using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Protocol;
using MySql.Data.MySqlClient;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using YiDa_WinForm.Config;
using MQTTnet.Packets;

namespace YiDa_WinForm.Service.Mqtt
{
    /// <summary>
    /// MQTT连接Service
    /// </summary>
    public class MqttClientService
    {
        // MQTT连接配置
        private readonly IMqttClient _mqttClient;
        private readonly MqttClientOptions _options;
        
        // 数据库连接配置
        private readonly string _connectionString = AppConfig.MySqlConnectionString;

        // 通知UI层
        public event Action<string> MessageReceived; 
        

        /// <summary>
        /// 构造器
        /// </summary>
        public MqttClientService()
        {
            var factory = new MqttFactory();
            _mqttClient = factory.CreateMqttClient();

            // 连接成功事件
            _mqttClient.ConnectedAsync += async e =>
            {
                MessageReceived?.Invoke("已连接MQTT服务器！");
                // 定义要订阅的多个 Topic 和对应的 QoS
                var topicFilters = new List<MqttTopicFilter>
                {
                    new MqttTopicFilter { Topic = "fg_yida/#", QualityOfServiceLevel = MqttQualityOfServiceLevel.AtLeastOnce }
                };
                // 构建批量订阅选项
                var subscribeOptions = new MqttClientSubscribeOptions
                {
                    TopicFilters = topicFilters
                };
                // 执行订阅并仅校验
                try
                {
                    await _mqttClient.SubscribeAsync(subscribeOptions, CancellationToken.None);
                    MessageReceived?.Invoke("已订阅主题：fg_yida");
                }
                catch (Exception ex)
                {
                    MessageReceived?.Invoke($"订阅失败：{ex.Message}");
                }
            };

            // 断开事件
            _mqttClient.DisconnectedAsync += e =>
            {
                MessageReceived?.Invoke("已断开连接！");
                return Task.CompletedTask;
            };

            // 收到消息事件
            _mqttClient.ApplicationMessageReceivedAsync += async e =>
            {
                string topic = e.ApplicationMessage.Topic;
                string payload = Encoding.UTF8.GetString(e.ApplicationMessage.PayloadSegment.ToArray());

                MessageReceived?.Invoke($" 收到消息：{topic} → {payload}");

                await SaveMessageToDatabaseAsync(topic, payload);
            };
            
            // 构建连接参数
            _options = new MqttClientOptionsBuilder()
                .WithClientId("fg_yida_server_07")
                .WithTcpServer("192.168.1.103", 1883)
                .WithCredentials("admin", "admin123")
                .WithCleanSession()
                .Build();
        }

        /// <summary>
        /// 开启连接
        /// </summary>
        public async Task MqttClientStartAsync()
        {
            await _mqttClient.ConnectAsync(_options);
        }

        /// <summary>
        /// 断开连接
        /// </summary>
        public async Task MqttClientStopAsync()
        {
            if (_mqttClient.IsConnected)
            {
                await _mqttClient.DisconnectAsync();
                MessageReceived?.Invoke("手动断开连接。");
            }
        }
        
        /// <summary>
        /// 保存MQTT数据到数据库
        /// </summary>
        /// <param name="topic"></param>
        /// <param name="payload"></param>
        private async Task SaveMessageToDatabaseAsync(string topic, string payload)
        {
            try
            {
                // 新topic示例: fg_yida/424949da1b1e/fg_ht_zs_01/device/data/push
                string[] topics = topic.Split('/');

                // 默认 unknown
                string deviceCode = "unknown";

                if (topics.Length >= 3)
                {
                    // 第三个部分是设备代号，例如 fg_ht_zs_01、fg_ht_zs_02
                    string deviceName = topics[2];

                    //  fg_ht_zs_01 → device1，fg_ht_zs_02 → device2
                    switch (deviceName)
                    {
                        case "fg_ht_zs_01":
                            deviceCode = "device1";
                            break; 
                        case "fg_ht_zs_02":
                            deviceCode = "device2";
                            break;
                        case "fg_ht_wk_01":
                            deviceCode = "device3";
                            break;
                        case "fg_ht_wk_02":
                            deviceCode = "device4";
                            break;
                        default:
                            deviceCode = deviceName; // 新设备直接使用原始名称
                            break;
                            
                    }
                }
                
                // 解析 payload 获取时间戳
                JObject json = JObject.Parse(payload);
                long timestamp = json["time"]?.Value<long>() ?? 0;
                DateTime timeReceive = DateTimeOffset.FromUnixTimeMilliseconds(timestamp).LocalDateTime;

                using (var conn = new MySqlConnection(_connectionString))
                {
                    await conn.OpenAsync();
                    string sql = @"INSERT INTO yida_mqtt_message (device_code, receive_data, receive_time, create_time)
                               VALUES (@device_code, @receive_data, @receive_time, @create_time)";
                    DateTime timeSave = DateTime.Now;
                    using (var cmd = new MySqlCommand(sql, conn))
                    {
                        cmd.Parameters.AddWithValue("@device_code", deviceCode);
                        cmd.Parameters.AddWithValue("@receive_data", payload);
                        cmd.Parameters.AddWithValue("@receive_time", timeReceive);
                        cmd.Parameters.AddWithValue("@create_time", timeSave);
                        await cmd.ExecuteNonQueryAsync();
                    }
                }
                MessageReceived?.Invoke("数据已保存到数据库。");
            }
            catch (Exception ex)
            {
                MessageReceived?.Invoke($"保存数据库时出错：{ex.Message} {ex.InnerException?.Message}");
            }
        }
        
    }
}