#!/usr/bin/env python3

import os
import random
import string

import pytest
from kazoo.client import KazooClient

import helpers.keeper_utils as keeper_utils
from helpers.cluster import ClickHouseCluster

cluster = ClickHouseCluster(__file__)

# clickhouse itself will use external zookeeper
node = cluster.add_instance(
    "node",
    main_configs=["configs/enable_keeper.xml"],
    stay_alive=True,
)


def random_string(length):
    return "".join(random.choices(string.ascii_lowercase + string.digits, k=length))


def create_random_path(prefix="", depth=1):
    if depth == 0:
        return prefix
    return create_random_path(os.path.join(prefix, random_string(3)), depth - 1)


@pytest.fixture(scope="module")
def started_cluster():
    try:
        cluster.start()

        yield cluster

    finally:
        cluster.shutdown()


def get_connection_zk(nodename, timeout=30.0):
    _fake_zk_instance = KazooClient(
        hosts=cluster.get_instance_ip(nodename) + ":9181", timeout=timeout
    )
    _fake_zk_instance.start()
    return _fake_zk_instance


def restart_clickhouse():
    node.restart_clickhouse(kill=True)
    keeper_utils.wait_until_connected(cluster, node)


def test_state_after_restart(started_cluster):
    keeper_utils.wait_until_connected(started_cluster, node)
    node_zk = None
    node_zk2 = None
    try:
        node_zk = get_connection_zk("node")

        node_zk.create("/test_state_after_restart", b"somevalue")
        strs = []
        for i in range(100):
            strs.append(random_string(123).encode())
            node_zk.create("/test_state_after_restart/node" + str(i), strs[i])

        existing_children = []
        for i in range(100):
            if i % 7 == 0:
                node_zk.delete("/test_state_after_restart/node" + str(i))
            else:
                existing_children.append("node" + str(i))

        restart_clickhouse()

        node_zk2 = get_connection_zk("node")

        assert node_zk2.get("/test_state_after_restart")[0] == b"somevalue"
        for i in range(100):
            if i % 7 == 0:
                assert (
                    node_zk2.exists("/test_state_after_restart/node" + str(i)) is None
                )
            else:
                data, stat = node_zk2.get("/test_state_after_restart/node" + str(i))
                assert len(data) == 123
                assert data == strs[i]
                assert stat.ephemeralOwner == 0

        assert list(sorted(existing_children)) == list(
            sorted(node_zk2.get_children("/test_state_after_restart"))
        )
    finally:
        try:
            if node_zk is not None:
                node_zk.stop()
                node_zk.close()

            if node_zk2 is not None:
                node_zk2.stop()
                node_zk2.close()
        except:
            pass


def test_ephemeral_after_restart(started_cluster):
    keeper_utils.wait_until_connected(started_cluster, node)
    node_zk = None
    node_zk2 = None
    try:
        node_zk = get_connection_zk("node")

        session_id = node_zk._session_id
        node_zk.create("/test_ephemeral_after_restart", b"somevalue")
        strs = []
        for i in range(100):
            strs.append(random_string(123).encode())
            node_zk.create(
                "/test_ephemeral_after_restart/node" + str(i), strs[i], ephemeral=True
            )

        existing_children = []
        for i in range(100):
            if i % 7 == 0:
                node_zk.delete("/test_ephemeral_after_restart/node" + str(i))
            else:
                existing_children.append("node" + str(i))

        restart_clickhouse()

        node_zk2 = get_connection_zk("node")

        assert node_zk2.get("/test_ephemeral_after_restart")[0] == b"somevalue"
        for i in range(100):
            if i % 7 == 0:
                assert (
                    node_zk2.exists("/test_ephemeral_after_restart/node" + str(i))
                    is None
                )
            else:
                data, stat = node_zk2.get("/test_ephemeral_after_restart/node" + str(i))
                assert len(data) == 123
                assert data == strs[i]
                assert stat.ephemeralOwner == session_id
        assert list(sorted(existing_children)) == list(
            sorted(node_zk2.get_children("/test_ephemeral_after_restart"))
        )
    finally:
        try:
            if node_zk is not None:
                node_zk.stop()
                node_zk.close()

            if node_zk2 is not None:
                node_zk2.stop()
                node_zk2.close()
        except:
            pass


def test_invalid_snapshot(started_cluster):
    keeper_utils.wait_until_connected(started_cluster, node)
    node_zk = None
    try:
        node_zk = get_connection_zk("node")
        node_zk.create("/test_invalid_snapshot", b"somevalue")
        keeper_utils.send_4lw_cmd(started_cluster, node, "csnp")
        node.stop_clickhouse()
        snapshots = (
            node.exec_in_container(["ls", "/var/lib/clickhouse/coordination/snapshots"])
            .strip()
            .split("\n")
        )

        def snapshot_sort_key(snapshot_name):
            snapshot_prefix_size = len("snapshot_")
            last_log_idx = snapshot_name.split(".")[0][snapshot_prefix_size:]
            return int(last_log_idx)

        snapshots.sort(key=snapshot_sort_key)
        last_snapshot = snapshots[-1]
        node.exec_in_container(
            [
                "truncate",
                "-s",
                "0",
                f"/var/lib/clickhouse/coordination/snapshots/{last_snapshot}",
            ]
        )
        node.start_clickhouse(start_wait_sec=120, expected_to_fail=True)
        assert node.contains_in_log("Failure to load from latest snapshot with index")
        assert node.contains_in_log(
            "Manual intervention is necessary for recovery. Problematic snapshot can be removed but it will lead to data loss"
        )

        node.stop_clickhouse()
        node.exec_in_container(
            [
                "rm",
                f"/var/lib/clickhouse/coordination/snapshots/{last_snapshot}",
            ]
        )
        node.start_clickhouse()
    finally:
        try:
            if node_zk is not None:
                node_zk.stop()
                node_zk.close()
        except:
            pass


def test_snapshot_size(started_cluster):
    keeper_utils.wait_until_connected(started_cluster, node)
    node_zk = None
    try:
        node_zk = get_connection_zk("node")

        node_zk.create("/test_state_size", b"somevalue")
        strs = []
        for i in range(100):
            strs.append(random_string(123).encode())
            node_zk.create("/test_state_size/node" + str(i), strs[i])

        node_zk.stop()
        node_zk.close()

        keeper_utils.send_4lw_cmd(started_cluster, node, "csnp")
        node.wait_for_log_line("Created persistent snapshot")

        def get_snapshot_size():
            return int(
                next(
                    filter(
                        lambda line: "zk_latest_snapshot_size" in line,
                        keeper_utils.send_4lw_cmd(started_cluster, node, "mntr").split(
                            "\n"
                        ),
                    )
                ).split("\t")[1]
            )

        assert get_snapshot_size() != 0
        restart_clickhouse()
        assert get_snapshot_size() != 0
    finally:
        try:
            if node_zk is not None:
                node_zk.stop()
                node_zk.close()

        except:
            pass