using System;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Drab.LocalDb;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;

namespace Drab.Logic.Services;

public class OldOrdersCleanupService : BackgroundService
{
    private readonly IServiceProvider _services;
    private readonly ILogger<OldOrdersCleanupService> _logger;
    private readonly TimeSpan _interval = TimeSpan.FromHours(24);

    public OldOrdersCleanupService(IServiceProvider services, ILogger<OldOrdersCleanupService> logger)
    {
        _services = services;
        _logger = logger;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        while (!stoppingToken.IsCancellationRequested)
        {
            try
            {
                using var scope = _services.CreateScope();
                var dbContext = scope.ServiceProvider.GetRequiredService<LocalDbContext>();

                var threshold = DateTime.Now.AddDays(-45);
                var oldOrders = dbContext.Orders
                    .Where(o => o.Created < threshold)
                    .ToList();

                if (oldOrders.Count != 0)
                {
                    dbContext.Orders.RemoveRange(oldOrders);
                    await dbContext.SaveChangesAsync(stoppingToken);

                    _logger.LogInformation("Usunięto {OldOrdersCount} starych zamówień.", oldOrders.Count);
                }
                else
                {
                    _logger.LogInformation("Nie znaleziono starych zamówień do usunięcia.");
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Błąd podczas usuwania starych zamówień.");
            }

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