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

id = 95
number = 3
visible = True
facts = 'family_relations'

solution = '''\
grandparent(X, Y) :-
  parent(X, Z),
  parent(Z, Y).
'''

hint_type = {
    'no_common_z': Hint('no_common_z'),
    'gender_is_irrelevant_markup': HintPopup('gender_is_irrelevant_markup'),
    'gender_is_irrelevant': Hint('gender_is_irrelevant'),
    'or_instead_of_and': Hint('or_instead_of_and'),
    'x_must_be_parent': Hint('x_must_be_parent'),
    'x_need_not_have_parent': Hint('x_need_not_have_parent'),
    'y_must_have_parent': Hint('y_must_have_parent'),
    'y_need_not_be_parent': Hint('y_need_not_be_parent'),
    'predicate_always_false': Hint('predicate_always_false'),
}

test_cases = [
    ('grandparent(X, _)',
        [{'X': 'aleksandr'}, {'X': 'ana'}, {'X': 'andrew'}, {'X': 'estelle'}, {'X': 'frank'},
         {'X': 'helen'}, {'X': 'jill'}, {'X': 'margaret'}, {'X': 'morty'}, {'X': 'patricia'},
         {'X': 'sally'}, {'X': 'thomas'}, {'X': 'tina'}, {'X': 'william'}]),
    ('grandparent(_, X)',
        [{'X': 'andrew'}, {'X': 'anna'}, {'X': 'daniela'}, {'X': 'joanne'}, {'X': 'john'},
         {'X': 'kramer'}, {'X': 'luana'}, {'X': 'melanie'}, {'X': 'michael'}, {'X': 'michelle'},
         {'X': 'patricia'}, {'X': 'steve'}, {'X': 'susan'}, {'X': 'vanessa'}]),
    ('grandparent(tina, X)',
        [{'X': 'vanessa'}, {'X': 'patricia'}]),
]

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)

        # TODO: generic hint for:
        # TODO: parent(X, Z1), parent(Z2, Y), Z1 = Z2

        # gender testing is redundant
        # this is not necessarily wrong, but worth mentioning anyway
        targets = [prolog.util.Token('NAME', 'male'), prolog.util.Token('NAME', 'female'),
                   prolog.util.Token('NAME', 'mother'), prolog.util.Token('NAME', 'father')]
        marks = [(t.pos, t.pos + len(t.val)) for t in tokens if t in targets]
        if marks:
            return [{'id': 'gender_is_irrelevant_markup', 'start': m[0], 'end': m[1]} for m in marks] + \
                   [{'id': 'gender_is_irrelevant'}]

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

        # broken "link" mistake -- no common parent/child Z
        # warning: due to speed considerations this (1024) is knowledge base dependent
        # independent: findall(_, (parent(X, Z1), parent(Z2, Y)), L)
        if prolog.engine.ask_truth(engine_id,
            'findall(_, grandparent(X, Y), L), length(L, 1024)'):
            return [{'id': 'no_common_z'}]

        # 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 (64) is knowledge base dependent
        if prolog.util.Token('SEMI', ';') in tokens and prolog.engine.ask_truth(engine_id,
            'findall(_, grandparent(X, Y), L), length(L, 64)'):
            return [{'id': 'or_instead_of_and'}]

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

        # Y must have a parent
        if prolog.engine.ask_truth(engine_id,
            'grandparent(_, Y), \+ parent(_, Y)'):
            return [{'id': 'y_must_have_parent'}]

        # stop further hint testing if target predicate is always true or always false
        if prolog.engine.ask_truth(engine_id,
            '\+ grandparent(_, _) ; findall(X/Y, grandparent(X, Y), [A/B]), var(A), var(B)'):
            return []

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

        # Y does not necessarily need to be a parent
        if prolog.engine.ask_truth(engine_id, 'grandparent(_, Y)') and \
           prolog.engine.ask_one(engine_id, 'grandparent(_, 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 []