#include <cstdlib>
#include <fcntl.h>
#include <map>
#include <iostream>
#include <iomanip>
#include <memory>
#include <optional>
#include <Common/ThreadStatus.h>
#include <boost/program_options.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <filesystem>
#include <string>
#include "Client.h"
#include "Client/ConnectionString.h"
#include "Core/Protocol.h"
#include "Parsers/formatAST.h"

#include <Access/AccessControl.h>

#include <Common/Config/ConfigProcessor.h>
#include <Common/Config/getClientConfigPath.h>
#include <Common/CurrentThread.h>
#include <Common/Exception.h>
#include <Common/TerminalSize.h>
#include <Common/config_version.h>
#include <Common/formatReadable.h>
#include <Core/Settings.h>
#include <Columns/ColumnString.h>

#include <IO/ReadBufferFromString.h>
#include <IO/ReadHelpers.h>
#include <IO/UseSSL.h>
#include <IO/WriteBufferFromOStream.h>
#include <IO/WriteHelpers.h>
#include <IO/copyData.h>

#include <Parsers/ASTCreateQuery.h>
#include <Parsers/ASTDropQuery.h>
#include <Parsers/ASTSetQuery.h>
#include <Parsers/ASTUseQuery.h>
#include <Parsers/ASTInsertQuery.h>
#include <Parsers/ASTSelectQuery.h>

#include <Processors/Transforms/getSourceFromASTInsertQuery.h>

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

#include <Poco/Util/Application.h>

#include "buzz-house/ast/sql_query_proto_to_string.h"
#include "buzz-house/generator/query_oracle.h"
#include "buzz-house/generator/statement_generator.h"

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


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

namespace ErrorCodes
{
    extern const int BAD_ARGUMENTS;
    extern const int UNKNOWN_PACKET_FROM_SERVER;
    extern const int SYNTAX_ERROR;
    extern const int TOO_DEEP_RECURSION;
    extern const int NETWORK_ERROR;
    extern const int AUTHENTICATION_FAILED;
    extern const int NO_ELEMENTS_IN_CONFIG;
    extern const int USER_EXPIRED;
}


void Client::processError(const String & query) const
{
    if (server_exception)
    {
        fmt::print(stderr, "Received exception from server (version {}):\n{}\n",
                server_version,
                getExceptionMessage(*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.
    assert(have_error == (client_exception || server_exception));
}


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

void Client::parseConnectionsCredentials(Poco::Util::AbstractConfiguration & config, const std::string & connection_name)
{
    std::optional<String> default_connection_name;
    if (hosts_and_ports.empty())
    {
        if (config.has("host"))
            default_connection_name = config.getString("host");
    }
    else
    {
        default_connection_name = hosts_and_ports.front().host;
    }

    String connection;
    if (!connection_name.empty())
        connection = connection_name;
    else
        connection = default_connection_name.value_or("localhost");

    Strings keys;
    config.keys("connections_credentials", keys);
    bool connection_found = false;
    for (const auto & key : keys)
    {
        const String & prefix = "connections_credentials." + key;

        const String & name = config.getString(prefix + ".name", "");
        if (name != connection)
            continue;
        connection_found = true;

        String connection_hostname;
        if (config.has(prefix + ".hostname"))
            connection_hostname = config.getString(prefix + ".hostname");
        else
            connection_hostname = name;

        config.setString("host", connection_hostname);
        if (config.has(prefix + ".port"))
            config.setInt("port", config.getInt(prefix + ".port"));
        if (config.has(prefix + ".secure"))
            config.setBool("secure", config.getBool(prefix + ".secure"));
        if (config.has(prefix + ".user"))
            config.setString("user", config.getString(prefix + ".user"));
        if (config.has(prefix + ".password"))
            config.setString("password", config.getString(prefix + ".password"));
        if (config.has(prefix + ".database"))
            config.setString("database", config.getString(prefix + ".database"));
        if (config.has(prefix + ".history_file"))
        {
            String history_file = config.getString(prefix + ".history_file");
            if (history_file.starts_with("~") && !home_path.empty())
                history_file = home_path + "/" + history_file.substr(1);
            config.setString("history_file", history_file);
        }
        if (config.has(prefix + ".accept-invalid-certificate"))
            config.setBool("accept-invalid-certificate", config.getBool(prefix + ".accept-invalid-certificate"));
    }

    if (!connection_name.empty() && !connection_found)
        throw Exception(ErrorCodes::NO_ELEMENTS_IN_CONFIG, "No such connection '{}' in connections_credentials", connection);
}

