telega_wisp

-module(telega_wisp).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/telega_wisp.gleam").
-export([handle_bot/3]).

-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/telega_wisp.gleam", 58).
-spec is_secret_token_valid(
    telega:telega(any(), any(), any()),
    gleam@http@request:request(any())
) -> boolean().
is_secret_token_valid(Telega, Req) ->
    Secret_header_value = begin
        _pipe = gleam@http@request:get_header(
            Req,
            <<"x-telegram-bot-api-secret-token"/utf8>>
        ),
        gleam@result:unwrap(_pipe, <<""/utf8>>)
    end,
    telega:is_secret_token_valid(Telega, Secret_header_value).

-file("src/telega_wisp.gleam", 69).
-spec is_bot_request(
    telega:telega(any(), any(), any()),
    gleam@http@request:request(wisp@internal:connection())
) -> boolean().
is_bot_request(Telega, Req) ->
    Path = begin
        _pipe = fun gleam@http@request:path_segments/1(Req),
        gleam@string:join(_pipe, <<"/"/utf8>>)
    end,
    telega:is_webhook_path(Telega, Path).

-file("src/telega_wisp.gleam", 29).
?DOC(
    " A middleware function to handle incoming requests from the Telegram API.\n"
    " Handles a request to the bot webhook endpoint, decodes the incoming message,\n"
    " validates the secret token, and passes the message to the bot for processing.\n"
    "\n"
    " ```gleam\n"
    " import wisp.{type Request, type Response}\n"
    " import telega.{type Bot}\n"
    " import telega_wisp\n"
    "\n"
    " fn handle_request(bot: Bot, req: Request) -> Response {\n"
    "   use <- telega_wisp.handle_bot(req, bot)\n"
    "   // ...\n"
    " }\n"
    " ```\n"
).
-spec handle_bot(
    telega:telega(any(), any(), any()),
    gleam@http@request:request(wisp@internal:connection()),
    fun(() -> gleam@http@response:response(wisp:body()))
) -> gleam@http@response:response(wisp:body()).
handle_bot(Telega, Req, Handler) ->
    gleam@bool:lazy_guard(
        not is_bot_request(Telega, Req),
        Handler,
        fun() ->
            wisp:require_json(
                Req,
                fun(Json) ->
                    gleam@bool:lazy_guard(
                        not is_secret_token_valid(Telega, Req),
                        fun() -> wisp:response(401) end,
                        fun() ->
                            gleam@bool:lazy_guard(
                                telega:is_draining(Telega),
                                fun() -> wisp:response(503) end,
                                fun() ->
                                    proc_lib:spawn_link(
                                        fun() ->
                                            case telega@update:decode_raw(Json) of
                                                {ok, Message} ->
                                                    telega:handle_update(
                                                        Telega,
                                                        Message
                                                    ),
                                                    nil;

                                                {error, E} ->
                                                    erlang:error(
                                                        #{gleam_error => panic,
                                                            message => (<<"Failed to decode update"/utf8,
                                                                (telega@error:to_string(
                                                                    E
                                                                ))/binary>>),
                                                            file => <<?FILEPATH/utf8>>,
                                                            module => <<"telega_wisp"/utf8>>,
                                                            function => <<"handle_bot"/utf8>>,
                                                            line => 51}
                                                    )
                                            end
                                        end
                                    ),
                                    wisp:ok()
                                end
                            )
                        end
                    )
                end
            )
        end
    ).