glitch

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

-export([new_client_credentials_provider/2, new_static_provider/2, new_refreshing_provider/4, client_id/1, access_token/1]).
-export_type([auth_provider/0]).

-opaque auth_provider() :: {client_credentials_auth_provider,
        gleam@option:option(glitch@types@access_token:access_token()),
        binary(),
        binary()} |
    {refreshing_auth_provider,
        glitch@types@access_token:access_token(),
        binary(),
        binary(),
        gleam@option:option(fun((glitch@types@access_token:access_token()) -> nil))} |
    {static_auth_provider, glitch@types@access_token:access_token(), binary()}.

-spec new_client_credentials_provider(binary(), binary()) -> auth_provider().
new_client_credentials_provider(Client_id, Client_secret) ->
    {client_credentials_auth_provider, none, Client_id, Client_secret}.

-spec new_static_provider(glitch@types@access_token:access_token(), binary()) -> auth_provider().
new_static_provider(Access_token, Client_id) ->
    {static_auth_provider, Access_token, Client_id}.

-spec new_refreshing_provider(
    glitch@types@access_token:access_token(),
    binary(),
    binary(),
    gleam@option:option(fun((glitch@types@access_token:access_token()) -> nil))
) -> auth_provider().
new_refreshing_provider(Access_token, Client_id, Client_secret, On_refresh) ->
    {refreshing_auth_provider,
        Access_token,
        Client_id,
        Client_secret,
        On_refresh}.

-spec client_id(auth_provider()) -> binary().
client_id(Auth_provider) ->
    case Auth_provider of
        {client_credentials_auth_provider, _, Client_id, _} ->
            Client_id;

        {refreshing_auth_provider, _, Client_id@1, _, _} ->
            Client_id@1;

        {static_auth_provider, _, Client_id@2} ->
            Client_id@2
    end.

-spec access_token_for_refreshing_provider(
    glitch@types@access_token:access_token(),
    binary(),
    binary(),
    gleam@option:option(fun((glitch@types@access_token:access_token()) -> nil))
) -> {ok, glitch@types@access_token:access_token()} |
    {error, glitch@error:twitch_error()}.
access_token_for_refreshing_provider(
    Access_token,
    Client_id,
    Client_secret,
    On_refresh
) ->
    case {glitch@types@access_token:is_expired(Access_token),
        glitch@types@access_token:needs_validated(Access_token)} of
        {true, _} ->
            gleam@result:'try'(
                glitch@types@access_token:refresh_token(Access_token),
                fun(Refresh_token) ->
                    Refresh_token_request = glitch@api@auth:new_refresh_token_grant_request(
                        Client_id,
                        Client_secret,
                        Refresh_token
                    ),
                    gleam@result:'try'(
                        glitch@api@auth:refresh_token(Refresh_token_request),
                        fun(Refreshed_token) -> case On_refresh of
                                none ->
                                    {ok, Refreshed_token};

                                {some, On_refresh@1} ->
                                    On_refresh@1(Refreshed_token),
                                    {ok, Refreshed_token}
                            end end
                    )
                end
            );

        {false, true} ->
            gleam@result:'try'(
                begin
                    _pipe = glitch@api@auth:validate_token(Access_token),
                    gleam@result:map_error(
                        _pipe,
                        fun(Error) ->
                            {auth_error, {validate_token_error, Error}}
                        end
                    )
                end,
                fun(Validate_token_response) ->
                    {ok,
                        glitch@types@access_token:set_expires_in(
                            Access_token,
                            erlang:element(6, Validate_token_response)
                        )}
                end
            );

        {false, false} ->
            {ok, Access_token}
    end.

-spec fetch_token(glitch@api@auth:get_token_request()) -> {ok,
        glitch@types@access_token:access_token()} |
    {error, glitch@error:twitch_error()}.
fetch_token(Request) ->
    _pipe = Request,
    _pipe@1 = glitch@api@auth:get_token(_pipe),
    gleam@result:map_error(
        _pipe@1,
        fun(Error) -> {auth_error, {token_fetcher_fetch_error, Error}} end
    ).

-spec access_token_for_client_credential_provider(
    gleam@option:option(glitch@types@access_token:access_token()),
    binary(),
    binary()
) -> {ok, glitch@types@access_token:access_token()} |
    {error, glitch@error:twitch_error()}.
access_token_for_client_credential_provider(
    Access_token,
    Client_id,
    Client_secret
) ->
    case Access_token of
        none ->
            fetch_token(
                glitch@api@auth:new_client_credentials_grant_request(
                    Client_id,
                    Client_secret
                )
            );

        {some, Access_token@1} ->
            case {glitch@types@access_token:is_expired(Access_token@1),
                glitch@types@access_token:needs_validated(Access_token@1)} of
                {true, _} ->
                    {error, {auth_error, access_token_expired}};

                {false, true} ->
                    gleam@result:'try'(
                        begin
                            _pipe = glitch@api@auth:validate_token(
                                Access_token@1
                            ),
                            gleam@result:map_error(
                                _pipe,
                                fun(Error) ->
                                    {auth_error, {validate_token_error, Error}}
                                end
                            )
                        end,
                        fun(Validate_token_response) ->
                            {ok,
                                glitch@types@access_token:set_expires_in(
                                    Access_token@1,
                                    erlang:element(6, Validate_token_response)
                                )}
                        end
                    );

                {false, false} ->
                    {ok, Access_token@1}
            end
    end.

-spec access_token(auth_provider()) -> {ok,
        glitch@types@access_token:access_token()} |
    {error, glitch@error:twitch_error()}.
access_token(Auth_provider) ->
    case Auth_provider of
        {client_credentials_auth_provider,
            Access_token,
            Client_id,
            Client_secret} ->
            access_token_for_client_credential_provider(
                Access_token,
                Client_id,
                Client_secret
            );

        {refreshing_auth_provider,
            Access_token@1,
            Client_id@1,
            Client_secret@1,
            On_refresh} ->
            access_token_for_refreshing_provider(
                Access_token@1,
                Client_id@1,
                Client_secret@1,
                On_refresh
            );

        {static_auth_provider, Access_token@2, _} ->
            {ok, Access_token@2}
    end.