"""Round 18: the 2026-07-02 "New backlog" batch.

1. Visualizer: gray-mode color slider pref + mode persists across launches.
2. External file drops insert at the drop position in a playlist.
3. Renaming artist/album/album_artist moves the file to keep the music
   folder organized (Artist/Album, Unknown Artist fallback).
"""

from PyQt6.QtCore import QObject, pyqtSignal
from PyQt6.QtGui import QColor

from lintunes import theme
from lintunes.preferences import Preferences
from lintunes.gui.visualizer import (
    VisualizerWidget, MODE_ON, MODE_DIM, MODE_OFF)


class _FakePlayer(QObject):
    audio_buffer = pyqtSignal(object)
    playing_changed = pyqtSignal(bool)
    track_changed = pyqtSignal(object)

    def __init__(self):
        super().__init__()
        self._playing = False

    def is_playing(self):
        return self._playing


# --------------------------------------------------------------------------
# 1. Visualizer: gray color pref + persistent mode
# --------------------------------------------------------------------------

class TestVisualizerModePersistence:
    def test_no_prefs_defaults_on(self, qapp):
        vis = VisualizerWidget(_FakePlayer())
        assert vis._mode == MODE_ON

    def test_saved_mode_restored(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("visualizer_mode", MODE_DIM)
        vis = VisualizerWidget(_FakePlayer(), prefs)
        assert vis._mode == MODE_DIM

    def test_saved_off_restored_and_stays_idle(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("visualizer_mode", MODE_OFF)
        vis = VisualizerWidget(_FakePlayer(), prefs)
        assert vis._mode == MODE_OFF
        vis._on_playing_changed(True)  # playback starts
        assert not vis._timer.isActive()

    def test_bogus_saved_mode_falls_back_to_on(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("visualizer_mode", "sparkle")  # hand-edited prefs file
        vis = VisualizerWidget(_FakePlayer(), prefs)
        assert vis._mode == MODE_ON

    def test_click_persists_mode_to_disk(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        vis = VisualizerWidget(_FakePlayer(), prefs)

        vis.mousePressEvent(None)  # on -> dim

        assert prefs.get("visualizer_mode") == MODE_DIM
        # A fresh Preferences (= next launch) sees it too.
        assert Preferences(tmp_path).get("visualizer_mode") == MODE_DIM


class TestVisualizerGrayColor:
    def test_default_gray_resolves_for_visualizer_key(self, qapp):
        value = theme.default_gray("color_visualizer_gray")
        assert isinstance(value, int)
        assert 0 <= value <= 255

    def test_slider_pref_drives_dim_color(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("color_visualizer_gray", 100)
        vis = VisualizerWidget(_FakePlayer(), prefs)
        vis._mode = MODE_DIM
        assert vis._bar_color() == QColor(100, 100, 100)

    def test_unset_pref_keeps_derived_color(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        with_prefs = VisualizerWidget(_FakePlayer(), prefs)
        without = VisualizerWidget(_FakePlayer())
        with_prefs._mode = MODE_DIM
        without._mode = MODE_DIM
        assert with_prefs._bar_color() == without._bar_color()

    def test_on_mode_ignores_gray_pref(self, qapp, tmp_path):
        prefs = Preferences(tmp_path)
        prefs.set("color_visualizer_gray", 100)
        vis = VisualizerWidget(_FakePlayer(), prefs)
        assert vis._mode == MODE_ON
        assert vis._bar_color() == QColor(vis.palette().highlight().color())

    def test_visualizer_row_in_preferences_dialog(self, qapp):
        from lintunes.gui.preferences_dialog import _COLOR_ROWS
        assert "color_visualizer_gray" in [key for key, _label in _COLOR_ROWS]