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

    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();
        parseConnectionsCredentials(*loaded_config.configuration, config().getString("connection", ""));
        config().add(loaded_config.configuration);
    }
    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);

    /// settings and limits could be specified in config file, but passed settings has higher priority
    for (const auto & setting : global_context->getSettingsRef().getUnchangedNames())
    {
        String name{setting};
        if (config().has(name))
            global_context->setSetting(name, config().getString(name));
    }

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

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


int Client::main(const std::vector<std::string> & /*args*/)
try
{
    UseSSL use_ssl;
    auto & thread_status = MainThreadStatus::getInstance();
    setupSignalHandler();

    std::cout << std::fixed << std::setprecision(3);
    std::cerr << std::fixed << std::setprecision(3);

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

    processConfig();
    adjustSettings();
    initTTYBuffer(toProgressOption(config().getString("progress", "default")),
        toProgressOption(config().getString("progress-table", "default")));
    initKeystrokeInterceptor();
    ASTAlterCommand::setFormatAlterCommandsWithParentheses(true);

    {
        // All that just to set DB::CurrentThread::get().getGlobalContext()
        // which is required for client timezone (pushed from server) to work.
        auto thread_group = std::make_shared<ThreadGroup>();
        const_cast<ContextWeakPtr&>(thread_group->global_context) = global_context;
        thread_status.attachToGroup(thread_group, false);
    }

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

    try
    {
        connect();
    }
    catch (const Exception & e)
    {
        if (e.code() != DB::ErrorCodes::AUTHENTICATION_FAILED ||
            config().has("password") ||
            config().getBool("ask-password", false) ||
            !is_interactive)
            throw;

        config().setBool("ask-password", true);
        connect();
    }

    /// 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 exception->code() != 0 ? 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 (const Exception & e)
{
    bool need_print_stack_trace = config().getBool("stacktrace", false) && e.code() != ErrorCodes::NETWORK_ERROR;
    std::cerr << getExceptionMessage(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 e.code() ? e.code() : -1;
}
catch (...)
{
    std::cerr << getCurrentExceptionMessage(false) << std::endl;
    return getCurrentExceptionCode();
}


void Client::connect()
{
    String server_name;
    UInt64 server_version_major = 0;
    UInt64 server_version_minor = 0;
    UInt64 server_version_patch = 0;

    if (hosts_and_ports.empty())
    {
        String host = config().getString("host", "localhost");
        UInt16 port = ConnectionParameters::getPortFromConfig(config(), host);
        hosts_and_ports.emplace_back(HostAndPort{host, port});
    }

    for (size_t attempted_address_index = 0; attempted_address_index < hosts_and_ports.size(); ++attempted_address_index)
    {
        try
        {
            connection_parameters = ConnectionParameters(
                config(), hosts_and_ports[attempted_address_index].host, hosts_and_ports[attempted_address_index].port);

            if (is_interactive)
                std::cout << "Connecting to "
                          << (!connection_parameters.default_database.empty() ? "database " + connection_parameters.default_database + " at "
                                                                              : "")
                          << connection_parameters.host << ":" << connection_parameters.port
                          << (!connection_parameters.user.empty() ? " as user " + connection_parameters.user : "") << "." << std::endl;

            connection = Connection::createConnection(connection_parameters, client_context);

            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);
            config().setString("host", connection_parameters.host);
            config().setInt("port", connection_parameters.port);
            break;
        }
        catch (const Exception & e)
        {
            /// This problem can't be fixed with reconnection so it is not attempted
            if (e.code() == DB::ErrorCodes::AUTHENTICATION_FAILED)
                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
                          << getExceptionMessage(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 (server_display_name = connection->getServerDisplayName(connection_parameters.timeouts); server_display_name.empty())
        server_display_name = config().getString("host", "localhost");

