using DeviceCommand.Base;
using Model;
using Model.Dto.Config;
using Model.Entity.Config;
using ORM;
using Service.Interface;
using Service.Interface.Config;
using SqlSugar;
using System;
using System.Net;
using System.Threading.Tasks;

namespace Service.Implement.Config
{
    /// <summary>
    /// 设备指令下发 服务实现
    /// 目前无网关运行时/采集引擎：每次调用先落一条设备日志（始终可验证），
    /// 设备在线时才实际尝试 Modbus 写（连接参数从网关表按 GatewayId 加载）。
    /// 每次下发都写审计日志（操作人/角色/时间/前后值），满足实验室审计要求。
    /// </summary>
    public class DeviceCommandService : IDeviceCommandService
    {
        private readonly IAuditRecorder _audit;

        public DeviceCommandService(IAuditRecorder audit)
        {
            _audit = audit;
        }

        public async Task<Result> SendCommandAsync(DeviceCommandDto dto)
        {
            if (dto == null || !long.TryParse(dto.Id, out var deviceId) || deviceId <= 0)
                return Result.Error("设备Id无效");
            if (string.IsNullOrWhiteSpace(dto.PointId) || !long.TryParse(dto.PointId, out var pointId) || pointId <= 0)
                return Result.Error("物模型点Id无效");

            var now = DateTime.Now;

            // 载入设备与点
            var device = await SqlSugarContext.DbContext.Queryable<IotDeviceEntity>()
                .Where(x => x.Id == deviceId && x.IsDel == 0).FirstAsync();
            if (device == null)
                return Result.Error("设备不存在或已被删除");

            var point = await SqlSugarContext.DbContext.Queryable<ThingModelPointEntity>()
                .Where(x => x.Id == pointId && x.OwnerType == ThingOwnerTypeEnum.Device && x.OwnerId == deviceId && x.IsDel == 0).FirstAsync();
            if (point == null)
                return Result.Error("物模型点不存在或不属于该设备");

            // 校验可写
            if (point.Rw == ThingRwEnum.ReadOnly)
                return Result.Error($"点【{point.Name ?? point.Code}】为只读，无法下发指令");
            if (device.ProtocolType != IotDeviceProtocolEnum.ModbusTcp)
                return Result.Error("当前仅支持 Modbus TCP 协议设备下发指令");

            try
            {
                // 模拟模式 / 设备离线 → 只记录、不发网络报文
                if (dto.IsSimulated || device.OnlineStatus != IotDeviceOnlineStatusEnum.Online)
                {
                    await WriteLogAsync(device, "Warn", "指令", dto.IsSimulated
                        ? $"【模拟】点 {point.Name ?? point.Code} 下发值 {dto.Value}（未发送网络报文）"
                        : $"设备离线，指令已记录但未发送（点 {point.Name ?? point.Code} 值 {dto.Value}）");
                    return dto.IsSimulated
                        ? Result.Success()
                        : Result.Error("设备离线，指令已记录但未发送");
                }

                // 从网关表加载连接参数
                var gateway = await SqlSugarContext.DbContext.Queryable<GatewayEntity>()
                    .Where(x => x.Id == device.GatewayId && x.IsDel == 0).FirstAsync();
                if (gateway == null)
                    return Result.Error($"设备关联的网关不存在（GatewayId={device.GatewayId}）");
                if (string.IsNullOrWhiteSpace(gateway.Host) || !gateway.Port.HasValue)
                    return Result.Error($"网关「{gateway.Code}」未配置 IP 地址或端口号");

                var host = gateway.Host!;
                var port = gateway.Port!.Value;

                // 实际 Modbus 写
                using var modbus = new ModbusTcp();
                modbus.ConfigureDevice(host, port, 3000, 3000);
                bool connected = await modbus.ConnectAsync();
                if (!connected)
                {
                    await WriteLogAsync(device, "Error", "指令",
                        $"网关 {gateway.Code}({host}:{port}) 连接失败，指令未发送（点 {point.Name ?? point.Code} 值 {dto.Value}）");
                    return Result.Error($"网关 {gateway.Code} 连接失败，指令未发送");
                }

