using System;
using System.Threading.Tasks;
using XP.Common.Logging.Interfaces;
using XP.Hardware.Plc.Abstractions;
using XP.Hardware.Plc.Exceptions;
using XP.Hardware.Plc.Services;
using XP.Hardware.PLC.Configs;
using XP.Hardware.PLC.Helpers;
using XP.Hardware.PLC.Models;
using XP.Hardware.PLC.Services;

namespace XP.Hardware.Plc.Services
{
    /// <summary>
    /// PLC 信号数据交互服务实现 | PLC signal data interaction service implementation
    /// 提供基于信号逻辑名称的缓存读取、队列写入和直接写入+回读校验操作
    /// Provides cache read, queue write, and direct write with read-back verification based on signal logical names
    /// </summary>
    public class SignalDataService : ISignalDataService
    {
        private readonly PlcService _plcService;
        private readonly PlcWriteQueue _writeQueue;
        private readonly IPlcClient _directWriteChannel;
        private readonly ILoggerService _logger;

        /// <summary>
        /// 直接写入通道引用，供 PlcService 管理连接生命周期
        /// Direct write channel reference, for PlcService to manage connection lifecycle
        /// </summary>
        public IPlcClient DirectWriteChannel => _directWriteChannel;

        /// <summary>
        /// 构造函数 | Constructor
        /// </summary>
        /// <param name="plcService">PLC 服务实例，提供缓存快照和信号查找 | PLC service instance for cache snapshot and signal lookup</param>
        /// <param name="writeQueue">PLC 写入队列，用于队列写入操作 | PLC write queue for enqueue write operations</param>
        /// <param name="directWriteChannel">直接写入通道，独立的 IPlcClient 实例用于高优先级写入 | Direct write channel, independent IPlcClient instance for high-priority writes</param>
        /// <param name="logger">日志服务 | Logger service</param>
        public SignalDataService(
            PlcService plcService,
            PlcWriteQueue writeQueue,
            IPlcClient directWriteChannel,
            ILoggerService logger)
        {
            _plcService = plcService ?? throw new ArgumentNullException(nameof(plcService));
            _writeQueue = writeQueue ?? throw new ArgumentNullException(nameof(writeQueue));
            _directWriteChannel = directWriteChannel ?? throw new ArgumentNullException(nameof(directWriteChannel));
            _logger = logger?.ForModule<SignalDataService>() ?? throw new ArgumentNullException(nameof(logger));
        }

        /// <summary>
        /// 从 ReadDbBlock 配置字符串中提取 DB 块号 | Extract DB block number from ReadDbBlock config string
        /// 例如 "DB1" → 1，"DB31" → 31 | e.g. "DB1" → 1, "DB31" → 31
        /// </summary>
        /// <param name="readDbBlock">ReadDbBlock 配置值 | ReadDbBlock config value</param>
        /// <returns>DB 块号 | DB block number</returns>
        private int ExtractDbNumber(string readDbBlock)
        {
            if (string.IsNullOrEmpty(readDbBlock))
                return -1;

            // 移除 "DB" 前缀，解析数字部分 | Remove "DB" prefix, parse numeric part
            var numStr = readDbBlock.StartsWith("DB", StringComparison.OrdinalIgnoreCase)
                ? readDbBlock.Substring(2)
                : readDbBlock;

            return int.TryParse(numStr, out var num) ? num : -1;
        }

        /// <summary>
        /// 格式化单点读取地址 | Format single-point read address
        /// bool 类型追加位索引 | Bool type appends bit index
        /// </summary>
        /// <param name="signal">信号定义条目 | Signal definition entry</param>
        /// <returns>格式化后的 PLC 地址字符串 | Formatted PLC address string</returns>
        private string FormatReadAddress(SignalEntry signal)
        {
            return signal.Type.ToLowerInvariant() switch
            {
                "bool" => $"DB{signal.DBNumber}.{signal.StartAddr}.{signal.IndexOrLength}",
                _ => $"DB{signal.DBNumber}.{signal.StartAddr}"
            };
        }