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

#ifndef CLICKHOUSE_CLOUD
        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)
        {
            std::cout << "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")
        {
            std::cout << "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;
        }
    }

    prompt_by_server_display_name = config().getRawString("prompt_by_server_display_name.default", "{display_name} :) ");

    Strings keys;
    config().keys("prompt_by_server_display_name", keys);
    for (const String & key : keys)
    {
        if (key != "default" && server_display_name.find(key) != std::string::npos)
        {
            prompt_by_server_display_name = config().getRawString("prompt_by_server_display_name." + key);
            break;
        }
    }

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

    /// Prompt may contain the following substitutions in a form of {name}.
    std::map<String, String> prompt_substitutions{
        {"host", connection_parameters.host},
        {"port", toString(connection_parameters.port)},
        {"user", connection_parameters.user},
        {"display_name", server_display_name},
    };

    /// Quite suboptimal.
    for (const auto & [key, value] : prompt_substitutions)
        boost::replace_all(prompt_by_server_display_name, "{" + key + "}", value);
}


// 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, toString(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");
}


static bool queryHasWithClause(const IAST & ast)
{
    if (const auto * select = dynamic_cast<const ASTSelectQuery *>(&ast); select && select->with())
    {
        return true;
    }

    // This full recursive walk is somewhat excessive, because most of the
    // children are not queries, but on the other hand it will let us to avoid
    // breakage when the AST structure changes and some new variant of query
    // nesting is added. This function is used in fuzzer, so it's better to be
    // defensive and avoid weird unexpected errors.
    for (const auto & child : ast.children)
    {
        if (queryHasWithClause(*child))
        {
            return true;
        }
    }

    return false;
}

std::optional<bool>
Client::processFuzzingStep(const String & query_to_execute, const ASTPtr & parsed_query, const bool ignore_deep_recursion)
{
    processParsedSingleQuery(query_to_execute, query_to_execute, parsed_query);

    const auto * exception = server_exception ? server_exception.get() : client_exception.get();
    // Sometimes you may get TOO_DEEP_RECURSION from the server,
    // and TOO_DEEP_RECURSION should not fail the fuzzer check.
    if (ignore_deep_recursion && have_error && exception->code() == ErrorCodes::TOO_DEEP_RECURSION)
    {
        have_error = false;
        server_exception.reset();
        client_exception.reset();
        return true;
    }

    if (have_error)
    {
        fmt::print(stderr, "Error on processing query '{}': {}\n", parsed_query->formatForErrorMessage(), exception->message());

        // Try to reconnect after errors, for two reasons:
        // 1. We might not have realized that the server died, e.g. if
        //    it sent us a <Fatal> trace and closed connection properly.
        // 2. The connection might have gotten into a wrong state and
        //    the next query will get false positive about
        //    "Unknown packet from server".
        try
        {
            connection->forceConnected(connection_parameters.timeouts);
        }
        catch (...)
        {
            // Just report it, we'll terminate below.
            fmt::print(stderr, "Error while reconnecting to the server: {}\n", getCurrentExceptionMessage(true));

            // The reconnection might fail, but we'll still be connected
            // in the sense of `connection->isConnected() = true`,
            // in case when the requested database doesn't exist.
            // Disconnect manually now, so that the following code doesn't
            // have any doubts, and the connection state is predictable.
            connection->disconnect();
        }
    }

    if (!connection->isConnected())
    {
        // Probably the server is dead because we found an assertion
        // failure. Fail fast.
        fmt::print(stderr, "Lost connection to the server.\n");

        // Print the changed settings because they might be needed to
        // reproduce the error.
        printChangedSettings();

        return false;
    }

    return std::nullopt;
}

/// Returns false when server is not available.
bool Client::processWithFuzzing(const String & full_query)
{
    ASTPtr orig_ast;

    try
    {
        const char * begin = full_query.data();
        orig_ast = parseQuery(
            begin,
            begin + full_query.size(),
            client_context->getSettingsRef(),
            /*allow_multi_statements=*/true);
    }
    catch (const Exception & e)
    {
        if (e.code() != ErrorCodes::SYNTAX_ERROR && e.code() != ErrorCodes::TOO_DEEP_RECURSION)
            throw;
    }

    if (!orig_ast)
    {
        // Can't continue after a parsing error
        return true;
    }

