//
//  MQTTService.swift
//  QuickLocation
//
//  Created by 八条 on 2026/6/12.
//

import Foundation
import CocoaMQTT
import UIKit
import _LocationEssentials

// MARK: - MQTT 模型

/// 位置上报类型
enum MqttType: String, Codable {
    case track = "track" // 追踪（获取)和更新用户状态
    case disconnect = "disconnect"
    case message = "message"
    case join = "join" // 加入群
    case leave = "leave" // 离开群
    case dismiss = "dismiss" // 解散群
    case kick = "kick" // 踢人
    case signIn = "signin" // 签到
    case sos = "sos" // 求助
    case needTrack = "needtrack" // 追踪上报
    case emote = "emote" // 接收表情
}

/// 单点位置
struct Points: Codable {
    let lat: Double
    let lon: Double
    let addr: String
    let time: Int64          // 毫秒时间戳
    let speed: Double
    let bearing: Double
    let altitude: Double
    let accuracy: Double
}

/// 位置上报数据（发送）
struct MqttLocation: Codable {
    let battery: String
    let points: [Points]
}

/// MQTT 收到的位置消息（接收解析用）
struct MqttIncomingMessage: Decodable {
    let type: String?
    let data: MqttIncomingData?
    let extra: String?
}

struct MqttIncomingData: Decodable {
    let points: [Points]?
    let battery: String?
}

// MARK: - MQTTService

/// MQTT 5.0 服务，管理连接、订阅和消息收发
final class MQTTService: NSObject {

    static let shared = MQTTService()

    private var mqtt: CocoaMQTT5?
    private var isConnected = false

    // MARK: - 连接状态回调
    var onConnected: (() -> Void)?
    var onDisconnected: (() -> Void)?

    /// 全局接收回调（所有未匹配 topicCallback 的消息）
    var onMessageReceived: ((CocoaMQTT5Message, UInt16, MqttPublishProperties) -> Void)?

    /// 按 topic 订阅的回调（优先匹配）
    private var topicCallbacks: [String: (CocoaMQTT5Message) -> Void] = [:]

    // MARK: - 配置
    private var host: String { "emqx.batiao8.com" }
    private var port: UInt16 { 1883 }
    /// 当前 clientID，切换用户时可更新后重连
    private(set) var clientID: String = ""
    private var userName = "batiao"
    private var password = "Batiao12B"
    private var topic = "smartdrive/"
    
    override private init() {}

    // MARK: - 连接
    func connect() {
        guard !isConnected else { return }

        if clientID.isEmpty {
            clientID = "smartdrive_\(AppContextManager.shared.userId)"
        }
        let mqtt = CocoaMQTT5(clientID: clientID, host: host, port: port)
        mqtt.username = userName
        mqtt.password = password
        mqtt.keepAlive = 60
        mqtt.autoReconnect = true
        mqtt.autoReconnectTimeInterval = 5
        mqtt.delegate = self
        mqtt.logLevel = .warning

        self.mqtt = mqtt
        _ = mqtt.connect()
    }

    // MARK: - 断开
    func disconnect() {
        mqtt?.disconnect()
        isConnected = false
    }

    // MARK: - 切换用户
    /// 更新 clientID 并重连（切换用户后调用）
    func updateClientID(_ newID: String) {
        clientID = newID
        disconnect()
        connect()
    }

    // MARK: - 订阅主题
    /// - Parameters:
    ///   - topic: 主题
    ///   - qos: 服务质量
    ///   - callback: 可选，该 topic 的专用回调，收到消息时优先于此回调
    func subscribe(topic: String, qos: CocoaMQTTQoS = .qos1, callback: ((CocoaMQTT5Message) -> Void)? = nil) {
        let subscription = MqttSubscription(topic: topic, qos: qos)
        mqtt?.subscribe([subscription])
        if let cb = callback {
            topicCallbacks[topic] = cb
        }
    }

    // MARK: - 取消订阅
    func unsubscribe(topic: String) {
        mqtt?.unsubscribe(topic)
        topicCallbacks.removeValue(forKey: topic)
    }

    /// 订阅指定圈子的所有成员位置 topic: smartdrive/<memberId>
    func subscribeGroupMembers(_ memberIds: [String]) {
        for id in memberIds {
            subscribe(topic: "\(topic)\(id)")
        }
    }

