extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_joystick_control.gd
# Verifies the virtual joystick steers the fleet: holding the stick in a
# direction flies the fleet that way, and releasing brings it to a stop
# rather than freezing it mid-flight. Replaces the old tap-to-move test,
# since tapping no longer issues move orders.
#
# Touch events are handed to the joystick directly rather than through
# Input.parse_input_event: headless mode's placeholder window rescales
# synthetic touch coordinates by an environment-specific factor, which
# would land them outside the joystick's rect for reasons that have nothing
# to do with the behaviour under test.

var main_scene: Node
var fleet: Node
var joystick: TouchJoystick
var stage: int = 0
var elapsed: float = 0.0
var start_centroid: Vector2
var moving_centroid: Vector2
var stop_check_frames: int = 0
# Release-coast tracking (Forgejo #13).
var released: bool = false
var speed_at_release: float = 0.0
var previous_speed: float = 0.0
var accelerated_after_release: bool = false


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


func _press(local: Vector2) -> void:
	var ev: InputEventScreenTouch = InputEventScreenTouch.new()
	ev.index = 0
	ev.pressed = true
	ev.position = joystick.global_position + local
	joystick.handle_touch(ev)


func _drag(local: Vector2) -> void:
	var ev: InputEventScreenDrag = InputEventScreenDrag.new()
	ev.index = 0
	ev.position = joystick.global_position + local
	joystick.handle_drag(ev)


func _release(local: Vector2) -> void:
	var ev: InputEventScreenTouch = InputEventScreenTouch.new()
	ev.index = 0
	ev.pressed = false
	ev.position = joystick.global_position + local
	joystick.handle_touch(ev)


func _max_ship_speed() -> float:
	var top: float = 0.0
	for ship in fleet.ships:
		top = maxf(top, ship.velocity.length())
	return top


func _process(delta: float) -> bool:
	elapsed += delta

	# Releasing the stick must be ONE continuous decelerating coast. It used
	# to stop dead and then accelerate into its own stopping distance,
	# halting a second time - felt in game as a pause followed by a small
	# extra lurch (#13). The ships were being aimed at a braking point ahead
	# while their own velocity was ~0, because the anchor had been carrying
	# them, so they started from rest.
	if released:
		var now: float = _max_ship_speed()
		if now > previous_speed + 1.0:
			accelerated_after_release = true
		previous_speed = now
	match stage:
		0:
			main_scene.get_node("AsteroidField").set_process(false)
			main_scene.get_node("EnemySpawner").set_process(false)
			start_centroid = fleet.get_centroid()

			# The joystick receives touches via GameController's
			# _unhandled_input, which never fires for a Control that
			# consumes them through the GUI system first. With Godot's
			# default mouse_filter (STOP) the stick silently does nothing
			# on a real device - it must be IGNORE. Checked structurally
			# because the rest of this test drives handle_touch() directly
			# and so cannot catch it.
			if joystick.mouse_filter != Control.MOUSE_FILTER_IGNORE:
				print("joystick mouse_filter=%d (needs IGNORE=%d)" % [
					joystick.mouse_filter, Control.MOUSE_FILTER_IGNORE
				])
				print("TEST_JOYSTICK_CONTROL: FAIL (stick would swallow its own touches)")
				quit(1)
				return true

			# Push the stick hard to the right.
			var centre: Vector2 = joystick.size / 2.0
			_press(centre)
			_drag(centre + Vector2(joystick.max_radius, 0.0))
			if joystick.direction.x < 0.9:
				print("joystick direction wrong: %s" % joystick.direction)
				print("TEST_JOYSTICK_CONTROL: FAIL (stick did not register)")
				quit(1)
				return true
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 1.5:
				return false
			moving_centroid = fleet.get_centroid()
			var moved_right: bool = moving_centroid.x - start_centroid.x > 100.0
			var stayed_level: bool = abs(moving_centroid.y - start_centroid.y) < 80.0
			print("moved from %s to %s (right=%s level=%s)" % [
				start_centroid, moving_centroid, moved_right, stayed_level
			])
			if not (moved_right and stayed_level):
				print("TEST_JOYSTICK_CONTROL: FAIL (fleet did not follow the stick)")
				quit(1)
				return true

			_release(joystick.size / 2.0)
			released = true
			speed_at_release = _max_ship_speed()
			previous_speed = speed_at_release
			if joystick.direction != Vector2.ZERO:
				print("TEST_JOYSTICK_CONTROL: FAIL (direction not cleared on release)")
				quit(1)
				return true
			elapsed = 0.0
			stage = 2
			return false
		2:
			# After release the fleet should coast to a halt, not freeze
			# instantly and not keep flying.
			if elapsed < 4.0:
				return false
			var speed: float = 0.0
			for ship in fleet.ships:
				speed = max(speed, ship.velocity.length())
			# Carrying the fleet's cruise speed, not starting from a standstill.
			if speed_at_release < fleet.cruise_speed * 0.5:
				print("speed one frame after release: %.1f (cruising at %.1f)" % [
					speed_at_release, fleet.cruise_speed
				])
				print("TEST_JOYSTICK_CONTROL: FAIL (the fleet stopped dead on release instead of coasting)")
				quit(1)
				return true
			if accelerated_after_release:
				print("TEST_JOYSTICK_CONTROL: FAIL (the fleet sped up again after release - pause then lurch, #13)")
				quit(1)
				return true
			print("release coast: %.1f -> 0 with no re-acceleration" % speed_at_release)

			var stopped: bool = speed < 1.0
			# Not merely "moved forward at all": the fleet cruises at
			# cruise_speed and brakes at Ship.acceleration, so the coast is
			# cruise_speed^2 / (2 * acceleration) ~ 75 units. Asserting a
			# real distance is what makes this a test of coasting - the old
			# `> moving_centroid.x` was satisfied by any float wobble, and
			# passed happily while the fleet stopped dead.
			var coast: float = fleet.get_centroid().x - moving_centroid.x
			var coasted: bool = coast > 40.0
			print("after release: max_speed=%.3f stopped=%s coasted=%.1f units (expected ~%.0f)" % [
				speed, stopped, coast,
				(fleet.cruise_speed * fleet.cruise_speed) / (2.0 * fleet.ships[0].acceleration)
			])
			if stopped and coasted:
				print("TEST_JOYSTICK_CONTROL: PASS")
				quit(0)
			else:
				print("TEST_JOYSTICK_CONTROL: FAIL (did not coast to a stop)")
				quit(1)
			return true
	return false