extends Control

## Spawns draggable modifier pieces along the bottom of the screen.
##
## For now it spawns ALL modifiers in the registry, one of each, and they never
## run out. That's a debug affordance — the real economy (random draws, rounds,
## consumption) is a later phase. Right now we just want to prove drag-and-drop
## works.

@export var drop_catcher: Control

@export_group("Layout")
@export var piece_size := Vector2(90, 110)
@export var spacing := 24.0
@export var bottom_margin := 30.0

@export_group("Behaviour")
## If false, pieces stay in the tray after a successful drop. Useful while
## testing; set true when the real economy lands.
@export var consume_on_use := false

const SectorSwatch := preload("res://core/ui/sector_swatch.gd")

var _pieces: Array[Control] = []


func _ready() -> void:
	# The tray itself must not eat mouse events — only its pieces should.
	mouse_filter = Control.MOUSE_FILTER_IGNORE

	if drop_catcher == null:
		push_error("ModifierTray: `drop_catcher` export is not set.")
		return

	spawn_all()


## Spawn one piece per registered modifier.
func spawn_all() -> void:
	_clear_pieces()

	var mods: Array[Modifier] = ModRegistry.modifiers
	if mods.is_empty():
		push_warning("ModifierTray: registry has no modifiers. Nothing to spawn.")
		return

	for mod in mods:
		_spawn_piece(mod)

	_layout()


func _spawn_piece(mod: Modifier) -> void:
	var piece := Control.new()
	piece.set_script(SectorSwatch)
	piece.custom_minimum_size = piece_size
	piece.size = piece_size
	piece.modifier = mod
	piece.paint_texture = mod.texture
	piece.drop_catcher = drop_catcher
	piece.tray = self
	add_child(piece)
	_pieces.append(piece)


func _layout() -> void:
	var count := _pieces.size()
	if count == 0:
		return

	var total_w := count * piece_size.x + (count - 1) * spacing
	var screen := get_viewport_rect().size
	var start_x := (screen.x - total_w) * 0.5
	var y := screen.y - piece_size.y - bottom_margin

	for i in count:
		_pieces[i].position = Vector2(start_x + i * (piece_size.x + spacing), y)


## Called by a piece after a successful drop.
func on_piece_used(piece: Control) -> void:
	if not consume_on_use:
		return   # piece snaps home; it's reusable

	_pieces.erase(piece)
	piece.queue_free()
	_layout()


func _clear_pieces() -> void:
	for p in _pieces:
		if is_instance_valid(p):
			p.queue_free()
	_pieces.clear()


func _notification(what: int) -> void:
	if what == NOTIFICATION_RESIZED:
		_layout()