using Microsoft.EntityFrameworkCore;
using RadicadeServer.DB;

namespace RadicadeServer.Utils
{










	public static class GameBlockMonitor
	{
		private static readonly object Lock = new();
		private static readonly SemaphoreSlim RefreshGate = new(1, 1);
		private static Dictionary<string, DateTime?> Active = new();
		private static DateTime LastRefresh = DateTime.MinValue;
		private const double RefreshIntervalSeconds = 10;





		public static async Task<bool> IsBlockedAsync(IDbContextFactory<RecDBContext> factory, string ipAddress)
		{
			if (string.IsNullOrWhiteSpace(ipAddress)) return false;

			DateTime lastRefresh;
			lock (Lock) lastRefresh = LastRefresh;
			if ((DateTime.UtcNow - lastRefresh).TotalSeconds > RefreshIntervalSeconds)
				await RefreshAsync(factory);

			lock (Lock)
			{
				if (Active.TryGetValue(NormalizeIp(ipAddress), out var expiresAt))
					return !expiresAt.HasValue || expiresAt.Value > DateTime.UtcNow;
				return false;
			}
		}





		public static void Invalidate()
		{
			lock (Lock) LastRefresh = DateTime.MinValue;
		}

		public static async Task RefreshAsync(IDbContextFactory<RecDBContext> factory)
		{
			await RefreshGate.WaitAsync();
			try
			{

				DateTime lastRefresh;
				lock (Lock) lastRefresh = LastRefresh;
				if ((DateTime.UtcNow - lastRefresh).TotalSeconds <= RefreshIntervalSeconds)
					return;

				try
				{
					await using var db = await factory.CreateDbContextAsync();
					var now = DateTime.UtcNow;
					var rows = await db.GameBlocks.AsNoTracking().ToListAsync();



					var expired = rows.Where(b => b.ExpiresAt.HasValue && b.ExpiresAt.Value < now).ToList();
					if (expired.Count > 0)
					{
						db.GameBlocks.RemoveRange(expired);
						await db.SaveChangesAsync();
					}

					var active = new Dictionary<string, DateTime?>();
					foreach (var row in rows.Where(b => !expired.Contains(b)))
						active[NormalizeIp(row.IpAddress)] = row.ExpiresAt;

					lock (Lock)
					{
						Active = active;
						LastRefresh = DateTime.UtcNow;
					}
				}
				catch
				{


					lock (Lock) LastRefresh = DateTime.UtcNow;
				}
			}
			finally
			{
				RefreshGate.Release();
			}
		}






		public static string NormalizeIp(string ip)
		{
			ip = (ip ?? "").Trim();
			if (ip.StartsWith("::ffff:", StringComparison.OrdinalIgnoreCase))
				ip = ip.Substring("::ffff:".Length);
			return ip;
		}
	}
}