extends Node
## Weichen: Route wählen, Übergang ohne Sprung, Bergstrecke erreichbar.
var main
var step := 0
var wait := 0.0
var ok := 0
var fail := 0
var last_pos := Vector3.ZERO
var worst_jump := 0.0
var jump_frames := 0
var _dbg := 0.0
var _cam_hits := 0
var _cam_pulled := 0
var _cam_yaw := 0

func chk(n: String, c: bool, i := "") -> void:
	if c: ok += 1; print("  OK   %s %s" % [n, i])
	else: fail += 1; print("  FAIL %s %s" % [n, i])

func _key(c: int, d: bool) -> void:
	var e := InputEventKey.new(); e.physical_keycode = c; e.keycode = c; e.pressed = d
	Input.parse_input_event(e)

func _watch(d: float) -> void:
	var t = main.train
	var p: Vector3 = t.cars[t.cars.size() - 1].global_position
	if last_pos != Vector3.ZERO and d > 0.0:
		var jump := p.distance_to(last_pos)
		var allowed: float = t.speed * d * 1.5 + 0.05
		if jump > allowed:
			jump_frames += 1
		worst_jump = maxf(worst_jump, jump - t.speed * d)
	last_pos = p

## Im Physik-Takt messen: dort bewegt sich der Zug genau einmal pro Aufruf.
func _physics_process(d: float) -> void:
	if main != null and main.started and step >= 1 and step <= 8:
		_watch(d)

func _process(d):
	if main == null:
		main = get_tree().current_scene
		return
	if not main.started:
		main._start_solo()
		return
	var t = main.train
	if wait > 0.0:
		wait -= d
		return
	match step:
		0:
			chk("Drei Abschnitte", main.track.segments.size() == 3)
			chk("Heimstrecke hat Weiche", main.track.is_switch(2))
			chk("Sechs Bahnhöfe", main.stations.size() == 6)
			main._park_at(main.stations[4])   # Ahornstadt, Heimstrecke
			chk("Start auf Heimstrecke", t.seg == 2, "seg=%d" % t.seg)
			chk("Weiche voraus erkannt", t.upcoming_switch() == 2)
			var nxt: Array = t.next_station()
			chk("Nächster Halt Waldkirch (links)", nxt[0].station_name == "Waldkirch",
				"%s" % nxt[0].station_name)
			t.switch_choice = 1
			var nxt2: Array = t.next_station()
			chk("Nächster Halt Bergblick (rechts)", nxt2[0].station_name == "Bergblick",
				"%s" % nxt2[0].station_name)
			t.switch_choice = 0
			main.driver_id = 1
			_key(KEY_W, true)
			last_pos = Vector3.ZERO
			wait = 1.0
		1:
			wait = 0.5
		2:
			if t.seg != 0:
				step -= 1
				wait = 0.3
				_dbg += 0.3
				if _dbg >= 2.0:
					_dbg = 0.0
					print("[dbg] seg=%d prog=%.1f/%.1f v=%.1f thr=%.1f driver=%d mode=%d" % [t.seg, t.progress,
						main.track.seg_length(t.seg), t.speed, t.throttle, main.driver_id, main.player.mode])
			else:
				_key(KEY_W, false)
				_key(KEY_S, true)
				chk("Links -> Talstrecke", t.seg == 0, "seg=%d" % t.seg)
				chk("Historie geführt", t.history.size() > 0 and t.history[t.history.size() - 1] == 2,
					"%s" % [t.history])
				chk("Letzter Wagen ohne Sprung", jump_frames == 0,
					"Sprungframes=%d, größter Sprung %.2f m" % [jump_frames, worst_jump])
				wait = 4.0
		3:
			_key(KEY_S, false)
			main._park_at(main.stations[4])
			t.switch_choice = 1
			last_pos = Vector3.ZERO
			jump_frames = 0
			worst_jump = 0.0
			_key(KEY_D, true)
			_key(KEY_W, true)
			wait = 1.0
		4:
			wait = 0.5
		5:
			if t.seg != 1:
				step -= 1
				wait = 0.3
			else:
				chk("Rechts -> Bergstrecke", t.seg == 1, "seg=%d" % t.seg)
				chk("D hält die Weiche rechts", t.switch_choice == 1)
				chk("Übergang rechts ohne Sprung", jump_frames == 0,
					"Sprungframes=%d" % jump_frames)
				_key(KEY_D, false)
				wait = 0.5
		6:
			var nxt: Array = t.next_station()
			chk("Bergblick voraus", nxt[0].station_name == "Bergblick", "%s" % nxt[0].station_name)
			wait = 0.5
		7:
			# bis kurz vor Bergblick fahren, dann bremsen
			var berg = main.stations[5]
			var ahead: float = t.distance_ahead(berg)
			if ahead > t.speed * t.speed / 16.0 + 8.0:
				step -= 1
				wait = 0.2
			else:
				_key(KEY_W, false)
				_key(KEY_S, true)
				wait = 6.0
		8:
			_key(KEY_S, false)
			chk("Zug steht", t.speed < 0.05, "v=%.2f" % t.speed)
			chk("Am Bergblick angekommen", t.docked_at != null and t.docked_at.station_name == "Bergblick",
				"dock=%s" % ("-" if t.docked_at == null else t.docked_at.station_name))
			# Sichtkontrolle: Kreuzung von oben
			main._park_at(main.stations[4])
			t.place_head(2, main.track.seg_length(2) - 6.0)
			main._toggle_camera()
			main.cam_rig.distance = 95.0
			main.cam_rig.pitch = deg_to_rad(-70.0)
			main.cam_rig.yaw = 0.4
			wait = 1.0
		9:
			get_viewport().get_texture().get_image().save_png("user://junction.png")
			t.place_head(0, main.track.seg_length(0) - 20.0)
			main.cam_rig.snap_to(t.cars[0].global_position)
			wait = 1.0
		10:
			get_viewport().get_texture().get_image().save_png("user://junction2.png")
			# Kamera-Kollision: Fokus auf den Bahnsteig, rundherum drehen
			var st = main.stations[0]
			main.cam_rig.target = null
			main.cam_rig.snap_to(st.global_position + Vector3(0, 0, 0))
			main.cam_rig.distance = 30.0
			main.cam_rig.pitch = deg_to_rad(-10.0)
			_cam_hits = 0
			_cam_yaw = 0
			wait = 0.2
		11:
			if _cam_yaw < 12:
				main.cam_rig.yaw = _cam_yaw * TAU / 12.0
				_cam_yaw += 1
				step -= 1
				wait = 0.15
				if main.cam_rig.blocked:
					_cam_hits += 1
					var dist: float = main.cam_rig._cam.global_position.distance_to(main.cam_rig.global_position)
					if dist < 29.0:
						_cam_pulled += 1
			else:
				chk("Kamera stößt am Gebäude an", _cam_hits > 0, "%d von 12 Richtungen" % _cam_hits)
				chk("Kamera rückt davor", _cam_pulled == _cam_hits, "%d/%d" % [_cam_pulled, _cam_hits])
		12:
			print("== %d ok, %d fail ==" % [ok, fail])
			get_tree().quit(1 if fail > 0 else 0)
	step += 1