#pragma once
#ifndef ANSCLOUD_GATEWAY_AGENT_H
#define ANSCLOUD_GATEWAY_AGENT_H

#include <anscloud/common/types.h>
#include <anscloud/common/i_message_broker.h>
#include <string>
#include <functional>
#include <memory>
#include <vector>
#include <future>

#ifdef ANSCLOUD_GATEWAY_EXPORTS
  #define ANSCLOUD_GATEWAY_API __declspec(dllexport)
#else
  #define ANSCLOUD_GATEWAY_API __declspec(dllimport)
#endif

namespace anscloud {

//=============================================================================
// Gateway Configuration
//=============================================================================
struct GatewayCredentials {
    std::string username;
    std::string password;
    std::string vhost = "/";
};

struct GatewayAgentConfig {
    BrokerConfig       broker;
    GatewayCredentials credentials;
    int  device_timeout_seconds         = 90;
    int  default_command_timeout_seconds = 30;
    int  max_pending_commands           = 1000;
};

struct GatewayStats {
    uint64_t commands_sent       = 0;
    uint64_t commands_responded  = 0;
    uint64_t commands_timed_out  = 0;
    uint64_t telemetry_received  = 0;
    uint64_t events_received     = 0;
    uint64_t heartbeats_received = 0;
    int      devices_online      = 0;
    int      devices_total       = 0;
    int      pending_commands    = 0;
    uint64_t uptime_seconds      = 0;
};

struct BatchResult {
    std::vector<std::pair<std::string, CommandResult>> results;  // device_id -> result
    int succeeded = 0;
    int failed    = 0;
    int timed_out = 0;
};

//=============================================================================
// GatewayAgent - CMS gateway for consuming device messages & sending commands
//
//   GatewayAgent gw([](){ return std::make_unique<MyRabbitMQBroker>(); });
//   gw.configure(config);
//   gw.on_telemetry([](const DeviceTelemetry& t){ /* store */ });
//   gw.on_event([](const DeviceEvent& e){ /* process */ });
//   gw.start();
//
//   auto result = gw.send_command("AIBOX-001", CommandType::GetConfig);
//
//=============================================================================
class ANSCLOUD_GATEWAY_API GatewayAgent {
public:
    explicit GatewayAgent(BrokerFactory factory);
    ~GatewayAgent();

    GatewayAgent(const GatewayAgent&) = delete;
    GatewayAgent& operator=(const GatewayAgent&) = delete;
    GatewayAgent(GatewayAgent&&) noexcept;
    GatewayAgent& operator=(GatewayAgent&&) noexcept;

    //--- Configuration -------------------------------------------------------
    void configure(const GatewayAgentConfig& config);

    //--- Lifecycle -----------------------------------------------------------
    bool start();
    void stop();
    bool is_running() const;
    bool is_connected() const;

    //--- Commands (synchronous RPC) ------------------------------------------
    CommandResult send_command(const std::string& device_id,
                               CommandType type,
                               const std::string& params_json = "{}",
                               int timeout_seconds = 0);  // 0 = use default

    std::future<CommandResult> send_command_async(const std::string& device_id,
                                                   CommandType type,
                                                   const std::string& params_json = "{}",
                                                   int timeout_seconds = 0);

    CommandResult send_custom_command(const std::string& device_id,
                                      const std::string& custom_type,
                                      const std::string& params_json = "{}",
                                      int timeout_seconds = 0);

    void send_command_fire_and_forget(const std::string& device_id,
                                      CommandType type,
                                      const std::string& params_json = "{}");

    BatchResult send_batch_command(const std::vector<std::string>& device_ids,
                                   CommandType type,
                                   const std::string& params_json = "{}",
                                   int timeout_seconds = 0);

    void send_broadcast(const std::string& message);

    //--- Device tracking -----------------------------------------------------
    std::vector<DeviceState> get_all_devices() const;
    DeviceState get_device(const std::string& device_id) const;
    std::vector<DeviceState> get_online_devices() const;
    bool is_device_online(const std::string& device_id) const;

    //--- Callbacks -----------------------------------------------------------
    using TelemetryCallback    = std::function<void(const DeviceTelemetry&)>;
    using HeartbeatCallback    = std::function<void(const Heartbeat&)>;
    using EventCallback        = std::function<void(const DeviceEvent&)>;
    using DeviceStatusCallback = std::function<void(const std::string& device_id, DeviceStatus status)>;

    void on_telemetry(TelemetryCallback cb);
    void on_heartbeat(HeartbeatCallback cb);
    void on_event(EventCallback cb);
    void on_device_status_changed(DeviceStatusCallback cb);
    void on_connection_changed(ConnectionCallback cb);
    void on_error(ErrorCallback cb);

    //--- Stats ---------------------------------------------------------------
    GatewayStats get_stats() const;

private:
    class Impl;
    std::unique_ptr<Impl> m_impl;
};

} // namespace anscloud

#endif // ANSCLOUD_GATEWAY_AGENT_H