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

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

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

        private async Task EnsureConnectedAsync()
        {
            if (_tcpClient == null || !_tcpClient.Connected)
            {
                _tcpClient = new TcpClient();
                await _tcpClient.ConnectAsync(_config.IpAddress, _config.Port);
                _master = ModbusIpMaster.CreateIp(_tcpClient);
            }
        }

        // 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）
        private async Task<float> ReadFloatAsync(ushort startAddress)
        {
            await EnsureConnectedAsync();

            // 读取两个寄存器（从站地址由配置指定）
            ushort[] registers = await _master.ReadHoldingRegistersAsync(_config.SlaveId, startAddress, 2);

            // 将两个16位寄存器合并为32位浮点数（大端）
            byte[] bytes = new byte[4];
            bytes[0] = (byte)(registers[0] >> 8);
            bytes[1] = (byte)(registers[0] & 0xFF);
            bytes[2] = (byte)(registers[1] >> 8);
            bytes[3] = (byte)(registers[1] & 0xFF);

            if (BitConverter.IsLittleEndian)
                Array.Reverse(bytes); // 如果系统是小端，需要反转字节顺序

            return BitConverter.ToSingle(bytes, 0);
        }

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

        public async Task<float> ReadWetFlowAsync() =>
            await ReadFloatAsync(_config.WetFlowRegister) * (float)_config.WetFlowFactor;

        public async Task<float> ReadDryFlowAsync() =>
            await ReadFloatAsync(_config.DryFlowRegister) * (float)_config.DryFlowFactor;


        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 _master.WriteSingleRegisterAsync(_config.SlaveId, registerAddress, value);
        }


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


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

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


        // 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);
        }

        /// <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;
        }

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


        /// <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;
        }


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