using S7.Net;
using System;
using System.IO;
using System.Net;
using System.Threading;
using System.Threading.Tasks;

namespace DeviceCommand.Base
{
    public class S7Device : IS7Device
    {
        // 保持和你一致的连接参数命名属性
        public string IPAddress { get; private set; } = "127.0.0.1";
        public CpuType CpuType { get; private set; } = CpuType.S71200;
        public short Rack { get; private set; } = 0;
        public short Slot { get; private set; } = 1;
        public int SendTimeout { get; private set; } = 3000;
        public int ReceiveTimeout { get; private set; } = 3000;

        private Plc _plc;
        public Plc PlcContext => _plc;

        // S7.Net 的 Plc.IsConnected 属性内部会通过 Socket 状态进行判断
        public bool IsConnected => _plc?.IsConnected ?? false;

        // 统一线程锁
        protected readonly SemaphoreSlim _commLock = new(1, 1);

        public S7Device()
        {
            // 初始化默认配置
            _plc = new Plc(CpuType, IPAddress, Rack, Slot);
        }

        /// <summary>
        /// 设备参数配置（符合你的命名风格）
        /// </summary>
        public void ConfigureDevice(string ipAddress, CpuType cpuType, short rack = 0, short slot = 1, int sendTimeout = 3000, int receiveTimeout = 3000)
        {
            IPAddress = ipAddress;
            CpuType = cpuType;
            Rack = rack;
            Slot = slot;
            SendTimeout = sendTimeout;
            ReceiveTimeout = receiveTimeout;
        }

        public virtual async Task<bool> ConnectAsync(CancellationToken ct = default)
        {
            await _commLock.WaitAsync(ct);
            try
            {
                // 如果已经连接，检查当前的 IP 和 CPU 类型是否一致，一致则直接复用
                if (_plc != null && _plc.IsConnected)
                {
                    if (_plc.IP == IPAddress && _plc.CPU == CpuType && _plc.Rack == Rack && _plc.Slot == Slot)
                        return true;
                }

                // 修复：释放并彻底清空旧连接实例
                if (_plc != null)
                {
                    _plc.Close();
                }

                // 重新实例化 Plc 对象并配置超时
                _plc = new Plc(CpuType, IPAddress, Rack, Slot)
                {
                    ReadTimeout = ReceiveTimeout,
                    WriteTimeout = SendTimeout
                };

                // 部分版本 S7.Net 的 OpenAsync 本身不接受 CancellationToken，我们通过 WaitAsync 实现超时
                await _plc.OpenAsync().WaitAsync(TimeSpan.FromMilliseconds(SendTimeout), ct);
                return _plc.IsConnected;
            }
            catch
            {
                return false;
            }
            finally
            {
                _commLock.Release();
            }
        }

        public virtual void Close()
        {
            if (_plc != null && _plc.IsConnected)
                _plc.Close();
        }

        public async Task WriteAsync(string address, object value, CancellationToken ct = default)
        {
            await _commLock.WaitAsync(ct);
            try
            {
                if (!IsConnected) throw new InvalidOperationException("PLC未连接。");

                await _plc.WriteAsync(address, value)
                          .WaitAsync(TimeSpan.FromMilliseconds(SendTimeout), ct);
            }
            finally
            {
                _commLock.Release();
            }
        }

        public async Task<object> ReadAsync(string address, CancellationToken ct = default)
        {
            await _commLock.WaitAsync(ct);
            try
            {
                if (!IsConnected) throw new InvalidOperationException("PLC未连接。");

                return await _plc.ReadAsync(address)
                          .WaitAsync(TimeSpan.FromMilliseconds(ReceiveTimeout), ct);
            }
            finally
            {
                _commLock.Release();
            }
        }

        public async Task<T> ReadAsync<T>(string address, CancellationToken ct = default)
        {
            var result = await ReadAsync(address, ct);
            return (T)result;
        }

        public async Task<byte[]> ReadBytesAsync(DataType dataType, int db, int startByteAdr, int count, CancellationToken ct = default)
        {
            await _commLock.WaitAsync(ct);
            try
            {
                if (!IsConnected) throw new InvalidOperationException("PLC未连接。");

                return await _plc.ReadBytesAsync(dataType, db, startByteAdr, count)
                                 .WaitAsync(TimeSpan.FromMilliseconds(ReceiveTimeout), ct);
            }
            finally
            {
                _commLock.Release();
            }
        }

        public async Task WriteBytesAsync(DataType dataType, int db, int startByteAdr, byte[] value, CancellationToken ct = default)
        {
            await _commLock.WaitAsync(ct);
            try
            {
                if (!IsConnected) throw new InvalidOperationException("PLC未连接。");

                await _plc.WriteBytesAsync(dataType, db, startByteAdr, value)
                          .WaitAsync(TimeSpan.FromMilliseconds(SendTimeout), ct);
            }
            finally
            {
                _commLock.Release();
            }
        }

        public void Dispose()
        {
            _plc?.Close();
            _commLock?.Dispose();
        }
    }
}