class_name SpawnCatalog
extends RefCounted
## Catalog of spawnable object templates for ScriptBehavior's
## `spawn_from_catalog` verb.
##
## Mirrors the loading convention of [AvatarCatalog]
## (assets/avatars/catalog.json / scripts/avatar/avatar_catalog.gd) --
## a data-driven JSON manifest, loaded once, looked up by id.
##
## Crucially, a ScriptBehavior rule only ever supplies a `catalog_id`
## *key* -- never a resource path. The mapping from key to actual asset
## path lives entirely in this trusted, code-shipped JSON file. A
## malicious/malformed catalog_id in UGC data just fails to resolve
## ([method resolve] returns an empty Dictionary); there's no way for the
## data to point anywhere else.

var _catalog: Dictionary = {}
var _loaded: bool = false
var _catalog_path: String = "res://assets/scripting/spawn_catalog.json"


## Load the catalog from disk. Call this before any lookups.
func load_catalog(path: String = _catalog_path) -> Error:
	_catalog_path = path
	_catalog = {}

	var file := FileAccess.open(path, FileAccess.READ)
	if file == null:
		return FileAccess.get_open_error()

	var json_text: String = file.get_as_text()
	file.close()

	var result: Variant = JSON.parse_string(json_text)
	if result == null or not (result is Dictionary) or not (result as Dictionary).has("templates"):
		return ERR_INVALID_DATA

	_catalog = (result as Dictionary)["templates"]
	_loaded = true
	return OK


func is_loaded() -> bool:
	return _loaded


## Resolve a catalog_id to its template Dictionary ({} if unknown/unloaded).
func resolve(catalog_id: String) -> Dictionary:
	if not _loaded:
		return {}
	return _catalog.get(catalog_id, {})


func has_template(catalog_id: String) -> bool:
	return _loaded and _catalog.has(catalog_id)