mRemoteNG/mRemoteV1/Config/Putty/AbstractPuttySessionsProvider.cs

using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Web;
using mRemoteNG.Connection;
using mRemoteNG.Tree.Root;
using System.Text;
// ReSharper disable ArrangeAccessorOwnerBody

namespace mRemoteNG.Config.Putty
{
    public abstract class AbstractPuttySessionsProvider
	{
        public virtual RootPuttySessionsNodeInfo RootInfo { get; } = new RootPuttySessionsNodeInfo();
        protected virtual List<PuttySessionInfo> Sessions
        {
            get { return RootInfo.Children.OfType<PuttySessionInfo>().ToList(); }
        }

	    #region Public Methods
        public abstract string[] GetSessionNames(bool raw = false);
		public abstract PuttySessionInfo GetSession(string sessionName);
		
		public virtual IEnumerable<PuttySessionInfo> GetSessions()
		{
		    var sessionNamesFromProvider = GetSessionNames(true);
            foreach (var sessionName in GetSessionNamesToAdd(sessionNamesFromProvider))
			{
				var sessionInfo = GetSession(sessionName);
			    AddSession(sessionInfo);
			}
		    foreach (var session in GetSessionToRemove(sessionNamesFromProvider))
		    {
		        RemoveSession(session);
		    }
            RootInfo.SortRecursive();
			return Sessions;
		}

        private IEnumerable<string> GetSessionNamesToAdd(IEnumerable<string> sessionNamesFromProvider)
        {
            var currentlyKnownSessionNames = Sessions.Select(session => session.Name);
            var sessionNamesToAdd = sessionNamesFromProvider.Except(currentlyKnownSessionNames);
            return sessionNamesToAdd;
        }

        private IEnumerable<PuttySessionInfo> GetSessionToRemove(IEnumerable<string> sessionNamesFromProvider)
        {
            var currentlyKnownSessionNames = Sessions.Select(session => session.Name);
            var normalizedSessionNames = sessionNamesFromProvider.Select(name => HttpUtility.UrlDecode(name, Encoding.GetEncoding("iso-8859-1")));
            var sessionNamesToRemove = currentlyKnownSessionNames.Except(normalizedSessionNames);
            return Sessions.Where(session => sessionNamesToRemove.Contains(session.Name));
        }

        protected virtual void AddSession(PuttySessionInfo sessionInfo)
        {
            if (string.IsNullOrEmpty(sessionInfo?.Name) || Sessions.Any(child => child.Name == sessionInfo.Name))
                return;
            RootInfo.AddChild(sessionInfo);
            RaisePuttySessionCollectionChangedEvent(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, sessionInfo));
        }

        protected virtual void RemoveSession(PuttySessionInfo sessionInfo)
        {
            if (!Sessions.Contains(sessionInfo)) return;
            RootInfo.RemoveChild(sessionInfo);
            RaisePuttySessionCollectionChangedEvent(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, sessionInfo));
        }
		
		public virtual void StartWatcher() { }
		
		public virtual void StopWatcher() { }
        #endregion
		
		public delegate void PuttySessionChangedEventHandler(object sender, PuttySessionChangedEventArgs e);
        public event PuttySessionChangedEventHandler PuttySessionChanged;
		protected virtual void RaiseSessionChangedEvent(PuttySessionChangedEventArgs args)
		{
            PuttySessionChanged?.Invoke(this, args);
		}

        public event NotifyCollectionChangedEventHandler PuttySessionsCollectionChanged;
        protected void RaisePuttySessionCollectionChangedEvent(NotifyCollectionChangedEventArgs args)
        {
            PuttySessionsCollectionChanged?.Invoke(this, args);
        }
    }
}