sledgemapper/Sledgemapper.Api/Hubs/SledgemapperHub.cs

using Microsoft.AspNetCore.SignalR;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Collections.Concurrent;
using Sledgemapper.Shared.Entities;
using Sledgemapper.Clients;
using System;
using Sledgemapper.Api.Data;
using Microsoft.AspNetCore.Authorization;
using Sledgemapper.Api.Models;
using Sledgemapper.Helpers;

namespace Sledgemapper.Api.Hubs
{
    [Authorize]
    public class SledgemapperHub : Hub<ISledgemapperClient>
    {
        private static readonly ConcurrentDictionary<int, string> UserColors = new();
        private readonly MyDbContext _dbContext;
        private readonly DataContext _datacontext;

        public SledgemapperHub(MyDbContext dbContext, DataContext datacontext)
        {
            _dbContext = dbContext;
            _datacontext = datacontext;
        }

        // other colors
        // #cca300, #20f200, #004011, #00e6d6, #005c73, #0057d9, #d900ca, #660029, #d9003a
        // private static Dictionary<string, Session> _sessions = new Dictionary<string, Session>();
        public List<string> Colors = new()
        {
            "#e6194B",
            "#f58231",
            "#3cb44b",
            "#000075",
            "#911eb4",
            "#800000",
            "#808000",
            "#469990"
        };

        public async Task NewTile(string sessionName, Tile tile)
        {
            await Clients.Group(sessionName).NewTile(tile);
        }

        public async Task NewWall(string sessionName, Wall tile)
        {
            await Clients.Group(sessionName).NewWall(tile);
        }

        public async Task NewOverlay(string sessionName, Overlay tile)
        {
            await Clients.Group(sessionName).NewOverlay(tile);
        }

        public async Task NewNote(string sessionName, Note note)
        {
            await Clients.Group(sessionName).NewNote(note);
        }

        public async Task DeleteTile(string sessionName, Tile tile)
        {
            await Clients.Group(sessionName).DeleteTile(tile);
        }

        public async Task DeleteWall(string sessionName, Wall tile)
        {
            await Clients.Group(sessionName).DeleteWall(tile);
        }

        public async Task DeleteOverlay(string sessionName, Overlay tile)
        {
            await Clients.Group(sessionName).DeleteOverlay(tile);
        }

        public async Task<Sledgemapper.Shared.Entities.Session> JoinSession(string sessionName)
        {
            var session = _dbContext.Sessions.FirstOrDefault(s => s.SessionName == sessionName);
            var userId = int.Parse(Context.User.Identity.Name);

            if (session != null)
            {
                var userSession = new SessionUser { SessionId = session.SessionId, UserId = userId };
                _dbContext.SessionUsers.Add(userSession);
                await _dbContext.SaveChangesAsync();
                await Groups.AddToGroupAsync(Context.ConnectionId, session.SessionName);
                var user = _datacontext.Users.First(u => u.Id == userId);

                var player = new Player { UserId = userId, Initials = user.Initials, Position = new Tile { X = 0, Y = 0 }, Color = UserColors[userId] };

                await Clients.Group(session.SessionName).NewPlayer(player);
                await Clients.Group(session.SessionName).RefreshPlayers();

                var newSession = new Sledgemapper.Shared.Entities.Session
                {
                    SessionName = session.SessionName,
                    SessionId = session.SessionId
                };

                return newSession;
            }
            else
            {
                return null;
            }
        }

        public async Task UpdatePosition(string sessionName, int sessionId, Tile tile)
        {
            var userId = int.Parse(Context.User.Identity.Name);
            var SessionUsers = _dbContext.SessionUsers.Where(m => m.SessionId == sessionId).OrderBy(m => m.UserId).ToList();
            var user = _datacontext.Users.First(u => u.Id == userId);
            var player = new Player { UserId = userId, Initials = user.Initials, Position = tile, Color = UserColors[userId]};
            await Clients.Group(sessionName).PlayerUpdate(player);
        }

        public override async Task OnConnectedAsync()
        {
            var userId = int.Parse(Context.User.Identity.Name);
            var userConnection = new UserConnection { ConnectionId = Context.ConnectionId, UserId = userId };
            _dbContext.UserConnections.Add(userConnection);
            await _dbContext.SaveChangesAsync();
            var availableColor = Colors.Where(m => !UserColors.Values.Contains(m)).First();
            UserColors.AddOrUpdate(userId, availableColor, (key, oldValue) => availableColor);
            await base.OnConnectedAsync();
        }

        public override async Task OnDisconnectedAsync(Exception exception)
        {
            var userConnection = _dbContext.UserConnections.FirstOrDefault(m => m.ConnectionId == Context.ConnectionId);
            var userId=userConnection.UserId;
            if (userConnection != null)
            {
                _dbContext.UserConnections.Remove(userConnection);
            }

            var userSessions = _dbContext.SessionUsers.Where(m => m.UserId == userId).ToList();
            {
                foreach (var userSession in userSessions)
                {
                    var session = _dbContext.Sessions.FirstOrDefault(m => m.SessionId == userSession.SessionId);
                    await Clients.Group(session.SessionName).PlayerUpdate(null); //send remove player
                    _dbContext.SessionUsers.Remove(userSession);
                }
            }
            await _dbContext.SaveChangesAsync();

            await base.OnDisconnectedAsync(exception);

        }
    }
}