Client.cpp

#include <Client.h>
#include <base/defines.h>
#include <Client/ConnectionString.h>
#include <Core/Protocol.h>
#include <Core/Settings.h>

/// musl defines stderr as (stderr) which is a self-referential macro
#pragma clang diagnostic ignored "-Wdisabled-macro-expansion"
#include <boost/algorithm/string/replace.hpp>
#include <boost/program_options.hpp>
#include <Common/Config/parseConnectionCredentials.h>
#include <Common/ThreadPool.h>
#include <Common/ThreadStatus.h>
#include <Common/scope_guard_safe.h>

#include <Access/AccessControl.h>

#include <Columns/ColumnString.h>
#include <Common/Config/ConfigHelper.h>
#include <Common/Config/ConfigProcessor.h>
#include <Common/Config/getClientConfigPath.h>
#include <Common/CurrentThread.h>
#include <Common/DateLUT.h>
#include <Common/DateLUTImpl.h>
#include <Common/DNSResolver.h>
#include <Common/QueryScope.h>
#include <Common/Exception.h>
#include <Common/TerminalSize.h>
#include <Common/config_version.h>
#include <Common/formatReadable.h>

#include <IO/ReadBufferFromString.h>
#include <IO/ReadHelpers.h>
#include <IO/SharedThreadPools.h>
#include <IO/WriteBufferFromOStream.h>
#include <IO/WriteHelpers.h>
#include <Interpreters/Context.h>

#include <Client/JWTProvider.h>
#include <Client/ClientBaseHelpers.h>
#include <Client/PortsProbe.h>
#include <Common/NetException.h>
#include <Core/Defines.h>

#include <AggregateFunctions/registerAggregateFunctions.h>
#include <Formats/FormatFactory.h>
#include <Formats/registerFormats.h>
#include <Functions/registerFunctions.h>

#include <Storages/MergeTree/MergeTreeSettings.h>

#include <Poco/Util/Application.h>
#include <Poco/URI.h>

#include <filesystem>

#include "config.h"

#if USE_BUZZHOUSE
#   include <Client/BuzzHouse/Generator/ExternalIntegrations.h>
#   include <Client/BuzzHouse/Generator/FuzzConfig.h>
#endif

namespace fs = std::filesystem;
using namespace std::literals;


namespace DB
{
namespace Setting
{
extern const SettingsBool use_client_time_zone;
}

namespace ErrorCodes
{
    extern const int BAD_ARGUMENTS;
    extern const int UNKNOWN_PACKET_FROM_SERVER;
    extern const int UNEXPECTED_PACKET_FROM_SERVER;
    extern const int NETWORK_ERROR;
    extern const int SOCKET_TIMEOUT;
    extern const int ATTEMPT_TO_READ_AFTER_EOF;
    extern const int AUTHENTICATION_FAILED;
    extern const int REQUIRED_SECOND_FACTOR;
    extern const int REQUIRED_PASSWORD;
    extern const int USER_EXPIRED;
}

Client::Client()
{
    fuzzer = QueryFuzzer(randomSeed(), &std::cout, &std::cerr);
}


Client::~Client() = default;

void Client::processError(std::string_view query) const
{
    if (server_exception)
    {
        fmt::print(
            stderr,
            "Received exception from server (version {}):\n{}\n",
            server_version,
            getExceptionMessageForLogging(*server_exception, print_stack_trace, true));

        if (server_exception->code() == ErrorCodes::USER_EXPIRED)
        {
            server_exception->rethrow();
        }

        if (is_interactive)
        {
            fmt::print(stderr, "\n");
        }
        else
        {
            fmt::print(stderr, "(query: {})\n", query);
        }
    }

    if (client_exception)
    {
        fmt::print(stderr, "Error on processing query: {}\n", client_exception->message());

        if (is_interactive)
        {
            fmt::print(stderr, "\n");
        }
        else
        {
            fmt::print(stderr, "(query: {})\n", query);
        }
    }

    // A debug check -- at least some exception must be set, if the error
    // flag is set, and vice versa.
    chassert(have_error == (client_exception || server_exception));
}


void Client::showWarnings()
{
    try
    {
        std::vector<String> messages = loadWarningMessages();
        if (!messages.empty())
        {
            output_stream << "Warnings:" << std::endl;
            for (const auto & message : messages)
                output_stream << " * " << message << std::endl;
            output_stream << std::endl;
        }
    }
    catch (const std::exception &) // NOLINT(bugprone-empty-catch)
    {
    }
}

/// Make query to get all server warnings
std::vector<String> Client::loadWarningMessages()
{
    /// Older server versions cannot execute the query loading warnings.
    constexpr UInt64 min_server_revision_to_load_warnings = DBMS_MIN_PROTOCOL_VERSION_WITH_VIEW_IF_PERMITTED;

    if (server_revision < min_server_revision_to_load_warnings)
        return {};

    std::vector<String> messages;

    /// Unlike `\h`, autocomplete and the AI metadata query, this probe is not settings-agnostic: it
    /// reads `system.warnings`, and part of that table is derived from the settings the server sees for
    /// this query - a changed obsolete setting produces a warning of its own. So send what an ordinary
    /// query sends (which also keeps a compatibility-derived value from being serialized as an explicit
    /// change, and thus from tripping a profile that pins it read-only), rather than only the
    /// compression knobs of `networkCompressionSettings`.
    ///
    /// The one setting that has to be overridden is `dialect`: the probe below is ClickHouse SQL, so a
    /// session that switched to another dialect could not parse it. `showWarnings` swallows any
    /// exception from here, so that failure would not be an error the user sees, but server warnings
    /// silently never being displayed.
    ///
    /// The override is unconditional: only changed settings are serialized, so leaving `dialect` alone
    /// when the local value is already `clickhouse` would let the server take the parser from the
    /// effective `dialect` of the authenticated user, which a profile may default to Kusto or PRQL.
    /// Sending the value a user already has is a no-op for setting constraints, so this does not trip a
    /// profile that pins `dialect` as read-only to `clickhouse`.
    Settings probe_settings = settingsWithoutCompatibilityDerived().value_or(client_context->getSettingsRef());
    probe_settings.set("dialect", String("clickhouse"));

    connection->sendQuery(connection_parameters.timeouts,
                          "SELECT * FROM viewIfPermitted(SELECT message FROM system.warnings ELSE null('message String'))",
                          {} /* query_parameters */,
                          "" /* query_id */,
                          QueryProcessingStage::Complete,
                          &probe_settings,
                          &client_context->getClientInfo(), false, {}, {});
    while (true)
    {
        Packet packet = connection->receivePacket();
        switch (packet.type)
        {
            case Protocol::Server::Data:
                if (!packet.block.empty())
                {
                    const ColumnString & column = typeid_cast<const ColumnString &>(*packet.block.getByPosition(0).column);

                    size_t rows = packet.block.rows();
                    for (size_t i = 0; i < rows; ++i)
                        messages.emplace_back(column[i].safeGet<String>());
                }
                continue;

            case Protocol::Server::Progress:
            case Protocol::Server::ProfileInfo:
            case Protocol::Server::Totals:
            case Protocol::Server::Extremes:
            case Protocol::Server::Log:
                continue;

            case Protocol::Server::Exception:
                packet.exception->rethrow();
                return messages;

            case Protocol::Server::EndOfStream:
                return messages;

            case Protocol::Server::ProfileEvents:
                continue;

            default:
                throw Exception(
                    ErrorCodes::UNKNOWN_PACKET_FROM_SERVER, "Unknown packet {} from server {}", packet.type, connection->getDescription());
        }
    }
}


Poco::Util::LayeredConfiguration & Client::getClientConfiguration()
{
    return config();
}

void Client::initialize(Poco::Util::Application & self)
{
    Poco::Util::Application::initialize(self);

    const char * home_path_cstr = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
    if (home_path_cstr)
        home_path = home_path_cstr;

    const char * env_host = getenv("CLICKHOUSE_HOST"); // NOLINT(concurrency-mt-unsafe)

    std::optional<std::string> config_path;
    if (config().has("config-file"))
        config_path.emplace(config().getString("config-file"));
    else
        config_path = getClientConfigPath(home_path);
    if (config_path.has_value())
    {
        ConfigProcessor config_processor(*config_path);
        auto loaded_config = config_processor.loadConfig();
        auto & configuration = *loaded_config.configuration;

        std::string default_host;
        if (!hosts_and_ports.empty())
            default_host = hosts_and_ports.front().host;
        else if (config().has("host"))
            default_host = config().getString("host");
        else if (configuration.has("host"))
            default_host = configuration.getString("host");
        else if (env_host)
            default_host = env_host;
        else
            default_host = "localhost";

        std::optional<std::string> connection_name;
        if (config().has("connection"))
            connection_name.emplace(config().getString("connection"));

