using MediatR;
using Microsoft.Extensions.Logging;
using CellularManagement.Domain.Common;
using CellularManagement.Domain.Entities.Device;
using CellularManagement.Domain.Repositories.Device;
using CellularManagement.Domain.Repositories.Base;
using CellularManagement.Domain.Services;
using CellularManagement.Domain.Repositories.NetworkProfile;
using X1.Domain.Models;
using System.Collections.Concurrent;
using X1.Domain.ThirdPartyDeviceHttpClient.Models;
using X1.Domain.ThirdPartyDeviceHttpClient;

namespace CellularManagement.Application.Features.DeviceRuntimes.Commands.StartDeviceRuntime;

/// <summary>
/// 启动设备运行时状态命令处理器
/// </summary>
public class StartDeviceRuntimeCommandHandler : IRequestHandler<StartDeviceRuntimeCommand, OperationResult<StartDeviceRuntimeResponse>>
{
    private readonly ICellularDeviceRuntimeRepository _deviceRuntimeRepository;
    private readonly ICellularDeviceRepository _deviceRepository;
    private readonly ILogger<StartDeviceRuntimeCommandHandler> _logger;
    private readonly IUnitOfWork _unitOfWork;
    private readonly ICurrentUserService _currentUserService;
    private readonly IInstrumentProtocolClient _protocolClient;
    private readonly INetworkStackConfigRepository _networkStackConfigRepository;
    private readonly ICellularDeviceRuntimeDetailRepository _detailRepository;

    /// <summary>
    /// 初始化命令处理器
    /// </summary>
    public StartDeviceRuntimeCommandHandler(
        INetworkStackConfigRepository networkStackConfigRepository,
        ICellularDeviceRuntimeRepository deviceRuntimeRepository,
        ICellularDeviceRepository deviceRepository,
        ILogger<StartDeviceRuntimeCommandHandler> logger,
        IUnitOfWork unitOfWork,
        ICurrentUserService currentUserService, 
        IInstrumentProtocolClient protocolClient,
        ICellularDeviceRuntimeDetailRepository detailRepository)
    {
        _deviceRuntimeRepository = deviceRuntimeRepository;
        _deviceRepository = deviceRepository;
        _logger = logger;
        _unitOfWork = unitOfWork;
        _currentUserService = currentUserService;
        _protocolClient = protocolClient;
        _networkStackConfigRepository = networkStackConfigRepository;
        _detailRepository = detailRepository;
    }

    /// <summary>
    /// 处理启动设备运行时状态命令
    /// </summary>
    public async Task<OperationResult<StartDeviceRuntimeResponse>> Handle(StartDeviceRuntimeCommand request, CancellationToken cancellationToken)
    {
        try
        {
            _logger.LogInformation("开始批量启动设备运行时状态，设备数量: {DeviceCount}", request?.DeviceRequests?.Count ?? 0);

            // 验证命令参数
            if (!request.IsValid())
            {
                _logger.LogWarning("命令参数验证失败");
                return OperationResult<StartDeviceRuntimeResponse>.CreateFailure("命令参数验证失败");
            }

            // 获取当前用户
            var currentUser = _currentUserService.GetCurrentUserId();
            if (string.IsNullOrEmpty(currentUser))
            {
                _logger.LogWarning("当前用户未登录");
                return OperationResult<StartDeviceRuntimeResponse>.CreateFailure("用户未登录");
            }

            _logger.LogDebug("开始获取网络堆栈配置，网络堆栈代码: {NetworkStackCodes}", 
                string.Join(", ", request.DeviceRequests.Select(r => r.NetworkStackCode)));

            // 获取网络堆栈配置
            var networkConfigs = await _networkStackConfigRepository.GetNetworkStackConfigsByCodesAsync(
                request.DeviceRequests.Select(s => s.NetworkStackCode).ToArray(), cancellationToken);

            if (networkConfigs == null || !networkConfigs.Any())
            {
                _logger.LogWarning("未找到指定的网络堆栈配置");
                return OperationResult<StartDeviceRuntimeResponse>.CreateFailure("未找到指定的网络堆栈配置");
            }

            _logger.LogDebug("成功获取网络堆栈配置，配置数量: {ConfigCount}", networkConfigs.Count());

            // 生成运行时编码
            var runtimeCode = await GenerateRuntimeCodeAsync(cancellationToken);
            if (string.IsNullOrEmpty(runtimeCode))
            {
                _logger.LogError("生成运行时编码失败");
                return OperationResult<StartDeviceRuntimeResponse>.CreateFailure("生成运行时编码失败");
            }
            _logger.LogInformation("生成运行时编码: {RuntimeCode}", runtimeCode);

