from pocketbook.app import ToggleStateMachine, EscapeStateMachine, navigate


class TestToggleStateMachine:
    def test_initial_state_visible(self):
        sm = ToggleStateMachine(start_hidden=False)
        assert sm.visible is True

    def test_initial_state_hidden(self):
        sm = ToggleStateMachine(start_hidden=True)
        assert sm.visible is False

    def test_toggle_alternates(self):
        sm = ToggleStateMachine(start_hidden=False)
        assert sm.visible is True
        sm.toggle()
        assert sm.visible is False
        sm.toggle()
        assert sm.visible is True

    def test_toggle_from_hidden(self):
        sm = ToggleStateMachine(start_hidden=True)
        assert sm.visible is False
        sm.toggle()
        assert sm.visible is True
        sm.toggle()
        assert sm.visible is False


class TestEscapeStateMachine:
    def test_escape_while_editing_returns_exit_edit(self):
        esc = EscapeStateMachine()
        toggle = ToggleStateMachine(start_hidden=False)
        action = esc.escape(is_editing=True, toggle=toggle)
        assert action == "exit_edit"
        # Toggle state should not change
        assert toggle.visible is True

    def test_escape_while_browsing_returns_hide(self):
        esc = EscapeStateMachine()
        toggle = ToggleStateMachine(start_hidden=False)
        action = esc.escape(is_editing=False, toggle=toggle)
        assert action == "hide"
        assert toggle.visible is False

    def test_escape_edit_then_browse_hides(self):
        """Simulates: editing → Escape (exit edit) → Escape (hide)."""
        esc = EscapeStateMachine()
        toggle = ToggleStateMachine(start_hidden=False)

        # First escape: exit edit mode
        action1 = esc.escape(is_editing=True, toggle=toggle)
        assert action1 == "exit_edit"
        assert toggle.visible is True

        # Second escape: now in browse mode, hide panel
        action2 = esc.escape(is_editing=False, toggle=toggle)
        assert action2 == "hide"
        assert toggle.visible is False

    def test_escape_hide_does_not_change_when_already_hidden(self):
        esc = EscapeStateMachine()
        toggle = ToggleStateMachine(start_hidden=True)
        assert toggle.visible is False
        action = esc.escape(is_editing=False, toggle=toggle)
        assert action == "hide"
        # Toggled again — now visible (edge case if called when hidden)
        assert toggle.visible is True


class TestNavigate:
    def test_no_notes(self):
        assert navigate(None, 0, 1) is None
        assert navigate(None, 0, -1) is None

    def test_no_focus_next_goes_to_first(self):
        assert navigate(None, 3, 1) == 0

    def test_no_focus_prev_goes_to_last(self):
        assert navigate(None, 3, -1) == 2

    def test_next_from_middle(self):
        assert navigate(1, 3, 1) == 2

    def test_prev_from_middle(self):
        assert navigate(1, 3, -1) == 0

    def test_next_clamps_at_end(self):
        assert navigate(2, 3, 1) == 2

    def test_prev_clamps_at_start(self):
        assert navigate(0, 3, -1) == 0

    def test_single_note(self):
        assert navigate(0, 1, 1) == 0
        assert navigate(0, 1, -1) == 0