        /// Connection credentials overrides should be set via loaded_config.configuration to have proper order.
        auto overrides = parseConnectionsCredentials(configuration, default_host, connection_name);
        if (overrides.hostname.has_value())
            configuration.setString("host", overrides.hostname.value());
        if (overrides.port.has_value())
            configuration.setInt("port", overrides.port.value());
        if (overrides.secure.has_value())
        {
            if (overrides.secure.value())
                configuration.setBool("secure", true);
            else
                configuration.setBool("no-secure", true);
        }
        if (overrides.user.has_value())
            configuration.setString("user", overrides.user.value());
        if (overrides.password.has_value())
            configuration.setString("password", overrides.password.value());
        if (overrides.database.has_value())
            configuration.setString("database", overrides.database.value());
        if (overrides.history_file.has_value())
        {
            auto history_file = overrides.history_file.value();
            if (history_file.starts_with("~/") && !home_path.empty())
                history_file = home_path / history_file.substr(2);
            configuration.setString("history_file", history_file);
        }
        if (overrides.history_max_entries.has_value())
            configuration.setUInt("history_max_entries", overrides.history_max_entries.value());
        if (overrides.accept_invalid_certificate.has_value())
            configuration.setBool("accept-invalid-certificate", overrides.accept_invalid_certificate.value());
        if (overrides.prompt.has_value())
            configuration.setString("prompt", overrides.prompt.value());

        config().add(loaded_config.configuration);

#if USE_JWT_CPP && USE_SSL
        /// If config file has user/password credentials, don't use auto-detected OAuth login for cloud endpoints
        if (login_was_auto_added &&
            (loaded_config.configuration->has("user") || loaded_config.configuration->has("password")))
        {
            /// Config file has auth credentials, so disable the auto-added login flag
            config().setBool("login", false);
        }
#endif
    }
    else if (config().has("connection"))
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "--connection was specified, but config does not exist");

    if (config().has("accept-invalid-certificate"))
    {
        config().setString("openSSL.client.invalidCertificateHandler.name", "AcceptCertificateHandler");
        config().setString("openSSL.client.verificationMode", "none");
    }

    /** getenv is thread-safe in Linux glibc and in all sane libc implementations.
      * But the standard does not guarantee that subsequent calls will not rewrite the value by returned pointer.
      *
      * man getenv:
      *
      * As typically implemented, getenv() returns a pointer to a string within the environment list.
      * The caller must take care not to modify this string, since that would change the environment of
      * the process.
      *
      * The implementation of getenv() is not required to be reentrant. The string pointed to by the return value of getenv()
      * may be statically allocated, and can be modified by a subsequent call to getenv(), putenv(3), setenv(3), or unsetenv(3).
      */

    const char * env_user = getenv("CLICKHOUSE_USER"); // NOLINT(concurrency-mt-unsafe)
    if (env_user && !config().has("user"))
        config().setString("user", env_user);

    const char * env_password = getenv("CLICKHOUSE_PASSWORD"); // NOLINT(concurrency-mt-unsafe)
    if (env_password && !config().has("password"))
        config().setString("password", env_password);

    if (env_host && !config().has("host"))
        config().setString("host", env_host);

    /// settings and limits could be specified in config file, but passed settings has higher priority
    for (const auto & setting : client_context->getSettingsRef().getUnchangedNames())
    {
        String name{setting};
        /// The `format` config key is owned by the client-side `--format` option, which in
        /// `clickhouse-client` is output-only: it is mirrored into the `output_format` setting by
        /// `setDefaultFormatsAndCompressionFromConfiguration` (see `mappedFormatOptionSetting`).
        /// Feeding it into the bidirectional `format` setting here would make `--format` override
        /// the `FORMAT` clause of `INSERT` queries on the input side.
        if (name == "format")
            continue;
        if (config().has(name))
            client_context->setSetting(name, config().getString(name));
    }

    /// Set path for format schema files
    if (config().has("format_schema_path"))
        client_context->setFormatSchemaPath(fs::weakly_canonical(config().getString("format_schema_path")));

    /// Set the path for google proto files
    if (config().has("google_protos_path"))
        client_context->setGoogleProtosPath(fs::weakly_canonical(config().getString("google_protos_path")));

    /// Use <server_client_version_message/> unless --server-client-version-message is specified
    if (!config().has("no-server-client-version-message") && !config().getBool("server_client_version_message", true))
        config().setBool("no-server-client-version-message", true);

    /// Use <warnings/> unless --no-warnings is specified
    if (!config().has("no-warnings") && !config().getBool("warnings", true))
        config().setBool("no-warnings", true);

    /// Use <echo_formatted/>, <echo_query_id/>, <enable_progress_table_toggle/> unless the
    /// corresponding dashed CLI option is specified. Shared with `clickhouse-local`.
    remapClientConfigurationAliases();

    /// The config file is loaded after the command line is processed, so the option parser
    /// never sees values that come only from the file. Validate them now, before any query
    /// can start: a config typo must not fail open (e.g. run a mutating query and only then
    /// throw from a lazy read at the use site).
    validateClientConfiguration();
}


int Client::main(const std::vector<std::string> & /*args*/)
try
{
    setupSignalHandler();

    output_stream << std::fixed << std::setprecision(3);
    error_stream << std::fixed << std::setprecision(3);

    registerFormats();
    registerFunctions();
    registerAggregateFunctions();

    processConfig();
    adjustSettings(client_context);

    initTTYBuffer(
        toProgressOption(config().getString("progress", "default")), toProgressOption(config().getString("progress-table", "default")));
    initKeystrokeInterceptor();

    /// Includes delayed_interactive.
    if (is_interactive)
    {
        clearTerminal();
        showClientVersion();
    }

#if USE_JWT_CPP && USE_SSL
    if (config().getBool("login", false))
    {
        login();
    }
#endif

    bool asked_password = false;
    bool asked_2fa = false;
    for (;;)
    {
        try
        {
            connect();
            break;
        }
        catch (const Exception & e)
        {
            auto code = e.code();

            bool should_ask_password = !asked_password && is_interactive &&
                (code == ErrorCodes::AUTHENTICATION_FAILED || code == ErrorCodes::REQUIRED_PASSWORD) &&
                !config().has("password") && !config().getBool("ask-password", false) &&
                !config().has("ssh-key-file");

            if (should_ask_password)
            {
                asked_password = true;
                config().setBool("ask-password", true);
                preserve_announced_endpoint_for_retry = true;
                continue;
            }

            bool should_ask_2fa = !asked_2fa && (code == ErrorCodes::REQUIRED_SECOND_FACTOR) &&
                (config().getBool("ask-password", false) || is_interactive) && !config().has("one-time-password");

            if (should_ask_2fa)
            {
                asked_2fa = true;
                if (!connection_parameters.password.empty())
                    config().setString("password", connection_parameters.password);
                config().setBool("ask-password", false);
                config().setBool("ask-password-2fa", true);
                preserve_announced_endpoint_for_retry = true;
                continue;
            }

            throw;
        }
    }

    /// Show warnings at the beginning of connection.
    if (is_interactive && !config().has("no-warnings"))
        showWarnings();

    /// Set user password complexity rules
    auto & access_control = client_context->getAccessControl();
    access_control.setPasswordComplexityRules(connection->getPasswordComplexityRules());

    if (is_interactive && !delayed_interactive && !buzz_house)
    {
        runInteractive();
    }
    else
    {
        connection->setDefaultDatabase(connection_parameters.default_database);

        runNonInteractive();

        // If exception code isn't zero, we should return non-zero return
        // code anyway.
        const auto * exception = server_exception ? server_exception.get() : client_exception.get();

        if (exception)
        {
            return static_cast<UInt8>(exception->code()) ? exception->code() : -1;
        }

        if (have_error)
        {
            // Shouldn't be set without an exception, but check it just in
            // case so that at least we don't lose an error.
            return -1;
        }

        if (delayed_interactive)
            runInteractive();
    }

    return 0;
}
catch (Exception & e)
{
    bool need_print_stack_trace = config().getBool("stacktrace", false) && e.code() != ErrorCodes::NETWORK_ERROR;
    std::cerr << getExceptionMessageForLogging(e, need_print_stack_trace, true) << std::endl << std::endl;
    /// If exception code isn't zero, we should return non-zero return code anyway.
    return static_cast<UInt8>(e.code()) ? e.code() : -1;
}
catch (...)
{
    std::cerr << getCurrentExceptionMessage(false) << std::endl;
    return getCurrentExceptionCode();
}

