open Core;
module Unix = Core_unix;

open Lib;

let main = () => {
  let argv = Sys.get_argv();
  switch (Util.get_args(argv)) {
  | Ok((layout_directory, flake_specifier, other_args)) => {
      switch (preflight(layout_directory)) {
      | Ok() => {
          switch (Lib.Watches.get()) {
          | Ok(watches) => {
              let paths = Array.map(~f=watch => watch.path, watches);
              let hash = Util.hash_files(paths);
              let profile = layout_directory ++ "/flake-profile-" ++ hash;
              let profile_rc = profile ++ ".rc";

              switch ((Sys_unix.is_file(profile_rc), Sys_unix.is_file(profile))) {
              | (`Yes, `Yes) => {
                  let profile_rc_mtime = Unix.stat(profile_rc).st_mtime;
                  let all_older = Array.map(
                    ~f=watch => watch.modtime, watches)
                  |> Array.for_all(
                      ~f=watch_mtime => watch_mtime <= int_of_float(profile_rc_mtime)
                    )
                  if (all_older) {
                    print_cur_cache(profile_rc)
                  } else {
                    freshen_cache(layout_directory, hash, flake_specifier, other_args)
                  }
                }
              | _ => freshen_cache(layout_directory, hash, flake_specifier, other_args)
              }
            };
          | Error(e) => {
              Printf.eprintf("%s\n", e);
              exit(1);
            }
          }
        }
      | Error(e) => {
          Printf.eprintf("%s\n", e);
          exit(1);
        }
      };
    }
  | Error() => {
      Printf.eprintf("%s  <layout_directory> <flake specifier> <...args>\n", argv[0]);
      exit(1);
    }
  }
};

let () = main();