MusicPlayer/player/music_player.gd

class_name MusicPlayer
extends Control
## The bar that plays the songs, with play, restart, progress and volume. Whether a song
## repeats is a quiz setting ([code]Settings.auto_repeat_song[/code]).
##
## The buttons grow a little under the mouse and the play button pops when it switches
## between play and pause, see [ButtonBounce].
##
## With Short songs on ([member Settings.short_songs]) only a part of each quiz song plays:
## [member Settings.short_song_seconds] from a random point between
## [constant SHORT_START_MIN] and [constant SHORT_START_MAX] of the song. The progress bar,
## the time and seeking all stay within that part, and its end counts as the song ending.

signal update_song_list
signal play_next_song

var play_icon: Texture = preload("res://icons/play_button_icon.svg")
var pause_icon: Texture = preload("res://icons/pause_button_icon.svg")
var is_changing: bool = false
var playback_position: float
var stream: AudioStream
var song_finished: bool = false

## Where in the song the part played with Short songs may start, as a share of its length.
## Many songs have a quiet intro, so the start is never right at the beginning.
const SHORT_START_MIN: float = 0.1
const SHORT_START_MAX: float = 0.6

# The part of the song that plays: its start in seconds, and its length (0: to the end)
var _clip_start: float = 0.0
var _clip_length: float = 0.0

@onready var play_button: Button = %PlayButton
@onready var restart_button: Button = %RestartButton
@onready var audio_player: AudioStreamPlayer = $AudioStreamPlayer
@onready var sound_player: AudioStreamPlayer = $AudioSoundPlayer
@onready var sound_effect_player: AudioStreamPlayer = $AudioSoundEffectPlayer
@onready var progress_slider: HSlider = %MusicPlayerSlider
@onready var volume_slider: VolumeSlider = %VolumeSlider
@onready var music_time_label: Label = %MusicTimeLabel


func _ready() -> void:
	play_button.pressed.connect(play_or_pause)
	restart_button.pressed.connect(restart)
	ButtonBounce.add_to(play_button)
	ButtonBounce.add_to(restart_button)
	progress_slider.drag_started.connect(_on_drag_started)
	progress_slider.drag_ended.connect(_on_drag_ended)

	audio_player.finished.connect(_on_finished)


func _process(_delta: float) -> void:
	if audio_player.has_stream_playback() && !is_changing && !audio_player.stream_paused \
			&& audio_player.playing:
		var position: float = position_in_part()
		if _clip_length > 0.0 && position >= _clip_length:
			# The short part has played, which counts as the song ending
			audio_player.stop()
			progress_slider.value = _clip_length
			_on_finished()
			return
		if !Settings.hide_beginning || position > Settings.hide_for_seconds:
			progress_slider.value = position
		music_time_label.text = format_text(progress_slider.value, part_length())


## How long the part of the song that plays is: the short part, or the whole song.
func part_length() -> float:
	if _clip_length > 0.0:
		return _clip_length
	return stream.get_length() if stream != null else 0.0


## How far into the part that plays the song is, in seconds.
func position_in_part() -> float:
	return audio_player.get_playback_position() - _clip_start


## Plays only part of [param song_object]'s song when Short songs is on and the song is
## longer than the part. The part's start is picked once per song.
func choose_part(song_object: SongObject, song: AudioStream) -> void:
	_clip_start = 0.0
	_clip_length = 0.0
	var length: float = song.get_length()
	if !Settings.short_songs || song_object == null || length <= Settings.short_song_seconds:
		return
	if song_object.short_start < 0.0:
		var latest: float = minf(length * SHORT_START_MAX, length - Settings.short_song_seconds)
		var earliest: float = minf(length * SHORT_START_MIN, latest)
		song_object.short_start = randf_range(earliest, latest)
	_clip_start = minf(song_object.short_start, length - Settings.short_song_seconds)
	_clip_length = Settings.short_song_seconds


## Whether the play button shows pause, because a song is playing.
func shows_playing() -> bool:
	return play_button.icon == pause_icon


# Shows pause on the play button while a song plays, and play otherwise
func _show_playing(playing: bool) -> void:
	var icon: Texture = pause_icon if playing else play_icon
	if play_button.icon != icon:
		play_button.icon = icon
		ButtonBounce.pop(play_button)


# The progress bar and time show the length of the part that plays
func _show_length() -> void:
	var length: float = part_length()
	progress_slider.max_value = round(length)
	progress_slider.tick_count = 0 if Settings.hide_ticks else round(length / 60)
	music_time_label.text = format_text(progress_slider.value, length)


func format_time(time: float) -> String:
	var total_seconds: int = roundi(time)
	@warning_ignore("integer_division")
	return "%02d:%02d" % [total_seconds / 60, total_seconds % 60]


func format_text(part: float, total: float) -> String:
	if (Settings.hide_beginning && part < Settings.hide_for_seconds) && Settings.hide_length:
		return "??:?? / ??:??"
	elif Settings.hide_length:
		return format_time(part) + " / ??:??"
	elif Settings.hide_beginning && part < Settings.hide_for_seconds:
		return "??:?? / " + format_time(total)
	else:
		return format_time(part) + " / " + format_time(total)


func play_or_pause() -> void:
	if song_finished:
		restart()
	elif audio_player.stream_paused:
		_show_playing(true)
		audio_player.stream_paused = false
		song_finished = false
		audio_player.seek(playback_position)
		GameLog.debug("continue")
		_show_length()
	else:
		pause()


func pause() -> void:
	audio_player.stream_paused = true
	playback_position = audio_player.get_playback_position()
	_show_playing(false)