#if USE_JWT_CPP && USE_SSL
void Client::login()
{
    /// `hosts_and_ports` is filled from explicit --host arguments only; the default host is added
    /// later, in `connect`. A host given via config, --connection or the environment is still
    /// sitting in the configuration at this point.
    std::string host = hosts_and_ports.empty()
        ? getClientConfiguration().getString("host", "localhost")
        : hosts_and_ports.front().host;
    std::string auth_url = getClientConfiguration().getString("oauth-url", "");
    std::string client_id = getClientConfiguration().getString("oauth-client-id", "");
    std::string audience = getClientConfiguration().getString("oauth-audience", "");

    if ((auth_url.empty() || client_id.empty()) && !isCloudEndpoint(host))
    {
        throw Exception(
            ErrorCodes::BAD_ARGUMENTS,
            "Could not retrieve authentication endpoints for host '{}'. Please specify --oauth-url and --oauth-client-id if you are "
            "not using ClickHouse Cloud.",
            host);
    }

    jwt_provider = createJwtProvider(auth_url, client_id, audience, host, output_stream, error_stream);
    if (jwt_provider)
    {
        std::string jwt = jwt_provider->getJWT();
        if (!jwt.empty())
        {
            getClientConfiguration().setString("jwt", jwt);
        }
        else
        {
            throw Exception(ErrorCodes::AUTHENTICATION_FAILED, "Login failed. Please check your credentials and try again.");
        }
    }
}
#endif

void Client::connect()
{
    /// Only the immediate password or 2FA retry may reuse the previous announcement. Any later
    /// reconnect is a separate attempt and must announce its endpoint, even if an earlier reconnect failed.
    if (!preserve_announced_endpoint_for_retry)
        announced_endpoint.clear();
    preserve_announced_endpoint_for_retry = false;

    String server_name;
    UInt64 server_version_major = 0;
    UInt64 server_version_minor = 0;
    UInt64 server_version_patch = 0;

    /// Capture the client local time zone before the branch below may switch the process default
    /// to the server time zone. `serverTimezoneInstance()` reads the process default directly and
    /// ignores `session_timezone`; `instance()` would fold in an explicit `--session_timezone` and
    /// cache the wrong zone. `connect()` can run again on reconnect, so only capture once.
    if (client_local_timezone.empty())
        client_local_timezone = DateLUT::serverTimezoneInstance().getTimeZone();

    if (hosts_and_ports.empty())
    {
        String host = config().getString("host", "localhost");
        /// Keep the port unset when the configuration does not specify it: this enables the automatic
        /// choice between the plain and the secure port below.
        std::optional<UInt16> port;
        if (config().has("port"))
            port = static_cast<UInt16>(config().getInt("port"));
        hosts_and_ports.emplace_back(HostAndPort{host, port, {}, {}, false});
    }

    for (size_t attempted_address_index = 0; attempted_address_index < hosts_and_ports.size(); ++attempted_address_index)
    {
        try
        {
            const auto host = ConnectionParameters::Host{hosts_and_ports[attempted_address_index].host};
            const auto database = ConnectionParameters::Database{default_database};

            connection_parameters = ConnectionParameters(
                config(), host, database, hosts_and_ports[attempted_address_index].port);

            /// Reuse the transport that already worked for this address (see below), so that a reconnect
            /// does not have to probe the ports again.
            if (hosts_and_ports[attempted_address_index].secure.has_value())
                connection_parameters.security
                    = *hosts_and_ports[attempted_address_index].secure ? Protocol::Secure::Enable : Protocol::Secure::Disable;

#if USE_JWT_CPP && USE_SSL
            connection_parameters.jwt_provider = jwt_provider;
#endif

            /// Candidate endpoints for the connection, in the order of preference. Normally there is a
            /// single candidate, resolved by `ConnectionParameters`. But when neither the port nor the TLS
            /// mode is specified explicitly, both the plain and the secure default ports are probed
            /// concurrently, and the one that answers first is used, with TLS enabled automatically when
            /// it is the secure one. The probing is concurrent because waiting for a connection attempt to
            /// time out first would take too long (for example, play.clickhouse.com serves TLS on 9440
            /// while the plain port is silently firewalled).
            struct Candidate
            {
                UInt16 port;
                Protocol::Secure security;

                /// The address to start from on this port, if any: the host can resolve to several
                /// addresses, and the connection has to start with the right one, or it pays a whole
                /// connection timeout for every unresponsive address in front of the working one.
                std::optional<Poco::Net::SocketAddress> address;

                /// The connection the probe has established, if it is this candidate that the probe chose.
                /// It is taken over by the `Connection` instead of opening a second one, so that the
                /// automatic choice does not leave a short-lived session on the server for every client
                /// connection. Only the chosen candidate carries it: by the time a fallback candidate is
                /// tried, the first one has spent an unbounded amount of time failing (a TLS handshake can
                /// wait out `handshake_timeout_ms`), and the server drops a connection that has not
                /// finished its handshake within `handshake_timeout_milliseconds`, so a connection the
                /// probe left idle in the meantime is not safe to reuse.
                std::optional<Poco::Net::StreamSocket> socket;
            };

            std::vector<Candidate> candidates;

            const bool port_unspecified = !hosts_and_ports[attempted_address_index].port.has_value() && !config().has("port");
            const bool secure_unspecified = !hosts_and_ports[attempted_address_index].secure.has_value() && !config().has("secure")
                && !config().has("no-secure") && !isCloudEndpoint(host.toUnderType());

            /// Without TLS support in the build there is nothing to choose between: probing the secure port
            /// would only replace a working plain connection with `SUPPORT_IS_DISABLED`, which
            /// `Connection::connect` throws for every secure connection in such a build.
#if USE_SSL
            const bool build_supports_tls = true;
#else
            const bool build_supports_tls = false;
#endif
            const bool detect_transport = port_unspecified && secure_unspecified && build_supports_tls;

            if (detect_transport)
            {
                const auto plain_port = connection_parameters.port;
                const auto secure_port = static_cast<UInt16>(config().getInt("tcp_port_secure", DBMS_DEFAULT_SECURE_PORT));

                /// The addresses of a port are attempted one at a time, this much apart, so that a host
                /// that resolves to several reachable backends is not connected to on all of them at once
                /// (see `probePlainAndSecurePorts`). This is the default of RFC 8305 (Happy Eyeballs).
                static const Poco::Timespan address_attempt_delay(0, 250000);

                PortsProbeResult probe;
                try
                {
                    probe = probePlainAndSecurePorts(
                        connection_parameters.host,
                        connection_parameters.bind_host,
                        plain_port,
                        secure_port,
                        connection_parameters.timeouts.connection_timeout,
                        address_attempt_delay);
                }
                catch (...)
                {
                    /// The probe runs before any `Connection` is created, so it has to drop possibly stale
                    /// DNS cache entries on its own: `Connection::connect` does it for every connect-level
                    /// failure, and without it a later reconnect or failover would reuse the same dead
                    /// addresses instead of resolving the host again.
                    DNSResolver::instance().removeHostFromCache(connection_parameters.host);
                    throw;
                }

                if (probe.endpoint)
                {
                    const bool secure = probe.endpoint->secure;
                    candidates.push_back(
                        {secure ? secure_port : plain_port,
                         secure ? Protocol::Secure::Enable : Protocol::Secure::Disable,
                         probe.endpoint->address,
                         probe.endpoint->socket});

