using Microsoft.AspNetCore.HttpOverrides;
using OpenAuth.App.ServiceApp;
using OpenAuth.Repository.Domain;
using Org.BouncyCastle.Crypto.Tls;
using SqlSugar;

namespace OpenAuth.WebApi.Model.mqtt.ChannelDB
{
    public class LogBatchWriter : BackgroundService
    {
        private readonly LogQueueService _queue;
        private readonly IServiceScopeFactory _scopeFactory;
        private readonly ILogger<LogBatchWriter> _logger;

        private const int BatchSize = 100;
        private const int FlushIntervalMs = 10000;

        public LogBatchWriter(LogQueueService queue, IServiceScopeFactory scopeFactory, ILogger<LogBatchWriter> logger)
        {
            _queue = queue;
            _scopeFactory = scopeFactory;
            _logger = logger;
        }

        protected override async Task ExecuteAsync(CancellationToken stoppingToken)
        {
            var buffer = new List<LasaLog>(BatchSize);

            while (!stoppingToken.IsCancellationRequested)
            {
                buffer.Clear();
                var deadline = DateTime.UtcNow.AddMilliseconds(FlushIntervalMs);

                while (buffer.Count < BatchSize && DateTime.UtcNow < deadline)
                {
                    var remaining = deadline - DateTime.UtcNow;
                    if (remaining <= TimeSpan.Zero) break;

                    try
                    {
                        using var cts = CancellationTokenSource.CreateLinkedTokenSource(stoppingToken);
                        cts.CancelAfter(remaining);
                        var log = await _queue.Reader.ReadAsync(cts.Token);
                        buffer.Add(log);
                    }
                    catch (OperationCanceledException)
                    {
                        break;
                    }
                }

                if (buffer.Count > 0)
                {
                    await FlushAsync(buffer, stoppingToken);
                }
            }
        }

        private async Task FlushAsync(List<LasaLog> logs, CancellationToken ct)
        {
            try
            {
                using var scope = _scopeFactory.CreateScope();

                // 直接从 DI 拿 SqlSugar 的 ISqlSugarClient
                var db = scope.ServiceProvider.GetRequiredService<ISqlSugarClient>();

                // SqlSugar 批量插入
                await db.Insertable(logs).ExecuteCommandAsync();

                _logger.LogDebug($"批量写入 {logs.Count} 条日志");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"批量写入失败，丢失 {logs.Count} 条");
            }
        }
    }
}