using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace Admin.NET.Plugin.AiDOP.DataPlatform.Schema;

/// <summary>
/// HTTP 已开始监听后再执行历史来源身份回填，避免数据迁移阻塞宿主启动。
/// </summary>
public sealed class MdpSourceIdentityBackfillWorker : BackgroundService
{
    private readonly IServiceScopeFactory _scopeFactory;
    private readonly IHostApplicationLifetime _lifetime;
    private readonly ILogger<MdpSourceIdentityBackfillWorker> _logger;

    public MdpSourceIdentityBackfillWorker(
        IServiceScopeFactory scopeFactory,
        IHostApplicationLifetime lifetime,
        ILogger<MdpSourceIdentityBackfillWorker> logger)
    {
        _scopeFactory = scopeFactory;
        _lifetime = lifetime;
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        var started = new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously);
        using var registration = _lifetime.ApplicationStarted.Register(() => started.TrySetResult());
        try
        {
            await started.Task.WaitAsync(stoppingToken);
        }
        catch (OperationCanceledException)
        {
            return;
        }

        try
        {
            using var scope = _scopeFactory.CreateScope();
            var db = scope.ServiceProvider.GetRequiredService<ISqlSugarClient>();
            await MdpSchemaAligner.BackfillProvenSourceAsync(db);
        }
        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
        {
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "中台历史来源身份回填失败；不影响 HTTP 服务");
        }
    }
}