#include "TaskCluster.h"

namespace DB
{

namespace ErrorCodes
{
    extern const int BAD_ARGUMENTS;
}

TaskCluster::TaskCluster(const String & task_zookeeper_path_, const String & default_local_database_)
    : task_zookeeper_path(task_zookeeper_path_)
    , default_local_database(default_local_database_)
{}

void DB::TaskCluster::loadTasks(const Poco::Util::AbstractConfiguration & config, const String & base_key)
{
    String prefix = base_key.empty() ? "" : base_key + ".";

    clusters_prefix = prefix + "remote_servers";
    if (!config.has(clusters_prefix))
        throw Exception(ErrorCodes::BAD_ARGUMENTS, "You should specify list of clusters in {}", clusters_prefix);

    Poco::Util::AbstractConfiguration::Keys tables_keys;
    config.keys(prefix + "tables", tables_keys);

    for (const auto & table_key : tables_keys)
    {
        table_tasks.emplace_back(*this, config, prefix + "tables", table_key);
    }
}

void DB::TaskCluster::reloadSettings(const Poco::Util::AbstractConfiguration & config, const String & base_key)
{
    String prefix = base_key.empty() ? "" : base_key + ".";

    max_workers = config.getUInt64(prefix + "max_workers");

    settings_common = Settings();
    if (config.has(prefix + "settings"))
        settings_common.loadSettingsFromConfig(prefix + "settings", config);

    settings_common.prefer_localhost_replica = false;

    settings_pull = settings_common;
    if (config.has(prefix + "settings_pull"))
        settings_pull.loadSettingsFromConfig(prefix + "settings_pull", config);

    settings_push = settings_common;
    if (config.has(prefix + "settings_push"))
        settings_push.loadSettingsFromConfig(prefix + "settings_push", config);

    auto set_default_value = [] (auto && setting, auto && default_value)
    {
        setting = setting.changed ? setting.value : default_value;
    };

    /// Override important settings
    settings_pull.readonly = 1;
    settings_pull.prefer_localhost_replica = false;
    settings_push.distributed_foreground_insert = true;
    settings_push.prefer_localhost_replica = false;

    set_default_value(settings_pull.load_balancing, LoadBalancing::NEAREST_HOSTNAME);
    set_default_value(settings_pull.max_threads, 1);
    set_default_value(settings_pull.max_block_size, 8192UL);
    set_default_value(settings_pull.preferred_block_size_bytes, 0);

    set_default_value(settings_push.distributed_background_insert_timeout, 0);
    set_default_value(settings_push.alter_sync, 2);
}

}