-spec add_friend(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.

-spec create_group(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.

-spec friends(cowboy_req:req()) -> {json, map()}.

-spec join_group(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.

-spec kick_member(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.

-spec leave_group(cowboy_req:req()) -> {json, integer(), map(), map()}.

-spec list_members(cowboy_req:req()) -> {json, map()} | {status, integer()}.

-spec remove_friend(cowboy_req:req()) -> {json, map()} | {status, integer()}.

-spec show_group(cowboy_req:req()) -> {json, map()} | {status, integer()}.

-spec update_friend(cowboy_req:req()) -> {json, map()} | {status, integer()}.

-spec update_group(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.

-spec update_member_role(cowboy_req:req()) -> {json, map()} | {json, integer(), map(), map()}.