using MediatR;
using Microsoft.Extensions.Logging;
using CellularManagement.Domain.Common;
using CellularManagement.Domain.Services;
using CellularManagement.Domain.Repositories;
using CellularManagement.Domain.Entities;
using System.Threading;
using System.Threading.Tasks;
using System.Security.Claims;
using System.Collections.Generic;
using System.Diagnostics;
using CellularManagement.Domain.Entities.Logging;
using Microsoft.AspNetCore.Http;
using CellularManagement.Domain.Repositories.Base;
using CellularManagement.Domain.Repositories.Identity;

namespace CellularManagement.Application.Features.Auth.Commands.Logout;

/// <summary>
/// 登出命令处理器
/// </summary>
public class LogoutCommandHandler : IRequestHandler<LogoutCommand, OperationResult<bool>>
{
    private readonly IJwtProvider _jwtProvider;
    private readonly ILogger<LogoutCommandHandler> _logger;
    private readonly ILoginLogRepository _loginLogRepository;
    private readonly IUnitOfWork _unitOfWork;
    private readonly IHttpContextAccessor _httpContextAccessor;
    private static readonly Action<ILogger, string, Exception?> LogTokenValidationError = 
        LoggerMessage.Define<string>(LogLevel.Warning, new EventId(1, "TokenValidationError"), "令牌验证错误: {Message}");
    private static readonly Action<ILogger, string, string, Exception?> LogTokenProcessingError = 
        LoggerMessage.Define<string, string>(LogLevel.Error, new EventId(2, "TokenProcessingError"), "处理令牌 {TokenType} 时发生错误: {Message}");

    /// <summary>
    /// 初始化处理器
    /// </summary>
    public LogoutCommandHandler(
        IJwtProvider jwtProvider,
        ILogger<LogoutCommandHandler> logger,
        ILoginLogRepository loginLogRepository,
        IUnitOfWork unitOfWork,
        IHttpContextAccessor httpContextAccessor)
    {
        _jwtProvider = jwtProvider;
        _logger = logger;
        _loginLogRepository = loginLogRepository;
        _unitOfWork = unitOfWork;
        _httpContextAccessor = httpContextAccessor;
    }

    /// <summary>
    /// 处理登出请求
    /// </summary>
    public async Task<OperationResult<bool>> Handle(LogoutCommand request, CancellationToken cancellationToken)
    {
        var sw = Stopwatch.StartNew();
        var correlationId = Guid.NewGuid().ToString();
        _logger.LogInformation("[{CorrelationId}] 开始处理登出请求", correlationId);

        try
        {
            // 快速验证令牌存在性
            if (string.IsNullOrEmpty(request.AccessToken) || string.IsNullOrEmpty(request.RefreshToken))
            {
                _logger.LogWarning("[{CorrelationId}] 令牌为空", correlationId);
                return OperationResult<bool>.CreateFailure("无效的请求");
            }

            _logger.LogDebug("[{CorrelationId}] 开始验证令牌", correlationId);
            string? userId = null;
            bool isAccessTokenValid = false;
            bool isRefreshTokenValid = false;
            var tokenValidationSw = Stopwatch.StartNew();

            try
            {
                // 验证访问令牌
                _logger.LogDebug("[{CorrelationId}] 开始验证访问令牌", correlationId);
                var accessTokenClaims = _jwtProvider.GetClaimsFromToken(request.AccessToken);
                if (accessTokenClaims.Any())
                {
                    var tokenType = accessTokenClaims.FirstOrDefault(c => c.Type == "token_type")?.Value;
                    _logger.LogDebug("[{CorrelationId}] 访问令牌类型: {TokenType}", correlationId, tokenType);

                    if (tokenType == "access_token")
                    {
                        userId = accessTokenClaims.FirstOrDefault(c => c.Type == ClaimTypes.NameIdentifier)?.Value;
                        isAccessTokenValid = !string.IsNullOrEmpty(userId);
                        _logger.LogDebug("[{CorrelationId}] 访问令牌验证结果: {IsValid}, 用户ID: {UserId}", 
                            correlationId, isAccessTokenValid, userId);
                    }
                    else
                    {
                        _logger.LogWarning("[{CorrelationId}] 访问令牌类型不匹配: {TokenType}", correlationId, tokenType);
                    }
                }
            }
            catch (Exception ex)
            {
                LogTokenValidationError(_logger, "访问令牌验证失败", ex);
            }

            try
            {
                // 验证刷新令牌
                _logger.LogDebug("[{CorrelationId}] 开始验证刷新令牌", correlationId);
                var refreshTokenClaims = _jwtProvider.GetClaimsFromToken(request.RefreshToken);
                if (refreshTokenClaims.Any())
                {
                    var tokenType = refreshTokenClaims.FirstOrDefault(c => c.Type == "token_type")?.Value;
                    _logger.LogDebug("[{CorrelationId}] 刷新令牌类型: {TokenType}", correlationId, tokenType);

                    if (tokenType == "refresh_token")
                    {
                        var refreshTokenUserId = refreshTokenClaims.FirstOrDefault(c => c.Type == ClaimTypes.NameIdentifier)?.Value;
                        isRefreshTokenValid = !string.IsNullOrEmpty(refreshTokenUserId) && 
                                           (string.IsNullOrEmpty(userId) || userId == refreshTokenUserId);
                        