            // 构建网络配置请求
            var networkRequests = BuildNetworkConfigurationRequests(request, networkConfigs, runtimeCode);

            _logger.LogInformation("成功构建网络配置请求，请求数量: {RequestCount}", networkRequests?.Count ?? 0);

            // 检查是否有有效的网络配置请求
            if (networkRequests == null || !networkRequests.Any())
            {
                _logger.LogWarning("没有有效的网络配置请求，无法启动设备运行时");
                return OperationResult<StartDeviceRuntimeResponse>.CreateFailure("没有有效的网络配置请求，无法启动设备运行时");
            }

            // 并行启动网络并收集结果
            var (successfulDevices, failedDevices) = await StartNetworksInParallelAsync(networkRequests, cancellationToken);

            if (failedDevices.Any())
            {
                _logger.LogWarning("部分设备网络启动失败，失败设备: {FailedDevices}", 
                    string.Join(", ", failedDevices.Select(f => f.DeviceCode)));
            }

            // 只为成功启动网络的设备创建运行时详情和更新状态
            var runtimeDetails = new List<CellularDeviceRuntimeDetail>();
            var updatedRuntimes = new List<CellularDeviceRuntime>();
            
            foreach (var deviceRequest in request.DeviceRequests)
            {
                // 只处理网络启动成功的设备
                if (!successfulDevices.Contains(deviceRequest.DeviceCode))
                {
                    _logger.LogWarning("跳过处理网络启动失败的设备，设备代码: {DeviceCode}", deviceRequest.DeviceCode);
                    continue;
                }

                _logger.LogDebug("处理设备运行时，设备代码: {DeviceCode}", deviceRequest.DeviceCode);

                // 创建运行时详情
                var detail = CellularDeviceRuntimeDetail.Create(
                    deviceRequest.DeviceCode, 
                    runtimeCode, 
                    deviceRequest.NetworkStackCode, 
                    currentUser, true);
                runtimeDetails.Add(detail);

                // 获取并更新设备运行时状态
                var deviceRuntime = await _deviceRuntimeRepository.GetRuntimeByDeviceCodeAsync(deviceRequest.DeviceCode, cancellationToken);
                if (deviceRuntime == null)
                {
                    _logger.LogWarning("设备运行时不存在，设备代码: {DeviceCode}", deviceRequest.DeviceCode);
                    continue;
                }

                deviceRuntime.Start(deviceRequest.NetworkStackCode, runtimeCode);
                _deviceRuntimeRepository.UpdateRuntime(deviceRuntime);
                updatedRuntimes.Add(deviceRuntime);

                _logger.LogDebug("设备运行时状态已更新，设备代码: {DeviceCode}, 网络堆栈代码: {NetworkStackCode}", 
                    deviceRequest.DeviceCode, deviceRequest.NetworkStackCode);
            }

            // 批量保存运行时详情
            if (runtimeDetails.Any())
            {
                _logger.LogDebug("保存运行时详情，详情数量: {DetailCount}", runtimeDetails.Count);
                await _detailRepository.AddRangeAsync(runtimeDetails);
            }

            // 保存所有更改
            await _unitOfWork.SaveChangesAsync(cancellationToken);
            _logger.LogInformation("批量启动设备运行时状态完成，运行时代码: {RuntimeCode}, 成功设备数: {SuccessCount}, 失败设备数: {FailureCount}", 
                runtimeCode, successfulDevices.Count, failedDevices.Count);

            return OperationResult<StartDeviceRuntimeResponse>.CreateSuccess(new StartDeviceRuntimeResponse 
            { 
                Summary = new BatchOperationSummary
                {
                    TotalCount = request.DeviceRequests.Count,
                    SuccessCount = successfulDevices.Count,
                    FailureCount = failedDevices.Count
                }
            });
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "批量启动设备运行时状态失败");
            return OperationResult<StartDeviceRuntimeResponse>.CreateFailure($"批量启动设备运行时状态失败: {ex.Message}");
        }
    }