        /// <summary>
        /// 通过单点读取获取信号值 | Get signal value via single-point read
        /// 根据信号类型调用对应的 ReadAsync 方法 | Call corresponding ReadAsync method based on signal type
        /// </summary>
        /// <param name="signal">信号定义条目 | Signal definition entry</param>
        /// <param name="address">PLC 地址 | PLC address</param>
        /// <returns>读取的信号值 | Read signal value</returns>
        private object ReadSinglePoint(SignalEntry signal, string address)
        {
            // 使用 Task.Run 在线程池执行异步读取，避免 UI 线程 SynchronizationContext 死锁
            // Use Task.Run to execute async read on thread pool, avoiding UI thread SynchronizationContext deadlock
            return signal.Type.ToLowerInvariant() switch
            {
                "bool" => Task.Run(() => _plcService.ReadValueAsync<bool>(address)).GetAwaiter().GetResult(),
                "byte" => Task.Run(() => _plcService.ReadValueAsync<byte>(address)).GetAwaiter().GetResult(),
                "short" => Task.Run(() => _plcService.ReadValueAsync<short>(address)).GetAwaiter().GetResult(),
                "int" => Task.Run(() => _plcService.ReadValueAsync<int>(address)).GetAwaiter().GetResult(),
                "single" => Task.Run(() => _plcService.ReadValueAsync<float>(address)).GetAwaiter().GetResult(),
                "double" => Task.Run(() => _plcService.ReadValueAsync<double>(address)).GetAwaiter().GetResult(),
                "string" => Task.Run(() => _plcService.ReadStringAsync(address,
                    int.TryParse(signal.IndexOrLength, out var len) ? (ushort)len : (ushort)1)).GetAwaiter().GetResult(),
                _ => throw new PlcException(
                    $"不支持的信号类型: {signal.Type}, 信号: {signal.Name} | " +
                    $"Unsupported signal type: {signal.Type}, signal: {signal.Name}")
            };
        }

        /// <inheritdoc />
        public object GetValueByName(string signalName)
        {
            // 查找信号定义 | Look up signal definition
            var signal = _plcService.FindSignal(signalName);

            // 提取批量读取参数 | Extract bulk read parameters
            var bulkDbNumber = ExtractDbNumber(_plcService.Config.ReadDbBlock);
            var bulkStart = _plcService.Config.ReadStartAddress;
            var bulkEnd = bulkStart + _plcService.Config.ReadLength - 1;

            // 判断是否走批量缓存：DB 号匹配 且 信号地址在缓存范围内
            // Route to bulk cache: DB number matches AND signal address within cache range
            var useBulkCache = signal.DBNumber == bulkDbNumber
                               && signal.StartAddr >= bulkStart
                               && signal.StartAddr <= bulkEnd;

            object result;

            if (useBulkCache)
            {
                // 匹配批量读取范围，走缓存解析逻辑 | Within bulk read range, use cache parsing logic
                var dataBlock = _plcService.GetCacheSnapshot();
                if (dataBlock == null)
                {
                    throw new PlcException("数据缓存未就绪 | Data cache not ready");
                }

                try
                {
                    result = ParseSignalValue(signal, dataBlock);
                }
                catch (PlcException)
                {
                    throw;
                }
                catch (Exception ex)
                {
                    throw new PlcException(
                        $"信号解析失败: {signal.Name}, 原因: {ex.Message} | Signal parsing failed: {signal.Name}, reason: {ex.Message}",
                        ex);
                }
            }
            else
            {
                // 不在批量读取范围内，走单点读取逻辑 | Outside bulk read range, use single-point read
                var address = FormatReadAddress(signal);
                try
                {
                    result = ReadSinglePoint(signal, address);
                }
                catch (PlcException)
                {
                    throw;
                }
                catch (Exception ex)
                {
                    throw new PlcException(
                        $"单点读取失败: 信号={signal.Name}, DB块={signal.DBNumber}, 原因={ex.Message} | " +
                        $"Single-point read failed: signal={signal.Name}, DB={signal.DBNumber}, reason={ex.Message}",
                        ex);
                }
            }

