using System;
using System.ComponentModel.DataAnnotations.Schema;
using Microsoft.EntityFrameworkCore;

namespace EFCoreGuidEmptyRepro
{
    class Program
    {
        static void Main(string[] args)
        {
            using (var db = new MyDbContext())
            {
                var capsId = Guid.NewGuid();
                db.Capses.Add(new CapsEntity
                {
                    Id = capsId
                });
                db.CapsShares.Add(new CapsShare
                {
                    CapsId = capsId,
                    UserId = Guid.Empty
                });
                db.SaveChanges();
            }
        }
    }

    class MyDbContext : DbContext
    {
        public DbSet<UserEntity> Users { get; set; }
        public DbSet<CapsEntity> Capses { get; set; }
        public DbSet<CapsShare> CapsShares { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<UserEntity>().ForNpgsqlUseXminAsConcurrencyToken();

            modelBuilder.Entity<CapsEntity>().ForNpgsqlUseXminAsConcurrencyToken();

            modelBuilder.Entity<CapsShare>().HasKey(s => new { s.CapsId, s.UserId });
            modelBuilder.Entity<CapsShare>().HasOne(s => s.Caps).WithMany().HasForeignKey(s => s.CapsId);
            modelBuilder.Entity<CapsShare>().HasOne(s => s.User).WithMany().HasForeignKey(s => s.UserId);
            modelBuilder.Entity<CapsShare>().ForNpgsqlUseXminAsConcurrencyToken();
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseNpgsql("Host=localhost;Database=efdebug;Username=postgres;Password=Add1t1v3", options =>
            {
                options.UseNetTopologySuite();
                options.EnableRetryOnFailure();
            });
            optionsBuilder.EnableSensitiveDataLogging();
        }
    }

    [Table("users")]
    class UserEntity
    {
        [Column("id")]
        public Guid Id { get; set; }
    }

    [Table("capses")]
    class CapsEntity
    {
        [Column("id")]
        public Guid Id { get; set; }
    }

    [Table("caps_shares")]
    class CapsShare
    {
        [Column("caps_id")]
        public Guid CapsId { get; set; }
        [Column("user_id")]
        [DatabaseGenerated(DatabaseGeneratedOption.None)]
        public Guid UserId { get; set; }

        public CapsEntity Caps { get; set; }
        public UserEntity User { get; set; }
    }
}