using S7.Net; // 确保引用 S7.Net 库
using System;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace RIZO.Service.PLC
{



    public class  PlcConntectHepler : IDisposable
    {
        private Plc _plc;
        private readonly string _ipAddress;
        private readonly CpuType _cpuType;
        private readonly short _rack;
        private readonly short _slot;
        private readonly SemaphoreSlim _semaphore = new SemaphoreSlim(1, 1);
        private bool _disposed;

        public PlcConntectHepler(string ipAddress, CpuType cpuType = CpuType.S71200, short rack = 0, short slot = 1)
        {
            _ipAddress = ipAddress;
            _cpuType = cpuType;
            _rack = rack;
            _slot = slot;
        }

        private async Task ConnectAsync(CancellationToken cancellationToken = default)
        {
            int maxRetries = 3;
            int retryDelayMs = 2000;
            int attempt = 0;

            while (attempt < maxRetries)
            {
                attempt++;
                try
                {
                    _plc = new Plc(_cpuType, _ipAddress, _rack, _slot);
                    await Task.Run(() => _plc.Open(), cancellationToken); // 在线程池中执行同步Open
                    Console.WriteLine($"成功连接到PLC: {_ipAddress} (尝试{attempt}/{maxRetries})");
                    return;
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"连接尝试 {attempt}/{maxRetries} 失败: {ex.Message}");

                    if (attempt < maxRetries)
                    {
                        Console.WriteLine($"{retryDelayMs / 1000}秒后重试...");
                        await Task.Delay(retryDelayMs, cancellationToken);
                    }
                    else
                    {
                        Console.WriteLine("无法建立PLC连接，请检查网络和设备状态");
                        _plc?.Close();
                        _plc = null;
                    }
                }
            }
        }
        /// <summary>
        /// 读取指定类型数据
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="address"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>

        public async Task<T> ReadAsync<T>(string address, CancellationToken cancellationToken = default)
        {
            await _semaphore.WaitAsync(cancellationToken);
            try
            {
                if (_plc == null || !_plc.IsConnected)
                {
                    await ConnectAsync(cancellationToken);
                    if (_plc == null || !_plc.IsConnected)
                        throw new InvalidOperationException("PLC未连接");
                }

                var result = await Task.Run(() => _plc.Read(address), cancellationToken);

                // 根据泛型类型转换结果
                return ConvertResult<T>(result);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Read error: {ex.Message}");
                return default(T);
            }
            finally
            {
                _semaphore.Release();
            }
        }

     
        /// <summary>
        /// 写入指定类型数据
        /// </summary>
        /// <param name="address"></param>
        /// <param name="value"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public async Task WriteAsync(string address, object value, CancellationToken cancellationToken = default)
        {
            await _semaphore.WaitAsync(cancellationToken);
            try
            {
                if (_plc == null || !_plc.IsConnected)
                {
                    await ConnectAsync(cancellationToken);
                    if (_plc == null || !_plc.IsConnected)
                        throw new InvalidOperationException("PLC未连接");
                }

                await Task.Run(() => _plc.Write(address, value), cancellationToken);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Write error: {ex.Message}");
            }
            finally
            {
                _semaphore.Release();
            }
        }



        private T ConvertResult<T>(object result)
        {
            if (result == null) return default(T);

            if (typeof(T).IsAssignableFrom(result.GetType()))
            {
                return (T)result;
            }

            return typeof(T) switch
            {
                Type t when t == typeof(bool) => (T)(object)Convert.ToBoolean(result),
                Type t when t == typeof(short) => (T)(object)Convert.ToInt16(result),
                Type t when t == typeof(int) => (T)(object)Convert.ToInt32(result),
                Type t when t == typeof(float) => (T)(object)Convert.ToSingle(result),
                Type t when t == typeof(double) => (T)(object)Convert.ToDouble(result),
                Type t when t == typeof(string) => (T)(object)result.ToString(),
                _ => throw new InvalidCastException($"无法将类型 {result.GetType()} 转换为 {typeof(T)}")
            };
        }

        /// <summary>
        /// 从PLC读取字符串（主要方法）
        /// </summary>
        /// <param name="address">地址字符串（如："DB1001.DBB1000"）</param>
        /// <returns>读取到的字符串</returns>
        public async Task<string> ReadStringAsync(string address)
        {
            return await ReadStringAsync(address, CancellationToken.None);
        }

        /// <summary>
        /// 从PLC读取字符串（带取消令牌）
        /// </summary>
        /// <param name="address">地址字符串（如："DB1001.DBB1000"）</param>
        /// <param name="cancellationToken">取消令牌</param>
        /// <returns>读取到的字符串</returns>
        public async Task<string> ReadStringAsync(string address, CancellationToken cancellationToken = default)
        {
            await _semaphore.WaitAsync(cancellationToken);
            try
            {
                if (_plc == null || !_plc.IsConnected)
                {
                    await ConnectAsync(cancellationToken);
                    if (_plc == null || !_plc.IsConnected)
                        throw new InvalidOperationException("PLC未连接");
                }

