#! /usr/bin/env escript

%% ZX install script

-spec main(Argv :: [string()]) -> no_return().

main(_) ->
    ZompDir = zomp_dir(),
    case filelib:is_dir(ZompDir) of
        false -> unpack(ZompDir);
        true  -> halt(0)
    end.


-spec unpack(ZompDir :: file:filename()) -> no_return().

unpack(ZompDir) ->
    ZompFile = filename:join(ZompDir, "zomp.conf"),
    ok = filelib:ensure_dir(ZompFile),
    ok = erl_tar:extract("zx.tgz", [compressed, {cwd, ZompFile}]),
    halt(0).


-spec zomp_dir() -> file:filename().
%% @private
%% Check the host OS and return the absolute path to the zomp filesystem root.

zomp_dir() ->
    case os:type() of
        {unix, _} ->
            Home = os:getenv("HOME"),
            Dir = ".zomp",
            filename:join(Home, Dir);
        {win32, _} ->
            Drive = os:getenv("HOMEDRIVE"),
            Path = os:getenv("HOMEPATH"),
            Dir = "zomp",
            filename:join([Drive, Path, Dir]);
        Unknown ->
            ok = io:format("zx_install: ERROR Unknown host system type: ~tp", [Unknown]),
            halt(1)
    end.