client.hpp

/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * Copyright (C) 2026 Marco Craveiro <marco.craveiro@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 3 of the License, or (at your option) any later
 * version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
#ifndef ORES_NATS_SERVICE_CLIENT_HPP
#define ORES_NATS_SERVICE_CLIENT_HPP
 
#include <chrono>
#include <memory>
#include <span>
#include <string>
#include <string_view>
#include <unordered_map>
#include <cstddef>
#include <boost/asio/awaitable.hpp>
#include "ores.nats/config/nats_options.hpp"
#include "ores.nats/domain/message.hpp"
#include "ores.nats/service/jetstream_admin.hpp"
#include "ores.nats/service/subscription.hpp"
 
namespace ores::nats::service {
 
class client {
public:
    explicit client(config::nats_options opts);
    ~client();
 
    client(const client&) = delete;
    client& operator=(const client&) = delete;
 
    // -------------------------------------------------------------------------
    // Lifecycle
    // -------------------------------------------------------------------------
 
    void connect();
 
    void disconnect();
 
    [[nodiscard]] bool is_connected() const noexcept;
 
    // -------------------------------------------------------------------------
    // Core pub/sub (ephemeral — no persistence)
    // -------------------------------------------------------------------------
 
    void publish(std::string_view subject,
        std::span<const std::byte> data,
        std::unordered_map<std::string, std::string> headers = {});
 
    [[nodiscard]] message request_sync(
        std::string_view subject,
        std::span<const std::byte> data,
        std::unordered_map<std::string, std::string> headers = {},
        std::chrono::milliseconds timeout = std::chrono::seconds(30));
 
    [[nodiscard]] boost::asio::awaitable<message> request(
        std::string_view subject,
        std::span<const std::byte> data,
        std::unordered_map<std::string, std::string> headers = {},
        std::chrono::milliseconds timeout = std::chrono::seconds(30));
 
    [[nodiscard]] subscription subscribe(std::string_view subject,
        message_handler handler);
 
    [[nodiscard]] subscription queue_subscribe(std::string_view subject,
        std::string_view queue_group,
        message_handler handler);
 
    // -------------------------------------------------------------------------
    // JetStream (durable, persistent)
    // -------------------------------------------------------------------------
 
    void js_publish(std::string_view subject,
        std::span<const std::byte> data,
        std::unordered_map<std::string, std::string> headers = {});
 
    [[nodiscard]] subscription js_subscribe(std::string_view subject,
        std::string_view durable_name,
        message_handler handler);
 
    [[nodiscard]] subscription js_queue_subscribe(std::string_view subject,
        std::string_view durable_name,
        std::string_view queue_group,
        message_handler handler);
 
    [[nodiscard]] jetstream_admin make_admin();
 
    // -------------------------------------------------------------------------
    // Shutdown
    // -------------------------------------------------------------------------
 
    void drain();
 
    // -------------------------------------------------------------------------
    // Subject helpers
    // -------------------------------------------------------------------------
 
    [[nodiscard]] std::string make_subject(std::string_view relative) const;
 
private:
    struct impl;
    std::unique_ptr<impl> impl_;
};
 
}
 
#endif