class_name Player
extends CharacterBody3D
## The player character controller.
##
## A CharacterBody3D with WASD/arrow locomotion, gravity, jump, and a
## third-person camera (SpringArm3D behind the player) with mouse-look --
## yaw turns the body, pitch orbits the camera. Reads the spawn point from
## the current scene's `PlayerSpawn` Marker3D.


# ---------------------------------------------------------------------------
# Movement 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


# ---------------------------------------------------------------------------
# Input state
# ---------------------------------------------------------------------------

var _input_direction := Vector2.ZERO
var _camera_pitch: float = -0.12
var _spawn_position: Vector3 = Vector3(0, 1.5, 0)

## 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

## Third-person pitch limits (radians): a bit up, a lot down (looking over
## the avatar's shoulder toward the ground).
const PITCH_MIN: float = -1.1
const PITCH_MAX: float = 0.45

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

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


# ---------------------------------------------------------------------------
# _ready — spawn at PlayerSpawn marker, capture the mouse for look
# ---------------------------------------------------------------------------

func _ready() -> void:
	# Per §3 of pc2_test_level.md: look up PlayerSpawn from the current
	# scene root.  The lookup walks the full subtree (recursive=true) so
	# it finds the marker whether it is a direct child of the level or
	# nested deeper.
	#
	# current_scene is null in headless --script mode and in any scene
	# before the main scene is fully swapped in, so guard it rather than
	# blindly dereferencing.
	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
		# Align player forward with spawn yaw (optional polish).
		var spawn_yaw := (spawn as Node3D).rotation.y
		rotation.y = spawn_yaw
	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 (they're
	# on the same layer), or the camera gets yanked right up against the
	# player's head.
	var arm := $CameraPivot/SpringArm3D as SpringArm3D
	arm.add_excluded_object(self)

	# Start the camera arm tilted down a little so the avatar is framed.
	_camera_pivot.rotation.x = _camera_pitch

	# Capture the mouse for look. Headless/test runs have no real window to
	# capture input for, so guard against that rather than error.
	if DisplayServer.get_name() != "headless":
		Input.mouse_mode = Input.MOUSE_MODE_CAPTURED

	_apply_avatar()


## Show the player's assembled avatar and hide the placeholder capsule.
## AvatarSystem.build_current_avatar() is self-sufficient now (loads the
## catalog + falls back to a default loadout), so this only no-ops if the
## avatar assets themselves are missing.
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
	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
	# ground 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)


# ---------------------------------------------------------------------------
# _unhandled_input — capture keyboard / mouse for movement
# ---------------------------------------------------------------------------

func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventKey:
		var key := event as InputEventKey
		if key.pressed and not key.echo:
			_update_input_direction(key)
		elif not key.pressed:
			_clear_input_direction(key)
		# Escape exits the level back to the world browse list, mirroring
		# the Back button pattern already used in world_list.gd/main_menu.gd.
		if key.pressed and key.keycode == KEY_ESCAPE:
			Input.mouse_mode = Input.MOUSE_MODE_VISIBLE
			get_tree().change_scene_to_file("res://scenes/world_list.tscn")
	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:
	# Yaw rotates the whole body (so movement direction turns with the
	# look direction); pitch orbits the camera arm around the player, so the
	# capsule itself never tips over.
	rotation.y -= event.relative.x * MOUSE_SENSITIVITY
	_camera_pitch = clampf(_camera_pitch - event.relative.y * MOUSE_SENSITIVITY, PITCH_MIN, PITCH_MAX)
	_camera_pivot.rotation.x = _camera_pitch


# ---------------------------------------------------------------------------
# Physics — gravity, jump, move_and_slide
# ---------------------------------------------------------------------------

## The input frame this player applied last physics tick, in the shape the
## network layer sends: world-space move direction (already yaw-transformed and
## normalized), jump edge, body yaw. scripts/game.gd reads this each frame in
## networked mode and forwards it to the server.
var net_input: Dictionary = {"move_x": 0.0, "move_z": 0.0, "jump": false, "look_yaw": 0.0}


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

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

	# Build movement direction from input. Godot's local "forward" is -Z, not
	# +Z, so W (input.y = +1) must use -basis.z -- using +basis.z here would
	# move the player backward when pressing forward (confirmed by reading
	# Camera3D/Node3D's own convention: a node looks down its local -Z).
	var direction := (_input_direction.x * transform.basis.x -
		_input_direction.y * transform.basis.z).normalized()
	velocity.x = direction.x * WALK_SPEED
	velocity.z = direction.z * WALK_SPEED

	move_and_slide()

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

	# Safety net -- never fall forever if something goes wrong.
	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: called by scripts/game.gd when the local
## predicted position has drifted too far from the server's.
func apply_server_correction(pos: Vector3) -> void:
	global_position = pos
	velocity.x = 0.0
	velocity.z = 0.0