import random

import pytest

from helpers.cluster import ClickHouseCluster
from helpers.test_tools import TSV

cluster = ClickHouseCluster(__file__)

main_configs = [
    "configs/backups_disk.xml",
    "configs/cluster_different_versions.xml",
]

user_configs = []

new_node = cluster.add_instance(
    "new_node",
    main_configs=main_configs,
    user_configs=user_configs,
    external_dirs=["/backups/"],
    macros={"replica": "new_node", "shard": "shard1"},
    with_zookeeper=True,
)

old_node = cluster.add_instance(
    "old_node",
    image="clickhouse/clickhouse-server",
    tag="24.9.2.42",
    with_installed_binary=True,
    main_configs=main_configs,
    user_configs=user_configs,
    external_dirs=["/backups/"],
    macros={"replica": "old_node", "shard": "shard1"},
    with_zookeeper=True,
)

nodes = [new_node, old_node]


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


@pytest.fixture(autouse=True)
def cleanup_after_test():
    try:
        yield
    finally:
        new_node.query("DROP TABLE IF EXISTS tbl ON CLUSTER 'cluster_ver' SYNC")


backup_id_counter = 0


def new_backup_name():
    global backup_id_counter
    backup_id_counter += 1
    return f"Disk('backups', '{backup_id_counter}')"


# Gets a printable version the name of a node.
def get_node_name(node):
    return "new_node" if (node == new_node) else "old_node"


# Choose a random instance.
def random_node():
    return random.choice(nodes)


def test_different_versions():
    new_node.query(
        "CREATE TABLE tbl"
        " ON CLUSTER 'cluster_ver'"
        " (x UInt64) ENGINE=ReplicatedMergeTree('/clickhouse/tables/tbl/', '{replica}')"
        " ORDER BY tuple()"
    )

    new_node.query(f"INSERT INTO tbl VALUES (1)")
    old_node.query(f"INSERT INTO tbl VALUES (2)")

    backup_name = new_backup_name()

    initiator = random_node()
    print(f"Using {get_node_name(initiator)} as initiator for BACKUP")
    initiator.query(f"BACKUP TABLE tbl ON CLUSTER 'cluster_ver' TO {backup_name}")

    new_node.query("DROP TABLE tbl ON CLUSTER 'cluster_ver' SYNC")

    initiator = random_node()
    print(f"Using {get_node_name(initiator)} as initiator for RESTORE")
    initiator.query(f"RESTORE TABLE tbl ON CLUSTER 'cluster_ver' FROM {backup_name}")

    new_node.query("SYSTEM SYNC REPLICA ON CLUSTER 'cluster_ver' tbl")
    assert new_node.query("SELECT * FROM tbl ORDER BY x") == TSV([1, 2])
    assert old_node.query("SELECT * FROM tbl ORDER BY x") == TSV([1, 2])

    # Error NO_ELEMENTS_IN_CONFIG is unrelated.
    assert (
        new_node.query(
            "SELECT name, last_error_message FROM system.errors WHERE NOT ("
            "(name == 'NO_ELEMENTS_IN_CONFIG')"
            ")"
        )
        == ""
    )

    # Error FAILED_TO_SYNC_BACKUP_OR_RESTORE: "No connection to host new_node:9000 yet, will retry" is generated by the old version
    # when it fails to connect to other host because that other host hasn't started yet.
    # This is not an error actually, just an exception thrown and caught. The new version doesn't throw this exception.
    assert (
        old_node.query(
            "SELECT name, last_error_message FROM system.errors WHERE NOT ("
            "(name == 'NO_ELEMENTS_IN_CONFIG') OR"
            "((name == 'FAILED_TO_SYNC_BACKUP_OR_RESTORE') AND (last_error_message == 'No connection to host new_node:9000 yet, will retry'))"
            ")"
        )
        == ""
    )