:- use_module(library(lists)).

%% Teste Modelo 17/18

%participant(Id,Age,Performance)
participant(1234, 17, 'Pé coxinho').
participant(3423, 21, 'Programar com os pés').
participant(3788, 20, 'Sing a Bit').
participant(4865, 22, 'Pontes de esparguete').
participant(8937, 19, 'Pontes de pen-drives').
participant(2564, 20, 'Moodle hack').

%performance(Id,Times)
performance(1234,[120,120,120,120]).
performance(3423,[32,120,45,120]).
performance(3788,[110,2,6,43]).
performance(4865,[120,120,110,120]).
performance(8937,[97,101,105,110]).


% P1 madeItThrough(+Id)
madeItThrough(Id) :-
  performance(Id, Times),
  member(120, Times).

% P2 juriTimes(+Participants, +JuriMember, -Times, -Total)
juriTimes([], _, [], 0).
juriTimes([First | OtherParticipants], JuriMember, [FirstTime | OtherTimes], Total) :-
  performance(First, Times),
  nth1(JuriMember, Times, FirstTime),
  juriTimes(OtherParticipants, JuriMember, OtherTimes, NTotal),
  Total is NTotal + FirstTime.

% P3 patientJuri(+JuriMember)
patientJuri(JuriMember) :-
  performance(Id1, Times1),
  nth1(JuriMember, Times1, 120),
  performance(Id2, Times2),
  Id1 \= Id2,
  nth1(JuriMember, Times2, 120).

% P4 bestParticipant(+P1, +P2, -P)
bestParticipant(P1, P2, P) :-
  performance(P1, Times1),
  performance(P2, Times2),
  sum_list(Times1, Sum1),
  sum_list(Times2, Sum2),
  Diff is Sum1 - Sum2,
  bestParticipantAux(P1, P2, Diff, P).
bestParticipantAux(P1, _P2, Diff, P1) :-
  Diff > 0.
bestParticipantAux(_P1, P2, Diff, P2) :-
  Diff < 0.

sum_list([], 0).
sum_list([First | Rest], Sum) :-
  sum_list(Rest, RestSum),
  Sum is RestSum + First.

% P5 allPerfs
allPerfs :-
  performance(Id, Times),
  participant(Id, _, Name),
  write(Id), write(':'),
  write(Name), write(':'),
  write(Times), nl,
  fail.
allPerfs.

% P6 nSuccessfulParticipants(-N)
nSuccessfulParticipants(N) :-
  findall(Id, (performance(Id, Times), successfulTimes(Times)), Result),
  length(Result, N).

successfulTimes(Times) :-
  member(Elem, Times),
  Elem < 120, !, fail.
successfulTimes(_).

% P7 juriFans(-juriFansList)
juriFans(List) :-
  findall(Id-Fans, (performance(Id, Times), juriFansAux(Times, Fans, 1)), List).

juriFansAux([], [], _).
juriFansAux([120 | RestT], [Count | OtherFans], Count) :-
  !, NCount is Count + 1,
  juriFansAux(RestT, OtherFans, NCount).
juriFansAux([_ | RestT], OtherFans, Count) :-
  NCount is Count + 1,
  juriFansAux(RestT, OtherFans, NCount).

% P8 nextPhase(+N, -Participants)
nextPhase(N, Participants) :-
  setof(Score-Id-Name, eligibleOutcome(Id, Name, Score), AllParticipants),
  selectBestN(N, AllParticipants, Participants).

eligibleOutcome(Id,Perf,TT) :-
    performance(Id,Times),
    madeItThrough(Id),
    participant(Id,_,Perf),
    sumlist(Times,TT).

selectBestN(0, _, []).
selectBestN(N, L, [LastElem | Rest]) :-
  N1 is N - 1,
  append(L1, [LastElem], L),
  selectBestN(N1, L1, Rest).

% P9 predX(+Idade, +L, -Ps)
predX(Q,[R|Rs],[P|Ps]) :-
    participant(R,I,P), I=<Q, !,
    predX(Q,Rs,Ps).
predX(Q,[R|Rs],Ps) :-
    participant(R,I,_), I>Q,
    predX(Q,Rs,Ps).
predX(_,[],[]).
%  O predicado predX/3 recebe um inteiro, Idade, e uma lista, L,  de Ids de
% participantes, e unifica o terceiro argumento com as performances cujo
% participante tem menos de Idade anos.


% P10
impoe(X,L) :-
    length(Mid,X),
    append(L1,[X|_],L), append(_,[X|Mid],L1).
%  O predicado impoe/2 avalia se é cumprida parte da condição enunciada, nomeadamente:
% que L tem uma sub-lista de tamanho X cujo primeiro e último elemento é X.


% P11 langford(+N, -L)
langford(N, L) :-
  N > 0,  N2 is N * 2,
  length(UninitializedList, N2),
  langfordAux(N, UninitializedList, L).


langfordAux(0, L, L).
langfordAux(N, UL, L) :-
  impoe(N, UL), N1 is N - 1,
  langfordAux(N1, UL, L).