import pytest
import os
import time
from helpers.cluster import ClickHouseCluster
from helpers.client import QueryTimeoutExceedException
from helpers.test_tools import assert_eq_with_retry

SCRIPT_DIR = os.path.dirname(os.path.realpath(__file__))
DICTIONARY_FILES = ['configs/dictionaries/cache_xypairs.xml', 'configs/dictionaries/executable.xml', 'configs/dictionaries/file.xml', 'configs/dictionaries/file.txt', 'configs/dictionaries/slow.xml']

cluster = ClickHouseCluster(__file__, base_configs_dir=os.path.join(SCRIPT_DIR, 'configs'))
instance = cluster.add_instance('instance', main_configs=DICTIONARY_FILES)


@pytest.fixture(scope="module")
def started_cluster():
    try:
        cluster.start()
        instance.query("CREATE DATABASE IF NOT EXISTS test")

        yield cluster

    finally:
        cluster.shutdown()


def get_status(dictionary_name):
    return instance.query("SELECT status FROM system.dictionaries WHERE name='" + dictionary_name + "'").rstrip("\n")


def get_last_exception(dictionary_name):
    return instance.query("SELECT last_exception FROM system.dictionaries WHERE name='" + dictionary_name + "'").rstrip("\n").replace("\\'", "'")


def get_loading_start_time(dictionary_name):
    s = instance.query("SELECT toTimeZone(loading_start_time, 'UTC') FROM system.dictionaries WHERE name='" + dictionary_name + "'").rstrip("\n")
    if s == "1970-01-01 00:00:00":
        return None
    return time.strptime(s, "%Y-%m-%d %H:%M:%S")

def get_last_successful_update_time(dictionary_name):
    s = instance.query("SELECT toTimeZone(last_successful_update_time, 'UTC') FROM system.dictionaries WHERE name='" + dictionary_name + "'").rstrip("\n")
    if s == "1970-01-01 00:00:00":
        return None
    return time.strptime(s, "%Y-%m-%d %H:%M:%S")


def get_loading_duration(dictionary_name):
    return float(instance.query("SELECT loading_duration FROM system.dictionaries WHERE name='" + dictionary_name + "'"))


def replace_in_file_in_container(file_name, what, replace_with):
    instance.exec_in_container('sed -i "s/' + what + '/' + replace_with + '/g" ' + file_name)


def test_reload_while_loading(started_cluster):
    query = instance.query

    # dictionaries_lazy_load == false, so this dictionary is not loaded.
    assert get_status('slow') == "NOT_LOADED"
    assert get_loading_duration('slow') == 0

    # It's not possible to get a value from the dictionary within 0.5 second, so the following query fails by timeout.
    with pytest.raises(QueryTimeoutExceedException):
        query("SELECT dictGetInt32('slow', 'a', toUInt64(5))", timeout = 0.5)

    # The dictionary is now loading.
    assert get_status('slow') == "LOADING"
    start_time, duration = get_loading_start_time('slow'), get_loading_duration('slow')
    assert duration > 0

    time.sleep(0.5) # Still loading.
    assert get_status('slow') == "LOADING"
    prev_start_time, prev_duration = start_time, duration
    start_time, duration = get_loading_start_time('slow'), get_loading_duration('slow')
    assert start_time == prev_start_time
    assert duration >= prev_duration

    # SYSTEM RELOAD DICTIONARY should restart loading.
    with pytest.raises(QueryTimeoutExceedException):
        query("SYSTEM RELOAD DICTIONARY 'slow'", timeout = 0.5)
    assert get_status('slow') == "LOADING"
    prev_start_time, prev_duration = start_time, duration
    start_time, duration = get_loading_start_time('slow'), get_loading_duration('slow')
    assert start_time > prev_start_time
    assert duration < prev_duration

    time.sleep(0.5) # Still loading.
    assert get_status('slow') == "LOADING"
    prev_start_time, prev_duration = start_time, duration
    start_time, duration = get_loading_start_time('slow'), get_loading_duration('slow')
    assert start_time == prev_start_time
    assert duration >= prev_duration

    # Changing the configuration file should restart loading again.
    replace_in_file_in_container('/etc/clickhouse-server/config.d/slow.xml', 'sleep 100', 'sleep 0')
    time.sleep(5) # Configuration files are reloaded once in 5 seconds.