            // 记录调试日志 | Log debug info
            _logger.Debug("读取信号: {SignalName}, DB块={DBNumber}, 结果: {Result} | Read signal: {SignalName}, DB={DBNumber}, result: {Result}",
                signalName, signal.DBNumber, result);

            return result;
        }

        /// <inheritdoc />
        public T GetValueByName<T>(string signalName)
        {
            // 调用非泛型方法获取解析结果 | Call non-generic method to get parsed result
            var result = GetValueByName(signalName);

            // 将结果转换为目标类型 T | Convert result to target type T
            try
            {
                return (T)Convert.ChangeType(result, typeof(T));
            }
            catch (Exception ex) when (ex is InvalidCastException || ex is FormatException || ex is OverflowException)
            {
                throw new PlcException(
                    $"类型转换失败: 信号 {signalName}, 期望类型: {typeof(T).Name}, 实际类型: {result?.GetType().Name ?? "null"} | " +
                    $"Type conversion failed: signal {signalName}, expected: {typeof(T).Name}, actual: {result?.GetType().Name ?? "null"}",
                    ex);
            }
        }

        /// <summary>
        /// 根据信号定义从数据块中解析信号值 | Parse signal value from data block based on signal definition
        /// </summary>
        /// <param name="signal">信号定义条目 | Signal definition entry</param>
        /// <param name="dataBlock">PLC 数据块快照 | PLC data block snapshot</param>
        /// <returns>解析后的信号值 | Parsed signal value</returns>
        private object ParseSignalValue(SignalEntry signal, PlcDataBlock dataBlock)
        {
            return signal.Type.ToLowerInvariant() switch
            {
                "bool" => dataBlock.GetBool(signal.StartAddr, int.TryParse(signal.IndexOrLength, out var bitIdx) ? bitIdx : 0),
                "byte" => dataBlock.GetByte(signal.StartAddr),
                "short" => dataBlock.GetInt16(signal.StartAddr),
                "int" => dataBlock.GetInt32(signal.StartAddr),
                "single" => dataBlock.GetFloat(signal.StartAddr),
                "double" => dataBlock.GetDouble(signal.StartAddr),
                "string" => dataBlock.GetString(signal.StartAddr, int.TryParse(signal.IndexOrLength, out var len) ? len : 1),
                _ => throw new PlcException(
                    $"不支持的信号类型: {signal.Type}, 信号: {signal.Name} | " +
                    $"Unsupported signal type: {signal.Type}, signal: {signal.Name}")
            };
        }

        /// <summary>
        /// 根据信号类型获取对应的 CLR 类型 | Get CLR type based on signal type
        /// </summary>
        /// <param name="signalType">信号类型字符串 | Signal type string</param>
        /// <returns>对应的 CLR 类型 | Corresponding CLR type</returns>
        private Type GetClrType(string signalType)
        {
            return signalType.ToLowerInvariant() switch
            {
                "bool" => typeof(bool),
                "byte" => typeof(byte),
                "short" => typeof(short),
                "int" => typeof(int),
                "single" => typeof(float),
                "double" => typeof(double),
                "string" => typeof(string),
                _ => throw new PlcException($"不支持的信号类型: {signalType} | Unsupported signal type: {signalType}")
            };
        }