    /// <summary>
    /// 生成唯一的运行时编码
    /// </summary>
    /// <param name="cancellationToken">取消令牌</param>
    /// <returns>生成的运行时编码</returns>
    /// <remarks>
    /// 运行时编码格式：RT-{时间戳}-{序号}
    /// - 时间戳：yyyyMMddHHmmssfff 格式，精确到毫秒
    /// - 序号：基于当前运行时总数自动递增，至少3位数字
    /// 
    /// 使用信号量确保在多线程环境下生成唯一的编码：
    /// 1. 防止并发访问导致的序号重复
    /// 2. 确保时间戳和序号的组合唯一性
    /// 3. 避免数据库查询和插入之间的竞态条件
    /// 4. 支持异步操作，避免死锁风险
    /// 5. 控制并发访问数量，提高性能
    /// </remarks>
    private static readonly SemaphoreSlim _runtimeCodeSemaphore = new SemaphoreSlim(1, 1);
    private async Task<string> GenerateRuntimeCodeAsync(CancellationToken cancellationToken)
    {
        // 使用信号量确保在多线程环境下生成唯一的运行时编码
        await _runtimeCodeSemaphore.WaitAsync(cancellationToken);
        
        try
        {
            _logger.LogDebug("开始生成运行时编码，线程ID: {ThreadId}", Thread.CurrentThread.ManagedThreadId);
            
            // 获取当前设备运行时总数（异步调用）
            var runtimeCount = await _deviceRuntimeRepository.GetRuntimeCountAsync(cancellationToken);
            _logger.LogDebug("当前运行时总数: {RuntimeCount}", runtimeCount);

            // 计算下一个序号
            var nextNumber = runtimeCount + 1;
            
            // 计算需要的位数，确保至少3位数
            var digitCount = CalculateRequiredDigits(nextNumber);
            
            // 格式化序号为指定位数
            var formattedNumber = nextNumber.ToString($"D{digitCount}");
            
            // 生成时间戳，精确到毫秒
            string timestamp = DateTime.Now.ToString("yyyyMMddHHmmssfff");
            
            // 组装运行时编码
            var runtimeCode = $"RT-{timestamp}-{formattedNumber}";
            
            _logger.LogDebug("成功生成运行时编码: {RuntimeCode}, 运行时总数: {RuntimeCount}, 序号: {NextNumber}, 位数: {DigitCount}, 线程ID: {ThreadId}", 
                runtimeCode, runtimeCount, nextNumber, digitCount, Thread.CurrentThread.ManagedThreadId);
            
            return runtimeCode;
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "生成运行时编码失败，线程ID: {ThreadId}", Thread.CurrentThread.ManagedThreadId);
            // 重新抛出异常的原因：
            // 1. 保持异常的原始堆栈跟踪信息，便于调试和问题定位
            // 2. 确保上层调用者能够捕获到原始异常，进行适当的错误处理
            // 3. 避免异常信息丢失，保持异常传播链的完整性
            // 4. 符合异常处理的最佳实践：记录日志后重新抛出
            throw;
        }
        finally
        {
            // 确保信号量被释放
            _runtimeCodeSemaphore.Release();
        }
    }

    /// <summary>
    /// 计算需要的位数
    /// </summary>
    private int CalculateRequiredDigits(int number)
    {
        if (number <= 0) return 3; // 从000开始，至少3位数
        
        // 计算位数：确保至少3位数，从000开始
        // 1-999用3位，1000-9999用4位，10000-99999用5位，以此类推
        var calculatedDigits = (int)Math.Floor(Math.Log10(number)) + 1;
        return Math.Max(calculatedDigits, 3); // 确保至少3位数
    }

              /// <summary>
     /// 构建网络配置请求
     /// </summary>
     /// <param name="request">启动设备运行时命令</param>
     /// <param name="networkConfigs">网络堆栈配置</param>
     /// <param name="runtimeCode">运行时编码</param>
     /// <returns>构建好的网络配置请求列表</returns>
     private List<CellularNetworkConfiguration> BuildNetworkConfigurationRequests(
         StartDeviceRuntimeCommand request, 
         IEnumerable<NetworkStackConfigBasicDto> networkConfigs, 
         string runtimeCode)
     {
         // 按NetworkStackCode分组网络配置，提高查询效率
         var networkConfigsByCode = networkConfigs
             .Where(nc => !string.IsNullOrEmpty(nc.NetworkStackCode))
             .GroupBy(nc => nc.NetworkStackCode!)
             .ToDictionary(g => g.Key, g => g.ToList());
         
