/**
 * @file mqtt_manager.h
 * @brief MQTT 通信管理器 (协议规范 V0.08)
 *
 * 上行: report/allpoints, status/{gateid}/online, status/{gateid}/offline,
 *       status/{gateid}/provision, response/{gateid}/cmd, response/{gateid}/provision
 * 下行: cmd/{gateid}/alarm, cmd/{gateid}/alarm/restore,
 *       cmd/{gateid}/control, cmd/{gateid}/provision/wifi
 */

#ifndef MQTT_MANAGER_H
#define MQTT_MANAGER_H

#include <Arduino.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include "config.h"

// ============================================================
// 回调函数类型
// ============================================================

// 告警指令回调 (alarm / alarm_restore)
typedef void (*MQTTAlarmCallback)(const AlarmCommand& cmd);

// 控制指令回调
typedef void (*MQTTControlCallback)(const ControlCommand& cmd);

// 配网指令回调 (WiFi 凭证下发)
typedef void (*MQTTProvisionCallback)(const ProvisionCommand& cmd);

// ============================================================
// MQTTManager 类
// ============================================================

class MQTTManager {
public:
    MQTTManager();
    ~MQTTManager();

    /** 初始化 */
    bool begin(const char* gateid);

    /** 主循环 */
    void loop();

    /** 连接/断开 */
    bool connect();
    void disconnect();
    bool isConnected();

    /** 设置服务器 */
    void setServer(const char* host, uint16_t port,
                   const char* user, const char* pass);

    // ============================================================
    // 上行: 发布方法 (协议规范 §4)
    // ============================================================

    /** 全量遥测上报 report/allpoints (§4.1) */
    void publishAllPoints(const TelemetryData& data, uint32_t sequence);

    /** 设备上线通知 status/{gateid}/online (§4.2) */
    void publishOnline();

    /** 设备离线通知 status/{gateid}/offline (§4.3) — 主动调用 */
    void publishOffline();

    /** 配网状态通知 status/{gateid}/provision (§4.4) */
    void publishProvisionStatus(const char* state, const char* bleName);

    /** 指令执行响应 response/{gateid}/cmd (§4.5) */
    void publishCmdResponse(const char* cmdId, const char* cmdType,
                            const char* alarmType, bool success,
                            const char* errorCode, const char* errorMsg);

    /** 配网指令响应 response/{gateid}/provision (§4.6) */
    void publishProvisionResponse(const char* cmdId, bool success,
                                  const char* errorCode, const char* errorMsg,
                                  const char* wifiSignal = "");

    /** 本地报警上报 status/{gateid}/alarm (§4.7 扩展) */
    void publishLocalAlarm(uint8_t alarmType, bool triggered, const char* desc);

    // ============================================================
    // 回调注册 (协议规范 §5)
    // ============================================================

    void onAlarmCommand(MQTTAlarmCallback cb);
    void onControlCommand(MQTTControlCallback cb);
    void onProvisionCommand(MQTTProvisionCallback cb);

    /** 获取 gateid */
    const char* getGateId() const { return _gateid; }

private:
    static void _mqttCallback(char* topic, byte* payload, unsigned int length);
    static MQTTManager* _instance;

    // 主题构建
    String _buildTopic(const char* tmpl) const;

    // 下行报文解析
    void _handleMessage(const char* topic, const char* payload);
    void _parseAlarm(const char* payload, bool isRestore);
    void _parseControl(const char* payload);
    void _parseProvision(const char* payload);

    // 发布辅助
    bool _publish(const char* topicTmpl, const char* payload, uint8_t qos, bool retain = false);

    WiFiClient      _wifiClient;
    PubSubClient    _mqtt;
    char            _gateid[16];

    // 服务器配置
    char     _server[64];
    uint16_t _port;
    char     _user[32];
    char     _pass[32];

    // 重连
    uint32_t _reconnectInterval;
    uint32_t _lastReconnectAttempt;
    bool     _connected;

    // 回调
    MQTTAlarmCallback     _alarmCb;
    MQTTControlCallback   _controlCb;
    MQTTProvisionCallback _provisionCb;
};

#endif // MQTT_MANAGER_H