class_name Player
extends CharacterBody3D
## The player character controller.
##
## Roblox-style third-person controller:
##
##   * Classic camera (default): the mouse cursor is free; hold a mouse button
##     and drag to orbit the camera 360 in yaw (pitch clamped). Right button
##     also turns the character to face the camera while held. Scroll wheel
##     zooms; zoom all the way in -> first person.
##   * Shift Lock (toggle Left Shift): mouse locks to a centre crosshair, the
##     camera moves over the right shoulder, and the character's facing is
##     locked to the camera -- WASD strafes / backpedals.
##
## Movement is always camera-relative (W = away from the camera). Outside the
## camera-facing modes the body auto-rotates toward its movement direction.
## Spawn point comes from the current scene's `PlayerSpawn` Marker3D.


# ---------------------------------------------------------------------------
# Movement / camera constants
# ---------------------------------------------------------------------------

const WALK_SPEED: float = 5.0
const JUMP_VELOCITY: float = 4.5
const GRAVITY: float = 9.8

## Mouse-look sensitivity (radians per pixel of relative motion).
const MOUSE_SENSITIVITY: float = 0.003

## Vertical offset applied to the assembled avatar so its feet (origin y=0)
## line up with the bottom of the player's collision capsule.
const AVATAR_FEET_OFFSET: float = -0.8

## Camera pitch limits (radians): near top-down to looking up from below.
## Yaw is deliberately unclamped -- full 360 orbit.
const PITCH_MIN: float = -1.35
const PITCH_MAX: float = 1.2

## Camera pivot height above the player origin, third-person vs first-person.
const PIVOT_Y_TP: float = 1.2
const PIVOT_Y_FP: float = 0.65

## Zoom (spring length) range, scroll step, and the distance at or below which
## we switch to first person.
const ZOOM_MIN: float = 0.4
const ZOOM_MAX: float = 9.0
const ZOOM_STEP: float = 0.6
const FIRST_PERSON_ZOOM: float = 0.6
const ZOOM_DEFAULT: float = 3.5

## How far right the camera sits in Shift Lock (metres).
const SHOULDER_OFFSET: float = 0.85

## How fast the body swings toward its target facing.
const BODY_TURN_SPEED: float = 12.0


# ---------------------------------------------------------------------------
# State
# ---------------------------------------------------------------------------

var _input_direction := Vector2.ZERO
var _camera_yaw: float = 0.0        # unclamped, wraps
var _camera_pitch: float = -0.12
var _zoom: float = ZOOM_DEFAULT
var _shift_lock: bool = false
var _mouse_look_held: bool = false  # LMB or RMB held (classic drag)
var _rmb_held: bool = false         # RMB specifically (turns the body)
var _spawn_position: Vector3 = Vector3(0, 1.5, 0)

@onready var _camera: Camera3D = $CameraPivot/SpringArm3D/Camera3D
@onready var _camera_pivot: Node3D = $CameraPivot
@onready var _spring_arm: SpringArm3D = $CameraPivot/SpringArm3D
@onready var _capsule_mesh: MeshInstance3D = $CapsuleMesh

var _avatar_view: Node3D = null
var _limb_anim: Node = null
var _crosshair: CanvasLayer = null


# ---------------------------------------------------------------------------
# _ready
# ---------------------------------------------------------------------------

func _ready() -> void:
	# Per §3 of pc2_test_level.md: look up PlayerSpawn from the current scene
	# root (recursive), guarding the null current_scene of headless runs.
	var current_scene: Node = get_tree().current_scene
	var spawn: Node = null
	if current_scene != null:
		spawn = current_scene.find_child("PlayerSpawn", true, false)

	if spawn is Node3D:
		global_position = (spawn as Node3D).global_position
		rotation.y = (spawn as Node3D).rotation.y
	else:
		push_warning("player.gd: no PlayerSpawn marker found; spawning at origin")
		global_position = Vector3(0, 1.0, 0)
	_spawn_position = global_position

	# The spring arm must not collide with the player's own capsule (same
	# layer) or the camera gets yanked against the player's head.
	_spring_arm.add_excluded_object(self)

	# The camera pivot orbits the player freely -- it can't inherit the body's
	# yaw, so detach it and drive its world transform ourselves each frame.
	_camera_pivot.top_level = true
	_camera_yaw = rotation.y