         // 使用HashSet进行去重，提高性能
         var processedDeviceNetworkPairs = new HashSet<string>();
         
         return request.DeviceRequests
             .Where(deviceRequest => 
             {
                 // 检查是否已处理过相同的设备-网络堆栈组合
                 var deviceNetworkKey = $"{deviceRequest.DeviceCode}_{deviceRequest.NetworkStackCode}";
                 if (processedDeviceNetworkPairs.Contains(deviceNetworkKey))
                 {
                     _logger.LogWarning("设备代码 {DeviceCode} 与网络堆栈 {NetworkStackCode} 的组合已存在，跳过重复处理", 
                         deviceRequest.DeviceCode, deviceRequest.NetworkStackCode);
                     return false;
                 }
                 
                 // 检查是否存在对应的网络配置
                 if (!networkConfigsByCode.TryGetValue(deviceRequest.NetworkStackCode, out var deviceNetworkConfigs))
                 {
                     _logger.LogWarning("未找到对应的网络配置，设备代码: {DeviceCode}, 网络堆栈代码: {NetworkStackCode}", 
                         deviceRequest.DeviceCode, deviceRequest.NetworkStackCode);
                     return false;
                 }
                 
                 // 验证配置有效性
                 var hasValidRanConfig = deviceNetworkConfigs.Any(s => !string.IsNullOrEmpty(s.RanConfigContent));
                 var hasValidNetworkConfigs = deviceNetworkConfigs.Any(s => 
                     !string.IsNullOrEmpty(s.IMSConfigContent) && !string.IsNullOrEmpty(s.CoreNetworkConfigContent));
                 
                 if (!hasValidRanConfig && !hasValidNetworkConfigs)
                 {
                     _logger.LogWarning("设备 {DeviceCode} 的网络配置既缺少RAN配置内容，又缺少有效的IMS和核心网配置内容，跳过处理", 
                         deviceRequest.DeviceCode);
                     return false;
                 }
                 
                 processedDeviceNetworkPairs.Add(deviceNetworkKey);
                 return true;
             })
             .Select(deviceRequest =>
             {
                 var deviceNetworkConfigs = networkConfigsByCode[deviceRequest.NetworkStackCode];
                
                // 构建CoreNetworkImsConfiguration列表
                var coreNetworkImsConfigurations = deviceNetworkConfigs
                    .Where(s => !string.IsNullOrEmpty(s.IMSConfigContent) && !string.IsNullOrEmpty(s.CoreNetworkConfigContent))
                    .Select(networkConfig => new CoreNetworkImsConfiguration
                    {
                        Index = networkConfig.Index ?? 0,
                        Plmn = ExtractPlmnFromConfig(networkConfig.CoreNetworkConfigContent),
                         CoreNetworkConfiguration = networkConfig.CoreNetworkConfigContent!,
                         ImsServiceConfiguration = networkConfig.IMSConfigContent!
                     })
                     .ToList();
                 
                 // 获取RAN配置
                 var validRanConfig = deviceNetworkConfigs
                     .Where(s => !string.IsNullOrEmpty(s.RanConfigContent))
                     .Select(s => s.RanConfigContent)
                     .Distinct()
                     .FirstOrDefault() ?? string.Empty;
                 
                 // 创建网络配置
                 var configuration = new CellularNetworkConfiguration
                 {
                     RuntimeCode = runtimeCode,
                     DeviceCode = deviceRequest.DeviceCode,
                     RadioAccessNetworkConfiguration = validRanConfig,
                     CoreNetworkImsConfigurations = coreNetworkImsConfigurations
                 };
                 
                 _logger.LogDebug("构建网络配置请求，设备代码: {DeviceCode}, 网络堆栈代码: {NetworkStackCode}, 绑定关系数量: {BindingCount}", 
                     deviceRequest.DeviceCode, deviceRequest.NetworkStackCode, coreNetworkImsConfigurations.Count);
                 
                                   return configuration;
              })
              .ToList();
      }

    /// <summary>
    /// 并行启动网络并收集结果
    /// </summary>
    /// <param name="networkRequests">网络配置请求列表</param>
    /// <param name="cancellationToken">取消令牌</param>
    /// <returns>成功和失败的设备信息元组</returns>
    /// <remarks>
    /// 该方法使用并行执行来同时启动多个网络，提高性能：
    /// 1. 使用ConcurrentBag确保线程安全的结果收集
    /// 2. 使用SemaphoreSlim控制并发数量，避免资源竞争（可选）
    /// 3. 设置超时机制，防止任务无限等待
    /// 4. 提供详细的错误处理和日志记录
    /// 5. 确保资源正确释放
    /// </remarks>
    private async Task<(HashSet<string> SuccessfulDevices, List<(string DeviceCode, string ErrorMessage)> FailedDevices)> 
        StartNetworksInParallelAsync(List<CellularNetworkConfiguration> networkRequests, CancellationToken cancellationToken)
    {
        var networkResults = new ConcurrentBag<(bool Success, string DeviceCode, string ErrorMessage)>();
        _logger.LogInformation("开始并行启动网络，请求数量: {RequestCount}", networkRequests.Count);
        