    # This time loading should finish quickly.
    assert get_status('slow') == "LOADED"

    last_successful_update_time = get_last_successful_update_time('slow')
    assert last_successful_update_time > start_time
    assert query("SELECT dictGetInt32('slow', 'a', toUInt64(5))") == "6\n"


def test_reload_after_loading(started_cluster):
    query = instance.query

    assert query("SELECT dictGetInt32('executable', 'a', toUInt64(7))") == "8\n"
    assert query("SELECT dictGetInt32('file', 'a', toUInt64(9))") == "10\n"

    # Change the dictionaries' data.
    # FIXME we sleep before this, because Poco 1.x has one-second granularity
    # for mtime, and clickhouse will miss the update if we change the file too
    # soon. Should probably be fixed by switching to use std::filesystem.
    time.sleep(1)
    replace_in_file_in_container('/etc/clickhouse-server/config.d/executable.xml', '8', '81')
    replace_in_file_in_container('/etc/clickhouse-server/config.d/file.txt', '10', '101')

    # SYSTEM RELOAD 'name' reloads only the specified dictionary.
    query("SYSTEM RELOAD DICTIONARY 'executable'")
    assert query("SELECT dictGetInt32('executable', 'a', toUInt64(7))") == "81\n"
    assert query("SELECT dictGetInt32('file', 'a', toUInt64(9))") == "10\n"

    query("SYSTEM RELOAD DICTIONARY 'file'")
    assert query("SELECT dictGetInt32('executable', 'a', toUInt64(7))") == "81\n"
    assert query("SELECT dictGetInt32('file', 'a', toUInt64(9))") == "101\n"

    # SYSTEM RELOAD DICTIONARIES reloads all loaded dictionaries.
    time.sleep(1) # see the comment above
    replace_in_file_in_container('/etc/clickhouse-server/config.d/executable.xml', '81', '82')
    replace_in_file_in_container('/etc/clickhouse-server/config.d/file.txt', '101', '102')
    query("SYSTEM RELOAD DICTIONARIES")
    assert query("SELECT dictGetInt32('executable', 'a', toUInt64(7))") == "82\n"
    assert query("SELECT dictGetInt32('file', 'a', toUInt64(9))") == "102\n"

    # Configuration files are reloaded and lifetimes are checked automatically once in 5 seconds.
    # Wait slightly more, to be sure it did reload.
    time.sleep(1) # see the comment above
    replace_in_file_in_container('/etc/clickhouse-server/config.d/executable.xml', '82', '83')
    replace_in_file_in_container('/etc/clickhouse-server/config.d/file.txt', '102', '103')
    time.sleep(7)
    assert query("SELECT dictGetInt32('file', 'a', toUInt64(9))") == "103\n"
    assert query("SELECT dictGetInt32('executable', 'a', toUInt64(7))") == "83\n"


def test_reload_after_fail_by_system_reload(started_cluster):
    query = instance.query

    # dictionaries_lazy_load == false, so this dictionary is not loaded.
    assert get_status("no_file") == "NOT_LOADED"

    # We expect an error because the file source doesn't exist.
    no_such_file_error = "No such file"
    assert no_such_file_error in instance.query_and_get_error("SELECT dictGetInt32('no_file', 'a', toUInt64(9))")
    assert get_status("no_file") == "FAILED"

    # SYSTEM RELOAD should not change anything now, the status is still FAILED.
    assert no_such_file_error in instance.query_and_get_error("SYSTEM RELOAD DICTIONARY 'no_file'")
    assert no_such_file_error in instance.query_and_get_error("SELECT dictGetInt32('no_file', 'a', toUInt64(9))")
    assert get_status("no_file") == "FAILED"

    # Creating the file source makes the dictionary able to load.
    instance.copy_file_to_container(os.path.join(SCRIPT_DIR, "configs/dictionaries/file.txt"), "/etc/clickhouse-server/config.d/no_file.txt")
    query("SYSTEM RELOAD DICTIONARY 'no_file'")
    query("SELECT dictGetInt32('no_file', 'a', toUInt64(9))") == "10\n"
    assert get_status("no_file") == "LOADED"

