namespace JobTrackerApi.Services;

public sealed class EmailSendAttemptRecoveryHostedService(
    IServiceScopeFactory scopes,
    IStartupReadiness startupReadiness,
    ILogger<EmailSendAttemptRecoveryHostedService> logger) : BackgroundService
{
    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await startupReadiness.WaitUntilReadyAsync(stoppingToken);
        while (!stoppingToken.IsCancellationRequested)
        {
            try
            {
                await using var scope = scopes.CreateAsyncScope();
                var result = await scope.ServiceProvider.GetRequiredService<EmailSendAttemptStore>()
                    .ReconcileAbandonedAsync(stoppingToken);
                if (result.FailedPending > 0 || result.UncertainSending > 0)
                {
                    logger.LogWarning(
                        "Recovered abandoned email attempts: failedPending={FailedPending}, uncertainSending={UncertainSending}. No provider retry was attempted.",
                        result.FailedPending, result.UncertainSending);
                }
            }
            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
            {
                break;
            }
            catch (Exception ex)
            {
                logger.LogError(ex, "Email send-attempt recovery failed; provider delivery was not attempted.");
            }

            try
            {
                await Task.Delay(TimeSpan.FromMinutes(5), stoppingToken);
            }
            catch (OperationCanceledException)
            {
                break;
            }
        }
    }
}