# PlayerController —— Metin2 风移动 + 选目标（客户端预测，无服务端纠正）。
#   左键点地面 -> 走/跑过去（沿途查 attr.atr 可行走，遇阻停）
#   左键点实体 -> 选中（emit target_selected）
#   WASD/方向键 -> 直接移动（相对相机），覆盖点地
#   触屏（F7）：单指轻点 = 点地/点选（快速抬起且位移小）；单指拖拽归相机环绕，
#              双指手势时不产生点地。
# 需要：player(Node3D)、camera(GameCamera)、world(Metin2World)。
# 每帧 emit anim_state("wait"|"walk"|"run") 供上层切动画。
extends Node

signal anim_state(state: String)
signal target_selected(node: Node3D)
signal moved(pos: Vector3)

var player: Node3D
var camera: Camera3D
var world: Node
var pickables: Array[Node3D] = []      # 可点选实体（NPC/怪等）

const SPEED_WALK := 8.0
const SPEED_RUN := 18.0
const RUN_HOLD_KEY := KEY_SHIFT
const ARRIVE_EPS := 0.4
const PICK_RADIUS := 1.4               # 点选命中半径（米）

var force_run := false                 # 脚本化 / 自动跑
var frozen := false                    # 受击硬直等：本帧不响应移动输入（net_play 设）
var server_speed_scale := 1.0          # GC_CHANGE_SPEED moving_speed / 100

const _TAP_TRAVEL_MAX := 12.0          # 触点位移超过这么多像素 -> 视作拖拽（归相机），不是轻点
const _TAP_TIME_MAX := 0.35            # 按下到抬起超过这么久 -> 不是轻点

var _move_target := Vector3.ZERO
var _has_target := false
var _run := false
var _touch_count := 0
var _multi_gesture := false            # 曾有 ≥2 指同时按下 -> 本轮不产生点地
var _tap_index := -1
var _tap_press_pos := Vector2.ZERO
var _tap_press_t := 0.0

func set_server_speed(moving_speed: int) -> void:
	# Metin2 POINT_MOV_SPEED uses 100 as the normal baseline. Keep malformed or
	# pre-spawn zero values from freezing local prediction.
	if moving_speed <= 0:
		return
	server_speed_scale = clampf(float(moving_speed) / 100.0, 0.25, 3.0)

# 程序化下发一个点地目标（脚本化截图 / AI）
func walk_to(world_pos: Vector3) -> void:
	_move_target = Vector3(world_pos.x, 0.0, world_pos.z)
	_has_target = true

func _unhandled_input(e: InputEvent) -> void:
	if e is InputEventMouseButton and e.button_index == MOUSE_BUTTON_LEFT and e.pressed:
		_on_click(e.position)
	elif e is InputEventScreenTouch:
		_on_touch(e)
	elif e is InputEventScreenDrag:
		# 触点一旦拖出去，就不再是「轻点」，交给相机环绕
		if e.index == _tap_index and e.position.distance_to(_tap_press_pos) > _TAP_TRAVEL_MAX:
			_tap_index = -1

func _on_touch(e: InputEventScreenTouch) -> void:
	if e.pressed:
		_touch_count += 1
		if _touch_count >= 2:
			_multi_gesture = true
			_tap_index = -1
		elif not _multi_gesture:
			_tap_index = e.index
			_tap_press_pos = e.position
			_tap_press_t = Time.get_ticks_msec() / 1000.0
	else:
		_touch_count = max(0, _touch_count - 1)
		if e.index == _tap_index and not _multi_gesture:
			var travel := e.position.distance_to(_tap_press_pos)
			var held := Time.get_ticks_msec() / 1000.0 - _tap_press_t
			if travel <= _TAP_TRAVEL_MAX and held <= _TAP_TIME_MAX:
				_on_click(e.position)
			_tap_index = -1
		if _touch_count == 0:
			_multi_gesture = false

func _on_click(screen_pos: Vector2) -> void:
	if camera == null:
		return
	var from := camera.project_ray_origin(screen_pos)
	var dir := camera.project_ray_normal(screen_pos)

	# 1) 实体点选：射线 vs 每个 pickable 的网格世界包围盒（slab 相交，逐实体精确，
	#    大怪 / 小怪都不再被固定 1.4m 半径误判）。无网格的回退到胶囊近似。
	var best: Node3D = null
	var best_t := 1e20
	for n in pickables:
		if not is_instance_valid(n):
			continue
		var t := _ray_pick_t(from, dir, n)
		if t >= 0.0 and t < best_t:
			best_t = t
			best = n
	if best:
		target_selected.emit(best)
		return

	# 2) 点地：射线与地表求交（沿射线二分找 y == 地表高度）
	var hit: Variant = _ray_ground(from, dir)
	if hit != null:
		_move_target = hit
		_has_target = true

