from operator import itemgetter
import socket
import prolog.engine
import prolog.util
from server.hints import Hint
import server.problems

id = 94
number = 1
visible = True
facts = 'family_relations'

solution = '''\
mother(X, Y) :-
  parent(X, Y),
  female(X).
'''

hint_type = {
    'or_instead_of_and': Hint('or_instead_of_and'),
    'or_instead_of_and_two_rules': Hint('or_instead_of_and_two_rules'),
    'x_must_be_female': Hint('x_must_be_female'),
    'x_must_be_parent': Hint('x_must_be_parent'),
    'y_can_be_of_any_gender': Hint('y_can_be_of_any_gender'),
    'y_need_not_be_parent': Hint('y_need_not_be_parent'),
    'predicate_always_false': Hint('predicate_always_false'),
}

test_cases = [
    ('mother(X, _)',
        [{'X': 'ana'}, {'X': 'elaine'}, {'X': 'estelle'}, {'X': 'helen'},
         {'X': 'jill'}, {'X': 'joanne'}, {'X': 'margaret'}, {'X': 'nevia'},
         {'X': 'patricia'}, {'X': 'sally'}, {'X': 'tina'}, {'X': 'vanessa'}]),
    ('mother(_, X)',
        [{'X': 'aleksander'}, {'X': 'alessandro'}, {'X': 'andrew'},
         {'X': 'anna'}, {'X': 'daniela'}, {'X': 'george'}, {'X': 'jerry'},
         {'X': 'joanne'}, {'X': 'john'}, {'X': 'kramer'}, {'X': 'luana'},
         {'X': 'melanie'}, {'X': 'nevia'}, {'X': 'steve'}, {'X': 'susan'},
         {'X': 'william'}]),
    ('mother(joanne, X)',
        [{'X': 'steve'}]),
]

def test(code, aux_code):
    n_correct = 0
    engine_id = None
    try:
        engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)
        if engine_id is not None and 'error' not in map(itemgetter(0), output):
            # Engine successfully created, and no syntax error in program.
            for query, answers in test_cases:
                if prolog.engine.check_answers(engine_id, query=query, answers=answers, timeout=1.0):
                    n_correct += 1
    except socket.timeout:
        pass
    finally:
        if engine_id:
            prolog.engine.destroy(engine_id)

    hints = [{'id': 'test_results', 'args': {'passed': n_correct, 'total': len(test_cases)}}]
    return n_correct, len(test_cases), hints

def hint(code, aux_code):
    tokens = prolog.util.tokenize(code)

    try:
        engine_id, output = prolog.engine.create(code=code+aux_code, timeout=1.0)

        # target predicate seems to always be false
        if not prolog.engine.ask_truth(engine_id, 'mother(_, _)'):
            return [{'id': 'predicate_always_false'}]

        # OR (;) instead of AND (,)
        # this hint has to be before the next two
        # as otherwise those two would always override it
        # and not convey the same (amount of) help/information
        # warning: due to speed considerations this (50) is knowledge base dependent
        # independent: findall(_, (parent(X, Y) ; female(X)), L2)
        if prolog.util.Token('SEMI', ';') in tokens and prolog.engine.ask_truth(engine_id,
            'findall(_, mother(X, Y), L), length(L, 50)'):
            return [{'id': 'or_instead_of_and'}]

        # OR instead of AND written with two rules, namely:
        #    (r1) mother(X, Y):- female(X).  (r2) mother(X, Y):- parent(X, Y).
        if prolog.engine.ask_truth(engine_id,
            'findall(_, mother(X, Y), L), length(L, 50)'):
            return [{'id': 'or_instead_of_and_two_rules'}]

        # X must be female
        if prolog.engine.ask_truth(engine_id, 'male(X), mother(X, _)'):
            return [{'id': 'x_must_be_female'}]

        # X must be a parent
        if prolog.engine.ask_truth(engine_id,
            'mother(X, _), \+ parent(X, _)'):
            return [{'id': 'x_must_be_parent'}]

        # Y can be of any gender, incl. male
        if prolog.engine.ask_truth(engine_id, 'mother(_, Y)') and \
           prolog.engine.ask_one(engine_id, 'mother(_, Y), male(Y)') == 'false':
            return [{'id': 'y_can_be_of_any_gender'}]

        # Y does not necessarily need to be a parent
        if prolog.engine.ask_truth(engine_id, 'mother(_, Y)') and \
           prolog.engine.ask_one(engine_id, 'mother(_, Y), \+ parent(Y, _)') == 'false':
            return [{'id': 'y_need_not_be_parent'}]

    except socket.timeout as ex:
        pass

    finally:
        if engine_id:
            prolog.engine.destroy(engine_id)

    return None