                    /// The port that answered the probe is not necessarily the port that works: the
                    /// connection to it can still fail at the native protocol level, e.g. when a proxy in
                    /// front of the server accepts TCP on the plain port but serves only TLS there, or when
                    /// the certificate of the automatically chosen secure port is not trusted. The other
                    /// port is then worth a try before giving up.
                    ///
                    /// It matters the most for the secure port: TLS was not requested, it was chosen
                    /// automatically, so a secure port that turns out to be unusable must not make the
                    /// client fail. The plain port is what it would have connected to if there were no
                    /// automatic choice at all, so falling back to it takes nothing away from the user. The
                    /// common case is a server whose secure port has a self-signed or otherwise untrusted
                    /// certificate, which every client that does not pass `--accept-invalid-certificate`
                    /// rejects.
                    ///
                    /// The fallback starts from the other port of the address that answered, because the
                    /// same backend is the best guess for where that port is; it keeps the fallback from
                    /// walking the resolved addresses again and paying a whole connection timeout for every
                    /// unresponsive one in front of it.
                    const UInt16 other_port = secure ? plain_port : secure_port;
                    candidates.push_back(
                        {other_port,
                         secure ? Protocol::Secure::Disable : Protocol::Secure::Enable,
                         Poco::Net::SocketAddress(probe.endpoint->address.host(), other_port),
                         {}});
                }
                else
                {
                    /// See above: no connection was made, so the resolved addresses may be stale.
                    DNSResolver::instance().removeHostFromCache(connection_parameters.host);
                    throw NetException(
                        probe.timed_out ? ErrorCodes::SOCKET_TIMEOUT : ErrorCodes::NETWORK_ERROR,
                        "Cannot connect to {} on port {} or on the secure port {}: {}",
                        connection_parameters.host,
                        plain_port,
                        secure_port,
                        probe.failure_reason);
                }
            }
            else
            {
                candidates.push_back(
                    {connection_parameters.port,
                     connection_parameters.security,
                     hosts_and_ports[attempted_address_index].address,
                     {}});
            }

            /// Names a candidate the way the messages below refer to it.
            auto describe = [&](const Candidate & candidate)
            {
                return fmt::format(
                    "{}:{}{}",
                    connection_parameters.host,
                    candidate.port,
                    candidate.security == Protocol::Secure::Enable ? " with TLS" : "");
            };

            /// The failure of the candidate that was tried first, when the connection moved on to the next.
            std::exception_ptr first_error;
            size_t first_error_index = 0;

            for (size_t candidate_index = 0; candidate_index < candidates.size(); ++candidate_index)
            {
                const auto & candidate = candidates[candidate_index];

                connection_parameters.port = candidate.port;
                connection_parameters.security = candidate.security;
                connection_parameters.preferred_address = candidate.address;
                connection_parameters.adopted_socket = candidate.socket;

                const bool secure_auto_detected = secure_unspecified && candidate.security == Protocol::Secure::Enable;

                if (is_interactive)
                {
                    const auto announcement = fmt::format(
                        "Connecting to {}{}:{}{}{}.",
                        connection_parameters.default_database.empty()
                            ? ""
                            : "database " + connection_parameters.default_database + " at ",
                        connection_parameters.host,
                        connection_parameters.port,
                        secure_auto_detected ? " (secure)" : "",
                        connection_parameters.user.empty() ? "" : " as user " + connection_parameters.user);

                    /// The same endpoint can be attempted more than once before the connection is
                    /// established: a server that requires a password rejects the first attempt, and the
                    /// client prompts for the password and attempts the very same endpoint again. Repeating
                    /// the announcement tells the user nothing and reads as if the client had connected
                    /// twice, so announce an endpoint only when it differs from the one announced last.
                    if (announcement != announced_endpoint)
                    {
                        announced_endpoint = announcement;
                        output_stream << announcement << std::endl;
                    }
                }

                try
                {
                    connection = Connection::createConnection(connection_parameters, client_context);
                    /// The connection has taken the probed socket over; do not keep a handle to it here.
                    connection_parameters.adopted_socket.reset();

                    if (max_client_network_bandwidth)
                    {
                        ThrottlerPtr throttler = std::make_shared<Throttler>(max_client_network_bandwidth, 0, "");
                        connection->setThrottler(throttler);
                    }

                    connection->getServerVersion(
                        connection_parameters.timeouts,
                        server_name,
                        server_version_major,
                        server_version_minor,
                        server_version_patch,
                        server_revision);

                    break;
                }
                catch (Exception & e)
                {
                    /// The port accepted the TCP connection, but the connection itself failed: e.g. a proxy
                    /// in front of the server accepts TCP on the plain port but only serves TLS there, or
                    /// the certificate of the automatically chosen secure port is not trusted. Try the other
                    /// port before giving up, but only for connection-level failures.
                    ///
                    /// A TLS-only listener on the plain port answers the native `Hello` with a TLS
                    /// alert record, whose first byte the client reads as an unexpected packet type,
                    /// so `Connection::receiveHello` throws `UNEXPECTED_PACKET_FROM_SERVER`; that is
                    /// the normal outcome of the "plain port serves TLS" case and must be retriable.
                    ///
                    /// A timeout is not retriable, in contrast: a port that accepts the connection and then
                    /// does not answer belongs to a server that is unresponsive rather than to a listener of
                    /// the wrong protocol, and the other port of the same server is not going to answer
                    /// either. Retrying it would double the time the client waits before it reports the
                    /// failure, which is exactly the delay this feature is supposed to avoid.
                    const bool is_connection_error = e.code() == ErrorCodes::NETWORK_ERROR
                        || e.code() == ErrorCodes::ATTEMPT_TO_READ_AFTER_EOF
                        || e.code() == ErrorCodes::UNKNOWN_PACKET_FROM_SERVER
                        || e.code() == ErrorCodes::UNEXPECTED_PACKET_FROM_SERVER;
                    const bool is_transport_error = is_connection_error || e.code() == ErrorCodes::SOCKET_TIMEOUT;

                    if (candidate_index + 1 < candidates.size() && is_connection_error)
                    {
                        first_error = std::current_exception();
                        first_error_index = candidate_index;
                        if (is_interactive)
                            std::cerr << "Connection to " << describe(candidate) << " failed, trying "
                                      << describe(candidates[candidate_index + 1]) << "." << std::endl;
                        continue;
                    }

                    if (first_error && is_transport_error)
                    {
                        /// Both candidates failed at the connection level. Report the failure of the plain
                        /// port as the primary error, whichever order the two were tried in: that is the
                        /// port the client would have used if there were no automatic choice.
                        const auto & other = candidates[first_error_index];
                        auto note = [](const String & endpoint, const String & message)
                        {
                            return fmt::format("(also failed to connect to {}: {})", endpoint, message);
                        };

                        if (candidate.security == Protocol::Secure::Disable)
                        {
                            String first_message;
                            try
                            {
                                std::rethrow_exception(first_error);
                            }
                            catch (Exception & first_e)
                            {
                                first_message = first_e.message();
                            }
                            e.addMessage(note(describe(other), first_message));
                            throw;
                        }

                        const auto message = e.message();
                        try
                        {
                            std::rethrow_exception(first_error);
                        }
                        catch (Exception & first_e)
                        {
                            first_e.addMessage(note(describe(candidate), message));
                            throw;
                        }
                    }

                    throw;
                }
            }

            config().setString("host", connection_parameters.host);

            /// Remember the endpoint that has worked, so that a reconnect to the same address does not
            /// probe the ports again. It is remembered for this address only, and not in the global
            /// configuration: otherwise a failover to another address would be forced to the same port
            /// and the same TLS mode, e.g. a session with `--host secure-only --host plain-only` would
            /// keep connecting to the plain-only address on the secure port after the first address
            /// answered on it.
            hosts_and_ports[attempted_address_index].port = connection_parameters.port;
            hosts_and_ports[attempted_address_index].secure = connection_parameters.security == Protocol::Secure::Enable;
            if (detect_transport)
                hosts_and_ports[attempted_address_index].transport_auto_detected = true;
            if (hosts_and_ports[attempted_address_index].transport_auto_detected)
            {
                /// Remember the address that has answered as well, and not only the port and the TLS mode:
                /// the ports are not probed again on a reconnect, and without the address the connection
                /// would start from the first address of the host once more and pay a whole connection
                /// timeout for every unresponsive address in front of the one that works.
                ///
                /// The address is refreshed after every successful connect, and not only when the ports
                /// were probed: a reconnect can fall through from the remembered address to another
                /// resolved address of the same host when the old one stopped answering, and keeping
                /// the dead address would make every following reconnect wait out a whole connection
                /// timeout on it before falling through to the working one again.
                hosts_and_ports[attempted_address_index].address = assert_cast<Connection &>(*connection).getResolvedAddress();
            }

            settings_from_server = assert_cast<Connection &>(*connection).settingsFromServer();

            break;
        }
        catch (Exception & e)
        {
            /// Forget an automatically chosen transport after a failed connection attempt: it was only
            /// valid for the endpoints this host resolved to when the ports were probed. `Connection::connect`
            /// drops the `DNSResolver` cache entries for the host on a connect-level failure, so the next
            /// attempt can resolve to another backend, e.g. a secure-only backend can be replaced by a
            /// plain-only one; keeping the remembered port, TLS mode and address would make the client
            /// retry the secure port forever and never rediscover the healthy plain port.
            if (hosts_and_ports[attempted_address_index].transport_auto_detected)
            {
                hosts_and_ports[attempted_address_index].port.reset();
                hosts_and_ports[attempted_address_index].secure.reset();
                hosts_and_ports[attempted_address_index].address.reset();
                hosts_and_ports[attempted_address_index].transport_auto_detected = false;
            }

