extends Camera2D
# Handle zoom and move for player tracking

export var zoom_border = 100

var zoom_rate:float
var dist_max_x:float
var dist_max_y:float
var view:Viewport


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()

	# Compute axis aligned distances
	var dist_x = 0
	var dist_y = 0
	for i in range(players.size() - 1):
		for j in range(i + 1, players.size()):
			dist_x = max(dist_x, abs(players[i].position.x - players[j].position.x))
			dist_y = max(dist_y, abs(players[i].position.y - players[j].position.y))

	# Extend camera zoom if liners are far from each other
	var new_zoom = 1.0
	if dist_x > dist_max_x:
		new_zoom += (dist_x - dist_max_x) * zoom_rate
	if dist_y > dist_max_y:
		new_zoom = max(new_zoom, 1.0 + (dist_y - dist_max_y) * zoom_rate)

	zoom = Vector2(new_zoom, new_zoom)


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


func _on_size_changed():
	update_zoom_reference()