                // 解析地址
                if (!ParseAddress(address, out int dbNumber, out int startByte))
                {
                    throw new ArgumentException($"无效的地址格式: {address}");
                }

                // 读取第一个字节（字符串长度）
                byte stringLength = await Task.Run(() =>
                    (byte)_plc.Read(DataType.DataBlock, dbNumber, startByte, VarType.Byte, 1), cancellationToken);

                // 如果长度为0，直接返回空字符串
                if (stringLength == 0)
                    return string.Empty;

                // 读取字符串内容（从startByte+1开始，读取stringLength个字节）
                byte[] stringBytes = await Task.Run(() =>
                    (byte[])_plc.Read(DataType.DataBlock, dbNumber, startByte + 1, VarType.Byte, (int)stringLength), cancellationToken);

                // 将字节数组转换为ASCII字符串
                return Encoding.ASCII.GetString(stringBytes);
            }
            catch (Exception ex)
            {
                Console.WriteLine($"ReadString error: {ex.Message}");
                return string.Empty;
            }
            finally
            {
                _semaphore.Release();
            }
        }

        /// <summary>
        /// 向PLC写入字符串
        /// </summary>
        /// <param name="address">地址字符串（如："DB1001.DBB1000"）</param>
        /// <param name="value">要写入的字符串</param>
        /// <returns>是否写入成功</returns>
        public async Task<bool> WriteStringAsync(string address, string value)
        {
            return await WriteStringAsync(address, value, CancellationToken.None);
        }

        /// <summary>
        /// 向PLC写入字符串（带取消令牌）
        /// </summary>
        /// <param name="address">地址字符串（如："DB1001.DBB1000"）</param>
        /// <param name="value">要写入的字符串</param>
        /// <param name="cancellationToken">取消令牌</param>
        /// <returns>是否写入成功</returns>
        public async Task<bool> WriteStringAsync(string address, string value, CancellationToken cancellationToken = default)
        {
            await _semaphore.WaitAsync(cancellationToken);
            try
            {
                if (_plc == null || !_plc.IsConnected)
                {
                    await ConnectAsync(cancellationToken);
                    if (_plc == null || !_plc.IsConnected)
                        throw new InvalidOperationException("PLC未连接");
                }

                if (value == null)
                    value = string.Empty;

                // 限制字符串长度（S7字符串最大254字符）
                if (value.Length > 254)
                {
                    value = value.Substring(0, 254);
                }

                // 准备写入的数据
                List<byte> writeData = new List<byte>();

                // 第一个字节：字符串长度
                writeData.Add((byte)value.Length);

                // 后续字节：字符串内容（ASCII编码）
                byte[] contentBytes = Encoding.ASCII.GetBytes(value);
                writeData.AddRange(contentBytes);

                // 解析地址
                if (!ParseAddress(address, out int dbNumber, out int startByte))
                {
                    throw new ArgumentException($"无效的地址格式: {address}");
                }

                // 写入数据
                await Task.Run(() =>
                    _plc.WriteBytes(DataType.DataBlock, dbNumber, startByte, writeData.ToArray()), cancellationToken);

                return true;
            }
            catch (Exception ex)
            {
                Console.WriteLine($"WriteString error: {ex.Message}");
                return false;
            }
            finally
            {
                _semaphore.Release();
            }
        }

        /// <summary>
        /// 解析PLC地址字符串，提取DB号和起始字节
        /// 支持格式：DB1001.DBB1000, DB1001.DBW1000, DB1001.DBD1000 等
        /// </summary>
        private bool ParseAddress(string address, out int dbNumber, out int startByte)
        {
            dbNumber = 0;
            startByte = 0;

            try
            {
                // 移除空格并转为大写
                address = address.Replace(" ", "").ToUpper();

                // 分割DB部分和数据部分
                string[] parts = address.Split('.');
                if (parts.Length < 2) return false;

                // 解析DB号
                string dbPart = parts[0];
                if (!dbPart.StartsWith("DB") || !int.TryParse(dbPart.Substring(2), out dbNumber))
                    return false;

                // 解析起始字节
                string dataPart = parts[1];

                // 提取偏移量数字（去掉DBB/DBW/DBD前缀）
                string offsetStr = "";
                if (dataPart.StartsWith("DBB"))
                    offsetStr = dataPart.Substring(3);
                else if (dataPart.StartsWith("DBW"))
                    offsetStr = dataPart.Substring(3);
                else if (dataPart.StartsWith("DBD"))
                    offsetStr = dataPart.Substring(3);
                else
                    return false;

                if (!int.TryParse(offsetStr, out startByte))
                    return false;

                return true;
            }
            catch
            {
                return false;
            }
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (_disposed) return;

            if (disposing)
            {
                _semaphore.Dispose();
                _plc?.Close();
                (_plc as IDisposable)?.Dispose();
            }
            _disposed = true;
        }
    }

}