class_name Mech extends Node3D

@export_group("Skeleton")
@export var _skeleton: Skeleton3D
@export var _pelvis_attachment: BoneAttachment3D

@export_subgroup("Left")
@export var _ankle_bone_l: String = "Ankle_L"
@export var _leg_ik_l: SkeletonIK3D
@export var _leg_foot_body_l: CharacterBody3D
@export var _leg_ik_target_l: Node3D
@export var _leg_ik_magnet_l: Node3D

@export_subgroup("Right")
@export var _ankle_bone_r: String = "Ankle_R"
@export var _leg_ik_r: SkeletonIK3D
@export var _leg_foot_body_r: CharacterBody3D
@export var _leg_ik_target_r: Node3D
@export var _leg_ik_magnet_r: Node3D

@export_group("Physics")
@export var _foot_fall_acceleration: float = 1

@export_group("Walking")
@export var _mouse_walk_sensitivity: float = 1

var _mouse_relative: Vector2
var _is_moving_leg_l: bool
var _is_moving_leg_r: bool


func _ready() -> void:
	_leg_ik_l.start()
	_leg_ik_r.start()
	_ready_leg_ik(_leg_foot_body_l, _ankle_bone_l)
	_ready_leg_ik(_leg_foot_body_r, _ankle_bone_r)


func _process(_delta: float) -> void:
	_process_leg_ik(_leg_ik_l, _leg_ik_magnet_l)
	_process_leg_ik(_leg_ik_r, _leg_ik_magnet_r)
	_process_position()
	Debugger.text("_is_moving_leg_l", _is_moving_leg_l, 2)
	Debugger.text("_is_moving_leg_r", _is_moving_leg_r, 2)


func _physics_process(_delta: float) -> void:
	if _is_moving_leg_l:
		_handle_leg_moving(_mouse_relative, _leg_foot_body_l)
	else:
		_handle_leg_physics(_leg_foot_body_l)

	if _is_moving_leg_r:
		_handle_leg_moving(_mouse_relative, _leg_foot_body_r)
	else:
		_handle_leg_physics(_leg_foot_body_r)

	_mouse_relative = Vector2.ZERO


func _unhandled_input(event: InputEvent) -> void:
	if event is InputEventMouseMotion:
		var event_mouse := event as InputEventMouseMotion
		_mouse_relative = event_mouse.screen_relative
	else:
		_mouse_relative = Vector2.ZERO

	if event is InputEventMouseButton:
		var event_mouse := event as InputEventMouseButton
		if event_mouse.is_pressed():
			Input.mouse_mode = Input.MOUSE_MODE_CAPTURED
		else:
			Input.mouse_mode = Input.MOUSE_MODE_VISIBLE

		if event_mouse.button_index == MOUSE_BUTTON_LEFT:
			_is_moving_leg_l = event_mouse.is_pressed()
		if event_mouse.button_index == MOUSE_BUTTON_RIGHT:
			_is_moving_leg_r = event_mouse.is_pressed()


func _ready_leg_ik(foot_body: Node3D, bone: String) -> void:
	foot_body.position = (
		_skeleton.get_bone_global_rest(_skeleton.find_bone(bone)).origin
	)


func _process_leg_ik(ik: SkeletonIK3D, ik_magnet: Node3D) -> void:
	ik.magnet = to_local(ik_magnet.global_position)


func _process_position() -> void:
	var leg_target_pos_l := _leg_ik_target_l.global_position
	var leg_target_pos_r := _leg_ik_target_r.global_position

	var root_position := _pelvis_attachment.global_position
	root_position.y = minf(leg_target_pos_l.y, leg_target_pos_r.y)

	global_position = root_position


func _handle_leg_moving(mouse_delta: Vector2, foot_body: CharacterBody3D) -> void:
	var velocity_local := Vector3(
		0,
		-mouse_delta.y * _mouse_walk_sensitivity,
		mouse_delta.x * _mouse_walk_sensitivity
	)
	foot_body.velocity = transform.basis * velocity_local
	foot_body.move_and_slide()
	foot_body.velocity = Vector3.ZERO


func _handle_leg_physics(foot_body: CharacterBody3D) -> void:
	if foot_body.is_on_floor():
		foot_body.velocity = Vector3.ZERO
		return

	foot_body.velocity.x = 0
	foot_body.velocity.z = 0
	foot_body.velocity.y -= _foot_fall_acceleration
	foot_body.move_and_slide()