extends Node

const BASE_NODE_PATH := "res://classes/deck/nodes/"
const NODE_INDEX_CACHE_PATH := "user://nodes_index.json"

# Dictionary[node_type, NodeDescriptor]
var nodes: Dictionary = {}


func _init() -> void:
	if load_node_index():
		return

	var dir := DirAccess.open(BASE_NODE_PATH)
	dir.list_dir_begin()
	var current_file := dir.get_next()
	while current_file != "":
		print(current_file)
		if current_file.ends_with(".gd"):
			var script_path := BASE_NODE_PATH.path_join(current_file)
			var node: DeckNode = load(script_path).new() as DeckNode
			var aliases: String = node.aliases.reduce(
				func(accum, el) -> void:
					accum += el
			, "")
			var descriptor := NodeDescriptor.new(script_path, node.name, node.description, aliases)
			nodes[node.node_type] = descriptor
		current_file = dir.get_next()

	save_node_index()


func instance_node(type: String) -> DeckNode:
	if !nodes.has(type):
		return null

	return load(nodes[type]["script_path"]).new()


func save_node_index() -> void:
	var d := {}
	for node_type in nodes:
		var nd: NodeDescriptor = nodes[node_type] as NodeDescriptor
		d[node_type] = nd.to_dictionary()

	var json := JSON.stringify(d, "\t")
	var f := FileAccess.open(NODE_INDEX_CACHE_PATH, FileAccess.WRITE)
	f.store_string(json)


func load_node_index() -> bool:
	var f := FileAccess.open(NODE_INDEX_CACHE_PATH, FileAccess.READ)
	if f == null:
		print("node index file does not exist")
		return false

	var data: Dictionary = JSON.parse_string(f.get_as_text()) as Dictionary
	if data.is_empty():
		print("node index file exists, but is empty")
		return false

	for node_type in data:
		var nd_dict: Dictionary = data[node_type]
		var nd := NodeDescriptor.from_dictionary(nd_dict)
		nodes[node_type] = nd

	print("node index file exists, loaded")
	return true


class NodeDescriptor:
	var name: String
	var description: String
	var aliases: String

	var script_path: String


	func _init(p_script_path: String, p_name: String, p_description: String, p_aliases: String) -> void:
		script_path = p_script_path

		name = p_name
		description = p_description
		aliases = p_aliases


	func to_dictionary() -> Dictionary:
		var d := {
			"name": name,
			"description": description,
			"aliases": aliases,
			"script_path": script_path
		}
		return d


	static func from_dictionary(data: Dictionary) -> NodeDescriptor:
		var nd := NodeDescriptor.new(
			data.get("script_path", ""),
			data.get("name", ""),
			data.get("description", ""),
			data.get("aliases", ""))

		return nd