    // `USE db` should not be executed
    // since this will break every query after `DROP db`
    if (orig_ast->as<ASTUseQuery>())
    {
        return true;
    }

    // Kusto is not a subject for fuzzing (yet)
    if (client_context->getSettingsRef()[Setting::dialect] == DB::Dialect::kusto)
    {
        return true;
    }
    if (auto * q = orig_ast->as<ASTSetQuery>())
    {
        if (auto * set_dialect = q->changes.tryGet("dialect"); set_dialect && set_dialect->safeGet<String>() == "kusto")
            return true;
    }

    // Don't repeat:
    // - INSERT -- Because the tables may grow too big.
    // - CREATE -- Because first we run the unmodified query, it will succeed,
    //             and the subsequent queries will fail.
    //             When we run out of fuzzer errors, it may be interesting to
    //             add fuzzing of create queries that wraps columns into
    //             LowCardinality or Nullable.
    //             Also there are other kinds of create queries such as CREATE
    //             DICTIONARY, we could fuzz them as well.
    // - DROP   -- No point in this (by the same reasons).
    // - SET    -- The time to fuzz the settings has not yet come
    //             (see comments in Client/QueryFuzzer.cpp)
    size_t this_query_runs = query_fuzzer_runs;
    ASTs queries_for_fuzzed_tables;

    if (orig_ast->as<ASTSetQuery>())
    {
        this_query_runs = 1;
    }
    else if (const auto * create = orig_ast->as<ASTCreateQuery>())
    {
        if (QueryFuzzer::isSuitableForFuzzing(*create))
            this_query_runs = create_query_fuzzer_runs;
        else
            this_query_runs = 1;
    }
    else if (const auto * /*insert*/ _ = orig_ast->as<ASTInsertQuery>())
    {
        this_query_runs = 1;
        queries_for_fuzzed_tables = fuzzer.getInsertQueriesForFuzzedTables(full_query);
    }
    else if (const auto * drop = orig_ast->as<ASTDropQuery>())
    {
        this_query_runs = 1;
        queries_for_fuzzed_tables = fuzzer.getDropQueriesForFuzzedTables(*drop);
    }

    String query_to_execute;
    ASTPtr fuzz_base = orig_ast;

    for (size_t fuzz_step = 0; fuzz_step < this_query_runs; ++fuzz_step)
    {
        fmt::print(stderr, "Fuzzing step {} out of {}\n", fuzz_step, this_query_runs);

        ASTPtr ast_to_process;
        try
        {
            WriteBufferFromOwnString dump_before_fuzz;
            fuzz_base->dumpTree(dump_before_fuzz);
            auto base_before_fuzz = fuzz_base->formatForErrorMessage();

            ast_to_process = fuzz_base->clone();

            WriteBufferFromOwnString dump_of_cloned_ast;
            ast_to_process->dumpTree(dump_of_cloned_ast);

            // Run the original query as well.
            if (fuzz_step > 0)
            {
                fuzzer.fuzzMain(ast_to_process);
            }

            auto base_after_fuzz = fuzz_base->formatForErrorMessage();

            // Check that the source AST didn't change after fuzzing. This
            // helps debug AST cloning errors, where the cloned AST doesn't
            // clone all its children, and erroneously points to some source
            // child elements.
            if (base_before_fuzz != base_after_fuzz)
            {
                printChangedSettings();

                fmt::print(
                    stderr,
                    "Base before fuzz: {}\n"
                    "Base after fuzz: {}\n",
                    base_before_fuzz,
                    base_after_fuzz);
                fmt::print(stderr, "Dump before fuzz:\n{}\n", dump_before_fuzz.str());
                fmt::print(stderr, "Dump of cloned AST:\n{}\n", dump_of_cloned_ast.str());
                fmt::print(stderr, "Dump after fuzz:\n");

                WriteBufferFromOStream cerr_buf(std::cerr, 4096);
                fuzz_base->dumpTree(cerr_buf);
                cerr_buf.finalize();

                fmt::print(
                    stderr,
                    "Found error: IAST::clone() is broken for some AST node. This is a bug. The original AST ('dump before fuzz') and its "
                    "cloned copy ('dump of cloned AST') refer to the same nodes, which must never happen. This means that their parent "
                    "node doesn't implement clone() correctly.");

