using LMS.Common.Extensions;
using LMS.DAO;
using LMS.Repository.MJPackage;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Quartz;
using System.Data;
using System.Text;

namespace LMS.Tools.MJPackage
{
    [DisallowConcurrentExecution]
    public class TokenSyncService : IJob
    {
        private readonly TokenUsageTracker _usageTracker;
        private readonly IServiceProvider _serviceProvider;
        private readonly ILogger<TokenSyncService> _logger;

        // 活动阈值：5分钟内有活动的Token才同步
        private readonly TimeSpan _activityThreshold = TimeSpan.FromMinutes(5);

        public TokenSyncService(
            TokenUsageTracker usageTracker,
            IServiceProvider serviceProvider,
            ILogger<TokenSyncService> logger)
        {
            _usageTracker = usageTracker;
            _serviceProvider = serviceProvider;
            _logger = logger;
        }

        public async Task Execute(IJobExecutionContext context)
        {
            _logger.LogInformation($"开始同步Token信息 - 同步间隔: 30 秒, 活动阈值: {_activityThreshold.TotalMinutes}分钟 (使用EF Core)");

            var startTime = BeijingTimeExtension.GetBeijingTime();
            try
            {
                var syncResult = await SyncActiveTokensToDatabase();
                var duration = BeijingTimeExtension.GetBeijingTime() - startTime;

                if (syncResult.ActiveTokenCount > 0)
                {
                    _logger.LogInformation(
                        "Token同步完成: {ActiveTokens}/{TotalTokens} 个活跃Token已同步, 耗时: {Duration}ms, 更新记录: {RecordsUpdated}",
                        syncResult.ActiveTokenCount,
                        syncResult.TotalTokenCount,
                        duration.TotalMilliseconds,
                        syncResult.RecordsUpdated);
                }
                else
                {
                    _logger.LogDebug(
                        "Token同步跳过: 无活跃Token (总计: {TotalTokens}, 耗时: {Duration}ms)",
                        syncResult.TotalTokenCount,
                        duration.TotalMilliseconds);
                }
            }
            catch (Exception ex)
            {
                var duration = BeijingTimeExtension.GetBeijingTime() - startTime;
                _logger.LogError(ex, "Token同步失败，耗时: {Duration}ms", duration.TotalMilliseconds);
            }
        }

        /// <summary>
        /// 同步活跃Token数据到数据库
        /// </summary>
        /// <returns>同步结果</returns>
        private async Task<SyncResult> SyncActiveTokensToDatabase()
        {
            // 先 删除10分钟内不活跃得Token
            var (act, nact) = _usageTracker.RemoveNotActiveTokens(TimeSpan.FromMinutes(10));
            _logger.LogInformation($"删除不活跃的 Token 数 {nact}，删除后活跃 Token 数：{act}，判断不活跃时间：{10} 分钟");

            // 1. 获取活跃Token（最近5分钟内有活动的Token）
            var activeTokens = _usageTracker.GetActiveTokens(_activityThreshold).ToList();
            var totalTokens = _usageTracker.GetAllTokens().Count();

            if (!activeTokens.Any())
            {
                _logger.LogInformation("0 条活跃Token，跳过同步！");
                return new SyncResult
                {
                    TotalTokenCount = totalTokens,
                    ActiveTokenCount = 0,
                    RecordsUpdated = 0
                };
            }

            // 2. 创建数据库上下文
            using var scope = _serviceProvider.CreateScope();
            var dbContext = scope.ServiceProvider.GetRequiredService<ApplicationDbContext>();

            var today = BeijingTimeExtension.GetBeijingTime().Date;
            var recordsUpdated = 0;

            // 3. 构造批量数据
            var batchData = activeTokens.Select(token => new TokenUsageData
            {
                TokenId = token.Id,
                Date = today,
                DailyUsage = token.DailyUsage,
                TotalUsage = token.TotalUsage,
                LastActivityTime = token.LastActivityTime
            }).ToList();

            // 4. 使用EF Core事务批量更新数据库
            using var transaction = await dbContext.Database.BeginTransactionAsync();
            try
            {
                recordsUpdated = await BatchUpdateTokenUsageWithEfCore(dbContext, batchData);
                await transaction.CommitAsync();

                _logger.LogDebug(
                    "批量更新完成: {RecordsUpdated} 条活跃Token记录已更新，跳过 {SkippedCount} 条非活跃Token",
                    recordsUpdated,
                    totalTokens - activeTokens.Count);
            }
            catch (Exception ex)
            {
                await transaction.RollbackAsync();
                _logger.LogError(ex, "数据库事务失败，已回滚");
                throw;
            }

            return new SyncResult
            {
                TotalTokenCount = totalTokens,
                ActiveTokenCount = activeTokens.Count,
                RecordsUpdated = recordsUpdated
            };
        }

        /// <summary>
        /// 使用EF Core批量更新Token使用数据
        /// </summary>
        /// <param name="dbContext">数据库上下文</param>
        /// <param name="batchData">批量数据</param>
        /// <returns>更新的记录数</returns>
        private async Task<int> BatchUpdateTokenUsageWithEfCore(ApplicationDbContext dbContext, List<TokenUsageData> batchData)
        {
            int batchSize = 500;
            if (!batchData.Any()) return 0;

            var recordsUpdated = 0;

            // 分批处理
            for (int i = 0; i < batchData.Count; i += batchSize)
            {
                var batch = batchData.Skip(i).Take(batchSize).ToList();

                // 构建真正的批量 SQL
                var sqlBuilder = new StringBuilder();
                var parameters = new List<object>();

                sqlBuilder.AppendLine("INSERT INTO MJApiTokenUsage (TokenId, Date, DailyUsage, TotalUsage, LastActivityAt) VALUES ");

                // 为每条记录构建 VALUES 子句
                for (int j = 0; j < batch.Count; j++)
                {
                    if (j > 0) sqlBuilder.Append(", ");

                    var paramIndex = j * 5;
                    sqlBuilder.Append($"({{{paramIndex}}}, {{{paramIndex + 1}}}, {{{paramIndex + 2}}}, {{{paramIndex + 3}}}, {{{paramIndex + 4}}})");

                    parameters.AddRange(new object[]
                    {
                        batch[j].TokenId,
                        batch[j].Date,
                        batch[j].DailyUsage,
                        batch[j].TotalUsage,
                        batch[j].LastActivityTime
                    });
                }

                sqlBuilder.AppendLine(@"
                    ON DUPLICATE KEY UPDATE 
                        Date = VALUES(Date),
                        DailyUsage = VALUES(DailyUsage),
                        TotalUsage = VALUES(TotalUsage),
                        LastActivityAt = VALUES(LastActivityAt)");

                // 一次性执行整个批次
                var affectedRows = await dbContext.Database.ExecuteSqlRawAsync(
                    sqlBuilder.ToString(),
                    parameters.ToArray());

                recordsUpdated += affectedRows;

                _logger.LogInformation($"批量更新完成: 批次 {i / batchSize + 1}, 记录数: {batch.Count}, 影响行数: {affectedRows}");
            }

            return recordsUpdated;
        }
    }
}