# retoor <retoor@molodetz.nl>

from devplacepy.services.nodes.circuit import CLOSED, HALF_OPEN, OPEN, CircuitBreaker


class Clock:
    def __init__(self):
        self.now = 0.0

    def __call__(self):
        return self.now


def make(failures=3, open_seconds=60):
    clock = Clock()
    return CircuitBreaker(failures, open_seconds, clock), clock


def test_unknown_keys_are_closed():
    breaker, _ = make()
    assert breaker.state("x") == CLOSED and breaker.allows("x")


def test_it_opens_at_the_threshold_and_not_before():
    breaker, _ = make(failures=3)
    breaker.failure("x")
    breaker.failure("x")
    assert breaker.allows("x")
    breaker.failure("x")
    assert breaker.state("x") == OPEN and not breaker.allows("x")


def test_a_success_resets_the_streak():
    breaker, _ = make(failures=3)
    breaker.failure("x")
    breaker.failure("x")
    breaker.success("x")
    breaker.failure("x")
    breaker.failure("x")
    assert breaker.allows("x")


def test_it_goes_half_open_after_the_cooldown_and_admits_one_probe():
    breaker, clock = make(failures=1, open_seconds=60)
    breaker.failure("x")
    clock.now = 59
    assert breaker.state("x") == OPEN
    clock.now = 60
    assert breaker.state("x") == HALF_OPEN and breaker.allows("x")
    breaker.begin("x")
    assert not breaker.allows("x")


def test_a_failed_probe_reopens_for_a_full_cooldown():
    breaker, clock = make(failures=1, open_seconds=60)
    breaker.failure("x")
    clock.now = 70
    breaker.begin("x")
    breaker.failure("x")
    assert breaker.state("x") == OPEN
    clock.now = 129
    assert breaker.state("x") == OPEN
    clock.now = 131
    assert breaker.state("x") == HALF_OPEN


def test_a_successful_probe_closes_it():
    breaker, clock = make(failures=1)
    breaker.failure("x")
    clock.now = 100
    breaker.begin("x")
    breaker.success("x")
    assert breaker.state("x") == CLOSED and breaker.allows("x")


def test_keys_are_independent():
    breaker, _ = make(failures=1)
    breaker.failure(("node", "a"))
    assert not breaker.allows(("node", "a"))
    assert breaker.allows(("node", "b"))
    assert breaker.allows(("destination", "a"))


def test_open_count_and_forget():
    breaker, _ = make(failures=1)
    breaker.failure("a")
    breaker.failure("b")
    assert breaker.open_count() == 2
    breaker.forget("a")
    assert breaker.open_count() == 1


def test_a_zero_threshold_still_needs_one_failure():
    breaker = CircuitBreaker(failures=0)
    assert breaker.allows("x")
    breaker.failure("x")
    assert not breaker.allows("x")