                _exit(1);
            }

            auto fuzzed_text = ast_to_process->formatForErrorMessage();
            if (fuzz_step > 0 && fuzzed_text == base_before_fuzz)
            {
                fmt::print(stderr, "Got boring AST\n");
                continue;
            }

            query_to_execute = ast_to_process->formatForErrorMessage();
            if (auto res = processFuzzingStep(query_to_execute, ast_to_process, true))
                return *res;
        }
        catch (...)
        {
            if (!ast_to_process)
                fmt::print(stderr, "Error while forming new query: {}\n", getCurrentExceptionMessage(true));

            // Some functions (e.g. protocol parsers) don't throw, but
            // set last_exception instead, so we'll also do it here for
            // uniformity.
            // Surprisingly, this is a client exception, because we get the
            // server exception w/o throwing (see onReceiveException()).
            client_exception
                = std::make_unique<Exception>(getCurrentExceptionMessageAndPattern(print_stack_trace), getCurrentExceptionCode());
            have_error = true;
        }

        // The server is still alive, so we're going to continue fuzzing.
        // Determine what we're going to use as the starting AST.
        if (have_error)
        {
            // Query completed with error, keep the previous starting AST.
            // Also discard the exception that we now know to be non-fatal,
            // so that it doesn't influence the exit code.
            server_exception.reset();
            client_exception.reset();
            fuzzer.notifyQueryFailed(ast_to_process);
            have_error = false;
        }
        else if (ast_to_process->formatForErrorMessage().size() > 500)
        {
            // ast too long, start from original ast
            fmt::print(stderr, "Current AST is too long, discarding it and using the original AST as a start\n");
            fuzz_base = orig_ast;
        }
        else
        {
            // fuzz starting from this successful query
            fmt::print(stderr, "Query succeeded, using this AST as a start\n");
            fuzz_base = ast_to_process;
        }
    }

    for (const auto & query : queries_for_fuzzed_tables)
    {
        std::cout << std::endl;
        WriteBufferFromOStream ast_buf(std::cout, 4096);
        formatAST(*query, ast_buf, false /*highlight*/);
        ast_buf.finalize();
        if (const auto * insert = query->as<ASTInsertQuery>())
        {
            /// For inserts with data it's really useful to have the data itself available in the logs, as formatAST doesn't print it
            if (insert->hasInlinedData())
            {
                String bytes;
                {
                    auto read_buf = getReadBufferFromASTInsertQuery(query);
                    WriteBufferFromString write_buf(bytes);
                    copyData(*read_buf, write_buf);
                }
                std::cout << std::endl << bytes;
            }
        }
        std::cout << std::endl << std::endl;

        try
        {
            query_to_execute = query->formatForErrorMessage();
            if (auto res = processFuzzingStep(query_to_execute, query, false))
                return *res;
        }
        catch (...)
        {
            client_exception
                = std::make_unique<Exception>(getCurrentExceptionMessageAndPattern(print_stack_trace), getCurrentExceptionCode());
            have_error = true;
        }

        if (have_error)
        {
            server_exception.reset();
            client_exception.reset();
            fuzzer.notifyQueryFailed(query);
            have_error = false;
        }
    }

    return true;
}

void Client::ProcessQueryAndLog(std::ofstream & outf, const std::string & full_query)
{
    processTextAsSingleQuery(full_query);
    outf << full_query << std::endl;
}

bool Client::ProcessBuzzHouseQuery(const std::string & full_query)
{
    bool server_up = true;
    ASTPtr orig_ast;

    have_error = false;
    try
    {
        const char * begin = full_query.data();

        if ((orig_ast = parseQuery(begin, begin + full_query.size(), client_context->getSettingsRef(), false)))
        {
            String query_to_execute = orig_ast->formatForErrorMessage();
            const auto res = processFuzzingStep(query_to_execute, orig_ast, false);
            server_up &= res.value_or(true);
        }
        else
        {
            have_error = true;
        }
    }
    catch (...)
    {
        // Some functions (e.g. protocol parsers) don't throw, but
        // set last_exception instead, so we'll also do it here for
        // uniformity.
        // Surprisingly, this is a client exception, because we get the
        // server exception w/o throwing (see onReceiveException()).
        client_exception = std::make_unique<Exception>(getCurrentExceptionMessageAndPattern(print_stack_trace), getCurrentExceptionCode());
        have_error = true;
    }
    if (have_error)
    {
        // Query completed with error, keep the previous starting AST.
        // Also discard the exception that we now know to be non-fatal,
        // so that it doesn't influence the exit code.
        server_exception.reset();
        client_exception.reset();
    }
    return server_up;
}

