-module(olive).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([main/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-file("src/olive.gleam", 65).
-spec listen_to_file_changes(
    olive@config:config(),
    gleam@erlang@process:subject(olive@watcher:message()),
    olive@client_registry:client_registry()
) -> any().
listen_to_file_changes(Config, Subject, Clients) ->
    Msg = gleam_erlang_ffi:'receive'(Subject),
    case Msg of
        {files_changed, File_name} ->
            olive@logging:notice(<<"File changed: "/utf8, File_name/binary>>),
            case olive@server_run:reload_server_code(erlang:element(5, Config)) of
                {ok, _} ->
                    olive@client_registry:trigger(Clients);

                {error, Msg@1} ->
                    olive@logging:error(Msg@1)
            end
    end,
    listen_to_file_changes(Config, Subject, Clients).

-file("src/olive.gleam", 35).
-spec run_olive(olive@config:config()) -> nil.
run_olive(Config) ->
    Clients = olive@client_registry:start(),
    Subject = gleam@erlang@process:new_subject(),
    case olive@watcher:start(Config, Subject) of
        {error, init_timeout} ->
            olive@logging:error(
                <<"Watcher took too much time to initialize"/utf8>>
            );

        {error, {init_crashed, _}} ->
            olive@logging:error(<<"Watcher crashed!"/utf8>>);

        {error, {init_failed, {abnormal, Msg}}} ->
            olive@logging:error(Msg);

        {error, {init_failed, killed}} ->
            olive@logging:error(
                <<"Watcher was killed before initialisation"/utf8>>
            );

        {error, {init_failed, normal}} ->
            olive@logging:error(
                <<"Watcher shutdown before end of initialisation"/utf8>>
            );

        {ok, _} ->
            case olive@server_run:start_server(
                erlang:element(5, Config),
                erlang:element(6, Config)
            ) of
                {ok, _} ->
                    _assert_subject = olive@proxy:start_http(Config, Clients),
                    {ok, _} = case _assert_subject of
                        {ok, _} -> _assert_subject;
                        _assert_fail ->
                            erlang:error(#{gleam_error => let_assert,
                                        message => <<"Pattern match failed, no pattern matched the value."/utf8>>,
                                        value => _assert_fail,
                                        module => <<"olive"/utf8>>,
                                        function => <<"run_olive"/utf8>>,
                                        line => 51})
                    end,
                    listen_to_file_changes(Config, Subject, Clients);

                {error, Reason} ->
                    olive@logging:error(
                        <<"Could not start server for this reason: "/utf8,
                            (erlang:atom_to_binary(Reason))/binary>>
                    )
            end
    end.

-file("src/olive.gleam", 18).
?DOC(
    " Process is as follow:\n"
    " - Start a client registry\n"
    " - Start watcher, giving it a subject we will listen to.\n"
    " - Every time watcher sends us a message:\n"
    "   - Reload server code\n"
    "   - Send reload message to clients\n"
).
-spec main() -> nil.
main() ->
    case olive@cli:get_options() of
        {error, nil} ->
            nil;

        {ok, Options} ->
            olive@logging:configure_logs(erlang:element(5, Options)),
            case olive@config:read_config(Options) of
                {error, Error} ->
                    olive@logging:error(Error);

                {ok, Config} ->
                    run_olive(Config)
            end,
            gleam_erlang_ffi:sleep(400)
    end.