-module(kvs_product).
-copyright('Synrc Research Center s.r.o.').
-include_lib("kvs/include/kvs.hrl").
-include_lib("kvs/include/products.hrl").
-include_lib("kvs/include/purchases.hrl").
-include_lib("kvs/include/users.hrl").
-include_lib("kvs/include/groups.hrl").
-include_lib("kvs/include/feeds.hrl").
-include_lib("kvs/include/accounts.hrl").
-include_lib("kvs/include/config.hrl").
-include_lib("kvs/include/feed_state.hrl").
-include_lib("mqs/include/mqs.hrl").
-compile(export_all).

init(Backend) ->
    ?CREATE_TAB(product),
    ?CREATE_TAB(user_product),
    ?CREATE_TAB(product_category),
    ok.

delete(Name) ->
  case kvs:get(product, Name) of
    {ok, Product} ->
      [kvs_group:leave(Name, Gid) || Gid <- kvs_group:participate(Name)],
      kvs:remove(product, Name),
      {ok, Product};
    E -> E end.

subscription_mq(Type, Action, Who, Whom) ->
    case mqs:open([]) of
        {ok,Channel} ->
            case {Type,Action} of 
                {user,add}     -> mqs_channel:bind_exchange(Channel, ?USER_EXCHANGE(Who), ?NOTIFICATIONS_EX, rk_product_feed(Whom));
                {user,remove}  -> mqs_channel:unbind_exchange(Channel, ?USER_EXCHANGE(Who), ?NOTIFICATIONS_EX, rk_product_feed(Whom)) end,
            mqs_channel:close(Channel);
        {error,Reason} -> error_logger:info_msg("subscription_mq error: ~p",[Reason]) end.

init_mq(Product=#product{}) ->
    Groups = kvs_group:participate(Product),
    ProductExchange = ?USER_EXCHANGE(Product#product.id),
    ExchangeOptions = [{type, <<"fanout">>}, durable, {auto_delete, false}],
    case mqs:open([]) of
        {ok, Channel} ->
            error_logger:info_msg("Cration Exchange: ~p,",[{Channel,ProductExchange,ExchangeOptions}]),
            mqs_channel:create_exchange(Channel, ProductExchange, ExchangeOptions),
            Relations = build_product_relations(Product, Groups),
            [ mqs_channel:bind_exchange(Channel, ?USER_EXCHANGE(Product#product.id), ?NOTIFICATIONS_EX, Route) || Route <- Relations],
            mqs_channel:close(Channel);
        {error,Reason} -> error_logger:info_msg("init_mq error: ~p",[Reason]) end.

build_product_relations(Product, Groups) -> [
    mqs:key( [kvs_product, '*', Product]),
    mqs:key( [kvs_feed, product, Product, '*', '*', '*']),
    mqs:key( [kvs_feed, product, Product, '*'] ),
    mqs:key( [kvs_payment, product, Product, '*']),
    mqs:key( [kvs_account, product, Product, '*']),
    mqs:key( [kvs_meeting, product, Product, '*']),
    mqs:key( [kvs_purchase, product, Product, '*']) |
  [ mqs:key( [kvs_feed, group, G, '*', '*', '*']) || G <- Groups ]
    ].

rk_product_feed(Product) -> mqs:key([kvs_feed, product, Product, '*', '*', '*']).

retrieve_connections(Id,Type) ->
    Friends = case Type of 
        user -> kvs_product:list_subscr_usernames(Id);
        _ -> kvs_group:list_group_members(Id) end,
    case Friends of
        [] -> [];
        Full -> Sub = lists:sublist(Full, 10),
            case Sub of
                [] -> [];
                _ ->
                    Data = [begin
                        case kvs:get(user,Who) of
                            {ok,Product} -> RealName = kvs_product:user_realname_user(Product),
                            Paid = kvs_payment:user_paid(Who),
                            {Who,Paid,RealName};
                        _ -> undefined end end || Who <- Sub],
                    [ X || X <- Data, X/=undefined ] end end.

handle_notice(["kvs_product", "subscribe", Who],
    Message, #state{owner = _Owner, type =_Type} = State) ->
    {Whom} = Message,
    kvs_product:subscribe(Who, Whom),
    subscription_mq(user, add, Who, Whom),
    {noreply, State};

handle_notice(["kvs_product", "unsubscribe", Who],
    Message, #state{owner = _Owner, type =_Type} = State) ->
    {Whom} = Message,
    kvs_product:unsubscribe(Who, Whom),
    subscription_mq(user, remove, Who, Whom),
    {noreply, State};

handle_notice(["kvs_product", "update", _Who],
    Message, #state{owner = _Owner, type =_Type} = State) ->
    {NewProduct} = Message,
    kvs:put(NewProduct),
    {noreply, State};

handle_notice(_Route, _Message, State) ->
  %error_logger:info_msg("Unknown USERS notice"),
  {noreply, State}.