@tool
class_name Timeline
extends Container

@export var track_list: VBoxContainer

@export var font_scale: float = 1.0
@export var time_offset: float = 0.0
@export var time_interval: float = 1000.0 # 1 second
@export var grid_space_ms: float = 250 # 0.25 seconds
@export var label_interval_ms: float = 1000.0 # 1 second
@export var line_thickness: int = 2
@export var major_line_step: int = 4
@export var cursor_width: int = 8
@export var zoom: float = 1.0

@export var start_time: float = 0.0
@export var end_time: float = 10000.0 # 10 seconds

@export var min_zoom: float = 0.1

func format_time_ms_hours(ms: float) -> String:
	var total_seconds = ms / 1000
	var hours = int(total_seconds / 3600)
	var minutes = int(total_seconds / 60) % 60
	var seconds = int(total_seconds) % 60
	var milliseconds = fmod(ms, 1000.0)
	return "%02d:%02d:%02d.%03d" % [hours, minutes, seconds, milliseconds]

func format_time_ms_minutes(ms: float) -> String:
	var total_seconds = ms / 1000
	var minutes = int(total_seconds / 60) % 60
	var seconds = int(total_seconds) % 60
	var milliseconds = fmod(ms, 1000.0)
	return "%02d:%02d.%03d" % [minutes, seconds, milliseconds]


func get_track_idx_by_y(y: float):
	var idx = 0
	for track in track_list.get_children():
		if y >= track.global_position.y and y <= track.global_position.y + track.size.y:
			return idx
		idx += 1
		pass
	return -1

func get_track_by_idx(idx: int) -> Control:
	return track_list.get_child(idx)

func get_pixels_per_unit() -> float:
	return 50.0 * zoom

func _draw():
	var primary_color = get_theme_color("line_primary_color", "Timeline")
	var secondary_color = get_theme_color("line_secondary_color", "Timeline")

	var font = get_theme_default_font()
	var font_size = get_theme_default_font_size()

	var time_label_offset_x = get_theme_constant("time_label_offset_x", "Timeline")
	var time_label_offset_y = get_theme_constant("time_label_offset_y", "Timeline")

	# background
	var background_stylebox = get_theme_stylebox("background", "Timeline")
	draw_style_box(background_stylebox, Rect2(0.0, 0.0, size.x, size.y))

	# top panel
	var stylebox = get_theme_stylebox("top_panel", "Timeline")
	draw_style_box(stylebox, Rect2(0.0, 0.0, size.x, 28.0))

	var timeline_y := size.y
	var screen_width := size.x

	var pixels_per_unit := 50.0 * zoom

	var start := (time_offset / pixels_per_unit) - 1
	var end := start + (screen_width / pixels_per_unit) + 2

	# measure lines
	for t in range(int(start), int(end) + 1):
		var x := t * pixels_per_unit - time_offset

		if x >= 0 and x <= screen_width:
			if t % 4 == 0:
				draw_line(Vector2(x, 28.0), Vector2(x, size.y), primary_color, line_thickness)
				var time = t * int(time_interval)
				draw_string(font, Vector2(x - time_label_offset_x, time_label_offset_y), format_time_ms_minutes(time), HORIZONTAL_ALIGNMENT_CENTER, -1, font_size, primary_color)
			else:
				draw_line(Vector2(x, 28.0), Vector2(x, timeline_y), secondary_color, line_thickness)
	pass
	
	# track lines
	for t in track_list.get_children():
		draw_line(Vector2(0.0, t.global_position.y - global_position.y + t.size.y), Vector2(size.x, t.global_position.y - global_position.y + t.size.y), secondary_color, line_thickness)
		pass
	
	queue_sort()
	pass

func _notification(what):
	if what == NOTIFICATION_SORT_CHILDREN:
		for c in get_children():
			if c is not AudioClip: continue

			var track = get_track_by_idx(c.track_idx)

			if track == null: return

			var pixels_per_unit := 50.0 * zoom
			var start = ((c.start_time / time_interval) * pixels_per_unit) - time_offset
			var width = (c.end_time - c.start_time) / time_interval * pixels_per_unit

			c.position = Vector2(start, track.global_position.y - global_position.y)
			c.size = Vector2(width, track.size.y)

func _gui_input(event):
	var zoom_factor = 1.1
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_WHEEL_DOWN:
		zoom /= zoom_factor
		queue_redraw()
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_WHEEL_UP:
		zoom *= zoom_factor
		queue_redraw()
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_WHEEL_LEFT:
		time_offset -= 10
		queue_redraw()
	if event is InputEventMouseButton and event.button_index == MOUSE_BUTTON_WHEEL_RIGHT:
		time_offset += 10
		queue_redraw()

	zoom = max(min_zoom, zoom)
	time_offset = max(0.0, time_offset)