#nullable enable
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.SignalR;

namespace gehGassi.Web.Hubs
{
    /// <summary>
    /// Hub der App-Nachrichten ermöglicht
    /// </summary>
    [Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)]
    public class AppHub : Hub, IAppHub
    {
        private readonly IHubContext<AppHub> _hubContext;
        private readonly IAppHubUsers _appHubUsers;

        /// <summary>
        /// Erstellt eine Instanz
        /// </summary>
        public AppHub(IHubContext<AppHub> hubContext, IAppHubUsers appHubUsers) : base()
        {
            _hubContext = hubContext;
            _appHubUsers = appHubUsers;
        }

        #region Benutzer

        /// <summary>
        /// Called when a new connection is established with the hub.
        /// </summary>
        /// <returns>A <see cref="T:System.Threading.Tasks.Task" /> that represents the asynchronous connect.</returns>
        public override Task OnConnectedAsync()
        {
            if (Context.User?.Identity != null)
            {
                var userName = Context.User.Identity.Name;
                _appHubUsers.ConnectedUsers.TryGetValue(userName, out var existingUserConnectionIds);
                existingUserConnectionIds ??= new List<string>();
                existingUserConnectionIds.Add(Context.ConnectionId);
                _appHubUsers.ConnectedUsers.TryAdd(userName, existingUserConnectionIds);
            }

            return base.OnConnectedAsync();
        }

        /// <summary>Called when a connection with the hub is terminated.</summary>
        /// <returns>A <see cref="T:System.Threading.Tasks.Task" /> that represents the asynchronous disconnect.</returns>
        public override Task OnDisconnectedAsync(Exception? exception)
        {
            if (Context.User?.Identity != null)
            {
                var userName = Context.User.Identity.Name;
                _appHubUsers.ConnectedUsers.TryGetValue(userName, out var existingUserConnectionIds);
                existingUserConnectionIds?.Remove(Context.ConnectionId);
                if (existingUserConnectionIds != null && existingUserConnectionIds.Count == 0)
                {
                    _appHubUsers.ConnectedUsers.TryRemove(userName, out var garbage);
                }
            }

            return base.OnDisconnectedAsync(exception);
        }

        #endregion

        /// <summary>
        /// Buchen der Events eines App-Users
        /// </summary>
        /// <param name="appUserId">ID des App-Users</param>
        /// <returns>Task</returns>
        public async Task JoinAppUser(string appUserId)
        {
            var group = $"appuser_{appUserId}";
            await _hubContext.Groups.AddToGroupAsync(Context.ConnectionId, group);
        }

        /// <summary>
        /// Abbsestellen der Events eines App-Users
        /// </summary>
        /// <param name="appUserId">ID des App-Users</param>
        /// <returns>Task</returns>
        public async Task LeaveAppUser(string appUserId)
        {
            var group = $"appuser_{appUserId}";
            await _hubContext.Groups.RemoveFromGroupAsync(Context.ConnectionId, group);
        }

        /// <summary>
        /// Buchen der Events einer Konversation für einen Benutzer
        /// </summary>
        /// <param name="conversationId">Id der Konversation</param>
        /// <param name="appUserId">ID des App-Users</param>
        /// <returns>Task</returns>
        public async Task JoinConversation(string conversationId, string appUserId)
        {
            var group = $"conversation_{conversationId}_{appUserId}";
            await _hubContext.Groups.AddToGroupAsync(Context.ConnectionId, group);
        }

        /// <summary>
        /// Abbsestellen der Events einer Konversation
        /// </summary>
        /// <param name="conversationId">Id der Konversation</param>
        /// <param name="appUserId">ID des App-Users</param>
        /// <returns>Task</returns>
        public async Task LeaveConversation(string conversationId, string appUserId)
        {
            var group = $"conversation_{conversationId}_{appUserId}";
            await _hubContext.Groups.RemoveFromGroupAsync(Context.ConnectionId, group);
        }

        
    }
}