// 
// CompletionListWindow.cs
//  
// Author:
//       Mike Krüger <mkrueger@novell.com>
// 
// Copyright (c) 2009 Novell, Inc (http://www.novell.com)
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using MonoDevelop.Core;
using MonoDevelop.Ide.Gui.Content;
using MonoDevelop.Ide.Editor.Extension;

namespace MonoDevelop.Ide.CodeCompletion
{
	public class CompletionWindowManager
	{
		static CompletionListWindow wnd;
		static bool isShowing;
		
		public static bool IsVisible {
			get {
				return isShowing || wnd != null && wnd.Visible;
			}
		}
		
		public static CompletionListWindow Wnd {
			get { return wnd; }
		}
		
		public static int X {
			get {
				return wnd.X;
			}
		}
		
		public static int Y {
			get {
				return wnd.Y;
			}
		}
		
		public static CodeCompletionContext CodeCompletionContext {
			get {
				return wnd.CodeCompletionContext;
			}
		}

		static CompletionWindowManager ()
		{
			if (IdeApp.Workbench != null) {
				IdeApp.Workbench.RootWindow.Destroyed += (sender, e) => DestroyWindow ();
				IdeApp.Workbench.RootWindow.WindowStateEvent += (o, args) => HideWindow ();
			}
			
			IdeApp.Preferences.ForceSuggestionMode.Changed += (s,a) => {
				if (wnd != null)
					wnd.AutoCompleteEmptyMatch = wnd.AutoSelect = !IdeApp.Preferences.ForceSuggestionMode;
			};
		}

		// ext may be null, but then parameter completion don't work
		internal static bool ShowWindow (CompletionTextEditorExtension ext, char firstChar, ICompletionDataList list, ICompletionWidget completionWidget, CodeCompletionContext completionContext)
		{
			PrepareShowWindow (ext, firstChar, completionWidget, completionContext);
			return ShowWindow (list, completionContext);
		}

		// ext may be null, but then parameter completion don't work
		internal static void PrepareShowWindow (CompletionTextEditorExtension ext, char firstChar, ICompletionWidget completionWidget, CodeCompletionContext completionContext)
		{
			isShowing = true;

			if (wnd == null) {
				wnd = new CompletionListWindow ();
				wnd.WordCompleted += HandleWndWordCompleted;
			}
			if (ext != null) {
				var widget = ext.Editor.GetNativeWidget<Gtk.Widget> ();
				wnd.TransientFor = widget?.Parent?.Toplevel as Gtk.Window;
			} else {
				var widget = completionWidget as Gtk.Widget;
				if (widget != null) {
					var window = widget.Toplevel as Gtk.Window;
					if (window != null)
						wnd.TransientFor = window;
				}
			}
			wnd.Extension = ext;

			wnd.InitializeListWindow (completionWidget, completionContext);
		}

		internal static bool ShowWindow (ICompletionDataList list, CodeCompletionContext completionContext)
		{
			if (wnd == null || !isShowing)
				return false;
			
			var completionWidget = wnd.CompletionWidget;
			var ext = wnd.Extension;
			wnd.EndOffset = wnd.CompletionWidget.CaretOffset;
			try {
				isShowing = false;
				if (!wnd.ShowListWindow (list, completionContext)) {
					if (list is IDisposable)
						((IDisposable)list).Dispose ();
					HideWindow ();
					return false;
				}
				
				if (IdeApp.Preferences.ForceSuggestionMode)
					wnd.AutoSelect = false;
				wnd.Show ();
				OnWindowShown (EventArgs.Empty);
				return true;
			} catch (Exception ex) {
				LoggingService.LogError ("Exception while showing completion window.", ex);
				return false;
			} finally {
				ParameterInformationWindowManager.UpdateWindow (ext, completionWidget);
			}
		}

		static void HandleWndWordCompleted (object sender, CodeCompletionContextEventArgs e)
		{
			EventHandler<CodeCompletionContextEventArgs> handler = WordCompleted;
			if (handler != null)
				handler (sender, e);
		}
		
		public static event EventHandler<CodeCompletionContextEventArgs> WordCompleted;

		static void DestroyWindow ()
		{
			if (wnd != null) {
				wnd.Destroy ();
				wnd = null;
			}
			OnWindowClosed (EventArgs.Empty);
		}
		
		public static bool PreProcessKeyEvent (KeyDescriptor descriptor)
		{
			if (!IsVisible)
				return false;
			return wnd.PreProcessKeyEvent (descriptor);
		}

		public static void UpdateCursorPosition ()
		{
			if (!IsVisible)
				return;
			if (wnd.IsInCompletion || isShowing)
				return;
			var caretOffset = wnd.CompletionWidget.CaretOffset;
			if (caretOffset < wnd.StartOffset || caretOffset > wnd.EndOffset + 1) {
				HideWindow ();
			}
		}

		public static void UpdateWordSelection (string text)
		{
			if (IsVisible) {
				wnd.CompletionString = text;
				wnd.UpdateWordSelection ();
			}
		}

		public static void PostProcessKeyEvent (KeyDescriptor descriptor)
		{
			if (!IsVisible)
				return;
			wnd.PostProcessKeyEvent (descriptor);
		}

		public static void RepositionWindow ()
		{
			if (!IsVisible)
				return;
			wnd.RepositionWindow ();
		}
		
		public static void HideWindow ()
		{
			isShowing = false;
			if (!IsVisible)
				return;
			if (wnd == null)
				return;
			ParameterInformationWindowManager.UpdateWindow (wnd.Extension, wnd.CompletionWidget);
			wnd.HideWindow ();
			OnWindowClosed (EventArgs.Empty);
			//DestroyWindow ();
		}
		
		
		static void OnWindowClosed (EventArgs e)
		{
			var handler = WindowClosed;
			if (handler != null)
				handler (null, e);
		}

		public static event EventHandler WindowClosed;
		
		static void OnWindowShown (EventArgs e)
		{
			var handler = WindowShown;
			if (handler != null)
				handler (null, e);
		}
		
		public static event EventHandler WindowShown;
	}
}