from playlist import Playlist

class MockPlayer:
    def __init__(self):
        self.songSetByCallback = None

    def setCurrentSong(self, path):
        self.songSetByCallback = path

def test_addAndSelectOneSong():
    songAddedByUser = "/path/to/song"
    mockPlayer = MockPlayer()

    uut = Playlist(mockPlayer)
    uut.addSong(songAddedByUser)
    uut.setCurrentSong(0)

    assert songAddedByUser == mockPlayer.songSetByCallback
    assert uut.getCurrentSong() == songAddedByUser
    assert uut.getSongs() == [songAddedByUser]

def test_addTwoSongsAndSelectBoth():
    songAddedByUser = ["/path/to/song", "/path/to/second/song"]
    mockPlayer = MockPlayer()

    uut = Playlist(mockPlayer)
    uut.addSong(songAddedByUser[0])
    uut.addSong(songAddedByUser[1])
    assert uut.getSongs() == songAddedByUser

    uut.setCurrentSong(0)
    assert songAddedByUser[0] == mockPlayer.songSetByCallback
    assert uut.getCurrentSong() == songAddedByUser[0]

    uut.setCurrentSong(1)
    assert songAddedByUser[1] == mockPlayer.songSetByCallback
    assert uut.getCurrentSong() == songAddedByUser[1]

def test_firstAddedSongIsNotSelected():
    songAddedByUser = "/path/to/song"
    mockPlayer = MockPlayer()

    uut = Playlist(mockPlayer)
    uut.addSong(songAddedByUser)

    assert mockPlayer.songSetByCallback == None
    assert uut.getCurrentSong() == None
    assert uut.getSongs() == [songAddedByUser]

def test_invalidSongSelection():
    songAddedByUser = "/path/to/song"
    mockPlayer = MockPlayer()

    uut = Playlist(mockPlayer)
    assert mockPlayer.songSetByCallback == None
    assert uut.getCurrentSong() == None

    uut.setCurrentSong(10)
    assert mockPlayer.songSetByCallback == None
    assert uut.getCurrentSong() == None

    uut.addSong(songAddedByUser)
    uut.setCurrentSong(10)
    assert mockPlayer.songSetByCallback == None
    assert uut.getCurrentSong() == None
    assert uut.getSongs() == [songAddedByUser]