DailyProjectionArticleBackgroundService.cs

using FantasyBasket.API.Models;

namespace FantasyBasket.API.Services;

/// <summary>
/// Regenerates the daily projections article for NBA and WNBA on a short interval.
/// The frequent cadence is intentional: it picks up last-minute injury changes
/// (OfficialInjuryService updates Player.InjuryStatus from ESPN) and re-projects
/// affected players. Generation upserts on (league, slate date), so re-running is
/// idempotent and only refreshes content.
/// </summary>
public class DailyProjectionArticleBackgroundService : BackgroundService
{
    // Short enough that a late scratch shows up within ~half an hour; the HTTP
    // ResponseCache (300s) already smooths read load, so this is purely write cadence.
    private static readonly TimeSpan Interval = TimeSpan.FromMinutes(30);

    private readonly IServiceScopeFactory _scopeFactory;
    private readonly ILogger<DailyProjectionArticleBackgroundService> _logger;

    public DailyProjectionArticleBackgroundService(
        IServiceScopeFactory scopeFactory,
        ILogger<DailyProjectionArticleBackgroundService> logger)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
    }

    private static TimeZoneInfo EasternZone()
    {
        try { return TimeZoneInfo.FindSystemTimeZoneById("America/New_York"); }
        catch (TimeZoneNotFoundException) { return TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time"); }
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        _logger.LogInformation("Daily Projection Article service is starting.");
        var et = EasternZone();

        while (!stoppingToken.IsCancellationRequested)
        {
            try
            {
                var slateDate = TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, et).Date;

                using var scope = _scopeFactory.CreateScope();
                var service = scope.ServiceProvider.GetRequiredService<DailyProjectionArticleService>();

                foreach (var league in new[] { ProLeagueType.NBA, ProLeagueType.WNBA })
                {
                    try
                    {
                        await service.GenerateAndStoreAsync(league, slateDate, stoppingToken);
                    }
                    catch (Exception ex)
                    {
                        _logger.LogError(ex, "Failed to generate projection article for {League}.", league);
                    }
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error in Daily Projection Article service loop.");
            }

            await Task.Delay(Interval, stoppingToken);
        }
    }
}