            /// This problem can't be fixed with reconnection so it is not attempted
            if (e.code() == ErrorCodes::AUTHENTICATION_FAILED || e.code() == ErrorCodes::REQUIRED_PASSWORD)
                throw;

            if (attempted_address_index == hosts_and_ports.size() - 1)
                throw;

            if (is_interactive)
            {
                std::cerr << "Connection attempt to database at " << connection_parameters.host << ":" << connection_parameters.port
                          << " resulted in failure" << std::endl
                          << getExceptionMessageForLogging(e, false) << std::endl
                          << "Attempting connection to the next provided address" << std::endl;
            }
        }
    }

    server_version = toString(server_version_major) + "." + toString(server_version_minor) + "." + toString(server_version_patch);
    load_suggestions
        = is_interactive && (server_revision >= Suggest::MIN_SERVER_REVISION) && !config().getBool("disable_suggestion", false);
    wait_for_suggestions_to_load = config().getBool("wait_for_suggestions_to_load", false);
    if (load_suggestions)
    {
        suggestion_limit = config().getInt("suggestion_limit", 10000);
    }

    server_display_name = connection->getServerDisplayName(connection_parameters.timeouts);
    if (server_display_name.empty())
        server_display_name = config().getString("host", "localhost");

    if (is_interactive)
    {
        output_stream << "Connected to " << server_name << " server version " << server_version << "." << std::endl << std::endl;

#if not CLICKHOUSE_CLOUD
        if (!config().has("no-server-client-version-message"))
        {
            auto client_version_tuple = std::make_tuple(VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH);
            auto server_version_tuple = std::make_tuple(server_version_major, server_version_minor, server_version_patch);

            if (client_version_tuple < server_version_tuple)
            {
                output_stream << "ClickHouse client version is older than ClickHouse server. "
                          << "It may lack support for new features." << std::endl
                          << std::endl;
            }
            else if (client_version_tuple > server_version_tuple && server_display_name != "clickhouse-cloud")
            {
                output_stream << "ClickHouse server version is older than ClickHouse client. "
                          << "It may indicate that the server is out of date and can be upgraded." << std::endl
                          << std::endl;
            }
        }
#endif
    }

    if (!client_context->getSettingsRef()[Setting::use_client_time_zone])
    {
        const auto & time_zone = connection->getServerTimezone(connection_parameters.timeouts);
        if (!time_zone.empty())
        {
            try
            {
                DateLUT::setDefaultTimezone(time_zone);
            }
            catch (...)
            {
                std::cerr << "Warning: could not switch to server time zone: " << time_zone
                          << ", reason: " << getCurrentExceptionMessage(/* with_stacktrace = */ false) << std::endl
                          << "Proceeding with local time zone." << std::endl
                          << std::endl;
            }
        }
        else
        {
            std::cerr << "Warning: could not determine server time zone. "
                      << "Proceeding with local time zone." << std::endl
                      << std::endl;
        }
    }

    /// A custom prompt can be specified
    /// - directly (possible as CLI parameter or in client.xml as top-level <prompt>...</prompt> or within client.xml's connection credentials)
    /// - via prompt_by_server_display_name (only possible in client.xml as top-level <prompt>...</prompt>).
    if (config().has("prompt"))
        prompt = config().getString("prompt");
    else if (config().has("prompt_by_server_display_name"))
    {
        if (config().has("prompt_by_server_display_name.default"))
            prompt = config().getRawString("prompt_by_server_display_name.default");

        Strings keys;
        config().keys("prompt_by_server_display_name", keys);
        for (const auto & key : keys)
        {
            if (key != "default" && server_display_name.contains(key))
            {
                prompt = config().getRawString("prompt_by_server_display_name." + key);
                break;
            }
        }
    }
    else
    {
        prompt = "{display_name}";
    }

    /// Prompt may contain escape sequences including \e[ or \x1b[ sequences to set terminal color.
    {
        String prompt_escaped;
        ReadBufferFromString in(prompt);
        readEscapedString(prompt_escaped, in);
        prompt = prompt_escaped;
    }

    /// Substitute placeholders in the form of {name}:
    const std::map<String, String> prompt_substitutions{
        {"host", connection_parameters.host},
        {"port", toString(connection_parameters.port)},
        {"user", connection_parameters.user},
        {"display_name", server_display_name},
    };

    for (const auto & [key, value] : prompt_substitutions)
        boost::replace_all(prompt, "{" + key + "}", value);

    prompt = appendSmileyIfNeeded(prompt);
}

// Prints changed settings to stderr. Useful for debugging fuzzing failures.
void Client::printChangedSettings() const
{
    auto print_changes = [](const auto & changes, std::string_view settings_name)
    {
        if (!changes.empty())
        {
            fmt::print(stderr, "Changed {}: ", settings_name);
            for (size_t i = 0; i < changes.size(); ++i)
            {
                if (i)
                    fmt::print(stderr, ", ");
                fmt::print(stderr, "{} = '{}'", changes[i].name, fieldToString(changes[i].value));
            }

            fmt::print(stderr, "\n");
        }
        else
        {
            fmt::print(stderr, "No changed {}.\n", settings_name);
        }
    };

    print_changes(client_context->getSettingsRef().changes(), "settings");
    print_changes(cmd_merge_tree_settings->changes(), "MergeTree settings");
}


String Client::getHelpHeader() const
{
    return fmt::format(
        "Usage: {0} [--query <query>]\n"
        "{0} is a client application that is used to connect to ClickHouse.\n\n"
        "It can run queries as a command line tool if you pass queries as an argument\n"
        "or as an interactive client.\n"
        "Queries can run one at a time, or in a multiquery mode.\n"
        "To change settings you may use SET statements and SETTINGS clause\n"
        "in queries or set them for a session with corresponding arguments.\n"
        "'{0}' command will try to connect to clickhouse-server running\n"
        "on the same server. If you have credentials set up, pass them with\n"
        "--user <username> --password <password> or with --ask-password argument\n"
        "that will open command prompt.\n\n"
        "Connect to tcp native port (9000) without encryption:\n"
        "    {0} --host clickhouse.example.com --password mysecretpassword\n"
        "Connect to secure endpoint:\n"
        "    {0} --secure --host clickhouse.example.com --password mysecretpassword\n",
        app_name);
}


String Client::getHelpFooter() const
{
    return fmt::format(
        "Note: if clickhouse is installed, you can use 'clickhouse-client' invocation with a dash.\n\n"
        "Example printing current longest running query on a server:\n"
        "    {0} --query \\\n"
        "        'SELECT * FROM system.processes ORDER BY elapsed LIMIT 1 FORMAT Vertical'\n"
        "Example creating table and inserting data:\n"
        "    {0} --multiquery --query \\\n"
        "        'CREATE TABLE t (a Int) ENGINE = Memory; INSERT INTO t VALUES (1), (2), (3)'\n",
        app_name);
}


void Client::printHelpMessage(const OptionsDescription & options_description)
{
    output_stream << getHelpHeader() << "\n";
    if (options_description.main_description.has_value())
        output_stream << options_description.main_description.value() << "\n";
    if (options_description.external_description.has_value())
        output_stream << options_description.external_description.value() << "\n";
    if (options_description.hosts_and_ports_description.has_value())
        output_stream << options_description.hosts_and_ports_description.value() << "\n";

    output_stream << "All settings are documented at https://clickhouse.com/docs/operations/settings/settings.\n";
    output_stream << getHelpFooter() << "\n";
    output_stream << "In addition, --param_name=value can be specified for substitution of parameters for parameterized queries.\n";
    output_stream << "\nSee also: https://clickhouse.com/docs/en/integrations/sql-clients/cli\n";
}


