glitch

-module(glitch@auth@redirect_server).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([start/1, shutdown/1, new/3]).
-export_type([redirect_server/0, status/0, message/0]).

-opaque redirect_server() :: {state,
        binary(),
        gleam@erlang@process:subject(binary()),
        gleam@option:option(gleam@erlang@process:subject(gleam@otp@supervisor:message())),
        gleam@uri:uri(),
        status()}.

-type status() :: running | stopped.

-type message() :: shutdown | start.

-spec start(gleam@erlang@process:subject(message())) -> nil.
start(Server) ->
    gleam@otp@actor:send(Server, start).

-spec shutdown(gleam@erlang@process:subject(message())) -> nil.
shutdown(Server) ->
    gleam@otp@actor:send(Server, shutdown).

-spec make_mist_body(gleam@option:option(binary())) -> mist:response_data().
make_mist_body(Body) ->
    _pipe = Body,
    _pipe@1 = gleam@option:unwrap(_pipe, <<""/utf8>>),
    _pipe@2 = gleam_stdlib:wrap_list(_pipe@1),
    {bytes, _pipe@2}.

-spec get_code_and_csrf_token_query_params(gleam@http@request:request(any())) -> {gleam@option:option(binary()),
    gleam@option:option(binary())}.
get_code_and_csrf_token_query_params(Req) ->
    Query_params = begin
        _pipe = gleam@http@request:get_query(Req),
        gleam@result:unwrap(_pipe, [])
    end,
    Code_result = gleam@list:key_find(Query_params, <<"code"/utf8>>),
    Csrf_state_result = gleam@list:key_find(Query_params, <<"state"/utf8>>),
    {gleam@option:from_result(Code_result),
        gleam@option:from_result(Csrf_state_result)}.

-spec bad_request_response(gleam@option:option(binary())) -> gleam@http@response:response(mist:response_data()).
bad_request_response(Message) ->
    _pipe = gleam@http@response:new(400),
    gleam@http@response:set_body(_pipe, make_mist_body(Message)).

-spec generic_bad_request_response() -> gleam@http@response:response(mist:response_data()).
generic_bad_request_response() ->
    bad_request_response(none).

-spec ok_response(gleam@option:option(binary())) -> gleam@http@response:response(mist:response_data()).
ok_response(Body) ->
    _pipe = gleam@http@response:new(200),
    gleam@http@response:set_body(_pipe, make_mist_body(Body)).

-spec send_response(redirect_server(), binary()) -> fun((any()) -> gleam@http@response:response(mist:response_data())).
send_response(Server, Code) ->
    fun(_) ->
        gleam@erlang@process:send_after(erlang:element(3, Server), 250, Code),
        ok_response(
            {some,
                <<"Successfully received redirect payload from Twitch."/utf8>>}
        )
    end.

-spec make_redirect_handler(redirect_server()) -> fun((gleam@http@request:request(mist@internal@http:connection())) -> gleam@http@response:response(mist:response_data())).
make_redirect_handler(Server) ->
    Handle_redirect = fun(Req) ->
        case get_code_and_csrf_token_query_params(Req) of
            {{some, Code}, {some, State}} when State =:= erlang:element(
                2,
                Server
            ) ->
                _pipe = mist:read_body(Req, 10485760),
                _pipe@1 = gleam@result:map(_pipe, send_response(Server, Code)),
                gleam@result:lazy_unwrap(
                    _pipe@1,
                    fun generic_bad_request_response/0
                );

            {{some, _}, {some, _}} ->
                bad_request_response({some, <<"Invalid csrf state"/utf8>>});

            {{some, _}, none} ->
                bad_request_response({some, <<"No csrf state received"/utf8>>});

            {none, _} ->
                bad_request_response({some, <<"No code received"/utf8>>})
        end
    end,
    Handle_redirect.

-spec new_router(redirect_server()) -> fun((gleam@http@request:request(mist@internal@http:connection())) -> gleam@http@response:response(mist:response_data())).
new_router(Server) ->
    Redirect_path = erlang:element(6, erlang:element(5, Server)),
    Router = fun(Req) ->
        case {erlang:element(2, Req), gleam@http@request:path_segments(Req)} of
            {get, [Path]} when Path =:= Redirect_path ->
                (make_redirect_handler(Server))(Req);

            {_, _} ->
                _pipe = gleam@http@response:new(404),
                gleam@http@response:set_body(
                    _pipe,
                    {bytes, gleam@bytes_builder:new()}
                )
        end
    end,
    Router.

-spec handle_message(message(), redirect_server()) -> gleam@otp@actor:next(message(), redirect_server()).
handle_message(Message, State) ->
    case Message of
        shutdown ->
            _assert_subject = begin
                _pipe = erlang:element(4, State),
                _pipe@1 = gleam@option:map(
                    _pipe,
                    fun gleam@erlang@process:subject_owner/1
                ),
                gleam@option:map(_pipe@1, fun gleam@erlang@process:kill/1)
            end,
            {some, nil} = case _assert_subject of
                {some, nil} -> _assert_subject;
                _assert_fail ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail,
                                module => <<"glitch/auth/redirect_server"/utf8>>,
                                function => <<"handle_message"/utf8>>,
                                line => 50})
            end,
            {stop, normal};

        start ->
            Port = gleam@option:unwrap(
                erlang:element(5, erlang:element(5, State)),
                3000
            ),
            _assert_subject@1 = begin
                _pipe@2 = mist:new(new_router(State)),
                _pipe@3 = mist:port(_pipe@2, Port),
                mist:start_http(_pipe@3)
            end,
            {ok, Mist_subject} = case _assert_subject@1 of
                {ok, _} -> _assert_subject@1;
                _assert_fail@1 ->
                    erlang:error(#{gleam_error => let_assert,
                                message => <<"Assertion pattern match failed"/utf8>>,
                                value => _assert_fail@1,
                                module => <<"glitch/auth/redirect_server"/utf8>>,
                                function => <<"handle_message"/utf8>>,
                                line => 60})
            end,
            gleam@otp@actor:continue(
                erlang:setelement(
                    6,
                    erlang:setelement(4, State, {some, Mist_subject}),
                    running
                )
            )
    end.

-spec new(binary(), gleam@erlang@process:subject(binary()), gleam@uri:uri()) -> {ok,
        gleam@erlang@process:subject(message())} |
    {error, gleam@otp@actor:start_error()}.
new(Csrf_state, Mailbox, Redirect_uri) ->
    State = {state, Csrf_state, Mailbox, none, Redirect_uri, stopped},
    gleam@otp@actor:start(State, fun handle_message/2).