class_name CliSceneLauncher
extends RefCounted
## Pure command-line argument parser for the Sandbox Stage scene loader.
## No scene-tree or OS access, so it is directly unit-testable. Parses
## OS.get_cmdline_user_args() output into a structured {scene_path, play, error}
## result; the caller (SandboxStage) is responsible for the error dialog and
## autosave policy.

static func parse(args: Array) -> Dictionary:
	var scene_path := ""
	var play := false
	var used_scene_flag := false
	var used_positional := false
	var error := ""
	var i := 0
	while i < args.size():
		var token := String(args[i])
		if token == "--play":
			play = true
		elif token == "--scene":
			used_scene_flag = true
			if i + 1 >= args.size():
				return {"scene_path": "", "play": play, "error": "--scene requires a path."}
			var value := String(args[i + 1])
			if value.is_empty():
				return {"scene_path": "", "play": play, "error": "--scene requires a path."}
			scene_path = value
			i += 1
		elif token.begins_with("--scene="):
			used_scene_flag = true
			var value := token.substr("--scene=".length())
			if value.is_empty():
				return {"scene_path": "", "play": play, "error": "--scene requires a path."}
			scene_path = value
		elif token.begins_with("--"):
			return {"scene_path": "", "play": play, "error": "Unknown option: %s" % token}
		else:
			if used_positional:
				return {"scene_path": "", "play": play, "error": "Specify the scene with either --scene or a single positional path."}
			used_positional = true
			scene_path = token
		i += 1
	if used_scene_flag and used_positional:
		error = "Specify the scene with either --scene or a single positional path."
	elif play and scene_path.is_empty():
		error = "--play requires --scene <path>."
	return {"scene_path": scene_path, "play": play, "error": error}