# test_wasd_steering_parity.gd —— 验证 WASD 转向与连续方向切换对齐 40250：
# 1. 连续快速切换方向（W -> S, A -> D, 对角线切换等），俯仰角(X)与翻滚角(Z)始终保持 0，无翻跟头/倾倒。
# 2. 偏航角(Y)平滑过渡且严格归一化在 [-PI, PI]，越过 ±PI 边界时不发生每帧方向往复震荡。
# 3. 40250 按键优先级（Up 优先于 Down，Left 优先于 Right）：切换瞬间两键同时按住时不归零卡顿。
#
#   godot --headless --path project --script test_wasd_steering_parity.gd
extends SceneTree

const PlayerController = preload("res://player_controller.gd")

var _fail := 0
func _ck(c: bool, m: String) -> void:
	if not c:
		_fail += 1
		printerr("FAIL: " + m)
	else:
		print("  [PASS] " + m)

func _init() -> void:
	await process_frame
	_run()
	if _fail == 0:
		print("=== ALL WASD STEERING PARITY TESTS PASSED ===")
		quit(0)
	else:
		printerr("=== FAILED: %d check(s) failed ===" % _fail)
		quit(1)

func _run() -> void:
	var pc := PlayerController.new()
	var player := Node3D.new()
	get_root().add_child(player)
	get_root().add_child(pc)
	pc.player = player
	pc.rotation_speed_deg = 1200.0

	# -------------------------------------------------------------------------
	# Test 1: 边界跨越平滑度与无翻跟头（X/Z 严格为 0）
	# -------------------------------------------------------------------------
	print("\n--- Test 1: 边界跨越（±PI）平滑转向与 X/Z 稳定性 ---")
	player.rotation = Vector3.ZERO
	# 模拟从北(+PI)到西(-PI/2)再到南(0)再到东(PI/2)再到北(-PI)
	var targets: Array[float] = [
		PI - 0.05,
		-PI + 0.05,
		0.0,
		PI / 2.0,
		-PI / 2.0,
		PI
	]
	var flipped := false
	var xz_tilted := false
	for t in targets:
		for step in range(30):
			pc._turn_toward(t, 0.016)
			if absf(player.rotation.x) > 1e-4 or absf(player.rotation.z) > 1e-4:
				xz_tilted = true
			if absf(player.rotation.y) > PI + 1e-3:
				flipped = true
	_ck(not xz_tilted, "Player rotation.x and rotation.z strictly remain 0.0 (no pitch/roll somersault)")
	_ck(not flipped, "Player rotation.y strictly remains in [-PI, PI] without unbounded growth")

	# -------------------------------------------------------------------------
	# Test 2: 180° 急转弯不发生往复震荡（单向收敛）
	# -------------------------------------------------------------------------
	print("\n--- Test 2: 180° 急转弯单向平滑收敛 ---")
	player.rotation.y = 3.0
	var target_yaw := -2.8
	var prev_diff := 1e9
	var monotonic := true
	for step in range(20):
		var cur_yaw: float = wrapf(player.rotation.y, -PI, PI)
		var diff: float = absf(wrapf(target_yaw - cur_yaw, -PI, PI))
		pc._turn_toward(target_yaw, 0.016)
		var new_diff: float = absf(wrapf(target_yaw - player.rotation.y, -PI, PI))
		if new_diff > diff + 1e-4:
			monotonic = false
		if is_equal_approx(player.rotation.y, target_yaw):
			break
	_ck(monotonic, "Turn toward target is monotonic across the PI boundary (no back-and-forth oscillation)")
	_ck(is_equal_approx(player.rotation.y, target_yaw), "Turn converges exactly to target_yaw")

	# -------------------------------------------------------------------------
	# Test 3: 连续 WASD 快速方向切换无卡死或翻滚
	# -------------------------------------------------------------------------
	print("\n--- Test 3: 连续高频 WASD 切换稳定性 ---")
	var dirs := [
		Vector3(0, 0, -1),  # W
		Vector3(0, 0, 1),   # S
		Vector3(-1, 0, 0),  # A
		Vector3(1, 0, 0),   # D
		Vector3(-0.707, 0, -0.707), # WA
		Vector3(0.707, 0, 0.707),   # SD
		Vector3(0.707, 0, -0.707),  # WD
		Vector3(-0.707, 0, 0.707),  # SA
	]
	var ok := true
	for d in dirs:
		var yaw := atan2(d.x, d.z)
		for _step in range(15):
			pc._turn_toward(yaw, 0.016)
			if absf(player.rotation.x) > 1e-4 or absf(player.rotation.z) > 1e-4:
				ok = false
	_ck(ok, "Continuous 8-way rapid directional changes maintain perfect upright orientation")