                string desc;
                if (point.RegisterType == ThingRegisterTypeEnum.Coil)
                {
                    bool coil = dto.Value != 0;
                    await modbus.WriteSingleCoilAsync(device.SlaveId, point.Address, coil);
                    desc = $"写线圈 {point.Name ?? point.Code} 地址 {point.Address} = {coil}";
                }
                else if (point.DataType == ThingDataTypeEnum.Int32 || point.DataType == ThingDataTypeEnum.Float)
                {
                    // 32 位类型占连续 2 个寄存器，走 FC16 连写（Int32 按有符号整数编码，Float 按 IEEE754 编码）
                    ushort[] words = ToWords(dto.Value, point);
                    await modbus.WriteMultipleRegistersAsync(device.SlaveId, point.Address, words);
                    desc = $"写双寄存器 {point.Name ?? point.Code} 地址 {point.Address}~{point.Address + 1} = [{words[0]}, {words[1]}]（工程值 {dto.Value}）";
                }
                else
                {
                    ushort raw = ToRaw(dto.Value, point);
                    await modbus.WriteSingleRegisterAsync(device.SlaveId, point.Address, raw);
                    desc = $"写寄存器 {point.Name ?? point.Code} 地址 {point.Address} = {raw}（工程值 {dto.Value}）";
                }

                await SqlSugarContext.DbContext.Updateable<IotDeviceEntity>()
                    .SetColumns(x => new IotDeviceEntity { LastCollectTime = now, LastError = null })
                    .Where(x => x.Id == device.Id).ExecuteCommandAsync();

                await WriteLogAsync(device, "Info", "指令", $"下发成功：{desc}");
                await _audit.RecordAsync("Command", "IotDevice", device.Id, device.Id,
                    oldValue: null,
                    newValue: $"点={point.Code}, 值={dto.Value}, 模拟={dto.IsSimulated}",
                    description: $"设备 {device.Code} 下发指令：{desc}");
                return Result.Success();
            }
            catch (Exception ex)
            {
                await WriteLogAsync(device, "Error", "指令", $"下发失败：{ex.Message}");
                return Result.Error($"指令下发异常：{ex.Message}", ex);
            }
        }

        /// <summary>
        /// 工程值 → 寄存器原始值：raw = (value - Offset) / Scale，取整并夹到寄存器范围
        /// Int16 按有符号处理（补码），其余类型按 0..65535
        /// </summary>
        private static ushort ToRaw(double value, ThingModelPointEntity point)
        {
            double raw = (value - point.Offset) / point.Scale;
            if (point.DataType == ThingDataTypeEnum.Int16)
            {
                if (raw <= short.MinValue) return unchecked((ushort)short.MinValue);
                if (raw >= short.MaxValue) return (ushort)short.MaxValue;
                return unchecked((ushort)(short)Math.Round(raw));
            }
            if (raw <= 0) return 0;
            if (raw >= 65535) return 65535;
            return (ushort)Math.Round(raw);
        }

        /// <summary>
        /// 工程值 → 32 位双寄存器字数组（raw32 = (value - Offset) / Scale）
        /// Int32 按有符号整数编码，Float 按 IEEE754 编码；字序按 Modbus 常规高字在前（AB CD）
        /// </summary>
        private static ushort[] ToWords(double value, ThingModelPointEntity point)
        {
            uint bits;
            if (point.DataType == ThingDataTypeEnum.Float)
            {
                bits = BitConverter.SingleToUInt32Bits((float)((value - point.Offset) / point.Scale));
            }
            else
            {
                double raw = Math.Round((value - point.Offset) / point.Scale);
                if (raw < int.MinValue) raw = int.MinValue;
                if (raw > int.MaxValue) raw = int.MaxValue;
                bits = unchecked((uint)(int)raw);
            }
            return new[] { (ushort)(bits >> 16), (ushort)(bits & 0xFFFF) };
        }

        /// <summary>
        /// 写一条设备日志（设备独享日志，前端设备日志抽屉可见）
        /// </summary>
        private static async Task WriteLogAsync(IotDeviceEntity device, string level, string logType, string message)
        {
            var now = DateTime.Now;
            await SqlSugarContext.DbContext.Insertable(new DeviceLogEntity
            {
                DeviceId = device.Id,
                DeviceCode = device.Code,
                Level = level,
                LogType = logType,
                Message = message,
                LogTime = now,
                CreateTime = now
            }).ExecuteCommandAsync();
        }
    }
}