"""Round 13: drag auto-scroll.

While dragging a track near the top/bottom edge of the list, it scrolls in
that direction so off-screen rows can be reached. Qt's built-in autoscroll
never runs (our dragMoveEvent accepts the event itself), so this is manual.
"""

from PyQt6.QtCore import QPoint

from lintunes.gui.track_table import TrackTableView, autoscroll_direction


class TestAutoscrollDirection:
    def test_top_edge_scrolls_up(self):
        assert autoscroll_direction(5, height=200, accepted=True) == -1

    def test_bottom_edge_scrolls_down(self):
        assert autoscroll_direction(195, height=200, accepted=True) == 1

    def test_middle_does_not_scroll(self):
        assert autoscroll_direction(100, height=200, accepted=True) == 0

    def test_not_a_drop_target_never_scrolls(self):
        assert autoscroll_direction(5, height=200, accepted=False) == 0
        assert autoscroll_direction(195, height=200, accepted=False) == 0


class TestAutoscrollTick:
    def test_tick_scrolls_by_direction(self, qapp):
        view = TrackTableView(playlist_mode=True)
        bar = view.verticalScrollBar()
        bar.setRange(0, 50)
        bar.setValue(10)

        view._autoscroll_dir = 1
        view._autoscroll_tick()
        assert bar.value() == 11

        view._autoscroll_dir = -1
        view._autoscroll_tick()
        assert bar.value() == 10

    def test_tick_stops_at_the_end(self, qapp):
        view = TrackTableView(playlist_mode=True)
        bar = view.verticalScrollBar()
        bar.setRange(0, 50)
        bar.setValue(50)  # already at the bottom

        view._autoscroll_dir = 1
        view._autoscroll_timer.start()
        view._autoscroll_tick()

        assert bar.value() == 50
        assert not view._autoscroll_timer.isActive()


class TestUpdateAutoscroll:
    def test_rejected_drop_keeps_timer_off(self, qapp):
        view = TrackTableView(playlist_mode=True)
        view._update_autoscroll(QPoint(10, 5), accepted=False)
        assert view._autoscroll_dir == 0
        assert not view._autoscroll_timer.isActive()

    def test_stop_autoscroll_resets(self, qapp):
        view = TrackTableView(playlist_mode=True)
        view._autoscroll_dir = 1
        view._autoscroll_timer.start()
        view._stop_autoscroll()
        assert view._autoscroll_dir == 0
        assert view._autoscroll_pos is None
        assert not view._autoscroll_timer.isActive()