## Plays the song, or its short part, from the beginning.
func restart() -> void:
	audio_player.stop()
	audio_player.stream_paused = false
	song_finished = false
	progress_slider.value = 0
	playback_position = _clip_start
	_show_playing(true)
	audio_player.play(_clip_start)


func _on_finished() -> void:
	_show_playing(false)
	song_finished = true
	if !Settings.stop_after_current:
		play_next_song.emit()
	if Settings.auto_repeat_song:
		restart()


func _on_drag_started() -> void:
	is_changing = true


func _on_drag_ended(_changed: bool) -> void:
	audio_player.seek(_clip_start + progress_slider.value)
	playback_position = _clip_start + progress_slider.value
	is_changing = false


## Jumps [param new_position] seconds forward, or back when negative, staying within the
## part that plays.
func seek(new_position: float) -> void:
	progress_slider.value += new_position
	is_changing = true
	audio_player.seek(_clip_start + progress_slider.value)
	playback_position = _clip_start + progress_slider.value
	is_changing = false


func change_volume(value: float) -> void:
	volume_slider.value += value
	volume_slider.change_volume(volume_slider.value)


func _on_point_triggered(point: String) -> void:
	if point == "first":
		var value: int = randi_range(0, 10)
		if value == 0:
			play_sound(preload("res://sounds/sound1.mp3"))
		elif value < 5:
			play_sound(preload("res://sounds/intro_long.mp3"))
		else:
			play_sound(preload("res://sounds/intro_short.mp3"))
	elif point == "match":
		play_sound(preload("res://sounds/sound0.mp3"))


func play_sound_effect(sound_effect_name: AudioStream) -> void:
	sound_effect_player.stream = sound_effect_name
	sound_effect_player.play()


func play_sound(sound_name: AudioStream) -> void:
	sound_player.stream = sound_name
	audio_player.stop()
	sound_player.play()
	song_finished = true
	_show_playing(false)
	progress_slider.value = 0


func play_song(song: AudioStream) -> void:
	# Sounds such as the winning song always play whole
	_clip_start = 0.0
	_clip_length = 0.0
	audio_player.stream = song
	audio_player.play()
	sound_player.stop()
	song_finished = false
	_show_playing(true)
	stream = audio_player.stream
	progress_slider.value = 0
	_show_length()


## Puts song [param song_object_no] in the player without playing it, e.g. the song that
## was playing when the game was closed. Play starts it from the beginning.
func load_song_object(song_object_no: int) -> void:
	var song: AudioStream = Playlist.get_song(song_object_no)
	if song == null:
		return
	audio_player.stream = song
	stream = song
	choose_part(Playlist.song_object_array[song_object_no], song)
	song_finished = true
	_show_playing(false)
	progress_slider.value = 0
	_show_length()


func play_song_object(song_object_no: int) -> void:
	GameLog.debug("play_song_object")
	var song: AudioStream = Playlist.get_song(song_object_no)
	if song == null:
		GameLog.warning("Song ", song_object_no, " has no file to play")
		return
	if audio_player.is_playing():
		audio_player.stop()
		await get_tree().create_timer(0.5).timeout
	audio_player.stream = song
	choose_part(Playlist.song_object_array[song_object_no], song)
	sound_player.stop()
	audio_player.play(_clip_start)
	song_finished = false
	_show_playing(true)
	# A new song makes the play button pop, also when it was already playing
	ButtonBounce.pop(play_button)
	stream = audio_player.stream
	progress_slider.value = 0
	_show_length()
	Playlist.set_currently_playing_song(song_object_no)
	Playlist.unset_is_playing()
	if !Settings.hide_next_track:
		GameLog.debug("Show answer now!!")
		Playlist.song_is_answered(song_object_no)
	Playlist.song_has_played(song_object_no)
	Playlist.song_is_playing(song_object_no)
	update_song_list.emit()


## Plays a song to test the sound: one from the server, or a song that comes with the
## game when playing from a music folder.
func get_sound_test_song() -> void:
	if Settings.is_offline():
		sound_test_local()
		return
	var test_sound: Callable = func test_sound(body: PackedByteArray) -> void:
		var sound: AudioStream = AudioStreamMP3.new()
		sound.data = body
		play_song(sound)
	MusicServerClient.fetch_sound_test_song(test_sound)


# The sound test without a server: a song that comes with the game
func sound_test_local() -> void:
	play_song(preload("res://sounds/01. Opening.mp3"))