_needed=False)
+        sm.update(agent_working=False, approval_needed=False)
+        assert sm.state == FlasherState.WAITING_FOR_USER
+        changed = sm.dismiss()
+        assert sm.state == FlasherState.IDLE
+        assert changed is True
+
+    def test_waiting_to_agent_working(self):
+        sm = StateMachine()
+        sm.update(agent_working=True, approval_needed=False)
+        sm.update(agent_working=False, approval_needed=False)
+        changed = sm.update(agent_working=True, approval_needed=False)
+        assert sm.state == FlasherState.AGENT_WORKING
+        assert changed is True
+
+    def test_no_change_returns_false(self):
+        sm = StateMachine()
+        sm.update(agent_working=True, approval_needed=False)
+        changed = sm.update(agent_working=True, approval_needed=False)
+        assert changed is False
+
+    def test_cooldown_prevents_immediate_retrigger(self):
+        sm = StateMachine(cooldown=5.0)
+        sm.update(agent_working=True, approval_needed=False)
+        sm.update(agent_working=False, approval_needed=False)
+        assert sm.state == FlasherState.WAITING_FOR_USER
+        sm.dismiss()
+        sm.update(agent_working=True, approval_needed=False)
+        changed = sm.update(agent_working=False, approval_needed=False)
+        assert sm.cooldown == 5.0
+
+    def test_direct_approval_from_idle(self):
+        """If we detect approval buttons without seeing agent_working first,
+        still transition to WAITING_FOR_USER."""
+        sm = StateMachine()
+        changed = sm.update(agent_working=False, approval_needed=True)
+        assert sm.state == FlasherState.WAITING_FOR_USER
+        assert changed is True