# datapack_manager.gd
extends Node

# --- CONFIGURATION ---
const DATAPACKS_DIR = "user://datapacks/"

# --- STATE ---
var loaded_packs: Dictionary[String, DatapackModel] = {}


func _ready():
	var dir = DirAccess.open("user://")
	if dir:
		if not dir.dir_exists("datapacks"):
			dir.make_dir("datapacks")
		
	load_all_local_packs()


## Scans the local DATAPACKS_DIR, loads all valid datapack subdirectories, 
## and registers them with the manager. This serves as the initial load and the refresh option.
func load_all_local_packs():
	print("DatapackManager: Starting scan for local datapacks in '%s'" % DATAPACKS_DIR)
	
	var loader = DatapackLoader.new()
	var dir = DirAccess.open(DATAPACKS_DIR)

	if dir == null:
		push_error("DatapackManager: Failed to open datapacks directory: %s" % DATAPACKS_DIR)
		return

	dir.list_dir_begin()
	var dir_name = dir.get_next()
	
	while dir_name != "":
		if dir_name == "." or dir_name == "..":
			dir_name = dir.get_next()
			continue
			
		if dir.current_is_dir():
			print("DatapackManager: Found pack directory: %s" % dir_name)
			
			var datapack: DatapackModel = loader.load_datapack(dir_name)
			
			if datapack:
				register_pack(datapack)
			else:
				push_warning("DatapackManager: Failed to load pack in directory: %s. Skipping." % dir_name)

		dir_name = dir.get_next()
		
	dir.list_dir_end()
	print("DatapackManager: Finished scanning local datapacks.")


func clear_loaded_packs():
	loaded_packs.clear()


func register_pack(datapack: DatapackModel):
	if datapack and datapack.guid:
		var guid_str = datapack.guid.to_string()
		loaded_packs[guid_str] = datapack
		print("DatapackManager: Registered pack '%s' (%s)" % [datapack.name, guid_str])
	else:
		push_error("DatapackManager: Attempted to register invalid or un-GUIDed datapack.")


func unregister_pack(pack_guid: String):
	if loaded_packs.has(pack_guid):
		loaded_packs.erase(pack_guid)
		print("DatapackManager: Unregistered pack with GUID %s." % pack_guid)

# ----------------------------------------------------------------------
# --- DEPENDENCY RESOLUTION ---
# ----------------------------------------------------------------------

## Resolves a single SzObject ID across all loaded packs.
## Used by SPECIFIC_DATASET mode when the pack GUID is unknown (or referencing local content).
func resolve_object_dependency(object_id: String) -> SzObject:
	for pack_guid in loaded_packs:
		var pack = loaded_packs[pack_guid]
		var obj = pack.get_object_by_id(object_id)
		
		if obj:
			return obj
			
	push_error("Dependency Resolution Failed: Could not find object with ID '%s' in any loaded datapack." % object_id)
	return null


## Finds all SzObjects (Datasets or Templates) across all loaded packs 
## that match a given sz_type string.
## Used by DATASET_TYPE_WILDCARD and CHARACTER_TEMPLATE_REF modes.
func resolve_type_wildcard(sz_type: String) -> Array[SzObject]:
	var matching_objects: Array[SzObject] = []
	for pack_guid in loaded_packs:
		var pack = loaded_packs[pack_guid]
		
		for obj in pack.sz_objects:
			if obj.sz_type == sz_type:
				matching_objects.append(obj)
				
	if matching_objects.is_empty():
		push_warning("Wildcard Resolution Failed: Could not find any object with sz_type '%s' in loaded datapacks." % sz_type)
		
	return matching_objects

## Main entry point for resolving a DependencySource defined in a Template.
## Returns an array of SzObjects (can be Datasets or Templates)
func resolve_dependency_source(source: DependencySource) -> Array:
	match source.mode:
		DependencySource.DependencyMode.SPECIFIC_DATASET:
			if source.target_datapack_guid.is_empty():
				var target_obj = resolve_object_dependency(source.target_sz_object_id)
				return [target_obj] if target_obj else []
			
			var target_pack = loaded_packs.get(source.target_datapack_guid)
			if target_pack:
				var target_obj = target_pack.get_object_by_id(source.target_sz_object_id)
				return [target_obj] if target_obj else []
			return []
			
		DependencySource.DependencyMode.DATASET_TYPE_WILDCARD:
			return resolve_type_wildcard(source.target_type_string)
			
	return []