# 射线 vs 实体(节点下所有 MeshInstance3D 的世界 AABB 合并)的进入距离 t;不命中返回 -1。
func _ray_pick_t(from: Vector3, dir: Vector3, node: Node3D) -> float:
	var box := AABB()
	var have := false
	for m in node.find_children("*", "MeshInstance3D", true, false):
		var mi := m as MeshInstance3D
		if mi.mesh == null:
			continue
		var wb: AABB = mi.get_global_transform() * mi.get_aabb()
		box = wb if not have else box.merge(wb)
		have = true
	if not have:
		# 无网格:退回胶囊近似(头顶 1m,半径 PICK_RADIUS)
		var to := node.global_position + Vector3(0, 1.0, 0) - from
		var tp := to.dot(dir)
		if tp < 0.0:
			return -1.0
		var perp := (from + dir * tp) - (node.global_position + Vector3(0, 1.0, 0))
		return tp if perp.length() < PICK_RADIUS else -1.0
	box = box.grow(0.15)   # 点选宽容度
	# slab 法求射线进入 box 的 t
	var tmin := -1e20
	var tmax := 1e20
	for axis in 3:
		var o: float = from[axis]
		var d: float = dir[axis]
		var lo: float = box.position[axis]
		var hi: float = box.position[axis] + box.size[axis]
		if absf(d) < 1e-9:
			if o < lo or o > hi:
				return -1.0
		else:
			var t1 := (lo - o) / d
			var t2 := (hi - o) / d
			if t1 > t2:
				var tmp := t1; t1 = t2; t2 = tmp
			tmin = maxf(tmin, t1)
			tmax = minf(tmax, t2)
			if tmin > tmax:
				return -1.0
	return tmin if tmin >= 0.0 else (tmax if tmax >= 0.0 else -1.0)

func _ray_ground(from: Vector3, dir: Vector3) -> Variant:
	if world == null or not world.has_method("sample_height"):
		return null
	var t := 0.0
	var last_above: bool = from.y - float(world.call("sample_height", from.x, from.z)) > 0.0
	for _i in 240:
		t += 1.0
		var p := from + dir * t
		if t > 800.0:
			break
		var above: bool = p.y - float(world.call("sample_height", p.x, p.z)) > 0.0
		if above != last_above:
			# 在 [t-1, t] 之间二分
			var a := t - 1.0
			var b := t
			for _j in 12:
				var m := (a + b) * 0.5
				var pm := from + dir * m
				if (pm.y - world.call("sample_height", pm.x, pm.z) > 0) == last_above:
					a = m
				else:
					b = m
			var pf := from + dir * b
			return Vector3(pf.x, float(world.call("sample_height", pf.x, pf.z)), pf.z)
		last_above = above
	return null

func _wasd() -> Vector2:
	var d := Vector2.ZERO
	if Input.is_key_pressed(KEY_W) or Input.is_key_pressed(KEY_UP): d.y -= 1
	if Input.is_key_pressed(KEY_S) or Input.is_key_pressed(KEY_DOWN): d.y += 1
	if Input.is_key_pressed(KEY_A) or Input.is_key_pressed(KEY_LEFT): d.x -= 1
	if Input.is_key_pressed(KEY_D) or Input.is_key_pressed(KEY_RIGHT): d.x += 1
	return d.normalized()

func _blocked(x: float, z: float) -> bool:
	return world != null and world.has_method("is_blocked") and bool(world.call("is_blocked", x, z))

func _process(dt: float) -> void:
	if player == null:
		return
	if frozen:
		_has_target = false
		anim_state.emit("wait")
		return
	_run = force_run or Input.is_key_pressed(RUN_HOLD_KEY)
	var wish := Vector3.ZERO
	var wasd := _wasd()

	if wasd != Vector2.ZERO:
		_has_target = false   # 键盘覆盖点地
		var yaw: float = (camera.heading() if camera and camera.has_method("heading") else 0.0)
		var fwd := Vector3(sin(yaw), 0, cos(yaw))
		var right := Vector3(fwd.z, 0, -fwd.x)
		wish = (fwd * -wasd.y + right * wasd.x).normalized()
	elif _has_target:
		var flat := Vector3(_move_target.x - player.position.x, 0, _move_target.z - player.position.z)
		if flat.length() <= ARRIVE_EPS:
			_has_target = false
		else:
			wish = flat.normalized()

	var speed := 0.0
	if wish != Vector3.ZERO:
		var want_speed := (SPEED_RUN if _run else SPEED_WALK) * server_speed_scale
		var before := player.position
		var np := player.position + wish * want_speed * dt
		if not _blocked(np.x, player.position.z):
			player.position.x = np.x
		if not _blocked(player.position.x, np.z):
			player.position.z = np.z
		# 动画看「实际位移」而非意图：贴墙磨蹭时该切回 wait
		var disp := Vector2(player.position.x - before.x, player.position.z - before.z).length()
		if disp > want_speed * dt * 0.25:
			speed = want_speed
			player.rotation.y = atan2(wish.x, wish.z)
		else:
			_has_target = false

	if world and world.has_method("sample_height"):
		player.position.y = float(world.call("sample_height", player.position.x, player.position.z))
	moved.emit(player.position)

	if speed <= 0.01:
		anim_state.emit("wait")
	elif not _run:
		anim_state.emit("walk")
	else:
		anim_state.emit("run")