extends Camera2D

export var zoom_border = 100

var zoom_rate:float

var view:Viewport
var dist_max:float

func _ready():
	view = get_tree().root
	view.connect("size_changed", self, "_on_size_changed")
	update_zoom_reference()

func _process(_d):
	move()

func move():
	if !get_tree().has_group("players"):
		return

	var running
	if get_tree().has_group("running"):
		running = get_tree().get_nodes_in_group("running")

	if !running or running.size() == 0:
		# Show every players
		var players = get_tree().get_nodes_in_group("players")
		center_on(players)
	else:
		# Show remaining players only
		center_on(running)

func center_on(players):
	var position_accumulator = Vector2(0.0, 0.0)
	for p in players:
		position_accumulator += p.position

	position = position_accumulator / players.size()

	var dist = 0
	for i in range(players.size() - 1):
		for j in range(i + 1, players.size()):
			dist = max(dist, players[i].position.distance_to(players[j].position))

	# Extend camera zoom if liners are far from each other
	var new_zoom = 1.0
	if dist > dist_max:
		new_zoom += (dist - dist_max) * zoom_rate

	zoom = Vector2(new_zoom, new_zoom)

func update_zoom_reference():
	var ref_length = min(view.size.x, view.size.y)
	dist_max = ref_length - 2 * zoom_border
	zoom_rate = 1.0 / dist_max

func _on_size_changed():
	update_zoom_reference()