# coding=utf-8

from operator import itemgetter
import prolog.engine
import server.problems

id = 107
number = 14
visible = True
facts = None

solution = '''\
del107(X, [X|T], T).
del107(X, [Y|T], [Y|L]) :-
  del107(X, T, L).
permute([], []).
permute(L, [X|P]) :-
  del107(X, L, L1),
  permute(L1, P).
'''

test_cases = [
    ('permute([], X)',
        [{'X': '[]'}]),
    ('permute([a, i, o, e], [i, X, o, e])',
        [{'X': 'a'}]),
    ('setof(L, permute([e, b, l], L), X)',
        [{'X': '[[b, e, l], [b, l, e], [e, b, l], [e, l, b], [l, b, e], [l, e, b]]'}]),
]

def test(program, solved_problems):
    code = (program + '\n' +
            server.problems.solutions_for_problems('prolog', solved_problems))

    n_correct = 0
    engine_id = None
    try:
        engine_id, output = prolog.engine.create(code=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
    finally:
        if engine_id:
            prolog.engine.destroy(engine_id)

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

def hint(program, solved_problems):
    # TODO
    return []