-module(ls_role).


-export([
         add/1,
         delete/1,
         get/1,
         grant/2,
         list/0,
         list/2,
         stream/3,
         revoke/2,
         revoke_prefix/2,
         set_metadata/2
        ]).

%%%===================================================================
%%% Ignore
%%%===================================================================

-ignore_xref([
              add/1,
              delete/1,
              get/1,
              grant/2,
              list/0,
              list/2,
              stream/3,
              revoke/2,
              revoke_prefix/2,
              set_metadata/2
             ]).

%%%===================================================================
%%% Role Functions
%%%===================================================================

-spec set_metadata(Role::fifo:role_id(), Attrs::fifo:attr_list()) ->
                          {error, no_servers} |
                          ok.
set_metadata(Role, Attrs) ->
    send(libsnarl_msg:role_set_metadata(r(), Role, Attrs)).

%%--------------------------------------------------------------------
%% @doc Retrievs a list of all role id's.
%% @spec list() ->
%%                 [term()]
%% @end
%%--------------------------------------------------------------------
-spec list() ->
                  {error, no_servers} |
                  {ok, [fifo:role_id()]}.
list() ->
    send(libsnarl_msg:role_list(r())).

%%--------------------------------------------------------------------
%% @doc Retrievs a filtered list for roles.
%% @end
%%--------------------------------------------------------------------
-spec list(Reqs::[fifo:matcher()], boolean()) ->
                  {error, no_servers} |
                  {ok, [{Rank::integer(), fifo:role_id()}]} |
                  {ok, [{Rank::integer(), fifo:role()}]}.
list(Reqs, Full) ->
    send(libsnarl_msg:role_list(r(), Reqs, Full)).

%%--------------------------------------------------------------------
%% @doc Streams the VM's in chunks.
%% @end
%%--------------------------------------------------------------------
-spec stream(Reqs::[fifo:matcher()], mdns_client_lib:stream_fun(), term()) ->
                  {ok, [{Ranking::integer(), fifo:role_id()}]} |
                  {ok, [{Ranking::integer(), fifo:role()}]} |
                  {'error', 'no_servers'}.
stream(Reqs, StreamFn, Acc0) ->
    case libsnarl_server:stream({role, stream, r(), Reqs}, StreamFn, Acc0) of
        {reply, Reply} ->
            Reply;
        noreply ->
            ok;
        E ->
            E
    end.

%%--------------------------------------------------------------------
%% @doc Retrieves role data from the server.
%% @spec get(Role::binary()) ->
%%                 {error, not_found|no_servers} | term()
%% @end
%%--------------------------------------------------------------------
-spec get(Role::fifo:role_id()) ->
                 not_found |
                 {error, no_servers} |
                 {ok, fifo:role()}.
get(Role) ->
    send(libsnarl_msg:role_get(r(), Role)).

%%--------------------------------------------------------------------
%% @doc Adds a new role.
%% @spec add(Role::binary()) ->
%%                 {error, duplicate} | ok
%% @end
%%--------------------------------------------------------------------
-spec add(Role::fifo:role_id()) ->
                 {error, no_servers} |
                 duplicate |
                 {ok, UUID :: fifo:role_id()}.
add(Role) ->
    send(libsnarl_msg:role_add(r(), Role)).

%%--------------------------------------------------------------------
%% @doc Deletes a role.
%% @spec delete(Role::binary()) ->
%%                    {error, not_found|no_servers} | ok
%% @end
%%--------------------------------------------------------------------
-spec delete(Role::fifo:role_id()) ->
                    {error, no_servers} |
                    not_found |
                    ok.
delete(Role) ->
    send(libsnarl_msg:role_delete(r(), Role)).

%%--------------------------------------------------------------------
%% @doc Grants a right of a role.
%% @spec grant(Role::binary(),
%%                   Permission::[atom()|binary()|string()]) ->
%%                   {error, not_found|no_servers} | ok
%% @end
%%--------------------------------------------------------------------
-spec grant(Role::fifo:role_id(),
            Permission::fifo:permission()) ->
                   {error, no_servers} |
                   not_found |
                   ok.
grant(Role, Permission) ->
    send(libsnarl_msg:role_grant(r(), Role, Permission)).

%%--------------------------------------------------------------------
%% @doc Revokes a right of a role.
%% @spec revoke(Role::binary(),
%%                    Permission::fifo:permission()) ->
%%                    {error, not_found|no_servers} | ok
%% @end
%%--------------------------------------------------------------------
-spec revoke(Role::fifo:role_id(),
             Permission::fifo:permission()) ->
                    {error, no_servers} |
                    not_found |
                    ok.
revoke(Role, Permission) ->
    send(libsnarl_msg:role_revoke(r(), Role, Permission)).

%%--------------------------------------------------------------------
%% @doc Revokes all rights matching a prefix from a role.
%% @end
%%--------------------------------------------------------------------
-spec revoke_prefix(Role::fifo:role_id(),
                    Prefix::fifo:permission()) ->
                           {error, no_servers} |
                           not_found |
                           ok.
revoke_prefix(Role, Prefix) ->
    send(libsnarl_msg:role_revoke_prefix(r(), Role, Prefix)).

%%%===================================================================
%%% Internal Functions
%%%===================================================================

%%--------------------------------------------------------------------
%% @private
%% @doc Sends a message.
%% @spec send(Msg::term()) -> {ok, Reply::term()} | {error, no_server}
%% @end
%%--------------------------------------------------------------------

-spec send(Msg::fifo:snarl_role_message()) ->
                  ok |
                  not_found |
                  duplicate |
                  {ok, Reply::term()} |
                  {error, no_servers}.
send(Msg) ->
    case libsnarl_server:call(Msg) of
        {reply, Reply} ->
            Reply;
        E ->
            E
    end.

r() ->
    application:get_env(libsnarl, realm, <<"default">>).