    # Removing the file source should not spoil the loaded dictionary.
    instance.exec_in_container("rm /etc/clickhouse-server/config.d/no_file.txt")
    assert no_such_file_error in instance.query_and_get_error("SYSTEM RELOAD DICTIONARY 'no_file'")
    query("SELECT dictGetInt32('no_file', 'a', toUInt64(9))") == "10\n"
    assert get_status("no_file") == "LOADED"


def test_reload_after_fail_by_timer(started_cluster):
    query = instance.query

    # dictionaries_lazy_load == false, so this dictionary is not loaded.
    assert get_status("no_file_2") == "NOT_LOADED"

    # We expect an error because the file source doesn't exist.
    expected_error = "No such file"
    assert expected_error in instance.query_and_get_error("SELECT dictGetInt32('no_file_2', 'a', toUInt64(9))")
    assert get_status("no_file_2") == "FAILED"

    # Passed time should not change anything now, the status is still FAILED.
    time.sleep(6);
    assert expected_error in instance.query_and_get_error("SELECT dictGetInt32('no_file_2', 'a', toUInt64(9))")
    assert get_status("no_file_2") == "FAILED"

    # Creating the file source makes the dictionary able to load.
    instance.copy_file_to_container(os.path.join(SCRIPT_DIR, "configs/dictionaries/file.txt"), "/etc/clickhouse-server/config.d/no_file_2.txt")
    time.sleep(6);
    query("SELECT dictGetInt32('no_file_2', 'a', toUInt64(9))") == "10\n"
    assert get_status("no_file_2") == "LOADED"

    # Removing the file source should not spoil the loaded dictionary.
    instance.exec_in_container("rm /etc/clickhouse-server/config.d/no_file_2.txt")
    time.sleep(6);
    query("SELECT dictGetInt32('no_file_2', 'a', toUInt64(9))") == "10\n"
    assert get_status("no_file_2") == "LOADED"


def test_reload_after_fail_in_cache_dictionary(started_cluster):
    query = instance.query
    query_and_get_error = instance.query_and_get_error

    # Can't get a value from the cache dictionary because the source (table `test.xypairs`) doesn't respond.
    expected_error = "Table test.xypairs doesn't exist"
    assert expected_error in query_and_get_error("SELECT dictGetUInt64('cache_xypairs', 'y', toUInt64(1))")
    assert get_status("cache_xypairs") == "LOADED"
    assert expected_error in get_last_exception("cache_xypairs")

    # Create table `test.xypairs`.
    query('''
        DROP TABLE IF EXISTS test.xypairs;
        CREATE TABLE test.xypairs (x UInt64, y UInt64) ENGINE=Log;
        INSERT INTO test.xypairs VALUES (1, 56), (3, 78);
        ''')

    # Cache dictionary now works.
    assert_eq_with_retry(instance, "SELECT dictGet('cache_xypairs', 'y', toUInt64(1))", "56", ignore_error=True)
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(2))") == "0"
    assert get_last_exception("cache_xypairs") == ""

    # Drop table `test.xypairs`.
    query('DROP TABLE test.xypairs')

    # Values are cached so we can get them.
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(1))") == "56"
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(2))") == "0"
    assert get_last_exception("cache_xypairs") == ""

    # But we can't get a value from the source table which isn't cached.
    assert expected_error in query_and_get_error("SELECT dictGetUInt64('cache_xypairs', 'y', toUInt64(3))")
    assert expected_error in get_last_exception("cache_xypairs")

    # Passed time should not spoil the cache.
    time.sleep(5);
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(1))") == "56"
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(2))") == "0"
    assert expected_error in query_and_get_error("SELECT dictGetUInt64('cache_xypairs', 'y', toUInt64(3))")
    assert expected_error in get_last_exception("cache_xypairs")

    # Create table `test.xypairs` again with changed values.
    query('''
        CREATE TABLE test.xypairs (x UInt64, y UInt64) ENGINE=Log;
        INSERT INTO test.xypairs VALUES (1, 57), (3, 79);
        ''')

    # The cache dictionary returns new values now.
    assert_eq_with_retry(instance, "SELECT dictGet('cache_xypairs', 'y', toUInt64(1))", "57")
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(2))") == "0"
    query("SELECT dictGet('cache_xypairs', 'y', toUInt64(3))") == "79"
    assert get_last_exception("cache_xypairs") == ""