/// Returns false when server is not available.
bool Client::buzzHouse()
{
    bool server_up = true;
    std::string full_query;
    buzzhouse::FuzzConfig fc(buzz_house_options_path);
    buzzhouse::ExternalDatabases ed(fc);

    full_query.reserve(8192);
    if (fc.read_log)
    {
        std::ifstream infile(fc.log_path);

        while (server_up && std::getline(infile, full_query))
        {
            server_up &= ProcessBuzzHouseQuery(full_query);
            full_query.resize(0);
        }
    }
    else
    {
        std::string full_query2;
        bool has_cloud_features = false;
        buzzhouse::RandomGenerator rg(fc.seed);
        std::ofstream outf(fc.log_path, std::ios::out | std::ios::trunc);
        sql_query_grammar::SQLQuery sq1, sq2, sq3, sq4;
        int nsuccessfull_create_database = 0, total_create_database_tries = 0, nsuccessfull_create_table = 0, total_create_table_tries = 0;

        GOOGLE_PROTOBUF_VERIFY_VERSION;

        processTextAsSingleQuery("DROP DATABASE IF EXISTS fuzztest;");
        processTextAsSingleQuery("CREATE DATABASE fuzztest Engine=Replicated('/test/db', 's1', 'r1');");
        processTextAsSingleQuery(
            "CREATE TABLE fuzztest.t0 (c0 Int) Engine=SharedMergeTree() ORDER BY tuple() SETTINGS storage_policy = 's3_with_keeper';");
        has_cloud_features |= !have_error;
        std::cout << "Cloud features " << (has_cloud_features ? "" : "not ") << "detected" << std::endl;
        processTextAsSingleQuery("DROP DATABASE IF EXISTS fuzztest;");

        outf << "--Session seed: " << rg.GetSeed() << std::endl;
        ProcessQueryAndLog(outf, "SET engine_file_truncate_on_insert = 1;");

        //Load collations
        full_query.resize(0);
        fc.GenerateCollationsQuery(full_query);
        processTextAsSingleQuery(full_query);
        fc.LoadCollations();

        full_query2.reserve(8192);
        buzzhouse::StatementGenerator gen(fc, ed, has_cloud_features);
        buzzhouse::QueryOracle qo(fc);
        while (server_up)
        {
            sq1.Clear();
            full_query.resize(0);

            if (total_create_database_tries < 10 && nsuccessfull_create_database < 3)
            {
                (void)gen.GenerateNextCreateDatabase(rg, sq1.mutable_inner_query()->mutable_create_database());
                buzzhouse::SQLQueryToString(full_query, sq1);
                outf << full_query << std::endl;
                server_up &= ProcessBuzzHouseQuery(full_query);

                gen.UpdateGenerator(sq1, ed, !have_error);
                nsuccessfull_create_database += (have_error ? 0 : 1);
                total_create_database_tries++;
            }
            else if (
                gen.CollectionHas<std::shared_ptr<buzzhouse::SQLDatabase>>(gen.attached_databases) && total_create_table_tries < 30
                && nsuccessfull_create_table < 10)
            {
                (void)gen.GenerateNextCreateTable(rg, sq1.mutable_inner_query()->mutable_create_table());
                buzzhouse::SQLQueryToString(full_query, sq1);
                outf << full_query << std::endl;
                server_up &= ProcessBuzzHouseQuery(full_query);

                gen.UpdateGenerator(sq1, ed, !have_error);
                nsuccessfull_create_table += (have_error ? 0 : 1);
                total_create_table_tries++;
            }
            else
            {
                const uint32_t noption = rg.NextLargeNumber();