	_build_crosshair()
	_refresh_mouse_mode()
	_update_camera()
	_apply_avatar()
	var avatars := get_node_or_null("/root/AvatarSystem")
	if avatars != null and avatars.has_signal("loadout_changed"):
		avatars.loadout_changed.connect(func(_lo): _apply_avatar())


func _build_crosshair() -> void:
	if DisplayServer.get_name() == "headless":
		return
	_crosshair = CanvasLayer.new()
	_crosshair.layer = 64
	var l := Label.new()
	l.text = "+"
	l.add_theme_font_size_override("font_size", 22)
	l.add_theme_color_override("font_color", Color(1, 1, 1, 0.85))
	l.add_theme_color_override("font_outline_color", Color(0, 0, 0, 0.8))
	l.add_theme_constant_override("outline_size", 4)
	l.set_anchors_preset(Control.PRESET_CENTER)
	l.horizontal_alignment = HORIZONTAL_ALIGNMENT_CENTER
	l.vertical_alignment = VERTICAL_ALIGNMENT_CENTER
	l.offset_left = -12
	l.offset_right = 12
	l.offset_top = -16
	l.offset_bottom = 16
	l.mouse_filter = Control.MOUSE_FILTER_IGNORE
	_crosshair.add_child(l)
	add_child(_crosshair)
	_crosshair.visible = false


## Show the player's assembled avatar and hide the placeholder capsule.
func _apply_avatar() -> void:
	var avatars := get_node_or_null("/root/AvatarSystem")
	if avatars == null or not avatars.has_method("build_current_avatar"):
		return
	var avatar: Node3D = avatars.build_current_avatar()
	if avatar == null:
		push_warning("player.gd: no avatar to show; keeping the placeholder capsule")
		return
	if _avatar_view != null and is_instance_valid(_avatar_view):
		remove_child(_avatar_view)
		_avatar_view.queue_free()
	if _limb_anim != null and is_instance_valid(_limb_anim):
		remove_child(_limb_anim)
		_limb_anim.queue_free()
		_limb_anim = null

	avatar.position = Vector3(0.0, AVATAR_FEET_OFFSET, 0.0)
	add_child(avatar)
	_avatar_view = avatar
	if _capsule_mesh:
		_capsule_mesh.visible = false

	# Procedural walk cycle -- no clips yet, just swing the limb bones with speed.
	var skel := avatar.find_child("Skeleton3D", true, false)
	if skel is Skeleton3D:
		_limb_anim = preload("res://scripts/avatar/limb_animator.gd").new()
		add_child(_limb_anim)
		_limb_anim.call("setup", skel)


# ---------------------------------------------------------------------------
# Input
# ---------------------------------------------------------------------------

func _is_first_person() -> bool:
	return _zoom <= FIRST_PERSON_ZOOM


## Mouse should be captured (hidden, locked) whenever the camera is in an
## aim-style mode or the player is mid-drag.
func _want_mouse_captured() -> bool:
	return _shift_lock or _is_first_person() or _mouse_look_held


## Body facing is slaved to the camera in Shift Lock, first person, or while
## the right mouse button is held.
func _want_face_camera() -> bool:
	return _shift_lock or _is_first_person() or _rmb_held


func _refresh_mouse_mode() -> void:
	if DisplayServer.get_name() == "headless":
		return
	Input.mouse_mode = Input.MOUSE_MODE_CAPTURED if _want_mouse_captured() \
		else Input.MOUSE_MODE_VISIBLE
	if _crosshair != null:
		_crosshair.visible = _shift_lock or _is_first_person()


func _set_zoom(v: float) -> void:
	var was_fp := _is_first_person()
	_zoom = clampf(v, ZOOM_MIN, ZOOM_MAX)
	if _is_first_person() != was_fp:
		_refresh_mouse_mode()
	_update_camera()


func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventKey:
		var key := event as InputEventKey
		if key.pressed and not key.echo:
			if key.keycode == KEY_SHIFT:
				_shift_lock = not _shift_lock
				_refresh_mouse_mode()
				_update_camera()
			else:
				_update_input_direction(key)
		elif not key.pressed:
			_clear_input_direction(key)
		# ESC (leave the world) is handled by game.gd, which owns the connection.