void Client::addExtraOptions(OptionsDescription & options_description)
{
    /// Main commandline options related to client functionality and all parameters from Settings.
    options_description.main_description->add_options()
        ("config,c", po::value<std::string>(), "config-file path (another shorthand)")
        ("connection", po::value<std::string>(), "connection to use (from the client config), by default connection name is hostname")
        ("secure,s", "Use TLS connection")
        ("tls-sni-override", po::value<std::string>(), "Override the SNI host name used for TLS connections")
        ("no-secure", "Don't use TLS connection")
        ("user,u", po::value<std::string>()->default_value("default"), "user")
        ("password", po::value<std::string>(), "password")
        ("ask-password", "ask-password")
        ("ssh-key-file", po::value<std::string>(), "File containing the SSH private key to authenticate with the server. "
            "If the file name is omitted, the key is looked up using SSH configuration: "
            "the identity files configured for this host in `~/.ssh/config`, the default identity files, such as `~/.ssh/id_ed25519`, "
            "and the keys held by the ssh-agent.")
        ("ssh-key-passphrase", po::value<std::string>(), "Passphrase for the SSH private key specified by --ssh-key-file.")
        ("quota_key", po::value<std::string>(), "A string to differentiate quotas when the user have keyed quotas configured on server")
        ("jwt", po::value<std::string>(), "Use JWT for authentication")
        ("one-time-password", po::value<std::string>(), "Time-based one-time password (TOTP) for two-factor authentication")
#if USE_JWT_CPP && USE_SSL
        ("login", po::bool_switch(), "Use OAuth 2.0 to login")
        ("oauth-url", po::value<std::string>(), "The base URL for the OAuth 2.0 authorization server")
        ("oauth-client-id", po::value<std::string>(), "The client ID for the OAuth 2.0 application")
        ("oauth-audience", po::value<std::string>(), "The audience for the OAuth 2.0 token")
#endif
        ("max_client_network_bandwidth",
            po::value<int>(),
            "the maximum speed of data exchange over the network for the client in bytes per second.")
        ("compression",
            po::value<bool>(),
            "enable or disable compression (enabled by default for remote communication and disabled for localhost communication).")
        ("query-fuzzer-runs",
            po::value<int>()->default_value(0),
            "After executing every SELECT query, do random mutations in it and run again specified number of times. This is used for "
            "testing to discover unexpected corner cases.")
        ("create-query-fuzzer-runs", po::value<int>()->default_value(0), "")
        ("buzz-house-config", po::value<std::string>(), "Path to configuration file for BuzzHouse")
        ("interleave-queries-file",
            po::value<std::vector<std::string>>()->multitoken(),
            "file path with queries to execute before every file from 'queries-file'; multiple files can be specified (--queries-file "
            "file1 file2...); this is needed to enable more aggressive fuzzing of newly added tests (see 'query-fuzzer-runs' option)")
        ("opentelemetry-traceparent",
            po::value<std::string>(),
            "OpenTelemetry traceparent header as described by W3C Trace Context recommendation")
        ("opentelemetry-tracestate",
            po::value<std::string>(),
            "OpenTelemetry tracestate header as described by W3C Trace Context recommendation")
        ("no-warnings", "disable warnings when client connects to server")
        ("no-server-client-version-message", "suppress server-client version mismatch message")
        /// TODO: Left for compatibility as it's used in upgrade check, remove after next release and use server setting ignore_drop_queries_probability
        ("fake-drop", "Ignore all DROP queries, should be used only for testing")
        ("accept-invalid-certificate",
            "Ignore certificate verification errors, equal to config parameters "
            "openSSL.client.invalidCertificateHandler.name=AcceptCertificateHandler and openSSL.client.verificationMode=none")
        ("inline-insert-data",
            "Send INSERT data as is in the query text instead of converting it to blocks in the native format. "
            "The server will parse the inline data itself, avoiding the round-trip to receive table structure.");

    /// Commandline options related to external tables.

    options_description.external_description.emplace(createOptionsDescription("External tables options", terminal_width));
    options_description.external_description->add_options()
        ("external", "marks the beginning of a clause. You may have multiple sections like this, for the number of tables being transmitted")
        ("file", po::value<std::string>(), "data file or - for stdin")
        ("name", po::value<std::string>()->default_value("_data"), "name of the table")
        ("format", po::value<std::string>()->default_value("TabSeparated"), "data format")
        ("structure", po::value<std::string>(), "structure")
        ("scalar", "Send as Scalar packet (not Data)")
        ("types", po::value<std::string>(), "types");

    /// Commandline options related to hosts and ports.
    options_description.hosts_and_ports_description.emplace(createOptionsDescription("Hosts and ports options", terminal_width));
    options_description.hosts_and_ports_description->add_options()
        ("host,h", po::value<String>()->default_value("localhost"),
            "Server hostname. Multiple hosts can be passed via multiple arguments"
            "Example of usage: '--host host1 --host host2 --port port2 --host host3 ...'"
            "Each '--port port' will be attached to the last seen host that doesn't have a port yet,"
            "if there is no such host, the port will be attached to the next first host or to default host.")
        ("port", po::value<UInt16>(), "server ports");
}


void Client::processOptions(
    const OptionsDescription & options_description,
    const CommandLineOptions & options,
    const std::vector<Arguments> & external_tables_arguments,
    const std::vector<Arguments> & hosts_and_ports_arguments)
{
    namespace po = boost::program_options;

    size_t number_of_external_tables_with_stdin_source = 0;
    for (size_t i = 0; i < external_tables_arguments.size(); ++i)
    {
        /// Parse commandline options related to external tables.
        po::parsed_options parsed_tables
            = po::command_line_parser(external_tables_arguments[i]).options(options_description.external_description.value()).run();
        po::variables_map external_options;
        po::store(parsed_tables, external_options);

        try
        {
            auto & external_data = external_options.contains("scalar") ? external_scalars : external_tables;
            external_data.emplace_back(external_options);
            if (external_data.back().file == "-")
                ++number_of_external_tables_with_stdin_source;
            if (number_of_external_tables_with_stdin_source > 1)
                throw Exception(ErrorCodes::BAD_ARGUMENTS, "Two or more external tables has stdin (-) set as --file field");
        }
        catch (Exception & e)
        {
            std::cerr << getExceptionMessageForLogging(e, false) << std::endl;
            std::cerr << "Table №" << i << std::endl << std::endl;
            /// Avoid the case when error exit code can possibly overflow to normal (zero).
            auto exit_code = e.code() % 256;
            if (exit_code == 0)
                exit_code = 255;
            _exit(exit_code);
        }
    }

    for (const auto & hosts_and_ports_argument : hosts_and_ports_arguments)
    {
        /// Parse commandline options related to external tables.
        po::parsed_options parsed_hosts_and_ports
            = po::command_line_parser(hosts_and_ports_argument).options(options_description.hosts_and_ports_description.value()).run();
        po::variables_map host_and_port_options;
        po::store(parsed_hosts_and_ports, host_and_port_options);
        std::string host = host_and_port_options["host"].as<std::string>();
        std::optional<UInt16> port
            = !host_and_port_options["port"].empty() ? std::make_optional(host_and_port_options["port"].as<UInt16>()) : std::nullopt;
        hosts_and_ports.emplace_back(HostAndPort{host, port, {}, {}, false});
    }

    send_external_tables = true;

    shared_context = Context::createShared();
    global_context = Context::createGlobal(shared_context.get());
    global_context->makeGlobalContext();
    global_context->setApplicationType(Context::ApplicationType::CLIENT);
    global_context->setSettings(*cmd_settings);

    /// Copy settings-related program options to config.
    /// TODO: Is this code necessary?
    global_context->getSettingsRef().addToClientOptions(config(), options, allow_repeated_settings);

    if (options.contains("config-file") && options.contains("config"))
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Two or more configuration files referenced in arguments");

