#warning-ignore-all:shadowed_variable
extends Node
const music := preload('res://scripts/loaders/snes/music_ff5.gd')
const EventType := music.EventType
var MUSIC := music.new()

var inst_map: Dictionary  # int keys, AudioStreamSample values
var tracks: Array
var num_tracks: int
var players: Array
var tempo: float  # Store as BPM
var seconds_per_pulse: float
var master_volume := 255
var channel_pointer := PoolIntArray()
var channel_instrument_idx := PoolByteArray()
var channel_next_pulse := PoolIntArray()
var channel_current_note := PoolByteArray()
var channel_velocity := PoolByteArray()
var channel_pan := PoolByteArray()  # Reversed from MIDI
var channel_octave := PoolByteArray()
var channel_transpose := PoolByteArray()
var channel_fine_tuning := PoolRealArray()
var channel_adsr_attack := PoolByteArray()
var channel_adsr_decay := PoolByteArray()
var channel_adsr_sustain := PoolByteArray()
var channel_adsr_release := PoolByteArray()
var channel_noise_freq := PoolByteArray()
var channel_noise_on := PoolByteArray()
var channel_pan_lfo_rate := PoolByteArray()
var channel_pan_lfo_depth := PoolByteArray()
var channel_pan_lfo_on := PoolByteArray()
var channel_tremolo_delay := PoolByteArray()
var channel_tremolo_rate := PoolByteArray()
var channel_tremolo_depth := PoolByteArray()
var channel_tremolo_on := PoolByteArray()
var channel_vibrato_delay := PoolByteArray()
var channel_vibrato_rate := PoolByteArray()
var channel_vibrato_depth := PoolByteArray()
var channel_vibrato_on := PoolByteArray()
var channel_pitchmod_on := PoolByteArray()
var channel_echo_on := PoolByteArray()
var channel_echo_volume := PoolByteArray()

func set_tempo(tempo: float):
	self.tempo = tempo
	self.seconds_per_pulse = 60.0 / (tempo * music.PPQN)

func _init(tracks: Array, instrument_map: Dictionary):
	self.tracks = tracks
	self.num_tracks = len(self.tracks)
	self.inst_map = instrument_map
	self.players = []
	self.set_tempo(120.0)
	for i in num_tracks:
		self.players.append(AudioStreamPlayer.new())
		add_child(self.players[-1])
		self.channel_pointer.append(0)
		self.channel_instrument_idx.append(0)
		self.channel_next_pulse.append(0)
		self.channel_current_note.append(0)
		self.channel_velocity.append(100)
		self.channel_pan.append(0)
		self.channel_octave.append(5)
		self.channel_transpose.append(0)
		self.channel_fine_tuning.append(1.0)
		self.channel_adsr_attack.append(0)
		self.channel_adsr_decay.append(0)
		self.channel_adsr_sustain.append(0)
		self.channel_adsr_release.append(0)
		self.channel_noise_freq.append(0)
		self.channel_noise_on.append(0)
		self.channel_pan_lfo_rate.append(0)
		self.channel_pan_lfo_depth.append(0)
		self.channel_pan_lfo_on.append(0)
		self.channel_tremolo_delay.append(0)
		self.channel_tremolo_rate.append(0)
		self.channel_tremolo_depth.append(0)
		self.channel_tremolo_on.append(0)
		self.channel_vibrato_delay.append(0)
		self.channel_vibrato_rate.append(0)
		self.channel_vibrato_depth.append(0)
		self.channel_vibrato_on.append(0)
		self.channel_pitchmod_on.append(0)
		self.channel_echo_on.append(0)
		self.channel_echo_volume.append(0)

