using System;
using System.Collections.Concurrent;
using System.Text;
using TSingSoft.WebPluginFramework;

namespace BWP.B3DogAuth {
  public class MobileAuthCenter {
    static ConcurrentDictionary<string, Tuple<string, DateTime>> mDic = new ConcurrentDictionary<string, Tuple<string, DateTime>>();

    public static string GenVerifyCode(string username) {
      var code = GenRandomCode();
      var tuple = GenRandomCode();
      mDic.AddOrUpdate(username, tuple, (arg1, arg2) => tuple);
      return tuple.Item1;
    }

    public static bool Auth(string username, string verifyCode) {
      Tuple<string, DateTime> tuple;
      if (mDic.TryGetValue(username, out tuple)) {
        if (tuple.Item2 < BLContext.Now) {
          mDic.TryRemove(username, out tuple);
          return false;
        }
        else if (tuple.Item1 == verifyCode) {
          return true;
        }
        else {
          return false;
        }
      }
      else {
        return false;
      }
    }


    static Tuple<string, DateTime> GenRandomCode() {
      var rand = new Random(BLContext.Now.GetHashCode());
      var builder = new StringBuilder();
      for (int i = 0; i < 4; i++) {
        builder.Append(rand.Next(9));
      }
      return new Tuple<string, DateTime>(builder.ToString(), BLContext.Now.AddMinutes(5));
    }

  }
}