/*
 * Copyright (C) 2019 pengjian.uestc @ gmail.com
 */

/*
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

#include <seastar/coroutine/switch_to.hh>
#include "timeout_config.hh"
#include "redis/controller.hh"
#include "redis/keyspace_utils.hh"
#include "redis/server.hh"
#include "service/storage_proxy.hh"
#include "db/config.hh"
#include "log.hh"
#include "auth/common.hh"

static logging::logger slogger("controller");

namespace redis {

controller::controller(seastar::sharded<service::storage_proxy>& proxy, seastar::sharded<auth::service>& auth_service,
        seastar::sharded<service::migration_manager>& mm, db::config& cfg, seastar::sharded<gms::gossiper>& gossiper,
        seastar::scheduling_group sg)
    : protocol_server(sg)
    , _proxy(proxy)
    , _db(proxy.local().data_dictionary())
    , _auth_service(auth_service)
    , _mm(mm)
    , _cfg(cfg)
    , _gossiper(gossiper)
{
}

controller::~controller()
{
}

future<> controller::listen(seastar::sharded<auth::service>& auth_service, db::config& cfg)
{
    if (_server) {
        return make_ready_future<>();
    }
    auto server = make_shared<seastar::sharded<redis_transport::redis_server>>();
    _server = server;

    auto preferred = cfg.rpc_interface_prefer_ipv6() ? std::make_optional(net::inet_address::family::INET6) : std::nullopt;
    auto family = cfg.enable_ipv6_dns_lookup() || preferred ? std::nullopt : std::make_optional(net::inet_address::family::INET);
    auto ceo = cfg.client_encryption_options();
    auto keepalive = cfg.rpc_keepalive();
    return utils::resolve(cfg.rpc_address, family, preferred).then([this, server, &cfg, keepalive, ceo = std::move(ceo), &auth_service] (seastar::net::inet_address ip) {
        auto get_config = sharded_parameter([&] {
            return redis_transport::redis_server_config {
                ._timeout_config = updateable_timeout_config(cfg),
                ._max_request_size = memory::stats().total_memory() / 10,
                ._read_consistency_level = make_consistency_level(cfg.redis_read_consistency_level()),
                ._write_consistency_level = make_consistency_level(cfg.redis_write_consistency_level()),
                ._total_redis_db_count = cfg.redis_database_count(),
            };
        });
        return server->start(std::ref(_query_processor), std::ref(auth_service), std::move(get_config)).then([this, server, &cfg, ip, ceo, keepalive]() {
            auto f = make_ready_future();
            struct listen_cfg {
                socket_address addr;
                std::shared_ptr<seastar::tls::credentials_builder> cred;
            };

            _listen_addresses.clear();
            std::vector<listen_cfg> configs;
            if (cfg.redis_port()) {
                configs.emplace_back(listen_cfg { {socket_address{ip, cfg.redis_port()}} });
                _listen_addresses.push_back(configs.back().addr);
            }

            // main should have made sure values are clean and neatish
            if (utils::is_true(utils::get_or_default(ceo, "enabled", "false"))) {
                auto cred = std::make_shared<seastar::tls::credentials_builder>();
                f = utils::configure_tls_creds_builder(*cred, std::move(ceo));

                slogger.info("Enabling encrypted REDIS connections between client and server");

                if (cfg.redis_ssl_port() && cfg.redis_ssl_port() != cfg.redis_port()) {
                    configs.emplace_back(listen_cfg{{ip, cfg.redis_ssl_port()}, std::move(cred)});
                    _listen_addresses.push_back(configs.back().addr);
                } else {
                    configs.back().cred = std::move(cred);
                }
            }

            return f.then([server, configs = std::move(configs), keepalive] {
                return parallel_for_each(configs, [server, keepalive](const listen_cfg & cfg) {
                    return server->invoke_on_all(&redis_transport::redis_server::listen, cfg.addr, cfg.cred, false, keepalive, std::nullopt).then([cfg] {
                        slogger.info("Starting listening for REDIS clients on {} ({})", cfg.addr, cfg.cred ? "encrypted" : "unencrypted");
                    });
                });
            });
        });
    }).handle_exception([this](auto ep) {
        return _server->stop().then([ep = std::move(ep)]() mutable {
            return make_exception_future<>(std::move(ep));
        });
    });
}

sstring controller::name() const {
    return "redis";
}

sstring controller::protocol() const {
    return "RESP";
}

sstring controller::protocol_version() const {
    return ::redis::version;
}

std::vector<socket_address> controller::listen_addresses() const {
    return _listen_addresses;
}

future<> controller::start_server()
{
    co_await coroutine::switch_to(_sched_group);
    // 1. Create keyspace/tables used by redis API if not exists.
    // 2. Initialize the redis query processor.
    // 3. Listen on the redis transport port.
    co_await redis::maybe_create_keyspace(_proxy, _db, _mm, _cfg, _gossiper);
    co_await _query_processor.start(std::ref(_proxy),
            seastar::sharded_parameter([&] { return _proxy.local().data_dictionary(); }));
    co_await _query_processor.invoke_on_all([] (auto& processor) {
        return processor.start();
    });
    co_await listen(_auth_service, _cfg);
}

future<> controller::stop_server()
{
    // If the redis protocol disable, the controller::init is not
    // invoked at all. Do nothing if `_server is null.
    if (_server) {
        return _server->stop().then([this] {
            _listen_addresses.clear();
            return _query_processor.stop();
        });
    }
    return make_ready_future<>();
}

future<> controller::request_stop_server() {
    return with_scheduling_group(_sched_group, [this] {
        return stop_server();
    });
}

}