                if (noption < 31)
                {
                    //correctness test query
                    (void)qo.GenerateCorrectnessTestFirstQuery(rg, gen, sq1);
                    buzzhouse::SQLQueryToString(full_query, sq1);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);
                    (void)qo.ProcessOracleQueryResult(true, !have_error, "Correctness query");

                    sq2.Clear();
                    full_query.resize(0);
                    (void)qo.GenerateCorrectnessTestSecondQuery(sq1, sq2);
                    buzzhouse::SQLQueryToString(full_query, sq2);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);
                    (void)qo.ProcessOracleQueryResult(false, !have_error, "Correctness query");
                }
                else if (gen.CollectionHas<buzzhouse::SQLTable>(gen.attached_tables) && noption < 41)
                {
                    bool second_success = true;
                    const buzzhouse::SQLTable & t
                        = rg.PickRandomlyFromVector(gen.FilterCollection<buzzhouse::SQLTable>(gen.attached_tables));

                    //test in and out formats
                    full_query2.resize(0);
                    (void)qo.DumpTableContent(rg, t, sq1);
                    buzzhouse::SQLQueryToString(full_query2, sq1);
                    outf << full_query2 << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query2);
                    (void)qo.ProcessOracleQueryResult(true, !have_error, "Dump and read table");

                    sq2.Clear();
                    (void)qo.GenerateExportQuery(rg, t, sq2);
                    buzzhouse::SQLQueryToString(full_query, sq2);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);
                    second_success &= !have_error;

                    sq3.Clear();
                    full_query.resize(0);
                    (void)qo.GenerateClearQuery(t, sq3);
                    buzzhouse::SQLQueryToString(full_query, sq3);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);
                    second_success &= !have_error;

                    sq4.Clear();
                    full_query.resize(0);
                    (void)qo.GenerateImportQuery(t, sq2, sq4);
                    buzzhouse::SQLQueryToString(full_query, sq4);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);
                    second_success &= !have_error;

                    outf << full_query2 << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query2);
                    second_success &= !have_error;
                    (void)qo.ProcessOracleQueryResult(false, second_success, "Dump and read table");
                }
                else if (noption < 71)
                {
                    //test running query with different settings
                    (void)qo.GenerateFirstSetting(rg, sq1);
                    buzzhouse::SQLQueryToString(full_query, sq1);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);

                    sq2.Clear();
                    full_query2.resize(0);
                    (void)qo.GenerateSettingQuery(rg, gen, sq2);
                    buzzhouse::SQLQueryToString(full_query2, sq2);
                    outf << full_query2 << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query2);
                    (void)qo.ProcessOracleQueryResult(true, !have_error, "Multi setting query");

                    sq3.Clear();
                    full_query.resize(0);
                    (void)qo.GenerateSecondSetting(sq1, sq3);
                    buzzhouse::SQLQueryToString(full_query, sq3);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);

                    outf << full_query2 << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query2);
                    (void)qo.ProcessOracleQueryResult(false, !have_error, "Multi setting query");
                }
                else
                {
                    (void)gen.GenerateNextStatement(rg, sq1);
                    buzzhouse::SQLQueryToString(full_query, sq1);
                    outf << full_query << std::endl;
                    server_up &= ProcessBuzzHouseQuery(full_query);

                    gen.UpdateGenerator(sq1, ed, !have_error);
                }
            }
        }
    }
    return false;
}

void Client::printHelpMessage(const OptionsDescription & options_description, bool verbose)
{
    std::cout << options_description.main_description.value() << "\n";
    std::cout << options_description.external_description.value() << "\n";
    std::cout << options_description.hosts_and_ports_description.value() << "\n";
    if (verbose)
        std::cout << "All settings are documented at https://clickhouse.com/docs/en/operations/settings/settings.\n\n";
    std::cout << "In addition, --param_name=value can be specified for substitution of parameters for parametrized queries.\n";
    std::cout << "\nSee also: https://clickhouse.com/docs/en/integrations/sql-clients/cli\n";
}


void Client::addOptions(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")
        ("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 for authenticate with the server.")
        ("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")

        ("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")
        /// 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")
    ;

