class_name LaunchOptions
extends RefCounted
## What the command line asks for. Godot passes the arguments after "--":
##   --profile=NAME   keeps key, save and recordings in a folder of their own,
##                    so that two windows on one machine are two players
##   --name=NAME      the player's name; like a name typed in the menu, it is
##                    remembered for the next start
##   --solo           starts playing alone at once, without the menu
##   --host           opens the world for guests at once
##   --port=PORT      the port an open world listens on
##   --join=ADDRESS   joins a host at once; ADDRESS may end in ":PORT"

## Longest profile name.
const MAX_PROFILE_LENGTH := 32
## Characters a profile name may contain.
const PROFILE_CHARACTERS := "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_"

var profile := ""
var player_name := ""
## How to start without the menu: "", "solo", "host" or "join".
var start := ""
var port := NetLink.DEFAULT_PORT
var address := ""
## Arguments that were not understood and are ignored.
var ignored := PackedStringArray()


## Reads `arguments`. Unknown arguments and bad values end up in `ignored`.
static func parse(arguments: PackedStringArray) -> LaunchOptions:
	var options := LaunchOptions.new()
	for argument in arguments:
		var value := argument.get_slice("=", 1) if argument.contains("=") else ""
		match argument.get_slice("=", 0):
			"--profile":
				if is_valid_profile(value):
					options.profile = value
				else:
					options.ignored.append(argument)
			"--name":
				options.player_name = value
			"--solo":
				options.start = "solo"
			"--host":
				options.start = "host"
			"--port":
				if value.is_valid_int() and value.to_int() >= 0 and value.to_int() <= 65535:
					options.port = value.to_int()
				else:
					options.ignored.append(argument)
			"--join":
				options.start = "join"
				options.address = value
			_:
				options.ignored.append(argument)
	return options


## Whether `name` can name a profile folder: up to 32 of the letters A to Z,
## digits, "-" and "_".
static func is_valid_profile(name: String) -> bool:
	if name.is_empty() or name.length() > MAX_PROFILE_LENGTH:
		return false
	for character in name:
		if not PROFILE_CHARACTERS.contains(character):
			return false
	return true


## The folder for the player's files. The default profile uses the user
## folder itself, so that saves of earlier versions stay where they are.
func storage_dir() -> String:
	if profile.is_empty():
		return "user://"
	return "user://profiles".path_join(profile)