using Microsoft.Extensions.Hosting;

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();

                var filesToDelete = oldOrders
                    .Select(o => Path.Combine(Constants.ReportsOutputPath, o.Filename))
                    .Where(p => !string.IsNullOrWhiteSpace(p) && File.Exists(p))
                    .ToList();

                foreach (var path in filesToDelete)
                {
                    try
                    {
                        File.Delete(path);
                    }
                    catch (Exception ex)
                    {
                        _logger.LogWarning(ex, "Failed to delete file: {FilePath}", path);
                    }
                }

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

                    _logger.LogInformation("Removed {OrderCount} old orders and deleted {FileCount} files.",
                        oldOrders.Count, filesToDelete.Count);
                }
                else
                {
                    _logger.LogInformation("Nothing to do.");
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error occured:");
            }

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