using System;
using System.Drawing;
using System.Windows.Forms;
using mRemoteNG.App;
using mRemoteNG.Connection;
using mRemoteNG.Connection.Protocol;

namespace mRemoteNG.UI.Controls
{
	public class QuickConnectComboBox : ToolStripComboBox
	{
		private readonly ComboBox _comboBox;
		private bool _ignoreEnter;
			
		public QuickConnectComboBox()
		{
			_comboBox = ComboBox;
		    if (_comboBox == null) return;
		    _comboBox.PreviewKeyDown += ComboBox_PreviewKeyDown;
		    _comboBox.SelectedIndexChanged += ComboBox_SelectedIndexChanged;
		    _comboBox.DrawItem += ComboBox_DrawItem;
		    _comboBox.DrawMode = DrawMode.OwnerDrawFixed;
				
		    // This makes it so that _ignoreEnter works correctly before any items are added to the combo box
		    _comboBox.Items.Clear();
		}
			
		private void ComboBox_PreviewKeyDown(object sender, PreviewKeyDownEventArgs e)
		{
			if (e.KeyCode == Keys.Enter & _comboBox.DroppedDown)
			{
				_ignoreEnter = true;
			}
		}
			
		protected override void OnKeyDown(KeyEventArgs e)
		{
			base.OnKeyDown(e);
			if (e.KeyCode == Keys.Enter)
			{
				// Only connect if Enter was not pressed while the combo box was dropped down
				if (!_ignoreEnter)
				{
					OnConnectRequested(new ConnectRequestedEventArgs(_comboBox.Text));
				}
				_ignoreEnter = false;
				e.Handled = true;
			}
			else if (e.KeyCode == Keys.Delete & _comboBox.DroppedDown)
			{
				if (_comboBox.SelectedIndex != -1)
				{
					// Items can't be removed from the ComboBox while it is dropped down without possibly causing
					// an exception so we must close it, delete the item, and then drop it down again. When we
					// close it programmatically, the SelectedItem may revert to Nothing, so we must save it first.
					var item = _comboBox.SelectedItem;
					_comboBox.DroppedDown = false;
					_comboBox.Items.Remove(item);
					_comboBox.SelectedIndex = -1;
					if (_comboBox.Items.Count != 0)
					{
						_comboBox.DroppedDown = true;
					}
				}
				e.Handled = true;
			}
		}
			
		private void ComboBox_SelectedIndexChanged(object sender, EventArgs e)
		{
			if (!(_comboBox.SelectedItem is HistoryItem))
			{
				return;
			}
			var historyItem = (HistoryItem) _comboBox.SelectedItem;
			OnProtocolChanged(new ProtocolChangedEventArgs(historyItem.ConnectionInfo.Protocol));
		}
			
		private static void ComboBox_DrawItem(object sender, DrawItemEventArgs e)
		{
			var comboBox = sender as ComboBox;
			if (comboBox == null)
			{
				return;
			}
			var drawItem = comboBox.Items[e.Index];
				
			string drawString;
			if (drawItem is HistoryItem)
			{
				var historyItem = (HistoryItem) drawItem;
				drawString = historyItem.ToString(true);
			}
			else
			{
				drawString = drawItem.ToString();
			}
				
			e.DrawBackground();
			e.Graphics.DrawString(drawString, e.Font, new SolidBrush(e.ForeColor), new RectangleF(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height));
			e.DrawFocusRectangle();
		}
			
		private struct HistoryItem : IEquatable<HistoryItem>
		{
				
			public ConnectionInfo ConnectionInfo {get; set;}
				
			public bool Equals(HistoryItem other)
			{
				if (ConnectionInfo.Hostname != other.ConnectionInfo.Hostname)
				{
					return false;
				}
				if (ConnectionInfo.Port != other.ConnectionInfo.Port)
				{
					return false;
				}

				return ConnectionInfo.Protocol == other.ConnectionInfo.Protocol;
			}
				
			public override string ToString()
			{
				return ToString(false);
			}
				
			public string ToString(bool includeProtocol)
			{
				var port = string.Empty;
				if (ConnectionInfo.Port != ConnectionInfo.GetDefaultPort())
				{
					port = $":{ConnectionInfo.Port}";
				}

				return includeProtocol ? $"{ConnectionInfo.Hostname}{port} ({ConnectionInfo.Protocol})" : $"{ConnectionInfo.Hostname}{port}";
			}
		}
			
		private bool Exists(HistoryItem searchItem)
		{
			foreach (var item in _comboBox.Items)
			{
				if (!(item is HistoryItem))
				{
					continue;
				}
				var historyItem = (HistoryItem) item;
				if (historyItem.Equals(searchItem))
				{
					return true;
				}
			}
			return false;
		}
			
		public void Add(ConnectionInfo connectionInfo)
		{
			try
			{
			    var historyItem = new HistoryItem {ConnectionInfo = connectionInfo};
			    if (!Exists(historyItem))
				{
					_comboBox.Items.Insert(0, historyItem);
				}
			}
			catch (Exception ex)
			{
				Runtime.MessageCollector.AddExceptionMessage(Language.strQuickConnectAddFailed, ex);
			}
		}
			
        #region Events
		public class ConnectRequestedEventArgs : EventArgs
		{
				
			public ConnectRequestedEventArgs(string connectionString)
			{
				ConnectionString = connectionString;
			}

		    public string ConnectionString { get; }
		}
			
		public delegate void ConnectRequestedEventHandler(object sender, ConnectRequestedEventArgs e);
		private ConnectRequestedEventHandler ConnectRequestedEvent;
			
		public event ConnectRequestedEventHandler ConnectRequested
		{
			add
			{
				ConnectRequestedEvent = (ConnectRequestedEventHandler) Delegate.Combine(ConnectRequestedEvent, value);
			}
			remove
			{
				ConnectRequestedEvent = (ConnectRequestedEventHandler) Delegate.Remove(ConnectRequestedEvent, value);
			}
		}


	    private void OnConnectRequested(ConnectRequestedEventArgs e)
	    {
            // TODO: Any reason to not jsut pass "e"?
            ConnectRequestedEvent?.Invoke(this, new ConnectRequestedEventArgs(e.ConnectionString));
	    }
			
		public class ProtocolChangedEventArgs : EventArgs
		{
				
			public ProtocolChangedEventArgs(ProtocolType protocol)
			{
				Protocol = protocol;
			}

		    public ProtocolType Protocol { get; }
		}
			
		public delegate void ProtocolChangedEventHandler(object sender, ProtocolChangedEventArgs e);
		private ProtocolChangedEventHandler ProtocolChangedEvent;
			
		public event ProtocolChangedEventHandler ProtocolChanged
		{
			add
			{
				ProtocolChangedEvent = (ProtocolChangedEventHandler) Delegate.Combine(ProtocolChangedEvent, value);
			}
			remove
			{
				ProtocolChangedEvent = (ProtocolChangedEventHandler) Delegate.Remove(ProtocolChangedEvent, value);
			}
		}


	    private void OnProtocolChanged(ProtocolChangedEventArgs e)
	    {
            // TODO: Any reason to not jsut pass "e"?
	        ProtocolChangedEvent?.Invoke(this, new ProtocolChangedEventArgs(e.Protocol));
	    }
        #endregion
	}
}