from operator import itemgetter
import socket

import prolog.engine
from server.hints import Hint, HintPopup

id = 124
number = 50
visible = True
facts = None

solution = '''\
pivoting(_, [], [], []).
pivoting(P, [H|T], [H|S], G) :-
  H =< P,
  pivoting(P, T, S, G).
pivoting(P, [H|T], S, [H|G]) :-
  H > P,
  pivoting(P, T, S, G).
'''

hint_type = {
    'eq_instead_of_equ_markup': HintPopup('eq_instead_of_equ_markup'),
    'eq_instead_of_equ': Hint('eq_instead_of_equ'),
    'predicate_always_false': Hint('predicate_always_false'),
    'base_case': Hint('base_case'),
    'recursive_case': Hint('recursive_case'),
    'timeout': Hint('timeout'),
    '>_and_<_mixed_up': Hint('>_and_<_mixed_up'),
    'duplicates_not_considered': Hint('duplicates_not_considered'),
    'all_elements_in_either_S_or_G': Hint('all_elements_in_either_S_or_G'),
    'arbitrary_solution': Hint('arbitrary_solution'),
    'unprotected_branch': Hint('unprotected_branch'),
    'forcing_result_onto_recursion': Hint('forcing_result_onto_recursion'),
    'no_recursion_in_one_branch': Hint('no_recursion_in_one_branch'),
}

test_cases = [
    ('pivoting(5, [], A, B)',
        [{'A': '[]', 'B': '[]'}]),
    ('pivoting(5, [6, 7, 6], A, B), msort(B, BS)',
        [{'A': '[]', 'BS': '[6, 6, 7]'}]),
    ('pivoting(4, [2, 1, 8, 9, 3, 4, 2], A, B), msort(A, AS), msort(B, BS)',
        [{'AS': '[1, 2, 2, 3, 4]', 'BS': '[8, 9]'}]),
    ('pivoting(4, [22, 1, 0, 8, 3, 5, 7, -2], A, B), msort(A, AS), msort(B, BS)',
        [{'AS': '[-2, 0, 1, 3]', 'BS': '[5, 7, 8, 22]'}]),
]

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)

        # strict equality testing instead of simple matching
        # this is usually (but not necessarily) wrong
        targets = [prolog.util.Token('EQ', '==')]
        marks = [(t.pos, t.pos + len(t.val)) for t in tokens if t in targets]
        if marks:
            return [{'id': 'eq_instead_of_equ_markup', 'start': m[0], 'end': m[1]} for m in marks] + \
                   [{'id': 'eq_instead_of_equ'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                pivoting(4, [3, 5, 9, 6, 3, 7, 2], A, B),
                msort(A, [5, 6, 7, 9]),
                msort(B, [2, 3, 3])'''):
            return [{'id': '>_and_<_mixed_up'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                pivoting(4, [2, 1, 3], [2, 1, 3], []),
                pivoting(4, [3, 5, 9, 5, 2], [3 | yowza], [5 | brix])
                ;
                pivoting(4, [6, 5, 7], [], [6, 5, 7]),
                pivoting(4, [3, 5, 9, 5, 2], [3 | yowza], [5 | brix])'''):
            return [{'id': 'no_recursion_in_one_branch'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                pivoting(4, [3, 5, 9, 6, 3, 7, 2], [3, 3, 2], [5, 9, 6, 7]),
                findall(q, pivoting(4, [3, 5, 9, 6, 3, 7, 2], _, _), [q, q | _])'''):
            return [{'id': 'unprotected_branch'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                pivoting(4, [3, 5, 9, 5, 2], [3, 2], [5, 9, 5]),
                \+ pivoting(4, [3, 5, 4, 5, 2], _, _)'''):
            return [{'id': 'duplicates_not_considered'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                pivoting(4, [5, 3], _, [5|yowza])
                ;
                pivoting(4, [3, 5], [3|yowza], _)'''):
            return [{'id': 'arbitrary_solution'}]

        if prolog.engine.ask_truthTO(engine_id,
                'pivoting(4, [3, 5, 9, 5, 2], S, G), (S = [] ; G = [])'):
            return [{'id': 'all_elements_in_either_S_or_G'}]

        if prolog.engine.ask_truthTO(engine_id, '''\
                \+ pivoting(4, [3, 5], _, _),
                (asserta(pivoting(4, [5], [3, 5], [yowza])),
                 pivoting(4, [3, 5], [5], [yowza]),
                 retract(pivoting(4, [5], [3, 5], [yowza]))
                 ;
                 asserta(pivoting(4, [3], [yowza], [5, 3])),
                 pivoting(4, [5, 3], [yowza], [3]),
                 retract(pivoting(4, [3], [yowza], [5, 3])))'''):
            return [{'id': 'forcing_result_onto_recursion'}]

        # missing/failed base case
        if not prolog.engine.ask_truthTO(engine_id, 'pivoting(_, [], [], [])'):
            return [{'id': 'base_case'}]

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

        # base case works, the recursive doesn't (but it doesn't timeout)
        # this may be left as the last, most generic hint
        if not prolog.engine.ask_truth(engine_id,
                'pivoting(4, [2, 1, 8, 9, 3, 4, 2], [2, 1, 3, 4, 2], [8, 9])'):
            return [{'id': 'recursive_case'}]

    except socket.timeout as ex:
        return [{'id': 'timeout'}]

    finally:
        if engine_id:
            prolog.engine.destroy(engine_id)

    return []