:- use_module(library(lists)).
:- dynamic film/4.

% Factos
film('A', [action, adventure, fantasy], 115, 7.6).
film('B', [biography, drama, romance], 131, 8.7).
film('C', [action, adventure, crime], 121, 6.4).
film('D', [drama, mystery, scifi], 116, 8.5).
film('E', [action, crime, drama], 127, 7.6).
film('F', [drama, mystery, thriller], 112, 6.7).

user(john, 1992, 'USA').
user(jack, 1989, 'UK').
user(peter, 1983, 'portugal').
user(harry, 1993, 'USA').
user(richard, 1982, 'USA').

vote(john, ['C'-7, 'A'-9, 'E'-6]).
vote(jack, ['C'-8, 'A'-8, 'E'-7]).
vote(peter, ['E'-4, 'B'-7, 'F'-3]).
vote(harry, ['C'-7, 'E'-6]).
vote(richard, ['C'-10, 'B'-10, 'D'-9]).


%% PERGUNTAS %%

% P1 curto(+)
curto(Nome) :-
  film(Nome, _, Duracao, _),
  Duracao < 125.

% P2 diff(+, +, -, +)
diff(User1, User2, Difference, Film) :-
  vote(User1, Votes1),
  vote(User2, Votes2),
  member(Film-Vote1, Votes1),
  member(Film-Vote2, Votes2),
  Difference is abs(Vote1 - Vote2).

% P3 niceGuy(+)
niceGuy(User) :-
  vote(User, Votes),
  exclude(lessThan8, Votes, Result),
  length(Result, Len),
  Len >= 2.

lessThan8(_Key-Value) :-
  Value < 8.

% P4 elemsComuns(+, -, +)
elemsComuns([], [], _) :- !.
elemsComuns(_, [], []) :- !.
elemsComuns([X1 | L1], [X1 | Common], L2) :-
  select(X1, L2, NewL2), !,
  elemsComuns(L1, Common, NewL2).
elemsComuns([_ | L1], Common, L2) :-
  elemsComuns(L1, Common, L2), !.

% P5 printCategory(+)
printCategory(Category) :-
  film(Name, List, Duration, Average),
  member(Category, List),
  write(Name), write(' ('), write(Duration),
  write(', '), write(Average), write('/10)'), nl,
  fail.
printCategory(_).

union(L1, L2, Union) :-
  append(L1, L2, Tmp),
  sort(Tmp, Union).

% P6 similarity(+, +, -)
similarity(Film1, Film2, Similarity) :-
  film(Film1, Cat1, Dur1, Score1),
  film(Film2, Cat2, Dur2, Score2),

  elemsComuns(Cat1, CommonCat, Cat2),
  length(CommonCat, NumCommCat),
  union(Cat1, Cat2, UnionCat),
  length(UnionCat, NumUnionCat),
  PercentCat is NumCommCat / NumUnionCat,

  DurDiff is abs(Dur1 - Dur2),

  ScoreDiff is abs(Score1 - Score2),

  Similarity is (PercentCat * 100) - 3 * DurDiff - 5 * ScoreDiff.

% P7 mostSimilar(+, -, -)
mostSimilar(Film, Similarity, FilmsList) :-
  findall(TmpSim-TmpFilm, (similarity(Film, TmpFilm, TmpSim), Film \= TmpFilm), Result),
  max_member(Similarity-_, Result),
  Similarity > 10, !,
  findall(TmpFilm, member(Similarity-TmpFilm, Result), FilmsList).
mostSimilar(_, 0, []).

% P8 distancia(+, -, +)
distancia(User1, Distancia, User2) :-
  vote(User1, Votes1),
  vote(User2, Votes2),
  findall(VoteDiff, (member(TmpFilm-V1, Votes1), member(TmpFilm-V2, Votes2), (VoteDiff is abs(V1 - V2))), Result),
  listAvg(Result, AvgDiff),

  ageDiff(User1, User2, AgeDiff),

  countryDiff(User1, User2, CountryDiff),

  Distancia is (AvgDiff + AgeDiff / 3 + CountryDiff).

ageDiff(User1, User2, AgeDiff) :-
  user(User1, Age1, _),
  user(User2, Age2, _),
  AgeDiff is abs(Age1 - Age2).

countryDiff(User1, User2, Diff) :-
  user(User1, _, Country),
  user(User2, _, Country),
  !, Diff = 0.
countryDiff(User1, User2, Diff) :-
  user(User1, _, C1),
  user(User2, _, C2),
  C1 \= C2, !, Diff = 2.

listSum([], 0) :- !.
listSum([X | List], NSum) :-
  listSum(List, Sum),
  NSum is Sum + X.

listAvg(List, Avg) :-
  listSum(List, Sum),
  length(List, Length),
  Avg is (Sum / Length).


% P9 update(+)
update(Film) :-
  findall(Vote, (vote(_, Votes), member(Film-Vote, Votes)), Result),
  listAvg(Result, NewScore),

  retract(film(Film, Cats, Duration, _)),
  assert(film(Film, Cats, Duration, NewScore)).

% P11 move(+, -)
move(Row/Col, Celulas) :-
  findall(R/C, (horseMove(Row, Col, R, C), validRowCol(R, C)), Celulas).
validRowCol(Row, Col) :-
  Row >= 1, Col >= 1,
  Row =< 8, Col =< 8.

possibleHorseCoordChange(1).
possibleHorseCoordChange(-1).
possibleHorseCoordChange(2).
possibleHorseCoordChange(-2).

horseMove(Row, Col, R, C) :-
  possibleHorseCoordChange(Change1),
  possibleHorseCoordChange(Change2),
  AbsChange1 is abs(Change1),
  AbsChange2 is abs(Change2),
  AbsChange1 \= AbsChange2,
  R is Row + Change1,
  C is Col + Change2.

% P12 podeMoverEmN(+, +, -)
podeMoverEmN(R/C, 0, [R/C]).
podeMoverEmN(R/C, N, Cells) :-
  N > 0,
  N1 is N - 1,
  move(R/C, TmpCells),
  findall(ResCells, (member(TmpCell, TmpCells), podeMoverEmN(TmpCell, N1, ResCells)), OtherCells),
  append(OtherCells, TmpCells2),
  append(TmpCells, TmpCells2, TmpCells3),
  sort(TmpCells3, Cells).

% P13 minJogadas(+, +, -)
minJogadas(Row, Col, Row, Col, 0).
minJogadas(InitR, InitC, EndR, EndC, N) :-
    minAux(InitR/InitC, EndR/EndC, 0, N).

minAux(IR/IC, ER/EC, Counter, N):-
    podeMoverEmN(IR/IC, Counter, Cells),
    member(ER/EC, Cells), !,
    N is Counter.
% P13 by Damas TM - blame him on the performance