    if (options.contains("config"))
        config().setString("config-file", options["config"].as<std::string>());
    if (options.contains("connection"))
        config().setString("connection", options["connection"].as<std::string>());
    if (options.contains("interleave-queries-file"))
        interleave_queries_files = options["interleave-queries-file"].as<std::vector<std::string>>();
    if (options.contains("secure"))
        config().setBool("secure", true);
    if (options.contains("tls-sni-override"))
        config().setString("tls-sni-override", options["tls-sni-override"].as<std::string>());
    if (options.contains("no-secure"))
        config().setBool("no-secure", true);
    if (options.contains("user") && !options["user"].defaulted())
        config().setString("user", options["user"].as<std::string>());
    if (options.contains("password"))
        config().setString("password", options["password"].as<std::string>());
    if (options.contains("ask-password"))
        config().setBool("ask-password", true);
    if (options.contains("one-time-password"))
        config().setString("one-time-password", options["one-time-password"].as<std::string>());
    if (options.contains("ssh-key-file"))
        config().setString("ssh-key-file", options["ssh-key-file"].as<std::string>());
    if (options.contains("ssh-key-passphrase"))
        config().setString("ssh-key-passphrase", options["ssh-key-passphrase"].as<std::string>());
    if (options.contains("quota_key"))
        config().setString("quota_key", options["quota_key"].as<std::string>());
    if (options.contains("max_client_network_bandwidth"))
        max_client_network_bandwidth = options["max_client_network_bandwidth"].as<int>();
    if (options.contains("compression"))
        config().setBool("compression", options["compression"].as<bool>());
    if (options.contains("no-warnings"))
        config().setBool("no-warnings", true);
    if (options.contains("no-server-client-version-message"))
        config().setBool("no-server-client-version-message", true);
    if (options.contains("fake-drop"))
        config().setString("ignore_drop_queries_probability", "1");
    if (options.contains("inline-insert-data"))
        config().setBool("inline-insert-data", true);
    if (options.contains("jwt"))
    {
        if (!options["user"].defaulted())
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "User and JWT flags can't be specified together");
        config().setString("jwt", options["jwt"].as<std::string>());
        config().setString("user", "");
    }
#if USE_JWT_CPP && USE_SSL
    if (options["login"].as<bool>())
    {
        if (!options["user"].defaulted())
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "User and login flags can't be specified together");
        if (config().has("jwt"))
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "JWT and login flags can't be specified together");
        config().setBool("login", true);
        config().setString("user", "");
    }
    if (options.contains("oauth-url"))
        config().setString("oauth-url", options["oauth-url"].as<std::string>());
    if (options.contains("oauth-client-id"))
        config().setString("oauth-client-id", options["oauth-client-id"].as<std::string>());
    if (options.contains("oauth-audience"))
        config().setString("oauth-audience", options["oauth-audience"].as<std::string>());
#endif
    if (options.contains("accept-invalid-certificate"))
    {
        config().setString("openSSL.client.invalidCertificateHandler.name", "AcceptCertificateHandler");
        config().setString("openSSL.client.verificationMode", "none");
    }
    else
        config().setString("openSSL.client.invalidCertificateHandler.name", "RejectCertificateHandler");

    query_fuzzer_runs = options["query-fuzzer-runs"].as<int>();
    buzz_house_options_path = options.contains("buzz-house-config") ? options["buzz-house-config"].as<std::string>() : "";
    buzz_house = !query_fuzzer_runs && !buzz_house_options_path.empty();
    if (query_fuzzer_runs || !buzz_house_options_path.empty())
    {
        // Ignore errors in parsing queries.
        config().setBool("ignore-error", true);
        ignore_error = true;
#if USE_BUZZHOUSE
        if (!buzz_house_options_path.empty())
        {
            fuzz_config = std::make_unique<BuzzHouse::FuzzConfig>(this, buzz_house_options_path);
            external_integrations = std::make_unique<BuzzHouse::ExternalIntegrations>(*fuzz_config);

            if (query_fuzzer_runs && fuzz_config->seed)
            {
                fuzzer.setSeed(fuzz_config->seed);
            }
        }
#endif
        if (query_fuzzer_runs)
        {
            fmt::print(stdout, "Using seed {} for AST fuzzer\n", fuzzer.getSeed());
        }
    }

    if ((create_query_fuzzer_runs = options["create-query-fuzzer-runs"].as<int>()))
    {
        // Ignore errors in parsing queries.
        config().setBool("ignore-error", true);

        global_context->setSetting("allow_suspicious_low_cardinality_types", true);
        ignore_error = true;
    }

    if (options.contains("opentelemetry-traceparent"))
    {
        String traceparent = options["opentelemetry-traceparent"].as<std::string>();
        String error;
        if (!global_context->getClientTraceContext().parseTraceparentHeader(traceparent, error))
            throw Exception(ErrorCodes::BAD_ARGUMENTS, "Cannot parse OpenTelemetry traceparent '{}': {}", traceparent, error);
    }

    if (options.contains("opentelemetry-tracestate"))
        global_context->getClientTraceContext().tracestate = options["opentelemetry-tracestate"].as<std::string>();

    initClientContext(Context::createCopy(global_context));
    /// Initialize query context for the current thread to avoid sharing global context (i.e. for obtaining session_timezone)
    query_scope = QueryScope::create(client_context);


    /// Allow to pass-through unknown settings to the server.
    client_context->getAccessControl().allowAllSettings();
}


void Client::processConfig()
{
    if (!queries.empty() && !queries_files.empty())
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Options '--query' and '--queries-file' cannot be specified at the same time");

    /// Batch mode is enabled if one of the following is true:
    /// - -q (--query) command line option is present.
    ///   The value of the option is used as the text of query (or of multiple queries).
    ///   If stdin is not a terminal, INSERT data for the first query is read from it.
    /// - stdin is not a terminal. In this case queries are read from it.
    /// - --queries-file command line option is present.
    ///   The value of the option is used as file with query (or of multiple queries) to execute.

    delayed_interactive = config().has("interactive") && (!queries.empty() || !queries_files.empty());
    if (stdin_is_a_tty && (delayed_interactive || (queries.empty() && queries_files.empty())))
    {
        is_interactive = true;
    }
    else
    {
        ignore_error = config().getBool("ignore-error", false);

        query_id = config().getString("query_id", "");
        if (!query_id.empty())
            client_context->setCurrentQueryId(query_id);
    }

    setupEchoAndHighlightSettings();

    if (is_interactive || delayed_interactive)
    {
        if (home_path.empty())
        {
            const char * home_path_cstr = getenv("HOME"); // NOLINT(concurrency-mt-unsafe)
            if (home_path_cstr)
                home_path = home_path_cstr;
        }

        /// Load command history if present.
        if (config().has("history_file"))
            history_file = config().getString("history_file");
        else
            history_file = ClientBase::getHistoryFilePath();
    }

    pager = config().getString("pager", "");
    enable_highlight = ConfigHelper::getBool(config(), "highlight", true);
    multiline = config().has("multiline");
    rainbow_parentheses = config().getBool("rainbow_parentheses", true);
    print_stack_trace = config().getBool("stacktrace", false);
    default_database = config().getString("database", "");
    /// `default_database` may have come from a config file (or a named connection in that file)
    /// rather than the `--database` CLI option. The `database` setting needs to know either
    /// way, so it ships with every query the client runs.
    if (!default_database.empty() && !cmd_settings->isChanged("database"))
    {
        cmd_settings->set("database", default_database);
        /// `processConfig` runs after `processOptions` already copied `cmd_settings` into `global_context`
        /// and `client_context`, and the later TCP sends read `client_context->getSettingsRef()[database]`,
        /// not `cmd_settings`. Apply the mirrored value to the live contexts too (mirroring what
        /// `setDefaultFormatsAndCompressionFromConfiguration` now does for the format settings), so a
        /// config / named-connection `database` is not overridden by a stale profile value in `executeQuery`.
        if (global_context)
            global_context->setSetting("database", default_database);
        if (client_context)
            client_context->setSetting("database", default_database);
    }
    inline_insert_data = config().getBool("inline-insert-data", false);

    if (inline_insert_data)
        client_context->setSetting("send_table_structure_on_insert_with_inline_data", false);

    setDefaultFormatsAndCompressionFromConfiguration();
}


void Client::readArguments(
    int argc,
    char ** argv,
    Arguments & common_arguments,
    std::vector<Arguments> & external_tables_arguments,
    std::vector<Arguments> & hosts_and_ports_arguments)
{
    // Default to oauth authentication for ClickHouse Cloud for a hostname argument.
    bool is_hostname_argument = false;
#if USE_JWT_CPP && USE_SSL
    if (argc >= 2)
    {
        std::string_view first_arg(argv[1]);

        /// Only process as positional hostname if it doesn't start with '-' (i.e., it's not a flag)
        if (!first_arg.starts_with('-'))
        {
            std::string hostname(argv[1]);
            std::string port;
            bool has_auth_in_connection_string = false;

            try
            {
                Poco::URI uri{hostname};
                if (const auto & host = uri.getHost(); !host.empty())
                {
                    hostname = host;
                    port = std::to_string(uri.getPort());
                }
                /// Check if connection string contains user credentials (e.g., clickhouse://user:password@host)
                has_auth_in_connection_string = !uri.getUserInfo().empty();
            }
            catch (const Poco::URISyntaxException &) // NOLINT(bugprone-empty-catch)
            {
                // intentionally ignored. argv[1] is not a uri, but could be a query.
            }

            if (isCloudEndpoint(hostname) && !has_auth_in_connection_string)
            {
                is_hostname_argument = true;