        /// <summary>
        /// 根据信号类型转换写入值 | Convert write value based on signal type
        /// 使用 System.Convert 执行安全类型转换 | Uses System.Convert for safe type conversion
        /// </summary>
        /// <param name="signalName">信号名称，用于异常消息 | Signal name for exception messages</param>
        /// <param name="signal">信号定义条目 | Signal definition entry</param>
        /// <param name="value">待转换的值 | Value to convert</param>
        /// <returns>转换后的值 | Converted value</returns>
        private object ConvertValue(string signalName, SignalEntry signal, object value)
        {
            try
            {
                var targetType = GetClrType(signal.Type);
                return Convert.ChangeType(value, targetType);
            }
            catch (Exception ex) when (ex is InvalidCastException || ex is OverflowException || ex is FormatException)
            {
                throw new PlcException(
                    $"类型转换失败: 信号 {signalName}, 期望类型: {signal.Type}, 实际类型: {value?.GetType().Name ?? "null"} | " +
                    $"Type conversion failed: signal {signalName}, expected: {signal.Type}, actual: {value?.GetType().Name ?? "null"}",
                    ex);
            }
        }

        /// <summary>
        /// 根据信号定义格式化 PLC 写入地址 | Format PLC write address based on signal definition
        /// 使用信号所属 DBNumber 拼接地址 | Uses signal's DBNumber to construct address
        /// bool 类型包含位索引，其他类型仅包含起始地址 | Bool type includes bit index, others only include start address
        /// </summary>
        /// <param name="signal">信号定义条目 | Signal definition entry</param>
        /// <returns>格式化后的 PLC 地址字符串 | Formatted PLC address string</returns>
        private string FormatWriteAddress(SignalEntry signal)
        {
            return signal.Type.ToLowerInvariant() switch
            {
                "bool" => $"DB{signal.DBNumber}.{signal.StartAddr}.{signal.IndexOrLength}",
                _ => $"DB{signal.DBNumber}.{signal.StartAddr}"
            };
        }

        /// <inheritdoc />
        public bool EnqueueWrite(string signalName, object value)
        {
            // 查找信号定义 | Look up signal definition
            var signal = _plcService.FindSignal(signalName);

            // 类型转换校验 | Type conversion validation
            var convertedValue = ConvertValue(signalName, signal, value);

            // 格式化写入地址 | Format write address
            var address = FormatWriteAddress(signal);

            // 检查队列状态 | Check queue status
            if (!_writeQueue.IsRunning)
            {
                _logger.Warn("写入队列未运行，无法入队: 信号={SignalName} | Write queue not running, cannot enqueue: signal={SignalName}", signalName);
                return false;
            }

            // 根据信号类型调用对应的入队方法 | Call corresponding enqueue method based on signal type
            var signalType = signal.Type.ToLowerInvariant();
            if (signalType == "string")
            {
                var strValue = convertedValue as string ?? convertedValue.ToString();
                var length = int.TryParse(signal.IndexOrLength, out var len) ? (ushort)len : (ushort)1;
                _writeQueue.EnqueueString(address, strValue, length);
            }
            else
            {
                // 根据具体类型调用泛型入队方法 | Call generic enqueue method based on specific type
                switch (signalType)
                {
                    case "bool":
                        _writeQueue.Enqueue(address, (bool)convertedValue);
                        break;
                    case "byte":
                        _writeQueue.Enqueue(address, (byte)convertedValue);
                        break;
                    case "short":
                        _writeQueue.Enqueue(address, (short)convertedValue);
                        break;
                    case "int":
                        _writeQueue.Enqueue(address, (int)convertedValue);
                        break;
                    case "single":
                        _writeQueue.Enqueue(address, (float)convertedValue);
                        break;
                    case "double":
                        _writeQueue.Enqueue(address, (double)convertedValue);
                        break;
                    default:
                        throw new PlcException($"不支持的信号类型: {signal.Type} | Unsupported signal type: {signal.Type}");
                }
            }

            // 记录调试日志 | Log debug info
            _logger.Debug("队列写入: 信号={SignalName}, 值={Value}, 地址={Address} | Queue write: signal={SignalName}, value={Value}, address={Address}",
                signalName, convertedValue, address);

            return true;
        }

        /// <inheritdoc />
        public async Task<bool> WriteDirectWithVerify(string signalName, object value)
        {
            // 查找信号定义 | Look up signal definition
            var signal = _plcService.FindSignal(signalName);

