class_name PantryStockVisual
extends Node3D

enum StockLevel { EMPTY, LOW, STOCKED }

const LOW_STOCK_THRESHOLD := 4.0
const REFILL_RESPONSE_START := Vector3(0.0, 0.08, -0.5)
const REFILL_RESPONSE_END := Vector3(0.0, 0.36, -0.5)

@onready var empty_root: Node3D = $EmptyStock
@onready var low_stock_root: Node3D = $LowStock
@onready var full_stock_root: Node3D = $FullStock
@onready var refill_response_root: Node3D = $RefillResponse
@onready var refill_response_visuals: Array[MeshInstance3D] = [
	$RefillResponse/Ring,
	$RefillResponse/MoteLeft,
	$RefillResponse/MoteCenter,
	$RefillResponse/MoteRight,
]

var displayed_amount := -1.0
var stock_level := StockLevel.EMPTY
var transition_tween: Tween
var refill_tween: Tween


func _ready() -> void:
	refill_response_root.visible = false


func set_food_amount(amount: float, animate: bool = true) -> void:
	var normalized_amount := maxf(amount, 0.0)
	var next_level := _get_stock_level(normalized_amount)
	if next_level == StockLevel.EMPTY:
		_stop_refill_response()
	var was_initialized := displayed_amount >= 0.0
	var was_empty := was_initialized and displayed_amount <= 0.001
	if was_initialized and next_level == stock_level:
		displayed_amount = normalized_amount
		return
	var should_animate := animate and was_initialized
	displayed_amount = normalized_amount
	stock_level = next_level
	if should_animate:
		_transition_to_level(next_level)
	else:
		_apply_level_immediately(next_level)
	if was_empty and normalized_amount > 0.001 and animate:
		_play_refill_response()


func get_stock_level() -> StockLevel:
	return stock_level


func _get_stock_level(amount: float) -> StockLevel:
	if amount <= 0.001:
		return StockLevel.EMPTY
	if amount < LOW_STOCK_THRESHOLD:
		return StockLevel.LOW
	return StockLevel.STOCKED


func _apply_level_immediately(level: StockLevel) -> void:
	_stop_transition()
	_set_root_visible(empty_root, level == StockLevel.EMPTY)
	_set_root_visible(low_stock_root, level in [StockLevel.LOW, StockLevel.STOCKED])
	_set_root_visible(full_stock_root, level == StockLevel.STOCKED)


func _transition_to_level(level: StockLevel) -> void:
	_stop_transition()
	transition_tween = create_tween().set_parallel(true)
	_transition_root(empty_root, level == StockLevel.EMPTY)
	_transition_root(low_stock_root, level in [StockLevel.LOW, StockLevel.STOCKED])
	_transition_root(full_stock_root, level == StockLevel.STOCKED)
	transition_tween.chain().tween_callback(_finish_transition.bind(level))


func _transition_root(root: Node3D, should_show: bool) -> void:
	if should_show:
		if not root.visible:
			root.visible = true
			root.scale = Vector3.ONE * 0.62
		(
			transition_tween
			. tween_property(root, "scale", Vector3.ONE, 0.28)
			. set_trans(Tween.TRANS_BACK)
			. set_ease(Tween.EASE_OUT)
		)
		return
	if not root.visible:
		return
	(
		transition_tween
		. tween_property(root, "scale", Vector3.ONE * 0.18, 0.16)
		. set_trans(Tween.TRANS_SINE)
		. set_ease(Tween.EASE_IN)
	)


func _finish_transition(level: StockLevel) -> void:
	transition_tween = null
	_set_root_visible(empty_root, level == StockLevel.EMPTY)
	_set_root_visible(low_stock_root, level in [StockLevel.LOW, StockLevel.STOCKED])
	_set_root_visible(full_stock_root, level == StockLevel.STOCKED)


func _set_root_visible(root: Node3D, is_visible: bool) -> void:
	root.visible = is_visible
	root.scale = Vector3.ONE


func _stop_transition() -> void:
	if transition_tween != null:
		transition_tween.kill()
		transition_tween = null


func _play_refill_response() -> void:
	_stop_refill_response()
	refill_response_root.visible = true
	refill_response_root.position = REFILL_RESPONSE_START
	refill_response_root.scale = Vector3.ONE * 0.45
	_set_refill_transparency(0.0)
	refill_tween = create_tween()
	refill_tween.set_trans(Tween.TRANS_SINE).set_ease(Tween.EASE_OUT)
	refill_tween.tween_property(refill_response_root, "scale", Vector3.ONE, 0.24)
	refill_tween.parallel().tween_method(_set_refill_transparency, 0.0, 1.0, 0.18)
	refill_tween.tween_property(refill_response_root, "position", REFILL_RESPONSE_END, 0.5)
	refill_tween.parallel().tween_method(_set_refill_transparency, 1.0, 0.0, 0.5)
	refill_tween.tween_callback(_stop_refill_response)


func _set_refill_transparency(value: float) -> void:
	for visual in refill_response_visuals:
		visual.transparency = clampf(1.0 - value, 0.0, 1.0)


func _stop_refill_response() -> void:
	if refill_tween != null:
		refill_tween.kill()
		refill_tween = null
	if refill_response_root == null:
		return
	refill_response_root.visible = false
	refill_response_root.position = REFILL_RESPONSE_START
	refill_response_root.scale = Vector3.ONE * 0.45
	_set_refill_transparency(0.0)