one_instruction(state(Acc, Pc, Mem, In, Out, Flag),
                state(NewAcc, NewPc, NewMem, NewIn, NewOut, NewFlag)):-
                nth0(Pc,Mem,Cell),
                Op is div(Cell,100),
                Address is mod(Cell,100),
                operator(Op,Address,Mem,Acc,NewAcc,Pc,NewPc, NewMem, In, NewIn,Out,NewOut, Flag, NewFlag).
%add
%

operator(1,Address,Mem,Acc,NewAcc,Pc,NewPc,Mem,In,In,Out,Out,Flag, NewFlag):-
                pc_update(Pc,NewPc),
                nth0(Address,Mem,Value),
                somma(NewAcc, Acc, Value, Flag, NewFlag).
%sub
%
operator(2,Address,Mem,Acc,NewAcc,Pc,NewPc,Mem,In,In,Out,Out,Flag,NewFlag):-
                pc_update(Pc,NewPc),
                nth0(Address,Mem,Value),
                sott(NewAcc, Acc, Value, Flag, NewFlag).
%store
operator(3,Address,Mem,Acc,Acc,Pc,NewPc,NewMem,In,In,Out,Out,_,_):-
                pc_update(Pc,NewPc),
                fun(Mem, Address, Acc, _, NewMem),!.

%load
operator(5,Address,Mem,_,NewAcc,Pc,NewPc,Mem,In,In,Out,Out,_,_):-
                pc_update(Pc,NewPc),
                nth0(Address, Mem, NewAcc).


%branch
operator(6,Address,Mem,Acc,Acc,_,Address,Mem,In,In,Out,Out,_,_):- Address < 100.

%branch if zero
operator(7,Address,Mem,Acc,Acc,_,Address,Mem,In,In,Out,Out,_,_):- Acc = 0.
operator(7,_,Mem,Acc,Acc,Pc,NewPc,Mem,In,In,Out,Out,_,_):- pc_update(Pc,NewPc).



%input:
operator(9, 01,Mem,_,NewAcc,Pc,NewPc,Mem, In, NewIn,Out,Out,_,_):-
                pc_update(Pc,NewPc),
                input(In, NewAcc),
               nth0(0, In, _, NewIn),!.

%operator(9,Address,Mem,Acc,_,Pc,_,_,In,_,Out,_,Flag, _):-
 %not(Address=1), not(Address=2), halted_state(state(Acc, Pc, Mem, In,
 %Out, Flag)),!.

                                                                                                                                 %output:
operator(9, 02, Mem,Acc,Acc,Pc,NewPc,Mem,In,In,Out,NewOut,_,_):- pc_update(Pc,NewPc), append(Out, [Acc], NewOut),!.



%fine
operator(0,_, Mem,NewAcc,NewAcc,NewPc,NewPc,Mem,NewIn,NewIn,_,NewOut,_,_):-
                halted_state(state(NewAcc, NewPc, Mem, NewIn, NewOut, Flag)), true.
operator(4,_, Mem,NewAcc,NewAcc,NewPc,NewPc,Mem,NewIn,NewIn,_,NewOut,_,_):-
                halted_state(state(NewAcc, NewPc, Mem, NewIn, NewOut, Flag)), true.



halted_state(state(_, Pc, Mem, _,_,_)):-
                nth0(Pc,Mem,Cell),
                Op is div(Cell,100),
                Op is 0,!.


execution_loop(state(NewAcc, NewPc, NewMem, NewIn, Out, Flag), Out):- halted_state(state(NewAcc, NewPc, NewMem, NewIn, NewOut, Flag)), write("finito"),!.

execution_loop(state(Acc, Pc, Mem, In, Out, Flag), Out2):-
                one_instruction(state(Acc, Pc, Mem, In, Out, Flag), state(NewAcc, NewPc, NewMem, NewIn, NewOut, NewFlag)),
                 execution_loop(state(NewAcc, NewPc, NewMem, NewIn, NewOut, NewFlag), Out2).





%Qui sotto lo schifo. Poi creiamo un secondo file di moduli magari
%
%
%


%aggiunge in posizione indice
fun(List, Indice, Val, NewList, X):- nth0(Indice, NewList, Val, List), NewIndice is Indice+1, fun2(NewList, NewIndice, _, X),!.
%%toglie da indice +1
fun2(List, Indice,_, NewList):- nth0(Indice, List, _, NewList).

%aggiunge in testa
input([H], H).
input([H | _], H).

%non serve, ma la memoria dovra' avere 100 posizioni
mem(Index,[0|T]):- Index < 100, NewIndex is 1+Index, mem(NewIndex,T),!.
mem(Index,[0]):- Index is 99.



pc_update(Pc,NewPc):-Pc<99,NewPc is Pc+1,!.
pc_update(Pc,NewPc):-Pc=99,NewPc is 0.


sott(NewAcc, Acc, Value, 0, NewFlag):-  Temp is Acc-Value, Temp < 0, NewAcc is Temp + 1000, NewFlag is 1,!.

sott(NewAcc, Acc, Value, 1, NewFlag):-  Temp is Acc-Value, Temp < 0, NewAcc is Temp + 1000, NewFlag is 0,!.

sott(NewAcc, Acc, Value, 0, NewFlag):-  Temp is Acc-Value, Temp > 0, NewAcc is Temp, NewFlag is 0,!.

sott(NewAcc, Acc, Value, 1, NewFlag):-  Temp is Acc-Value, Temp > 0, NewAcc is Temp, NewFlag is 1,!.





somma(NewAcc, Acc, Value, _, NewFlag) :- Temp is Acc+Value, Temp >= 1000,!, NewAcc is mod(Temp, 1000), NewFlag is 1.

somma(NewAcc, Acc, Value, Flag, NewFlag) :- Temp is Acc+Value,  NewAcc is Temp, flag(Flag, NewFlag).
flag(Flag, NewFlag):- Flag is 0, NewFlag is 0,!.
flag(Flag, NewFlag):- Flag is 1, NewFlag is 1,!.