	elif event is InputEventMouseButton:
		var mb := event as InputEventMouseButton
		match mb.button_index:
			MOUSE_BUTTON_WHEEL_UP:
				if mb.pressed:
					_set_zoom(_zoom - ZOOM_STEP)
			MOUSE_BUTTON_WHEEL_DOWN:
				if mb.pressed:
					_set_zoom(_zoom + ZOOM_STEP)
			MOUSE_BUTTON_LEFT, MOUSE_BUTTON_RIGHT:
				_mouse_look_held = Input.is_mouse_button_pressed(MOUSE_BUTTON_LEFT) \
					or Input.is_mouse_button_pressed(MOUSE_BUTTON_RIGHT)
				_rmb_held = Input.is_mouse_button_pressed(MOUSE_BUTTON_RIGHT)
				_refresh_mouse_mode()

	elif event is InputEventMouseMotion and Input.mouse_mode == Input.MOUSE_MODE_CAPTURED:
		_handle_mouse_look(event as InputEventMouseMotion)


func _update_input_direction(key: InputEventKey) -> void:
	match key.keycode:
		KEY_W, KEY_UP:
			_input_direction.y += 1.0
		KEY_S, KEY_DOWN:
			_input_direction.y -= 1.0
		KEY_A, KEY_LEFT:
			_input_direction.x -= 1.0
		KEY_D, KEY_RIGHT:
			_input_direction.x += 1.0


func _clear_input_direction(key: InputEventKey) -> void:
	match key.keycode:
		KEY_W, KEY_UP:
			_input_direction.y -= 1.0
		KEY_S, KEY_DOWN:
			_input_direction.y += 1.0
		KEY_A, KEY_LEFT:
			_input_direction.x += 1.0
		KEY_D, KEY_RIGHT:
			_input_direction.x -= 1.0


func _handle_mouse_look(event: InputEventMouseMotion) -> void:
	_camera_yaw = wrapf(_camera_yaw - event.relative.x * MOUSE_SENSITIVITY, -PI, PI)
	_camera_pitch = clampf(_camera_pitch - event.relative.y * MOUSE_SENSITIVITY,
		PITCH_MIN, PITCH_MAX)
	_update_camera()


## Place the orbit pivot at the player's head and point it per yaw/pitch.
## Applies the first-person / shoulder framing. Called from _ready, on input,
## and every physics frame (the player moves under it).
func _update_camera() -> void:
	if not is_instance_valid(_camera_pivot):
		return
	var fp := _is_first_person()
	_camera_pivot.global_position = global_position \
		+ Vector3(0.0, PIVOT_Y_FP if fp else PIVOT_Y_TP, 0.0)
	_camera_pivot.global_rotation = Vector3(_camera_pitch, _camera_yaw, 0.0)

	_spring_arm.spring_length = 0.0 if fp else _zoom
	_spring_arm.position.x = SHOULDER_OFFSET if (_shift_lock and not fp) else 0.0

	# Hide our own avatar in first person so the head doesn't fill the view.
	if _avatar_view != null and is_instance_valid(_avatar_view):
		_avatar_view.visible = not fp


# ---------------------------------------------------------------------------
# Physics
# ---------------------------------------------------------------------------

## Input frame forwarded to the server by scripts/game.gd each physics tick:
## world-space move direction (yaw-transformed, normalized), jump edge, body yaw.
var net_input: Dictionary = {"move_x": 0.0, "move_z": 0.0, "jump": false, "look_yaw": 0.0}


func _physics_process(delta: float) -> void:
	if not is_on_floor():
		velocity.y -= GRAVITY * delta

	var jumped := false
	if is_on_floor() and Input.is_action_just_pressed("ui_accept"):
		velocity.y = JUMP_VELOCITY
		jumped = true

	# Camera-relative movement. A node looks down its local -Z, so forward is
	# -cam_basis.z and W (input.y = +1) heads away from the camera.
	var cam_basis := Basis.from_euler(Vector3(0.0, _camera_yaw, 0.0))
	var direction := (_input_direction.x * cam_basis.x
		- _input_direction.y * cam_basis.z).normalized()
	velocity.x = direction.x * WALK_SPEED
	velocity.z = direction.z * WALK_SPEED

	# Body facing: locked to the camera in aim modes, otherwise turns toward
	# the movement direction.
	if _want_face_camera():
		rotation.y = _camera_yaw
	elif direction.length_squared() > 0.01:
		var target_yaw := atan2(-direction.x, -direction.z)
		rotation.y = lerp_angle(rotation.y, target_yaw,
			clampf(BODY_TURN_SPEED * delta, 0.0, 1.0))

	move_and_slide()
	_update_camera()

	if _limb_anim != null:
		_limb_anim.set("speed", Vector2(velocity.x, velocity.z).length())

	# Safety net -- never fall forever.
	if global_position.y < -10.0:
		global_position = _spawn_position
		velocity = Vector3.ZERO

	net_input = {
		"move_x": direction.x, "move_z": direction.z,
		"jump": jumped, "look_yaw": rotation.y,
	}


## Server-authoritative correction from scripts/game.gd when the local
## predicted position has drifted too far.
func apply_server_correction(pos: Vector3) -> void:
	global_position = pos
	velocity = Vector3.ZERO