-module(tale@watch).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/tale/watch.gleam").
-export([start/1]).
-export_type([watch_config/0]).

-type watch_config() :: {watch_config, list(binary()), fun(() -> nil)}.

-file("src/tale/watch.gleam", 43).
-spec gather(list(binary()), list(binary())) -> list(binary()).
gather(Paths, Acc) ->
    case Paths of
        [] ->
            Acc;

        [Path | Rest] ->
            Acc@1 = [Path | Acc],
            Contents = case simplifile_erl:is_directory(Path) of
                {ok, true} ->
                    _pipe = simplifile:get_files(Path),
                    _pipe@1 = gleam@result:map(_pipe, fun(Files) -> Files end),
                    gleam@result:unwrap(_pipe@1, []);

                _ ->
                    []
            end,
            gather(Rest, lists:append(Contents, Acc@1))
    end.

-file("src/tale/watch.gleam", 60).
-spec signature(binary()) -> binary().
signature(Path) ->
    case simplifile_erl:file_info(Path) of
        {ok, Info} ->
            <<<<Path/binary, ":"/utf8>>/binary,
                (erlang:integer_to_binary(erlang:element(10, Info)))/binary>>;

        {error, _} ->
            <<Path/binary, ":missing"/utf8>>
    end.

-file("src/tale/watch.gleam", 37).
-spec capture(list(binary())) -> list(binary()).
capture(Paths) ->
    _pipe = gather(Paths, []),
    _pipe@1 = gleam@list:map(_pipe, fun signature/1),
    gleam@list:sort(_pipe@1, fun(A, B) -> gleam@string:compare(A, B) end).

-file("src/tale/watch.gleam", 24).
-spec loop(list(binary()), list(binary()), fun(() -> nil)) -> any().
loop(Paths, State, Notify) ->
    gleam_erlang_ffi:sleep(1000),
    Next = capture(Paths),
    case State =:= Next of
        true ->
            nil;

        false ->
            logging:log(info, <<"Detected changes, rebuilding site…"/utf8>>),
            Notify()
    end,
    loop(Paths, Next, Notify).

-file("src/tale/watch.gleam", 19).
-spec run(list(binary()), fun(() -> nil)) -> any().
run(Paths, Notify) ->
    Snapshot = capture(Paths),
    loop(Paths, Snapshot, Notify).

-file("src/tale/watch.gleam", 15).
-spec start(watch_config()) -> gleam@erlang@process:pid_().
start(Config) ->
    proc_lib:spawn_link(
        fun() -> run(erlang:element(2, Config), erlang:element(3, Config)) end
    ).