extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_laser_auto_aim.gd
# Tapping the laser button without dragging used to do nothing whatsoever:
# the press was claimed and the aim begun, then releasing inside the aim
# deadzone threw the whole thing away. It reads as a dead button. A tap now
# fires at the nearest enemy in range; dragging is still how a shot is placed
# precisely.
#
# Covers:
#   A. a tap picks the NEAREST enemy, not merely any enemy, and fires
#   B. it fires at all - the shot lands and the target takes the hit
#   C. a tap with nothing in range does not fire, says so, and leaves the
#      shot unspent rather than wasting it on empty space
#   D. a tap does not consume the drag-aim path: dragging past the deadzone
#      still aims where it was dragged, not at the nearest enemy

var game_state: Node
var main: Node
var fleet: Node
var skill: Node
var shooter: Node2D
var near_enemy: Node
var far_enemy: Node
var near_position: Vector2 = Vector2.ZERO
var far_position: Vector2 = Vector2.ZERO
var stage: int = 0
var elapsed: float = 0.0


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.stored_vessels.clear()
	game_state.reset_progression()
	game_state.vessel_levels["unlock_laser"] = 1
	game_state.deposit_fleet_resource(GameState.RESOURCE_ENERGY, 500)
	main = load("res://Main.tscn").instantiate()
	root.add_child(main)
	current_scene = main
	fleet = main.get_node("Fleet")
	skill = main.get_node("LaserController")


func _tap() -> void:
	# Press and release at the same point - inside AIM_DEADZONE, so this is a
	# tap and not a drag.
	var button: Control = main.get_node("UI/LaserButton")
	var at: Vector2 = button.global_position + button.size * 0.5
	for pressed in [true, false]:
		var event := InputEventScreenTouch.new()
		event.index = 7
		event.position = at
		event.pressed = pressed
		main._handle_touch(event)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			if elapsed < 0.2:
				return false
			main.get_node("EnemySpawner").set_process(false)
			main.get_node("AsteroidField").set_process(false)
			# Whatever the world spawned would be a second, unintended target.
			for hazard in get_nodes_in_group("asteroids") + get_nodes_in_group("enemies"):
				if is_instance_valid(hazard):
					hazard.queue_free()

			fleet.spawn_ships(1, Vector2.ZERO, PackedStringArray([GameState.VESSEL_LASER]))
			skill._process(0.0)
			if not main.get_node("UI/LaserButton").visible:
				return _fail("a laser ship in the fleet did not reveal the laser control")
			shooter = skill._next_ready_laser_ship()
			if shooter == null:
				return _fail("no laser ship was ready right after spawning")
			stage = 1
			elapsed = 0.0
			return false
		1:
			if elapsed < 0.1:
				return false

			# --- C. nothing in range: no shot, and it says why ---------------
			_tap()
			if not skill.beams.is_empty():
				return _fail("tapping with no enemy in range fired anyway")
			if skill.aiming:
				return _fail("tapping with no target left the control stuck in aiming")
			if main.get_node("UI/LaserStatus").text == "":
				return _fail("tapping with no target fired nothing and said nothing")
			print("no target in range: no shot fired, status explains why")

			# --- A/B. two targets, the nearer one is picked ------------------
			# Deliberately placed in DIFFERENT directions, so hitting the near
			# one cannot be explained by the beam happening to pass through
			# both. Both are well inside range.
			far_enemy = _spawn_enemy(Vector2(0.0, -900.0))
			near_enemy = _spawn_enemy(Vector2(400.0, 0.0))
			far_position = far_enemy.global_position
			near_position = near_enemy.global_position
			stage = 2
			elapsed = 0.0
			return false
		2:
			if elapsed < 0.1:
				return false
			_tap()
			if skill.beams.is_empty():
				return _fail("tapping with an enemy in range did not fire")
			if skill.last_hit_count < 1:
				return _fail("the auto-aimed shot hit nothing")
			# Asserted on where it AIMED, not on a body count. Enemies have
			# hit points and a beam damages rather than always destroys, so
			# "did it die" would be measuring the damage numbers instead of
			# the targeting this test is about.
			if skill.aim_target.distance_to(near_position) > 1.0:
				return _fail("the tap aimed at %s, but the nearest enemy is at %s" \
					% [skill.aim_target, near_position])
			print("tap aimed at the nearest enemy (%.0f away), not the one %.0f away in another direction" \
				% [shooter.global_position.distance_to(near_position),
					shooter.global_position.distance_to(far_position)])

			# --- D. dragging still aims where it is dragged ------------------
			stage = 3
			elapsed = 0.0
			return false
		3:
			# Wait out the per-ship cooldown so the next shot is available.
			if elapsed < 6.0:
				return false
			if skill._next_ready_laser_ship() == null:
				return _fail("the laser ship never came off cooldown")
			var button: Control = main.get_node("UI/LaserButton")
			var at: Vector2 = button.global_position + button.size * 0.5
			var press := InputEventScreenTouch.new()
			press.index = 8
			press.position = at
			press.pressed = true
			main._handle_touch(press)
			# Dragged straight UP, towards the far enemy and away from where
			# auto-aim would have pointed.
			var drag := InputEventScreenDrag.new()
			drag.index = 8
			drag.position = at + Vector2(0.0, -300.0)
			main._handle_drag(drag)
			var release := InputEventScreenTouch.new()
			release.index = 8
			release.position = drag.position
			release.pressed = false
			main._handle_touch(release)

			# Dragged up, so the shot must go UP - not to the nearest enemy,
			# which lies to the right. Checked as a direction because the
			# laser always extends to its full range along the aimed heading.
			var heading: Vector2 = (skill.aim_target - shooter.global_position).normalized()
			if heading.y > -0.9:
				return _fail("dragging upward aimed along %s - auto-aim overrode a deliberate aim" % heading)
			print("dragging still aims where it is dragged (heading %s), not at the nearest enemy" % heading)

			print("TEST_LASER_AUTO_AIM: PASS")
			quit(0)
			return true
	return false


func _spawn_enemy(offset: Vector2) -> Node:
	var enemy: Node = load("res://Enemy.tscn").instantiate()
	enemy.position = shooter.global_position + offset
	main.add_child(enemy)
	enemy.speed = 0.0
	return enemy


func _fail(message: String) -> bool:
	print("TEST_LASER_AUTO_AIM: FAIL (%s)" % message)
	quit(1)
	return true