                        if (isRefreshTokenValid && string.IsNullOrEmpty(userId))
                        {
                            userId = refreshTokenUserId;
                        }
                        _logger.LogDebug("[{CorrelationId}] 刷新令牌验证结果: {IsValid}, 用户ID: {UserId}", 
                            correlationId, isRefreshTokenValid, refreshTokenUserId);
                    }
                    else
                    {
                        _logger.LogWarning("[{CorrelationId}] 刷新令牌类型不匹配: {TokenType}", correlationId, tokenType);
                    }
                }
            }
            catch (Exception ex)
            {
                LogTokenValidationError(_logger, "刷新令牌验证失败", ex);
            }

            tokenValidationSw.Stop();
            _logger.LogInformation("[{CorrelationId}] 令牌验证完成，耗时: {ElapsedMs}ms", 
                correlationId, tokenValidationSw.ElapsedMilliseconds);

            // 如果两个令牌都无效，直接返回成功
            if (!isAccessTokenValid && !isRefreshTokenValid)
            {
                _logger.LogInformation("[{CorrelationId}] 所有令牌无效，直接返回成功", correlationId);
                return OperationResult<bool>.CreateSuccess(true);
            }

            // 记录登出日志
            if (!string.IsNullOrEmpty(userId))
            {
                _logger.LogDebug("[{CorrelationId}] 开始记录登出日志，用户ID: {UserId}", correlationId, userId);
                var logSw = Stopwatch.StartNew();
                await RecordLogoutLogAsync(userId, correlationId, cancellationToken);
                logSw.Stop();
                _logger.LogInformation("[{CorrelationId}] 登出日志记录完成，耗时: {ElapsedMs}ms", 
                    correlationId, logSw.ElapsedMilliseconds);
            }

            // 异步处理令牌撤销和黑名单
            _ = Task.Run(async () =>
            {
                var tokenProcessingSw = Stopwatch.StartNew();
                try
                {
                    if (isAccessTokenValid)
                    {
                        _logger.LogDebug("[{CorrelationId}] 开始处理访问令牌撤销和黑名单", correlationId);
                        await ProcessTokenAsync(request.AccessToken, "访问令牌", correlationId);
                    }

                    if (isRefreshTokenValid)
                    {
                        _logger.LogDebug("[{CorrelationId}] 开始处理刷新令牌撤销和黑名单", correlationId);
                        await ProcessTokenAsync(request.RefreshToken, "刷新令牌", correlationId);
                    }
                }
                catch (Exception ex)
                {
                    LogTokenProcessingError(_logger, "令牌处理", "处理令牌撤销和黑名单时发生异常", ex);
                }
                finally
                {
                    tokenProcessingSw.Stop();
                    _logger.LogInformation("[{CorrelationId}] 令牌处理完成，耗时: {ElapsedMs}ms", 
                        correlationId, tokenProcessingSw.ElapsedMilliseconds);
                }
            });

            sw.Stop();
            _logger.LogInformation("[{CorrelationId}] 登出请求处理完成，总耗时: {ElapsedMs}ms", 
                correlationId, sw.ElapsedMilliseconds);
            return OperationResult<bool>.CreateSuccess(true);
        }
        catch (Exception ex)
        {
            sw.Stop();
            _logger.LogError(ex, "[{CorrelationId}] 处理登出请求时发生异常，耗时: {ElapsedMs}ms", 
                correlationId, sw.ElapsedMilliseconds);
            return OperationResult<bool>.CreateFailure("系统错误");
        }
    }

    /// <summary>
    /// 记录登出日志
    /// </summary>
    private async Task RecordLogoutLogAsync(string userId, string correlationId, CancellationToken cancellationToken)
    {
        try
        {
            var httpContext = _httpContextAccessor.HttpContext;
            var ipAddress = httpContext?.Connection.RemoteIpAddress?.ToString() ?? "Unknown";
            var userAgent = httpContext?.Request.Headers["User-Agent"].ToString() ?? "Unknown";

            // 解析设备信息
            var parser = UAParser.Parser.GetDefault();
            var clientInfo = parser.Parse(userAgent);

            var loginLog = LoginLog.Create(
                userId: userId,
                ipAddress: ipAddress,
                userAgent: userAgent,
                isSuccess: true,
                loginType: "Logout",
                loginSource: "Web",
                browser: clientInfo.UA.ToString(),
                operatingSystem: clientInfo.OS.ToString());

            await _loginLogRepository.AddAsync(loginLog, cancellationToken);
            await _unitOfWork.SaveChangesAsync(cancellationToken);
            _logger.LogDebug("[{CorrelationId}] 登出日志记录成功", correlationId);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "[{CorrelationId}] 记录登出日志时发生异常", correlationId);
            throw;
        }
    }

    /// <summary>
    /// 处理令牌撤销和黑名单
    /// </summary>
    private async Task ProcessTokenAsync(string token, string tokenType, string correlationId)
    {
        try
        {
            var sw = Stopwatch.StartNew();
            _jwtProvider.RevokeToken(token);
            _jwtProvider.AddToBlacklist(token);
            sw.Stop();
            _logger.LogDebug("[{CorrelationId}] {TokenType}处理完成，耗时: {ElapsedMs}ms", 
                correlationId, tokenType, sw.ElapsedMilliseconds);
            await Task.CompletedTask;
        }
        catch (Exception ex)
        {
            LogTokenProcessingError(_logger, tokenType, "处理令牌时发生异常", ex);
            throw;
        }
    }
}