/* MicroWatson 2015 */

'Some nigga':-
    write('232').


micro_watson:-
    write('1. Novels/Films of the 20th Century'),nl,
    write('2. Novels of the 19th Century'),nl,
    write('3. Novels of the 18th Century'),nl,
    write('Please enter a category number!'),nl,
    read(Category),
        (Category == 1 -> micro_watson2; write('Goodbye')).

micro_watson2:-
    write('Please give me an answer.'),nl,
    write('micro_watson: '),
        read(Sentence),
    sentence(Sentence,Output),
    write(Output),
        parse(Sentence,_,TargetList),
        write(TargetList).

sentence(Sentence,sentence(np(Noun_Phrase),vp(Verb_Phrase))):-
    /* so take a sentence (first arg) and parse it into a noun phrase and a verb phase */
    np(Sentence,Noun_Phrase,Rem),
    write(Noun_Phrase),nl,
    vp(Rem,Verb_Phrase),
    write(Verb_Phrase),nl.

/* NP -> Det NP2 */
np([X|T],np(det(X),NP2),Rem):-
    det(X),
    np2(T,NP2,Rem).

/* NP -> NP2 */
np(Sentence,Parse,Rem):- np2(Sentence,Parse,Rem).

/* NP -> NP PP */
np(Sentence,np(NP,PP),Rem):-
    np(Sentence,NP,Rem1),
    pp(Rem1,PP,Rem).

/* NP2 -> Noun */
np2([H|T],np2(noun(H)),T):- noun(H).

/* NP2 -> Adj NP2 */
np2([H|T],np2(adj(H),Rest),Rem):- adj(H),np2(T,Rest,Rem).

/* PP -> Prep NP */
pp([H|T],pp(prep(H),Parse),Rem):-
    prep(H),
    np(T,Parse,Rem).

/* VP -> Verb */
vp([H|[]],verb(H)):-verb(H).

/* VP -> Verb Adverb NP */
vp([H|[T|Rest]],vp(verb(H),adverb(T),RestParsed)):-
    verb(H),adverb(T),
    np(Rest,RestParsed,_).

/* Vp -> Verb Adverb */
vp([H|[T]],verb(H)):-adverb(T).

/* Vp -> Verb NP */
vp([H|Rest],vp(verb(H),RestParsed)):-
    verb(H),
    pp(Rest,RestParsed,_).

/* Vp -> Verb PP */
vp([H|Rest],vp(verb(H),RestParsed)):-
    verb(H),
    np(Rest,RestParsed,_).

/* extracting SOV */
parse(Sentence,VP_List,TargetList):-
    parse_SOV(Sentence,VP_List,TargetList).

parse_SOV(Sentence,VP_List,TargetList):-
    /* Grab the first noun from the sentence and assume it is the subject */
    member(Subject,Sentence),
    noun(Subject),
    /* Grab the first noun from the verb phrase and assume it is the object */
    member(Object,VP_List),
    noun(Object),
    /* Grab the verb from the verb phrase */
    member(Verb,VP_List),
    verb(Verb),
    nl,
    TargetList = parse_sov(subject(Subject),object(Object),verb(Verb)).


/* dictionary */
det(a).
det(the).
adj(young).
adj(middle_aged).
adj(magic).
adj(faithful).
adj(paranoid).
prep(on).
prep(by).
verb(finds).
verb(destroys).
verb(saves).
verb(is).
noun(expelled).
noun(hobbit).
noun(ring).
noun(valet).
noun(butler).
noun(robot).
noun(day).
noun(holden).
noun(marvin).
adverb(quietly).