    /// 取消订阅上一批成员
    func unsubscribeGroupMembers(_ memberIds: [String]) {
        for id in memberIds {
            mqtt?.unsubscribe("\(topic)\(id)")
        }
    }

    // MARK: - 发布消息
    @discardableResult
    func publish(topic: String, message: String, qos: CocoaMQTTQoS = .qos1) -> Int {
        let properties = MqttPublishProperties()
        return mqtt?.publish(topic, withString: message, qos: qos, DUP: false, retained: false, properties: properties) ?? -1
    }

    @discardableResult
    func publish(topic: String, data: Data, qos: CocoaMQTTQoS = .qos1) -> Int {
        let properties = MqttPublishProperties()
        let message = CocoaMQTT5Message(topic: topic, payload: [UInt8](data))
        return mqtt?.publish(message, DUP: false, retained: false, properties: properties) ?? -1
    }

    // MARK: - 位置上报
    /// 构建并上报位置数据（格式与 Android 一致）
    func reportLocation(lat: Double, lon: Double, addr: String,
                        speed: CLLocationSpeed, bearing: CLLocationDirection,
                        altitude: CLLocationDistance, accuracy: CLLocationAccuracy) {
        let battery = UIDevice.current.batteryLevel > 0
            ? Int(UIDevice.current.batteryLevel * 100)
            : 0

        let point = Points(
            lat: lat, lon: lon, addr: addr,
            time: Int64(Date().timeIntervalSince1970 * 1000),
            speed: speed, bearing: bearing,
            altitude: altitude, accuracy: accuracy
        )
        let location = MqttLocation(battery: battery.string, points: [point])

        guard let jsonData = try? JSONEncoder().encode(location),
              let dataDict = try? JSONSerialization.jsonObject(with: jsonData) as? [String: Any]
        else { return }

        // 外层包装，data 是 JSON 对象而非字符串
        let payload: [String: Any] = [
            "type": MqttType.track.rawValue,
            "extra": "",
            "data": dataDict
        ]
        
        publish(topic: "\(topic)\(AppContextManager.shared.userId)", message: payload.toJsonString())
    }
}

// MARK: - CocoaMQTT5Delegate
extension MQTTService: CocoaMQTT5Delegate {

    func mqtt5(_ mqtt5: CocoaMQTT5, didConnectAck ack: CocoaMQTTCONNACKReasonCode, connAckData: MqttDecodeConnAck?) {
        isConnected = true
        print("MQTT5 connected: \(ack)")
        onConnected?()
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didPublishMessage message: CocoaMQTT5Message, id: UInt16) {
        print("MQTT5 published: \(message.topic)")
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didPublishAck id: UInt16, pubAckData: MqttDecodePubAck?) {
        print("MQTT5 publish ack: \(id)")
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didPublishRec id: UInt16, pubRecData: MqttDecodePubRec?) {}

    func mqtt5(_ mqtt5: CocoaMQTT5, didReceiveMessage message: CocoaMQTT5Message, id: UInt16, publishData: MqttDecodePublish?) {
        // 优先 topic 专用回调
        if let cb = topicCallbacks[message.topic] {
            cb(message)
            return
        }
        // 没有专用回调时走全局回调
        if let payload = message.string {
            print("MQTT5 received on \(message.topic): \(payload)")
        }
        onMessageReceived?(message, id, MqttPublishProperties())
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didSubscribeTopics success: NSDictionary, failed: [String], subAckData: MqttDecodeSubAck?) {
        print("MQTT5 subscribe success: \(success), failed: \(failed)")
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didUnsubscribeTopics topics: [String], unsubAckData: MqttDecodeUnsubAck?) {
        print("MQTT5 unsubscribe: \(topics)")
    }

    func mqtt5(_ mqtt5: CocoaMQTT5, didReceiveDisconnectReasonCode reasonCode: CocoaMQTTDISCONNECTReasonCode) {}

    func mqtt5(_ mqtt5: CocoaMQTT5, didReceiveAuthReasonCode reasonCode: CocoaMQTTAUTHReasonCode) {}

    func mqtt5DidPing(_ mqtt5: CocoaMQTT5) {}

    func mqtt5DidReceivePong(_ mqtt5: CocoaMQTT5) {}

    func mqtt5DidDisconnect(_ mqtt5: CocoaMQTT5, withError err: Error?) {
        isConnected = false
        print("MQTT5 disconnected: \(err?.localizedDescription ?? "")")
        onDisconnected?()
    }
}