            // 类型转换校验 | Type conversion validation
            var convertedValue = ConvertValue(signalName, signal, value);

            // 格式化写入地址 | Format write address
            var address = FormatWriteAddress(signal);

            // 检查 Direct_Write_Channel 连接状态 | Check Direct_Write_Channel connection status
            if (!_directWriteChannel.IsConnected)
            {
                _logger.Error(null, "直接写入通道未连接: 信号={SignalName} | Direct write channel not connected: signal={SignalName}", signalName);
                return false;
            }

            try
            {
                var signalType = signal.Type.ToLowerInvariant();
                bool writeSuccess;
                object readBackValue;

                // 根据信号类型执行写入和回读操作 | Execute write and read-back based on signal type
                if (signalType == "string")
                {
                    var strValue = convertedValue as string ?? convertedValue.ToString();
                    var length = int.TryParse(signal.IndexOrLength, out var len) ? (ushort)len : (ushort)1;

                    // 写入字符串 | Write string
                    writeSuccess = await _directWriteChannel.WriteStringAsync(address, strValue, length);
                    if (!writeSuccess)
                    {
                        _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                            signalName, address);
                        return false;
                    }

                    // 回读字符串 | Read back string
                    readBackValue = await _directWriteChannel.ReadStringAsync(address, length);
                }
                else
                {
                    // 根据具体类型执行泛型写入和回读 | Execute generic write and read-back based on specific type
                    switch (signalType)
                    {
                        case "bool":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (bool)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<bool>(address);
                            break;
                        case "byte":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (byte)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<byte>(address);
                            break;
                        case "short":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (short)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<short>(address);
                            break;
                        case "int":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (int)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<int>(address);
                            break;
                        case "single":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (float)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<float>(address);
                            break;
                        case "double":
                            writeSuccess = await _directWriteChannel.WriteAsync(address, (double)convertedValue);
                            if (!writeSuccess)
                            {
                                _logger.Error(null, "直接写入失败: 信号={SignalName}, 地址={Address} | Direct write failed: signal={SignalName}, address={Address}",
                                    signalName, address);
                                return false;
                            }
                            readBackValue = await _directWriteChannel.ReadAsync<double>(address);
                            break;
                        default:
                            throw new PlcException(
                                $"不支持的信号类型: {signal.Type}, 信号: {signal.Name} | " +
                                $"Unsupported signal type: {signal.Type}, signal: {signal.Name}");
                    }
                }

                // 比较回读值与写入值 | Compare read-back value with written value
                var isMatch = convertedValue.Equals(readBackValue);

                // Info 级别记录信号名称、写入值、回读值和校验结果 | Log at Info level
                _logger.Info("直接写入校验: 信号={SignalName}, 写入值={WriteValue}, 回读值={ReadValue}, 结果={Result} | " +
                    "Direct write verify: signal={SignalName}, write={WriteValue}, readback={ReadValue}, result={Result}",
                    signalName, convertedValue, readBackValue, isMatch ? "通过|Pass" : "失败|Fail");

                if (!isMatch)
                {
                    _logger.Error(null, "回读校验失败: 信号={SignalName}, 写入值={WriteValue}, 回读值={ReadValue} | " +
                        "Read-back verification failed: signal={SignalName}, write={WriteValue}, readback={ReadValue}",
                        signalName, convertedValue, readBackValue);
                }

                return isMatch;
            }
            catch (PlcException)
            {
                throw;
            }
            catch (Exception ex)
            {
                _logger.Error(ex, "直接写入异常: 信号={SignalName}, 错误={Message} | Direct write exception: signal={SignalName}, error={Message}",
                    signalName, ex.Message);
                return false;
            }
        }
    }
}