public async Task <IActionResult> AddPlayers(CampaignUser campaignUser)
        {
            var campaignUsers = new List <string>();
            var keys          = Request.Form.Keys;

            foreach (var value in Request.Form["Campaign.CampaignUsers"])
            {
                var userId   = value;
                var user     = _context.Users.Single(u => u.Id == userId);
                var campaign = _context.Campaigns.Single(u => u.ID == Request.Form["Campaign.ID"]);
                var cu       = new CampaignUser {
                    UserID = userId, CampaignID = Request.Form["Campaign.ID"], User = user, Campaign = campaign
                };
                campaignUsers.Add(cu.User.Pseudo);
                _context.Add(cu);
                await _context.SaveChangesAsync();
            }


            return(Json(new { campaignUsers }));
        }
        public async Task <IActionResult> AddUserToCampaign(int CampaignId, string ApplicationUserId)
        {
            var campaign = await _context.Campaigns.FirstOrDefaultAsync(x => x.Id == CampaignId);

            var applicationUser = await _context.ApplicationUsers.FirstOrDefaultAsync(x => x.Id == ApplicationUserId);

            CampaignUser campaignUser = new CampaignUser
            {
                Id                      = applicationUser.Id + campaign.Id,
                CampaignId              = campaign.Id,
                CampaignName            = campaign.Name,
                ApplicationUserId       = applicationUser.Id,
                ApplicationUserFullName = applicationUser.FullName
            };

            if (!CampaignUserExists(campaignUser.Id))
            {
                _context.Add(campaignUser);
                await _context.SaveChangesAsync();
            }

            return(RedirectToAction(nameof(Index)));
        }