Innovenergy_trunk/csharp/App/Backend/Relations/Session.cs

using InnovEnergy.App.Backend.Database;
using InnovEnergy.App.Backend.DataTypes;
using SQLite;

namespace InnovEnergy.App.Backend.Relations;

public class Session : Relation<String, Int64>
{
    public static TimeSpan MaxAge { get; } = TimeSpan.FromDays(7);

    [Unique ] public String   Token    { get => Left ; init => Left  = value;}
    [Indexed] public Int64    UserId   { get => Right; init => Right = value;}
    [Indexed] public DateTime LastSeen { get; set; }

    [Ignore]  public Boolean Valid => DateTime.Now - LastSeen < MaxAge
                                   && (User) is not null;

    [Ignore] public User User => _User ??= Db.GetUserById(UserId)!;


    private User? _User;

    [Obsolete("To be used only by deserializer")]
    public Session()
    {}

    public Session(User user)
    {
        _User    = user;
        Token    = CreateToken();
        UserId   = user.Id;
        LastSeen = DateTime.Now;
    }
    
    private static String CreateToken()
    {
        var token = new Byte[24]; 
        Random.Shared.NextBytes(token);
        return Convert.ToBase64String(token);
    }
    
}