func play_channel(channel: int, time_offset: float = 0.0) -> int:
	# Executes the track events until it hits a note/rest, in which case it returns the pulse count to the next action, or the end of the events, in which case it returns -1
	# self.players[channel].stop()
	var track: Array = self.tracks[channel]
	var l := len(track)
	var player: AudioStreamPlayer = self.players[channel]
	while true:
		var ptr: int = self.channel_pointer[channel]
		if ptr >= l:
			break
		var event = track[ptr]
		self.channel_pointer[channel] += 1
		match event[0]:  # Control codes
			EventType.NOTE:
				var note = event[1]
				var duration = event[2]
				if note >= 0:  # Don't shift or play rests
					note += (12 * self.channel_octave[channel]) + self.channel_transpose[channel]
					player.pitch_scale = pow(2.0, (note - MUSIC.REFERENCE_NOTE)/12.0) #* self.channel_fine_tuning[channel]
					player.volume_db = linear2db((self.channel_velocity[channel]/255.0) * (self.master_volume/255.0))
					player.play(max((SoundLoader.PLAY_START - time_offset)/player.pitch_scale, 0))
					self.channel_current_note[channel] = note
				elif note == music.NOTE_IS_TIE:
					pass
				else:
					self.players[channel].stop()
					self.channel_current_note[channel] = -1
				# TODO: Confirm tempo scaling
				return duration  # Pulses to next instruction
			EventType.VOLUME:
				self.channel_velocity[channel] = event[1]
			EventType.VOLUME_SLIDE:  # TODO: implement slides
				var slide_duration: int = event[1]
				self.channel_velocity[channel] = event[2]
			EventType.PAN:  # TODO: implement slides
				self.channel_pan[channel] = event[1]
			EventType.PAN_SLIDE:  # TODO: implement slides
				var slide_duration: int = event[1]
				self.channel_pan[channel] = event[2]
			EventType.PITCH_SLIDE:  # TODO: implement slides
				var slide_duration: int = event[1]
				var target_pitch: int = event[2]  # Signed
			EventType.VIBRATO_ON:
				self.channel_vibrato_delay[channel] = event[1]
				self.channel_vibrato_rate[channel] = event[2]
				self.channel_vibrato_depth[channel] = event[3]
				self.channel_vibrato_on[channel] = 1
			EventType.VIBRATO_OFF:
				self.channel_vibrato_on[channel] = 0
			EventType.TREMOLO_ON:
				self.channel_tremolo_delay[channel] = event[1]
				self.channel_tremolo_rate[channel] = event[2]
				self.channel_tremolo_depth[channel] = event[3]
				self.channel_tremolo_on[channel] = 1
			EventType.TREMOLO_OFF:
				self.channel_tremolo_on[channel] = 0
			EventType.PAN_LFO_ON:
				self.channel_pan_lfo_depth[channel] = event[1]
				self.channel_pan_lfo_rate[channel] = event[2]
				self.channel_pan_lfo_on[channel] = 1
			EventType.PAN_LFO_OFF:
				self.channel_pan_lfo_on[channel] = 0
			EventType.NOISE_FREQ:
				self.channel_noise_freq[channel] = event[1]
			EventType.NOISE_ON:
				self.channel_noise_on[channel] = 1
			EventType.NOISE_OFF:
				self.channel_noise_on[channel] = 0
			EventType.PITCHMOD_ON:
				self.channel_pitchmod_on[channel] = 1
			EventType.PITCHMOD_OFF:
				self.channel_pitchmod_on[channel] = 0
			EventType.ECHO_ON:
				self.channel_echo_on[channel] = 1
			EventType.ECHO_OFF:
				self.channel_echo_on[channel] = 0
			EventType.OCTAVE:
				self.channel_octave[channel] = event[1]
			EventType.OCTAVE_UP:
				self.channel_octave[channel] += 1
			EventType.OCTAVE_DOWN:
				self.channel_octave[channel] -= 1
			EventType.TRANSPOSE_ABS:
				self.channel_transpose[channel] = event[1]
			EventType.TRANSPOSE_REL:
				self.channel_transpose[channel] += event[1]
			EventType.TUNING:
				var fine_tune: int = event[1]
				var scale: float
				if fine_tune < 0x80:
					scale = 1.0 + fine_tune/255.0
				else:
					scale = fine_tune/255.0
				self.channel_fine_tuning[channel] = scale
			EventType.PROGCHANGE:
				self.channel_instrument_idx[channel] = event[1]
				player.stream = self.inst_map[self.channel_instrument_idx[channel]]
				# TODO - grab instrument envelope
			EventType.ADSR_ATTACK:
				self.channel_adsr_attack[channel] = event[1]
			EventType.ADSR_DECAY:
				self.channel_adsr_decay[channel] = event[1]
			EventType.ADSR_SUSTAIN:
				self.channel_adsr_sustain[channel] = event[1]
			EventType.ADSR_RELEASE:
				self.channel_adsr_release[channel] = event[1]
			EventType.ADSR_DEFAULT:  # TODO - grab instrument envelope
				pass
			EventType.TEMPO:
				self.set_tempo(music.tempo_to_bpm(event[1]))
			EventType.TEMPO_SLIDE:
				self.set_tempo(music.tempo_to_bpm(event[2]))
				var slide_duration: int = event[1]
			EventType.ECHO_VOLUME:
				self.channel_echo_volume[channel] = event[1]
			EventType.ECHO_VOLUME_SLIDE:  # TODO: implement slides
				self.channel_echo_volume[channel] = event[2]
				var slide_duration: int = event[1]
			EventType.ECHO_FEEDBACK_FIR:  # TODO
				var feedback: int = event[1]
				var filterIndex: int = event[2]
			EventType.MASTER_VOLUME:
				self.master_volume = event[1]
			EventType.GOTO:
				self.channel_pointer[channel] = event[1]
			EventType.END:
				break
			_:
				break
	return -1  # End of track

func play_pulse(time_offset := 0.0) -> bool:  # Return true if any channel played
	var active_channels := 0
	for channel in self.num_tracks:
		if self.channel_next_pulse[channel] < 0:
			continue  # Channel not playing
		active_channels += 1
		if self.channel_next_pulse[channel] == 0:
			self.channel_next_pulse[channel] = self.play_channel(channel, time_offset)
		self.channel_next_pulse[channel] -= 1
	return active_channels > 0

var is_playing := false
var bgm_timestamp := 0.0  # Note this will be behind by the maximum delay
func _process(delta: float) -> void:
	if self.is_playing:
		bgm_timestamp += delta
		while bgm_timestamp > seconds_per_pulse:
			bgm_timestamp -= seconds_per_pulse
			self.is_playing = play_pulse(bgm_timestamp)
			if not self.is_playing:
				print('BGM finished playing')