gistfile1.hrl

-module(contact_model).

-behaviour(model).
-include("contact.hrl").


description() ->
    [ {rotate, 5}, {ensure, 2} ].

-define(CONTACTS_PERIOD, (1000000*60*60*24*30) ).

init(Self) ->
    ets_server:start_link(contacts_cache, [set,named_table] ).

get_contacts(Self, User) ->
    %model:super(Self, get_contacts, [User]) , 
    case ets_server:lookup_first(contacts_cache,User) of
        undef -> load_contacts(User);
        Contacts -> Contacts
    end.

get_contact(Self, User,ContactUser) ->
    LoadedContacts = model:call(Self, load_contacts, [User]), 
    case lists:filter( fun({_CG,CU}) -> CU =:= ContactUser end, LoadedContacts ) of
        [] -> undef;
        [C|_] -> C
    end.

add_to_contacts(Self, User, ContactGroup, ContactUser) ->
    ets_server:delete(contacts_cache,User), 
    model:write(Self,User,add,{User,ContactGroup,ContactUser}).

remove_from_contacts(Self, User,ContactUser)->
    ets_server:delete(contacts_cache,User), 
    model:write(Self,User,remove,{User,ContactUser}).

is_in_contacts(Self, User,ContactUser) ->
    LoadedContacts = model:call(Self, load_contacts, [User]), 
    lists:any( fun({_CG,CU}) -> CU =:= ContactUser end, LoadedContacts ).

load_contacts(Self, User) ->
    case ets_server:lookup_first(contacts_cache,User) of
        undef ->
            Res = model:read(Self, User, ?CONTACTS_PERIOD, get, User,),
            Contacts = case Res of 
                {ok, undef} -> #contacts{user = User};
                {ok, C} -> C;
                _ -> #contacts{user = User}
            end,
            error_logger:info_msg( "contact_server:load_contacts Contacts=~p~n", [Contacts] ),
            ets_server:insert(contacts_cache,{User, Contacts#contacts.contacts}),
            Contacts#contacts.contacts;
        CachedContacts -> CachedContacts
    end.




%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% Db server methods
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

% behaviour methods

db_init_node(Self) ->
    % model:super(Self, init_node),
    mnesia:create_schema([node()]),    
    mnesia:start(),
    Res = mnesia:create_table( contacts, [ 
        {type, set}, 
        {attributes, record_info(fields, contacts) }, 
        {disc_only_copies, [node()]}
    ] ),
    error_logger:info_msg("contacts_dbe:init_node create_table res: ~p~n",[Res]), 
    %NewSelf = model:set(Self,{Key,Value}),
    {ok, Self}.


db_init(Self) ->
    mnesia:start(),
    {ok, Self}.

db_terminate(Self, _Reason,_Counter) -> 
    mnesia:stop(),
    ok.

db_code_change(Self, _OldVsn, _Extra) -> Self.




% custom_methods

db_get(Self, User) -> 
    TrRes = mnesia:transaction( fun() ->
        Res = mnesia:read({contacts,User}),
        error_logger:info_msg("contacts_dbe:get read Res is ~p~n",[Res]),
        case Res of 
            [Contacts] -> Contacts;
            _ -> #contacts{user=User}
        end
    end ),
    error_logger:info_msg("contacts_dbe:get Res is ~p~n",[TrRes]),
    UserContacts = case TrRes of
        {atomic,C} -> C;
        _ -> undef
    end
    {ok, UserContacts, Self}.

db_set(Self, User) ->
    mnesia:transaction( fun() -> mnesia:write(Param) end ),
    {ok, Self}.

db_add(Self, User, ContactGroup, ContactUser) ->
            {} = Param,
            Res = mnesia:transaction( fun() ->  
                OldContacts = case mnesia:read({contacts,User}) of 
                    [C] -> C;
                    _ -> #contacts{user=User}
                end,
                AlreadyAdded = lists:any( fun({_Gr,C}) -> C =:= ContactUser end, OldContacts#contacts.contacts ),
                if 
                    not AlreadyAdded ->
                       NewContacts = OldContacts#contacts{ contacts=[{ContactGroup,ContactUser} | OldContacts#contacts.contacts] },
                       mnesia:write(NewContacts),
                       NewContacts;
                    true -> OldContacts
                end
            end ),
            error_logger:info_msg("contacts_dbe:get Res is ~p~n",[Res]),
            {ok, Self}.

db_remove(Self, User, ContactUser) ->
    mnesia:transaction( fun() ->  
        case mnesia:read({contacts,User}) of 
            [OldContacts] ->
                IsAdded = lists:any( fun({_Gr,C}) -> C =:= ContactUser end, OldContacts#contacts.contacts ),
                if
                    IsAdded -> 
                        NewContacts = OldContacts#contacts{ contacts = lists:filter( fun({_Gr,C}) -> C =/= ContactUser end, OldContacts#contacts.contacts ) },
                        mnesia:write(NewContacts);
                    true -> nope
                end;
            _ -> nope
        end
    end ),
    {ok, Self}.


resolve(RequestName, Param, Replies) ->
    case RequestName of
        get ->
            AllContacts = lists:append( lists:map( fun(C) -> C#contacts.contacts end, Replies ) ),
            Dict = dict:from_list( lists:map( fun({G,C}) -> {C,G} end, AllContacts ) ),
            #contacts{ user=Param, contacts=lists:map( fun({C,G}) -> {G,C} end, dict:to_list( Dict ) ) };
        _ ->
            error 
    end.