Blackjack scoring

-module(bj).
-export([deck/0,total/1,is_bust/1,is_blackjack/1,compare/2]).

ranks() -> ["A","2","3","4","5","6","7","8","9","10","J","Q","K"].
suits() -> [club,spade,heart,diamond].
deck()  -> Cards=[{R,S}||R<-ranks(),S<-suits()], shuffle(Cards).

shuffle(Deck) ->
 Gt=fun({A,_},{B,_})-> A > B end,
 Cards=[{random:uniform(),Card}||Card<-Deck],
 [Card||{_,Card}<-lists:sort(Gt,Cards)].

total(Aces_low,Has_ace) when Has_ace -> {Aces_low,Aces_low+10};
total(Total,_) -> Total.
total(Ranks) ->
 Total=lists:sum([value(Rank)||Rank<-Ranks]),
 Is_ace=fun(X) -> X =:= "A" end,
 Has_ace=lists:any(Is_ace,Ranks),
 total(Total,Has_ace).

is_bust({Lo,_}) -> is_bust(Lo);
is_bust(Total) -> Total > 21.

best({Lo,Hi}) ->
 Bust=is_bust(Hi),
 if not Bust -> Hi;
    Bust -> best(Lo)
 end;
best(Total) ->
 Bust=is_bust(Total),
 if not Bust -> Total
 end.

is_blackjack(["J","A"]) -> true;
is_blackjack(["A","J"]) -> true;
is_blackjack(_) -> false.

compare(Player,Dealer) ->
 Player_total=best(total(Player)),
 Dealer_total=best(total(Dealer)),
 if
    Player_total  >  Dealer_total -> win;
    Player_total =:= Dealer_total ->
      case {is_blackjack(Player),is_blackjack(Dealer)} of
       {true,false} -> win;
       {false,true} -> lose;
       {_,_} -> push
      end;
    Player_total =<  Dealer_total -> lose
 end.

value(Rank) ->
 Values=lists:zip(ranks(),[1,2,3,4,5,6,7,8,9,10,10,10,10]),
 lists:sum([Score||{Text,Score}<-Values,Text=:=Rank]).