public static AD randomAD(List <AD> ADS, DB db)
{
if (ADS.Count == 0)
{
return(null);
}
Random random = new Random();
int ID = random.Next(ADS.First().ID, ADS.Last().ID + 1);
AD ad = db.ADS.Find(ID);
if (ad == null)
{
return(randomAD(ADS, db));
}
else if (ADS.Contains(ad) == false)
{
return(randomAD(ADS, db));
}
else if (ISVALID(ad) == false)
{
ADS.Remove(ad);
return(randomAD(ADS, db));
}
else
{
db.ADWatch(ad.ID);
return(ad);
}
}