#TODO Split class into two.
# One should be responsible for storing arrays of data, like a NoteData class?
# Another represents a slice of the data, NoteView.
# Before that, figure out how the part of a hold note between the hold start
# and hold end will be implemented.
class_name NoteLayout extends Node

## Controls at what beat notes are visible.
@export_group("Note View Offset")
## At what beat offset from the current beat will notes will be visible.
## Example, spawn = 4.0 means notes are spawned 4 beats before
## they are meant to be hit.
@export var spawn: float = 4.0

## At what beat offset from the current beat will notes be invisible.
## Example, despawn = 4.0 means notes are despawned 4 beats after
## they are meant to be hit.
@export var despawn: float = 4.0


## The index in notes of the first active note.
func start() -> int:
	return _start


## The index in notes after the last active note.
func end() -> int:
	return _end


func size() -> int:
	return _beat.size()


func beat(index: int) -> float:
	return _beat[index]


func lane(index: int) -> int:
	return _lane[index]


func type(index: int) -> Note.TYPE:
	return _type[index]


# ======= IMPLEMENTATION ======== #

# All notes in the chart, arranged by ascending beat.
var _beat: Array[float] = []
var _lane: Array[int] = []
var _type: Array[Note.TYPE] = []

var _start: int = 0
var _end: int = 0


func _push_note(_note: Note) -> void:
	pass


# TODO FIX THESE
func _update_forward(new_beat: float) -> void:
	var spawn_beat = new_beat + spawn
	
	while _end < size() and _beat[_end] <= spawn_beat:
		_end += 1
	
	var despawn_beat = new_beat - despawn
	
	while _start < size() and _beat[_start] < despawn_beat:
		_start += 1

# TODO FIX THESE
#func _update_backward(new_beat: float) -> void:
	#var spawn_beat = new_beat + note_spawn_offset
	#
	#while _end >= 0 and _beat[_end] > spawn_beat:
		#_end -= 1
	#
	#var despawn_beat = new_beat - note_despawn_offset
	#
	#while _start >= 0 and _beat[_start] < despawn_beat:
		#_start -= 1