extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_asteroid_ship_collision.gd
# Verifies that a ship touching an asteroid destroys BOTH the ship (removed
# from the fleet) and the asteroid itself (mutual destruction), each leaving
# its own coherent VFX behind.
#
# #130 changed what the ship leaves. Its death is a sequence now - the hull
# breaks away from the fleet, drifts clear, and explodes out there - so what
# exists on the frame of the collision is the WRECK, and the explosion comes
# later, somewhere else. That the wreck really does drift and really does go
# up is test_ship_death's job; what matters here is that the collision still
# ends the ship, ends the rock, and leaves each of them something to look at.

const CHECK_DELAY: float = 0.05

var main_scene: Node
var fleet: Node
var target_ship: Node
var asteroid: Node2D
var elapsed: float = 0.0
var stage: int = 0


func _initialize() -> void:
	var packed: PackedScene = load("res://world/Main.tscn")
	main_scene = packed.instantiate()
	root.add_child(main_scene)
	fleet = main_scene.get_node("Fleet")


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			# Wait one tick so Fleet._ready() has run and fleet.ships is
			# populated before we grab a ship reference.
			target_ship = fleet.ships[0]
			var asteroid_scene: PackedScene = load("res://world/Asteroid.tscn")
			asteroid = asteroid_scene.instantiate()
			asteroid.position = target_ship.position
			asteroid.velocity = Vector2.ZERO
			main_scene.add_child(asteroid)
			stage = 1
			elapsed = 0.0
			return false
		1:
			if elapsed < CHECK_DELAY:
				return false
			_check_results()
			return true
	return false


func _check_results() -> void:
	var ship_destroyed: bool = not is_instance_valid(target_ship)
	var ship_removed_from_fleet: bool = fleet.ships.find(target_ship) == -1
	var asteroid_destroyed: bool = not is_instance_valid(asteroid)

	var ship_vfx_ok: bool = false
	var asteroid_vfx_ok: bool = false
	for child in root.get_children():
		if child is ShipWreckVFX:
			ship_vfx_ok = true
		elif child is AsteroidExplosionVFX:
			asteroid_vfx_ok = true

	print("ship_destroyed=%s ship_removed_from_fleet=%s asteroid_destroyed=%s ship_vfx_ok=%s asteroid_vfx_ok=%s" % [
		ship_destroyed, ship_removed_from_fleet, asteroid_destroyed, ship_vfx_ok, asteroid_vfx_ok
	])

	if ship_destroyed and ship_removed_from_fleet and asteroid_destroyed and ship_vfx_ok and asteroid_vfx_ok:
		print("TEST_ASTEROID_SHIP_COLLISION: PASS")
		quit(0)
	else:
		print("TEST_ASTEROID_SHIP_COLLISION: FAIL")
		quit(1)