    /// Commandline options related to external tables.

    options_description.external_description.emplace(createOptionsDescription("External tables options", terminal_width));
    options_description.external_description->add_options()
    (
        "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"
    )
    (
        "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
        {
            external_tables.emplace_back(external_options);
            if (external_tables.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 (const Exception & e)
        {
            std::cerr << getExceptionMessage(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});
    }

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

    if (options.count("config"))
        config().setString("config-file", options["config"].as<std::string>());
    if (options.count("connection"))
        config().setString("connection", options["connection"].as<std::string>());
    if (options.count("interleave-queries-file"))
        interleave_queries_files = options["interleave-queries-file"].as<std::vector<std::string>>();
    if (options.count("secure"))
        config().setBool("secure", true);
    if (options.count("no-secure"))
        config().setBool("no-secure", true);
    if (options.count("user") && !options["user"].defaulted())
        config().setString("user", options["user"].as<std::string>());
    if (options.count("password"))
        config().setString("password", options["password"].as<std::string>());
    if (options.count("ask-password"))
        config().setBool("ask-password", true);
    if (options.count("ssh-key-file"))
        config().setString("ssh-key-file", options["ssh-key-file"].as<std::string>());
    if (options.count("ssh-key-passphrase"))
        config().setString("ssh-key-passphrase", options["ssh-key-passphrase"].as<std::string>());
    if (options.count("quota_key"))
        config().setString("quota_key", options["quota_key"].as<std::string>());
    if (options.count("max_client_network_bandwidth"))
        max_client_network_bandwidth = options["max_client_network_bandwidth"].as<int>();
    if (options.count("compression"))
        config().setBool("compression", options["compression"].as<bool>());
    if (options.count("no-warnings"))
        config().setBool("no-warnings", true);
    if (options.count("fake-drop"))
        config().setString("ignore_drop_queries_probability", "1");
    if (options.count("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 (options.count("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.count("buzz-house-config") ? options["buzz-house-config"].as<std::string>() : "";
    buzz_house = buzz_house_options_path != "";
    if (query_fuzzer_runs || buzz_house)
    {
        // Ignore errors in parsing queries.
        config().setBool("ignore-error", true);
        ignore_error = true;
    }

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

    /// In case of clickhouse-client the `client_context` can be just an alias for the `global_context`.
    /// (There is no need to copy the context because clickhouse-client has no background tasks so it won't use that context in parallel.)
    client_context = global_context;
    initClientContext();

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


void Client::processConfig()
{
    if (!queries.empty() && config().has("queries-file"))
        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() || config().has("queries-file"));
    if (stdin_is_a_tty
        && (delayed_interactive || (queries.empty() && queries_files.empty())))
    {
        is_interactive = true;
    }
    else
    {
        echo_queries = config().getBool("echo", false);
        ignore_error = config().getBool("ignore-error", false);

        auto query_id = config().getString("query_id", "");
        if (!query_id.empty())
            global_context->setCurrentQueryId(query_id);
    }
    print_stack_trace = config().getBool("stacktrace", false);

    pager = config().getString("pager", "");

    setDefaultFormatsAndCompressionFromConfiguration();
}


void Client::readArguments(
    int argc,
    char ** argv,
    Arguments & common_arguments,
    std::vector<Arguments> & external_tables_arguments,
    std::vector<Arguments> & hosts_and_ports_arguments)
{
    bool has_connection_string = argc >= 2 && tryParseConnectionString(std::string_view(argv[1]), common_arguments, hosts_and_ports_arguments);
    int start_argument_index = has_connection_string ? 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];

        if (has_connection_string)
            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;
        }
        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.
            if (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
                common_arguments.emplace_back(arg);
        }
    }
    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});
}

}


#pragma clang diagnostic ignored "-Wunused-function"
#pragma clang diagnostic ignored "-Wmissing-declarations"

int mainEntryClickHouseClient(int argc, char ** argv)
{
    try
    {
        DB::Client client;
        // Initialize command line options
        client.init(argc, argv);
        return client.run();
    }
    catch (const DB::Exception & e)
    {
        std::cerr << DB::getExceptionMessage(e, false) << std::endl;
        return 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) << std::endl;
        return 1;
    }
}