                /// Check if user provided authentication credentials via command line
                bool has_auth_in_cmdline = false;
                for (int i = 1; i < argc; ++i)
                {
                    std::string_view arg(argv[i]);
                    if (arg.starts_with("--user") || arg.starts_with("--password") ||
                        arg.starts_with("--jwt") || arg.starts_with("--ssh-key-file") ||
                        arg == "-u")
                    {
                        has_auth_in_cmdline = true;
                        break;
                    }
                }

                /// Only auto-add --login if no authentication credentials provided via command line or connection string
                if (!has_auth_in_cmdline && !has_auth_in_connection_string)
                {
                    common_arguments.emplace_back("--login");
                    login_was_auto_added = true;
                }
                common_arguments.emplace_back("--secure");

                std::vector<std::string> host_and_port;
                host_and_port.push_back("--host=" + hostname);
                if (!port.empty())
                    host_and_port.push_back("--port=" + port);
                hosts_and_ports_arguments.push_back(std::move(host_and_port));
            }
        }
    }
#endif

    bool has_connection_string = !is_hostname_argument && argc >= 2 && tryParseConnectionString(std::string_view(argv[1]), common_arguments, hosts_and_ports_arguments);
    int start_argument_index = (has_connection_string || is_hostname_argument) ? 2 : 1;

    /** We allow different groups of arguments:
        * - common arguments;
        * - arguments for any number of external tables each in form "--external args...",
        *   where possible args are file, name, format, structure, types;
        * - param arguments for prepared statements.
        * Split these groups before processing.
        */
    bool in_external_group = false;

    std::string prev_host_arg;
    std::string prev_port_arg;

    for (int arg_num = start_argument_index; arg_num < argc; ++arg_num)
    {
        std::string_view arg = argv[arg_num];

        /// Support arguments with a space on both sides of equals sign.
        /// Ex: --param = value
        std::string fused_arg;
        if (arg.starts_with('-') && arg_num + 2 < argc)
        {
            std::string_view next_arg = argv[arg_num + 1];
            if (next_arg == "=" && !arg.contains('='))
            {
                fused_arg = std::string(arg);
                fused_arg += "=";
                fused_arg += argv[arg_num + 2];

                arg = fused_arg;
                arg_num += 2;
            }
        }

        if (has_connection_string || is_hostname_argument)
            checkIfCmdLineOptionCanBeUsedWithConnectionString(arg);

        if (arg == "--external")
        {
            in_external_group = true;
            external_tables_arguments.emplace_back(Arguments{""});
        }
        /// Options with value after equal sign.
        else if (
            in_external_group
            && (arg.starts_with("--file=") || arg.starts_with("--name=") || arg.starts_with("--format=") || arg.starts_with("--structure=")
                || arg.starts_with("--types=")))
        {
            external_tables_arguments.back().emplace_back(arg);
        }
        /// Options with value after whitespace.
        else if (in_external_group && (arg == "--file" || arg == "--name" || arg == "--format" || arg == "--structure" || arg == "--types"))
        {
            if (arg_num + 1 < argc)
            {
                external_tables_arguments.back().emplace_back(arg);
                ++arg_num;
                arg = argv[arg_num];
                external_tables_arguments.back().emplace_back(arg);
            }
            else
                break;
        }
        /// Options with no value
        else if (in_external_group && (arg == "--scalar"))
        {
            external_tables_arguments.back().emplace_back(arg);
        }
        else
        {
            in_external_group = false;
            if (arg == "--file"sv || arg == "--name"sv || arg == "--structure"sv || arg == "--types"sv)
                throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter must be in external group, try add --external before {}", arg);

            /// Parameter arg after underline or dash.
            if (arg.starts_with("--param_") || arg.starts_with("--param-"))
            {
                auto param_continuation = arg.substr(strlen("--param_"));
                auto equal_pos = param_continuation.find_first_of('=');

                if (equal_pos == std::string::npos)
                {
                    /// param_name value
                    ++arg_num;
                    if (arg_num >= argc)
                        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter requires value");
                    arg = argv[arg_num];
                    query_parameters.emplace(String(param_continuation), String(arg));
                }
                else
                {
                    if (equal_pos == 0)
                        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter name cannot be empty");

                    /// param_name=value
                    query_parameters.emplace(param_continuation.substr(0, equal_pos), param_continuation.substr(equal_pos + 1));
                }
            }
            else if (arg.starts_with("--host") || arg.starts_with("-h"))
            {
                std::string host_arg;
                /// --host host
                if (arg == "--host" || arg == "-h")
                {
                    ++arg_num;
                    if (arg_num >= argc)
                        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Host argument requires value");
                    arg = argv[arg_num];
                    host_arg = "--host=";
                    host_arg.append(arg);
                }
                else
                    host_arg = arg;

                /// --port port1 --host host1
                if (!prev_port_arg.empty())
                {
                    hosts_and_ports_arguments.push_back({host_arg, prev_port_arg});
                    prev_port_arg.clear();
                }
                else
                {
                    /// --host host1 --host host2
                    if (!prev_host_arg.empty())
                        hosts_and_ports_arguments.push_back({prev_host_arg});

                    prev_host_arg = host_arg;
                }
            }
            else if (arg.starts_with("--port"))
            {
                auto port_arg = String{arg};
                /// --port port
                if (arg == "--port")
                {
                    port_arg.push_back('=');
                    ++arg_num;
                    if (arg_num >= argc)
                        throw Exception(ErrorCodes::BAD_ARGUMENTS, "Port argument requires value");
                    arg = argv[arg_num];
                    port_arg.append(arg);
                }

                /// --host host1 --port port1
                if (!prev_host_arg.empty())
                {
                    hosts_and_ports_arguments.push_back({port_arg, prev_host_arg});
                    prev_host_arg.clear();
                }
                else
                {
                    /// --port port1 --port port2
                    if (!prev_port_arg.empty())
                        hosts_and_ports_arguments.push_back({prev_port_arg});

                    prev_port_arg = port_arg;
                }
            }
            else if (arg == "--allow_repeated_settings")
                allow_repeated_settings = true;
            else if (arg == "--allow_merge_tree_settings")
                allow_merge_tree_settings = true;
            else if (arg == "--password" && ((arg_num + 1) >= argc || std::string_view(argv[arg_num + 1]).starts_with('-')))
            {
                common_arguments.emplace_back(arg);
                /// if the value of --password is omitted, the password will be asked before
                /// connection start
                common_arguments.emplace_back(ConnectionParameters::ASK_PASSWORD);
            }
            else if (arg == "--ssh-key-file" && ((arg_num + 1) >= argc || std::string_view(argv[arg_num + 1]).starts_with('-')))
            {
                common_arguments.emplace_back(arg);
                /// If the file name is omitted, the key is looked up in `~/.ssh` and in the ssh-agent.
                common_arguments.emplace_back();
            }
            else
                common_arguments.emplace_back(arg); /// anything else, eg --hilite
        }
    }
    if (!prev_host_arg.empty())
        hosts_and_ports_arguments.push_back({prev_host_arg});
    if (!prev_port_arg.empty())
        hosts_and_ports_arguments.push_back({prev_port_arg});
}

}


int mainEntryClickHouseClient(int argc, char ** argv);

int mainEntryClickHouseClient(int argc, char ** argv)
{
    DB::MainThreadStatus::getInstance();

    /// Join global-pool threads before the statics they may have accessed are destroyed.
    /// That way, accesses happen-before destruction.
    SCOPE_EXIT_SAFE({
        DB::StaticThreadPool::shutdownAll();
        GlobalThreadPool::shutdown();
    });

    try
    {
        DB::Client client;
        // Initialize command line options
        client.init(argc, argv);
        return client.run();
    }
    catch (DB::Exception & e)
    {
        std::cerr << DB::getExceptionMessageForLogging(e, false) << std::endl;
        auto code = DB::getCurrentExceptionCode();
        return static_cast<UInt8>(code) ? code : 1;
    }
    catch (const boost::program_options::error & e)
    {
        std::cerr << "Bad arguments: " << e.what() << std::endl;
        return DB::ErrorCodes::BAD_ARGUMENTS;
    }
    catch (...)
    {
        std::cerr << DB::getCurrentExceptionMessage(true) << '\n';
        auto code = DB::getCurrentExceptionCode();
        return static_cast<UInt8>(code) ? code : 1;
    }
}