# coding=utf-8

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

id = 120
number = 27
visible = True
facts = None

solution = '''\
count(_, [], 0).
count(X, [X|T], N) :-
  count(X, T, NT),
  N is NT + 1.
count(X, [Y|T], NT) :-
  X \== Y,
  count(X, T, NT).
'''

test_cases = [
    ('count(a, [], X)',
        [{'X': '0'}]),
    ('count(r, [a,r,b,c,r], X)',
        [{'X': '2'}]),
    ('count(l, [l,l,l,1,2,3], X)',
        [{'X': '3'}]),
    ('count(z, [a,b,c,z,z], X)',
        [{'X': '2'}]),
]

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 []