import pytest

from helpers.cluster import ClickHouseCluster

cluster = ClickHouseCluster(__file__)

node = cluster.add_instance('node', main_configs=['configs/global_overcommit_tracker.xml'])

@pytest.fixture(scope='module', autouse=True)
def start_cluster():
    try:
        cluster.start()
        yield cluster
    finally:
        cluster.shutdown()

TEST_QUERY_A = 'SELECT number FROM numbers(1000) GROUP BY number SETTINGS max_guaranteed_memory_usage_for_user=1'
TEST_QUERY_B = 'SELECT number FROM numbers(1000) GROUP BY number SETTINGS max_guaranteed_memory_usage_for_user=2'

def test_overcommited_is_killed():
    node.query("CREATE USER A")
    node.query("GRANT ALL ON *.* TO A")
    node.query("CREATE USER B")
    node.query("GRANT ALL ON *.* TO B")

    responses_A = list()
    responses_B = list()
    for _ in range(100):
        responses_A.append(node.get_query_request(TEST_QUERY_A, user="A"))
        responses_B.append(node.get_query_request(TEST_QUERY_B, user="B"))

    overcommited_killed = False
    for response in responses_A:
        _, err = response.get_answer_and_error()
        if "MEMORY_LIMIT_EXCEEDED" in err:
            overcommited_killed = True
    finished = False
    for response in responses_B:
        _, err = response.get_answer_and_error()
        if err == "":
            finished = True

    assert overcommited_killed and finished, "no overcommited task was killed or all tasks are killed"

    node.query("DROP USER IF EXISTS A")
    node.query("DROP USER IF EXISTS B")