# coding=utf-8

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

id = 115
number = 22
visible = True
facts = None

solution = '''\
divide([], [], []).
divide([X], [X], []).
divide([H1,H2|T], [H1|L1], [H2|L2]) :-
  divide(T, L1, L2).
'''

test_cases = [
    ('divide([], A, B)',
        [{'A': '[]', 'B': '[]'}]),
    ('divide([q], A, B)',
        [{'A': '[q]', 'B': '[]'}]),
    ('divide([h, e, t, y, q, w], A, B)',
        [{'A': '[h, t, q]', 'B': '[e, y, w]'}]),
    ('divide([j, e, y, u, i], A, B)',
        [{'A': '[j, y, i]', 'B': '[e, u]'}]),
    ('divide(A, [t, q, y], [l, e, r])',
        [{'A': '[t, l, q, e, y, r]'}]),
]

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:
                # Limit inferences for each solution to curb unbounded recursion.
                limited = 'call_with_inference_limit(({}), 100000, _)'.format(query)
                if prolog.engine.check_answers(engine_id, query=limited, 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 []