Serena

%% Services module implementing gen_server behavior -module(services). -behaviour(gen_server). -include("../include/records.hrl"). -include("../include/types.hrl"). %% API exports -export([ start_link/0, stop/0, register_user/4, get_user/1, create_order/2, update_order_status/2, get_statistics/0 ]). %% gen_server callbacks -export([ init/1, handle_call/3, handle_cast/2, handle_info/2, terminate/2, code_change/3 ]). %% State record -record(state, { users = #{} :: map(), orders = #{} :: map(), next_user_id = 1 :: integer(), next_order_id = 1 :: integer() }). %%%=================================================================== %%% API %%%=================================================================== -spec start_link() -> {ok, pid()} | ignore | {error, term()}. start_link() -> gen_server:start_link({local, ?MODULE}, ?MODULE, [], []). -spec stop() -> ok. stop() -> gen_server:stop(?MODULE). -spec register_user(string(), email(), integer(), boolean()) -> {ok, user_id()} | {error, term()}. register_user(Name, Email, Age, Active) -> gen_server:call(?MODULE, {register_user, Name, Email, Age, Active}). -spec get_user(user_id()) -> {ok, #user{}} | {error, not_found}. get_user(UserId) -> gen_server:call(?MODULE, {get_user, UserId}). -spec create_order(user_id(), list()) -> {ok, integer()} | {error, term()}. create_order(UserId, Items) -> gen_server:call(?MODULE, {create_order, UserId, Items}). -spec update_order_status(integer(), atom()) -> ok | {error, term()}. update_order_status(OrderId, Status) -> gen_server:call(?MODULE, {update_order_status, OrderId, Status}). -spec get_statistics() -> #{atom() => integer()}. get_statistics() -> gen_server:call(?MODULE, get_statistics). %%%=================================================================== %%% gen_server callbacks %%%=================================================================== -spec init([]) -> {ok, #state{}}. init([]) -> {ok, #state{}}. -spec handle_call(term(), {pid(), term()}, #state{}) -> handle_call_result(). handle_call({register_user, Name, Email, Age, Active}, _From, State) -> UserId = State#state.next_user_id, User = models:create_user(UserId, Name, Email, Age), UpdatedUser = models:update_user(User, [{active, Active}]), NewUsers = maps:put(UserId, UpdatedUser, State#state.users), NewState = State#state{ users = NewUsers, next_user_id = UserId + 1 }, {reply, {ok, UserId}, NewState}; handle_call({get_user, UserId}, _From, State) -> case maps:get(UserId, State#state.users, not_found) of not_found -> {reply, {error, not_found}, State}; User -> {reply, {ok, User}, State} end; handle_call({create_order, UserId, Items}, _From, State) -> case maps:get(UserId, State#state.users, not_found) of not_found -> {reply, {error, user_not_found}, State}; _User -> OrderId = State#state.next_order_id, Order = models:create_order(OrderId, UserId, Items), NewOrders = maps:put(OrderId, Order, State#state.orders), NewState = State#state{ orders = NewOrders, next_order_id = OrderId + 1 }, {reply, {ok, OrderId}, NewState} end; handle_call({update_order_status, OrderId, Status}, _From, State) -> case maps:get(OrderId, State#state.orders, not_found) of not_found -> {reply, {error, order_not_found}, State}; Order -> UpdatedOrder = Order#order{status = Status}, NewOrders = maps:put(OrderId, UpdatedOrder, State#state.orders), NewState = State#state{orders = NewOrders}, {reply, ok, NewState} end; handle_call(get_statistics, _From, State) -> Stats = #{ total_users => maps:size(State#state.users), total_orders => maps:size(State#state.orders), next_user_id => State#state.next_user_id, next_order_id => State#state.next_order_id }, {reply, Stats, State}; handle_call(_Request, _From, State) -> {reply, {error, unknown_request}, State}. -spec handle_cast(term(), #state{}) -> {noreply, #state{}}. handle_cast(_Msg, State) -> {noreply, State}. -spec handle_info(term(), #state{}) -> {noreply, #state{}}. handle_info(_Info, State) -> {noreply, State}. -spec terminate(term(), #state{}) -> ok. terminate(_Reason, _State) -> ok. -spec code_change(term() | {down, term()}, #state{}, term()) -> {ok, #state{}}. code_change(_OldVsn, State, _Extra) -> {ok, State}.