extends Node3D
## First-Person-Spieler. Bewegt sich in Zugkoordinaten (s laengs, x quer),
## damit der Innenraum auch bei voller Fahrt stabil begehbar bleibt.

const Mat = preload("res://scripts/mat.gd")
const Deco = preload("res://scripts/deco.gd")
const Car = preload("res://scripts/car.gd")

signal interact_pressed(hotspot: Dictionary)

enum Mode { WALK, DRIVE }

const RADIUS := 0.30
const HEIGHT := 1.75
const EYE := 1.62
const WALK_SPEED := 2.6
const RUN_SPEED := 4.6
const ACCEL := 14.0
const REACH := 2.0
const MOUSE_SENS := 0.0022

var s := 0.0
var x := 0.0
var yaw := 0.0
var pitch := 0.0
var mode := Mode.WALK
var carrying := 0                ## getragene Getränke
var hotspot: Dictionary = {}     ## aktuell anvisierter Interaktionspunkt
var input_locked := false        ## wenn ein Menue offen ist

var camera: Camera3D
var train

var _vel := Vector2.ZERO         ## (quer, laengs)

func setup(train_node) -> void:
	train = train_node
	camera = Camera3D.new()
	camera.fov = 75.0
	camera.near = 0.05
	camera.far = 900.0
	add_child(camera)
	snap_to_cab()

func snap_to_cab() -> void:
	if train.cars.is_empty():
		return
	var loco = train.cars[0]
	s = loco.center_s + loco.inner_z1 - 2.4
	x = 0.0
	yaw = 0.0
	pitch = 0.0
	# Falls dort etwas steht, nach hinten ausweichen.
	var span: Vector2 = train.walk_range()
	var tries := 0
	while _blocked(x, s) and tries < 40:
		s = maxf(s - 0.25, span.x)
		tries += 1

## Aktuelles Lauftempo, für die Schrittgeräusche.
func move_speed() -> float:
	return _vel.length()

func capture_mouse(on: bool) -> void:
	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED if on else Input.MOUSE_MODE_VISIBLE

func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventMouseMotion and Input.mouse_mode == Input.MOUSE_MODE_CAPTURED:
		yaw -= event.relative.x * MOUSE_SENS
		pitch = clampf(pitch - event.relative.y * MOUSE_SENS, -1.35, 1.35)
	elif event is InputEventKey and event.pressed and not event.echo:
		if event.keycode == KEY_E and not input_locked:
			if not hotspot.is_empty():
				interact_pressed.emit(hotspot)

# --- Bewegung -------------------------------------------------------------

func forward_dir() -> Vector2:
	## (quer, laengs) im Zugsystem
	return Vector2(sin(yaw), cos(yaw))

## Bildschirm-rechts im Zugsystem. Godots Kamerabasis hat +X nach links,
## deshalb das umgekehrte Vorzeichen zu forward_dir().
func right_dir() -> Vector2:
	return Vector2(-cos(yaw), sin(yaw))

func _physics_process(delta: float) -> void:
	if train == null or train.cars.is_empty():
		return
	if mode == Mode.WALK and not input_locked:
		_walk(delta)
	else:
		_vel = Vector2.ZERO
	_update_transform()
	_pick_hotspot()

func _walk(delta: float) -> void:
	var move := Vector2.ZERO
	if Input.is_key_pressed(KEY_W):
		move += forward_dir()
	if Input.is_key_pressed(KEY_S):
		move -= forward_dir()
	if Input.is_key_pressed(KEY_D):
		move += right_dir()
	if Input.is_key_pressed(KEY_A):
		move -= right_dir()
	if move.length() > 0.001:
		move = move.normalized()
	var target: float = RUN_SPEED if Input.is_key_pressed(KEY_SHIFT) else WALK_SPEED
	_vel = _vel.move_toward(move * target, ACCEL * delta)

	var step := _vel * delta
	# Achsenweise schieben, damit man an Hindernissen entlanggleitet.
	if not _blocked(x + step.x, s):
		x += step.x
	if not _blocked(x, s + step.y):
		s += step.y

	var span: Vector2 = train.walk_range()
	s = clampf(s, span.x, span.y)

func _blocked(nx: float, ns: float) -> bool:
	var loc: Dictionary = train.locate(ns)
	var car = train.cars[int(loc["index"])]
	var lz: float = float(loc["local_z"])
	var half: float = Car.GANGWAY_HALF if bool(loc["gangway"]) else Car.INNER_HALF
	if absf(nx) > half - RADIUS:
		return true
	var y0: float = Car.FLOOR_Y + 0.05
	var y1: float = Car.FLOOR_Y + HEIGHT
	for b in car.blockers:
		var box: AABB = b
		if box.position.y + box.size.y <= y0 or box.position.y >= y1:
			continue
		if nx + RADIUS <= box.position.x or nx - RADIUS >= box.position.x + box.size.x:
			continue
		if lz + RADIUS <= box.position.z or lz - RADIUS >= box.position.z + box.size.z:
			continue
		return true
	return false

func _update_transform() -> void:
	var loc: Dictionary = train.locate(s)
	var xf: Transform3D = train.car_transform(int(loc["index"]))
	var lz: float = float(loc["local_z"])
	global_position = xf * Vector3(x, Car.FLOOR_Y, lz)
	var look := Vector3(sin(yaw) * cos(pitch), sin(pitch), cos(yaw) * cos(pitch))
	global_basis = xf.basis * Basis.looking_at(look, Vector3.UP)
	camera.position = Vector3(0, EYE, 0)

# --- Interaktion ----------------------------------------------------------

func _pick_hotspot() -> void:
	hotspot = {}
	if input_locked:
		return
	var best_score := 0.35
	var fwd := forward_dir()
	for ci in train.cars.size():
		var car = train.cars[ci]
		for h in car.hotspots:
			var p: Vector3 = h["pos"]
			var hs: float = car.center_s + p.z
			var d := Vector2(p.x - x, hs - s)
			var dist := d.length()
			if dist > REACH:
				continue
			if absf(p.y - (Car.FLOOR_Y + EYE)) > 1.7:
				continue
			var dir := d.normalized() if dist > 0.01 else fwd
			var score := fwd.dot(dir) * (1.0 - dist / (REACH * 2.0))
			if score > best_score:
				best_score = score
				hotspot = {"car": ci, "kind": String(h["kind"]), "seat": int(h["seat"]),
					"pos": p, "dist": dist}