# coding=utf-8

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

id = 106
number = 13
visible = True
facts = None

solution = '''\
del106(X, [X|T], T).
del106(X, [Y|T], [Y|L]) :-
  del106(X, T, L).
insert(X, List, BigList) :-
  del106(X, BigList, List).
'''

test_cases = [
    ('insert(l, [], X)',
        [{'X': '[l]'}]),
    ('insert(X, [h, t, w, j], [A, B, C, D, z])',
        [{'A': 'h', 'B': 't', 'C': 'w', 'D': 'j', 'X': 'z'}]),
    ('insert(i, [A, j], [c, X, j])',
        [{'A': 'c', 'X': 'i'}]),
]

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 []