# datapack_loader.gd
class_name DatapackLoader
extends RefCounted

const BASE_DATAPACKS_PATH = "user://datapacks/"
const METADATA_FILENAME = "config.szpack"
const DATAPACK_RESOURCE_FILENAME = "datapack.tres"

## Loads a DatapackModel resource and all its referenced content from the user://datapacks/ folder.
## Returns the loaded DatapackModel object or null on failure.
func load_datapack(pack_name: String) -> DatapackModel:
	var full_pack_name = pack_name.validate_node_name()
	if full_pack_name.is_empty():
		push_error("DatapackLoader: Invalid pack_name provided.")
		return null

	var pack_dir = BASE_DATAPACKS_PATH + full_pack_name + "/"
	var metadata_path = pack_dir + METADATA_FILENAME
	
	var config = ConfigFile.new()
	var error = config.load(metadata_path)
	
	if error != OK:
		push_error("DatapackLoader: Could not load external manifest at: %s (Error: %s)" % [metadata_path, error])
		return null
	
	var entry_point = config.get_value("Datapack", "entry_point", DATAPACK_RESOURCE_FILENAME)
	
	var resource_path = pack_dir + entry_point
	
	if not ResourceLoader.exists(resource_path):
		push_error("DatapackLoader: Main Resource file not found at path: %s" % resource_path)
		return null
	
	var datapack: DatapackModel = ResourceLoader.load(resource_path)
	
	if not datapack:
		push_error("DatapackLoader: Failed to load resource object from path: %s" % resource_path)
		return null
	
	datapack._build_content_map()
	
	print("Successfully loaded Datapack: %s (GUID: %s)" % [datapack.name, datapack.guid.to_string()])
	return datapack

# ----------------------------------------------------------------------
# Example Usage:
# var loader = DatapackLoader.new()
# var core_pack = loader.load_datapack("core_rules")
# 
# if core_pack:
#\t var item = core_pack.get_object_by_id("sword-long")
#\t if item:
#\t\t print("Found item: " + item.name)
# ----------------------------------------------------------------------