extends CharacterBody3D

const TARGET_FPS: float = 60.0
const BASE_SPEED: float = 5.0
const BOOST_FORCE: float = 20.0
const JUMP_FORCE: float = 8.0
const FRICTION: float = 0.3
const AIR_DRAG: float = 0.03
const INPUT_SENSITIVITY: float = 0.7
const TURN_SENSITIVITY: float = 0.04

# Get the gravity from the project settings to be synced with RigidBody nodes.
var gravity: float = ProjectSettings.get_setting("physics/3d/default_gravity")

@onready var camera_root: ThirdPersonCamera = $CameraRoot
@onready var mesh: Node3D = $Mesh
@onready var animation_tree: AnimationTree = $Mesh/Mech/AnimationTree
@onready var animation_player: AnimationPlayer = $AnimationPlayer

@onready var _crosshair: Crosshair = get_tree().get_first_node_in_group("CrosshairGroup")
@onready var _overlay: OverlayEffects = get_tree().get_first_node_in_group("OverlayEffectsGroup")


func is_boosting() -> bool:
	return animation_tree["parameters/boost/active"]


func _physics_process(delta: float) -> void:
	var delta_factor: float = delta * TARGET_FPS

	if is_boosting():
		_crosshair.jostle(Vector2(randf_range(-3, 3), randf_range(-3, 3)))
	else:
		# Add the gravity.
		if not is_on_floor():
			velocity.y -= gravity * delta
			animation_tree["parameters/jump_state/transition_request"] = "in_air"
			animation_tree["parameters/anim_state/transition_request"] = "air"
		elif animation_tree["parameters/anim_state/current_state"] == "air":
			# If not on floor but still in jump state, transition back to landing
			animation_tree["parameters/jump_state/transition_request"] = "end"

	# Handle jump.
	if Input.is_action_just_pressed("jump") and is_on_floor():
		velocity.y = JUMP_FORCE
		if is_boosting():
			# Jump cancels boost
			animation_tree["parameters/boost/request"] = 2  # Abort

	# Get the input direction and handle the movement/deceleration.
	var input_dir: Vector2 = Input.get_vector("left", "right", "forward", "backward")
	if input_dir:
		# Transform movement based on camera angle
		var movement: Vector3 = (
			(
				camera_root.global_transform.basis
				* Vector3(input_dir.x, 0.0, input_dir.y)
				* Vector3(-1.0, 0.0, -1.0)
			)
			. normalized()
		)
		if not is_boosting():
			velocity.x = lerpf(
				velocity.x, movement.x * BASE_SPEED, delta_factor * INPUT_SENSITIVITY
			)
			velocity.z = lerpf(
				velocity.z, movement.z * BASE_SPEED, delta_factor * INPUT_SENSITIVITY
			)

		if Input.is_action_just_pressed("boost"):
			velocity.x += movement.x * BOOST_FORCE
			velocity.z += movement.z * BOOST_FORCE
			velocity.y = 0.0
			mesh.rotation.y = atan2(velocity.x, velocity.z)
			animation_tree["parameters/boost/request"] = 1
			_overlay.play_boost()
			animation_player.play("boost_fov")
			animation_player.seek(0)

		# Slowly turn mesh towards camera vector when moving on ground
		if is_on_floor():
			mesh.rotation.y = lerp_angle(
				mesh.rotation.y, camera_root.rotation.y, delta_factor * TURN_SENSITIVITY
			)

	animation_tree["parameters/walk_space/blend_position"] = lerp(
		animation_tree["parameters/walk_space/blend_position"],
		input_dir,
		delta_factor * TURN_SENSITIVITY
	)

	var drag: float = FRICTION if (is_on_floor() and not is_boosting()) else AIR_DRAG
	velocity.x = lerpf(velocity.x, 0.0, delta_factor * drag)
	velocity.z = lerpf(velocity.z, 0.0, delta_factor * drag)

	move_and_slide()


func _on_mech_stomp() -> void:
	_crosshair.jostle(Vector2(randf_range(-1, 1), randf_range(-1, 5)))
	# camera_root.jostle(randf_range(-2, 2))