using Microsoft.EntityFrameworkCore;

namespace SpotiParty.Web.Services;

public class CleanupService(IServiceProvider services, ILogger<CleanupService> logger) : BackgroundService {
    protected override async Task ExecuteAsync(CancellationToken stoppingToken) {
        while (!stoppingToken.IsCancellationRequested) {
            await using (var scope = services.CreateAsyncScope()) {
                var context = scope.ServiceProvider.GetRequiredService<DatabaseContext>();
                
                var now = DateTime.Now;
                var oldEvents = await context.Events
                    .Where(e => e.End < now)
                    .ToArrayAsync(stoppingToken);
            
                context.Events.RemoveRange(oldEvents);
                await context.SaveChangesAsync(stoppingToken);
            
                if (oldEvents.Length > 0)
                    logger.LogInformation("Deleted {count} old events", oldEvents.Length);
            }

            var nextRun = DateTime.Today.AddDays(1).AddHours(3) - DateTime.Now;
            await Task.Delay(nextRun, stoppingToken);
        }
    }
}