using Modbus.Device;
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading.Tasks;
using System.Threading;
using System.Threading.Tasks;

namespace MembranePoreTester.Communication
{
    public class ModbusTcpPlcService : IPlcService, IDisposable
    {
        private readonly PlcConfiguration _config;
        private TcpClient _tcpClient;
        private IModbusMaster _master;

        public ModbusTcpPlcService(PlcConfiguration config)
        {
            _config = config;
        }

 public async Task EnsureConnectedAsync(int retryCount = 3)
    {
        if (_tcpClient != null && _tcpClient.Connected)
            return;

        for (int i = 0; i < retryCount; i++)
        {
            try
            {
                _tcpClient?.Close();
                _tcpClient = new TcpClient();
                using var cts = new CancellationTokenSource(TimeSpan.FromSeconds(3));
                // 现在可以直接使用扩展方法
                await _tcpClient.ConnectAsync(_config.IpAddress, _config.Port).WithCancellation(cts.Token);
                _master = ModbusIpMaster.CreateIp(_tcpClient);
                return;
            }
            catch (Exception ex) when (i < retryCount - 1)
            {
                System.Diagnostics.Debug.WriteLine($"连接失败，{500}ms 后重试... {ex.Message}");
                await Task.Delay(500);
            }
        }
        throw new Exception($"无法连接到 PLC ({_config.IpAddress}:{_config.Port})，请检查网络和 PLC 状态。");
    }

        // 读取两个连续的保持寄存器，转换为32位浮点数（假设大端模式）
        public async Task<float> ReadFloatAsync(ushort startAddress)
        {
            await EnsureConnectedAsync();
            var registers = await ReadHoldingRegistersAsync(startAddress, 2);
            return UshortToFloat(registers[1], registers[0]);
        }


        public async Task<float> ReadPressureAsync() =>
            await ReadFloatAsync(_config.PressureRegister);

        public async Task<float> ReadWetFlowAsync(int stationId)
        {
            ushort startAddress = stationId switch
            {
                1 => _config.WetFlowRegister,
                2 => _config.WetFlowRegister2,
                3 => _config.WetFlowRegister3,
            };
            return await ReadFloatAsync(startAddress);
        }

        public async Task<float> ReadDryFlowAsync(int stationId)
        {
            ushort startAddress = stationId switch
            {
                1 => _config.DryFlowRegister,
                2 => _config.DryFlowRegister2,
                3 => _config.DryFlowRegister3,
                _ => throw new ArgumentException("Invalid station")
            };
            return await ReadFloatAsync(startAddress);
        }


        public async Task WriteCoilAsync(ushort coilAddress, bool value)
        {
            await EnsureConnectedAsync();
            await _master.WriteSingleCoilAsync(_config.SlaveId, coilAddress, value);
        }

        public async Task WriteRegisterAsync(ushort registerAddress, ushort value)
        {
            await EnsureConnectedAsync();
            await Task.Delay(100);
            await _master.WriteSingleRegisterAsync(_config.SlaveId, registerAddress, value);
        }


        public async Task<bool> ReadCoilAsync(ushort coilAddress)
        {
            await EnsureConnectedAsync();
            await Task.Delay(100);
            bool[] result = await _master?.ReadCoilsAsync(_config.SlaveId, coilAddress, 1);
            return result[0];
        }

        public bool IsConnected => _tcpClient != null && _tcpClient.Connected;

        public async Task<ushort[]> ReadHoldingRegistersAsync(ushort startAddress, ushort count)
        {
            await EnsureConnectedAsync();
           // await Task.Delay(100);
            return await _master.ReadHoldingRegistersAsync(_config.SlaveId, startAddress, count);
        }

        public async Task WriteSingleRegisterAsync(ushort registerAddress, ushort value)
        {
            await EnsureConnectedAsync();
            int val = (int)value;
            await Task.Delay(100);
            await _master.WriteMultipleRegistersAsync(1, registerAddress, intToushorts(val));
        }

        public async Task WriteMultipleRegistersAsync(ushort registerAddress, float value)
        {
            await EnsureConnectedAsync();
            await Task.Delay(100);
            await _master.WriteMultipleRegistersAsync(_config.SlaveId, registerAddress, SplitFloatToUShortArray((float)value));
        }

        /// <summary>
        /// Int转为ushort数组发送
        /// </summary>
        /// <param name="res"></param>
        /// <returns>返回ushort数组</returns>
        private ushort[] intToushorts(int res)
        {
            ushort ust1 = (ushort)(res >> 16);
            ushort ust2 = (ushort)res;
            return new ushort[] { ust2, ust1 };
        }


        /// <summary>
        /// Float转为Ushort数组发送
        /// </summary>
        /// <param name="value"></param>
        /// <returns>返回ushort数组</returns>
        public ushort[] SplitFloatToUShortArray(float value)
        {
            byte[] floatBytes = BitConverter.GetBytes(value);
            ushort[] ushortArray = new ushort[floatBytes.Length / 2];

            for (int i = 0, j = 0; i < floatBytes.Length; i += 2, j++)
            {
                ushortArray[j] = BitConverter.ToUInt16(floatBytes, i);
            }

            return ushortArray;
        }

        /// <summary>
        /// ushort转为float类型
        /// </summary>
        /// <param name="P1"></param>
        /// <param name="P2"></param>
        /// <returns>float型数据</returns>
        public float UshortToFloat(ushort P1, ushort P2)
        {
            int intSign, intSignRest, intExponent, intExponentRest;
            float faResult, faDigit;
            intSign = P1 / 32768;
            intSignRest = P1 % 32768;
            intExponent = intSignRest / 128;
            intExponentRest = intSignRest % 128;
            faDigit = (float)(intExponentRest * 65536 + P2) / 8388608;
            faResult = (float)Math.Pow(-1, intSign) * (float)Math.Pow(2, intExponent - 127) * (faDigit + 1);
            return faResult;
        }

        // 新增读取压力（根据工位）
        public async Task<float> ReadPressureAsync(int stationId)
        {
            ushort startAddress = stationId switch
            {
                1 => _config.PressureRegisterStation1,
                2 => _config.PressureRegisterStation2,
                3 => _config.PressureRegisterStation3,
                _ => throw new ArgumentException("Invalid station")
            };
            return await ReadFloatAsync(startAddress);
        }


        public void Dispose()
        {
            _master?.Dispose();
            _tcpClient?.Close();
            _tcpClient?.Dispose();
        }
    }


    public static class TaskExtensions
    {
        public static async Task WithCancellation(this Task task, CancellationToken cancellationToken)
        {
            var tcs = new TaskCompletionSource<bool>();
            using (cancellationToken.Register(s => ((TaskCompletionSource<bool>)s).TrySetResult(true), tcs))
            {
                if (task != await Task.WhenAny(task, tcs.Task))
                    throw new OperationCanceledException(cancellationToken);
            }
            await task;
        }
    }
}