"""Round 12: cut (Ctrl-X), paste-above-selection, scrollbar click-to-jump.

- Cut copies the selection to the clipboard and, in a playlist, removes it
  *immediately* (so it visibly leaves); a paste re-inserts it at the target.
  A cut from the library has nothing to remove, so it's just a copy.
- Paste inserts *above the currently selected track*, not at the end.
- Clicking the scrollbar trough jumps there instead of paging a step.
"""

from PyQt6.QtWidgets import QApplication, QStyle

from lintunes.models import Library, Track
from lintunes.library_manager import LibraryManager
from lintunes.gui.track_table import (
    TrackTableView, make_tracks_mime, parse_tracks_mime, ClickToJumpScrollStyle)
from lintunes.gui.playlist_view import PlaylistView


def _manager(tmp_path, n=4):
    library = Library(tracks={i: Track(track_id=i, name=f"T{i}")
                              for i in range(1, n + 1)})
    return LibraryManager(library, tmp_path)


def _select_source_row(table, source_row):
    """Select the visual row backing a given source-model row (sort-proof)."""
    proxy_index = table.proxy.mapFromSource(table.model_.index(source_row, 0))
    table.selectRow(proxy_index.row())


# --------------------------------------------------------------------------
# clipboard helpers + cut signalling
# --------------------------------------------------------------------------

class TestCutSelection:
    def test_paste_anchor_row(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        table = TrackTableView(playlist_mode=True)
        table.set_tracks([manager.library.tracks[i] for i in (1, 2, 3)])
        assert table.paste_anchor_row() is None        # nothing selected
        _select_source_row(table, 1)
        assert table.paste_anchor_row() == 1

    def test_cut_in_playlist_copies_and_requests_removal(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        table = TrackTableView(playlist_mode=True)
        table.set_source_playlist("PID")
        table.set_tracks([manager.library.tracks[i] for i in (1, 2, 3)])
        removed = []
        table.cut_requested.connect(removed.append)

        _select_source_row(table, 0)
        table.cut_selection()

        assert removed == [[0]]  # asked the view to remove row 0 immediately
        payload = parse_tracks_mime(QApplication.clipboard().mimeData())
        assert payload["track_ids"] == [1]

    def test_cut_in_library_is_just_a_copy(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        table = TrackTableView(playlist_mode=False)  # library
        table.set_tracks([manager.library.tracks[i] for i in (1, 2, 3)])
        removed = []
        table.cut_requested.connect(removed.append)

        _select_source_row(table, 0)
        table.cut_selection()

        assert removed == []  # nothing to remove from the library
        payload = parse_tracks_mime(QApplication.clipboard().mimeData())
        assert payload["track_ids"] == [1]


# --------------------------------------------------------------------------
# scrollbar click-to-jump
# --------------------------------------------------------------------------

class TestScrollbarJump:
    def test_style_hint_enables_absolute_position(self, qapp):
        """Applied app-wide in main.run_gui via app.setStyle(); here we just
        confirm the proxy flips the left-click-jump hint on."""
        style = ClickToJumpScrollStyle()
        assert style.styleHint(
            QStyle.StyleHint.SH_ScrollBar_LeftClickAbsolutePosition) == 1


# --------------------------------------------------------------------------
# PlaylistView integration
# --------------------------------------------------------------------------

class TestPasteIntegration:
    def test_copy_paste_inserts_above_selection(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        b = manager.create_playlist("B")
        manager.add_tracks_to_playlist(b.persistent_id, [4])
        view = PlaylistView(manager)
        view.show_playlist(b)

        QApplication.clipboard().setMimeData(make_tracks_mime([1, 2]))
        _select_source_row(view.table, 0)  # above track 4
        view._on_paste()

        assert b.track_ids == [1, 2, 4]

    def test_cut_removes_now_then_paste_reinserts_elsewhere(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        a = manager.create_playlist("A")
        b = manager.create_playlist("B")
        manager.add_tracks_to_playlist(a.persistent_id, [1, 2, 3])
        manager.add_tracks_to_playlist(b.persistent_id, [4])
        view = PlaylistView(manager)

        view.show_playlist(a)
        _select_source_row(view.table, 0)  # track 1
        view.table.cut_selection()
        assert a.track_ids == [2, 3]       # gone immediately

        view.show_playlist(b)
        _select_source_row(view.table, 0)  # above track 4
        view._on_paste()
        assert b.track_ids == [1, 4]

    def test_cut_paste_same_playlist_reorders(self, qapp, tmp_path):
        manager = _manager(tmp_path)
        a = manager.create_playlist("A")
        manager.add_tracks_to_playlist(a.persistent_id, [1, 2, 3, 4])
        view = PlaylistView(manager)
        view.show_playlist(a)

        _select_source_row(view.table, 0)  # track 1
        view.table.cut_selection()
        assert a.track_ids == [2, 3, 4]

        _select_source_row(view.table, 1)  # above track 3
        view._on_paste()
        assert a.track_ids == [2, 1, 3, 4]