        // 设置超时时间，防止任务无限等待
        using var timeoutCts = new CancellationTokenSource(TimeSpan.FromMinutes(5)); // 5分钟超时
        using var combinedCts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken, timeoutCts.Token);
        
        // 完全并行执行，不受信号量限制
        var tasks = networkRequests.Select(async networkRequest =>
        {
            try
            {
                _logger.LogDebug("启动网络，设备代码: {DeviceCode}, 运行时代码: {RuntimeCode}", 
                    networkRequest.DeviceCode, networkRequest.RuntimeCode);
                
                // 创建包装请求对象
                var request = new StartCellularNetworkRequest
                {
                    CellularNetwork = networkRequest
                };
                
                var startResult = await _protocolClient.StartNetworkAsync(request);
                _logger.LogDebug("网络启动结果，设备代码: {DeviceCode}, 启动成功: {StartResult}", 
                    networkRequest.DeviceCode, startResult);
                
                if (startResult)
                {
                    _logger.LogDebug("网络启动成功，设备代码: {DeviceCode}", networkRequest.DeviceCode);
                    networkResults.Add((true, networkRequest.DeviceCode, string.Empty));
                }
                else
                {
                    var errorMessage = "网络启动返回失败状态";
                    _logger.LogWarning("网络启动返回失败状态，设备代码: {DeviceCode}", networkRequest.DeviceCode);
                    networkResults.Add((false, networkRequest.DeviceCode, errorMessage));
                }
            }
            catch (OperationCanceledException) when (timeoutCts.Token.IsCancellationRequested)
            {
                var errorMessage = "网络启动超时";
                _logger.LogWarning("网络启动超时，设备代码: {DeviceCode}", networkRequest.DeviceCode);
                networkResults.Add((false, networkRequest.DeviceCode, errorMessage));
            }
            catch (Exception ex)
            {
                var errorMessage = $"网络启动失败: {ex.Message}";
                _logger.LogError(ex, "网络启动失败，设备代码: {DeviceCode}", networkRequest.DeviceCode);
                networkResults.Add((false, networkRequest.DeviceCode, errorMessage));
            }
        });

        try
        {
            // 等待所有任务完成
            await Task.WhenAll(tasks);
        }
        catch (OperationCanceledException) when (timeoutCts.Token.IsCancellationRequested)
        {
            _logger.LogWarning("网络启动操作超时，部分设备可能未完成启动");
        }

        // 检查网络启动结果
        var successfulDevices = networkResults.Where(r => r.Success).Select(r => r.DeviceCode).ToHashSet();
        var failedDevices = networkResults.Where(r => !r.Success).Select(r => (r.DeviceCode, r.ErrorMessage)).ToList();

        _logger.LogInformation("网络启动完成，成功设备数: {SuccessCount}, 失败设备数: {FailureCount}", 
            successfulDevices.Count, failedDevices.Count);

        return (successfulDevices, failedDevices);
    }

    /// <summary>
    /// 从网络配置中提取PLMN值
    /// </summary>
    /// <param name="configContent">网络配置内容</param>
    /// <returns>提取的PLMN值，如果未找到则返回默认值"000000"</returns>
    private string ExtractPlmnFromConfig(string configContent)
    {
        if (string.IsNullOrEmpty(configContent))
        {
            return "000000";
        }

        try
        {
            // 使用正则表达式匹配PLMN值（支持双引号和单引号）
            var match = System.Text.RegularExpressions.Regex.Match(
                configContent, 
                @"""plmn""\s*:\s*[""']([^""']+)[""']", 
                System.Text.RegularExpressions.RegexOptions.IgnoreCase);

            if (match.Success && match.Groups.Count > 1)
            {
                var plmnValue = match.Groups[1].Value.Trim();
                _logger.LogDebug("从配置中提取到PLMN值: {PlmnValue}", plmnValue);
                return string.IsNullOrEmpty(plmnValue) ? "000000" : plmnValue;
            }

            _logger.LogDebug("未从配置中找到PLMN值，使用默认值: 000000");
            return "000000";
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "提取PLMN值时发生异常，使用默认值: 000000");
            return "000000";
        }
    }
}