cardmarketbot/CardMarketBot/CheckSevDeskInternalList.cs

using ConsoleApp3.Contracts;

namespace CardmarketBot
{
    internal class CheckSevDeskInternalList : ICheckSevDesk
    {
        private const string FILENAME = "usedList.csv";

        private List<string> Query => (from l in File.ReadAllLines("usedList.csv")
                                       select l.Split(',') into p
                                       select new string(p[0])).ToList();

        public CheckSevDeskInternalList()
        {
            if (!File.Exists("usedList.csv"))
            {
                File.Create("usedList.csv");
            }
        }

        public bool AlreadyKnown(string verkaufsnummer)
        {
            if (Query.Find((string x) => x.Equals(verkaufsnummer)) != null)
            {
                return false;
            }
            return true;
        }

        public bool Write(string verkaufsnummer)
        {
            verkaufsnummer += Environment.NewLine;
            File.AppendAllText("usedList.csv", verkaufsnummer);
            return true;
        }
    }

}