using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using System.Web;
using Microsoft.AspNet.SignalR;
using Microsoft.AspNet.SignalR.Hubs;

namespace MultiEditWithSignalRv2.SignalR
{
    [HubName("blogHub")]
    public class BlogHub : Hub
    {
        protected static ConcurrentDictionary<string, string> connectionGroups = new ConcurrentDictionary<string, string>();

        /// <summary>
        /// The method called from SignalR client (JS)
        /// </summary>
        /// <param name="message">String Data</param>
        /// <param name="append">A boolean value indicating
        /// if incoming value should be appended or overwritten
        /// when sent back to other clients</param>
        public void Send(string message, bool append = true)
        {
            // communicate only with group of clients
            // Clients.Group("group-name").ClientMethod();
            if (connectionGroups.TryGetValue(Context.ConnectionId, out string groupName))
            {
                // send the update to everyone in the group except the caller
                Clients.OthersInGroup(groupName).UpdateMessage(message, append);
            }
        }

        /// <summary>
        ///
        /// </summary>
        /// <param name="groupName"></param>
        public void JoinGroup(string groupName)
        {
            var joinedGroup = connectionGroups.AddOrUpdate(Context.ConnectionId, groupName,
                (key, existingVal) =>
                {
                    // If this delegate is invoked, then the key already exists.
                    Groups.Remove(key, existingVal);
                    return groupName;
                });
            Groups.Add(Context.ConnectionId, joinedGroup);
            // let this connection know they've joined the group
            Clients.Client(Context.ConnectionId).JoinedGroup(joinedGroup);
            // request an update from everyone else in the group
            Clients.OthersInGroup(joinedGroup).InitializeNewMember(Context.User.Identity.IsAuthenticated ?
                Context.User.Identity.Name :
                null);
        }

        /// <summary>
        ///
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="xPos"></param>
        /// <param name="yPos"></param>
        public void MouseMove(string userName, int xPos, int yPos)
        {
            if (connectionGroups.TryGetValue(Context.ConnectionId, out string groupName))
            {
                // send the update to everyone in the group except the caller
                Clients.OthersInGroup(groupName).MouseMove(userName, xPos, yPos);
            }
        }

        /// <summary>
        ///
        /// </summary>
        public void LeaveGroup()
        {
            if (connectionGroups.TryRemove(Context.ConnectionId, out string groupName))
            {
                Groups.Remove(Context.ConnectionId, groupName);
            }
        }

        public override Task OnConnected()
        {
            JoinGroup(Context.ConnectionId);
            return base.OnConnected();
        }

        public override Task OnDisconnected(bool stopCalled)
        {
            LeaveGroup();
            return base.OnDisconnected(stopCalled);
        }
    }
}