//
// TemplatedGroup.cs
//
// Author:
//       Jean-Philippe Bruyère <jp.bruyere@hotmail.com>
//
// Copyright (c) 2013-2017 Jean-Philippe Bruyère
//
// 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 System.Xml.Serialization;
using System.Xml;
using System.Reflection;
using System.Collections.Generic;
using System.ComponentModel;
using System.Collections;
using System.Threading;
using System.Linq;

namespace Crow
{
	public abstract class TemplatedGroup : TemplatedControl
	{
		#region CTOR
		public TemplatedGroup () : base(){}
		#endregion

		protected Group items;
		string _itemTemplate, _dataTest;

		#region events
		public event EventHandler<SelectionChangeEventArgs> SelectedItemChanged;
		public event EventHandler Loaded;
		#endregion

		IList data;
		int _selectedIndex = -1;
		Color selBackground, selForeground;

		int itemPerPage = 50;
		CrowThread loadingThread = null;

		bool isPaged = false;

		#region Templating
		//TODO: dont instantiate ItemTemplates if not used
		//but then i should test if null in msil gen
		public Dictionary<string, ItemTemplate> ItemTemplates = new Dictionary<string, Crow.ItemTemplate>();

		/// <summary>
		/// Default item template
		/// </summary>
		[XmlAttributeAttribute][DefaultValue("#Crow.Templates.ItemTemplate.goml")]
		public string ItemTemplate {
			get { return _itemTemplate; }
			set {
				if (value == _itemTemplate)
					return;

				_itemTemplate = value;

				//TODO:reload list with new template?
				NotifyValueChanged("ItemTemplate", _itemTemplate);
			}
		}
		protected override void loadTemplate(GraphicObject template = null)
		{
			base.loadTemplate (template);

			items = this.child.FindByName ("ItemsContainer") as Group;
			if (items == null)
				throw new Exception ("TemplatedGroup template Must contain a Group named 'ItemsContainer'");
			if (items.Children.Count == 0)
				NotifyValueChanged ("HasChildren", false);
			else
				NotifyValueChanged ("HasChildren", true);
		}
		/// <summary>
		/// Use to define condition on Data item for selecting among ItemTemplates.
		/// Default value is 'TypeOf' for selecting Template depending on Type of Data.
		/// Other possible values are properties of Data
		/// </summary>
		/// <value>The data property test.</value>
		[XmlAttributeAttribute][DefaultValue("TypeOf")]
		public string DataTest {
			get { return _dataTest; }
			set {
				if (value == _dataTest)
					return;

				_dataTest = value;

				NotifyValueChanged("DataTest", _dataTest);
			}
		}
		#endregion

		public virtual List<GraphicObject> Items{
			get {
				return isPaged ? items.Children.SelectMany(x => (x as Group).Children).ToList()
				: items.Children;
			}
		}
		[XmlAttributeAttribute][DefaultValue(-1)]public int SelectedIndex{
			get { return _selectedIndex; }
			set {
				if (value == _selectedIndex)
					return;

				if (_selectedIndex >= 0 && Items.Count > _selectedIndex) {
					Items[_selectedIndex].Foreground = Color.Transparent;
					Items[_selectedIndex].Background = Color.Transparent;
				}

				_selectedIndex = value;

				if (_selectedIndex >= 0 && Items.Count > _selectedIndex) {
					Items[_selectedIndex].Foreground = SelectionForeground;
					Items[_selectedIndex].Background = SelectionBackground;
				}

				NotifyValueChanged ("SelectedIndex", _selectedIndex);
				NotifyValueChanged ("SelectedItem", SelectedItem);
				SelectedItemChanged.Raise (this, new SelectionChangeEventArgs (SelectedItem));
			}
		}
		[XmlIgnore]public virtual object SelectedItem{
			get { return data == null ? null : _selectedIndex < 0 ? null : data[_selectedIndex]; }
		}
		[XmlIgnore]public bool HasItems {
			get { return Items.Count > 0; }
		}
		[XmlAttributeAttribute]public IList Data {
			get { return data; }
			set {
				if (value == data)
					return;

				cancelLoadingThread ();

				data = value;

				NotifyValueChanged ("Data", data);

				lock (CurrentInterface.LayoutMutex)
					ClearItems ();

				if (data == null)
					return;

				loadingThread = new CrowThread (this, loading);
				loadingThread.Finished += (object sender, EventArgs e) => (sender as TemplatedGroup).Loaded.Raise (sender, e);
				loadingThread.Start ();

				NotifyValueChanged ("SelectedIndex", _selectedIndex);
				NotifyValueChanged ("SelectedItem", SelectedItem);
				SelectedItemChanged.Raise (this, new SelectionChangeEventArgs (SelectedItem));
				NotifyValueChanged ("HasItems", HasItems);
			}
		}

		[XmlAttributeAttribute][DefaultValue("SteelBlue")]
		public virtual Color SelectionBackground {
			get { return selBackground; }
			set {
				if (value == selBackground)
					return;
				selBackground = value;
				NotifyValueChanged ("SelectionBackground", selBackground);
				RegisterForRedraw ();
			}
		}
		[XmlAttributeAttribute][DefaultValue("White")]
		public virtual Color SelectionForeground {
			get { return selForeground; }
			set {
				if (value == selForeground)
					return;
				selForeground = value;
				NotifyValueChanged ("SelectionForeground", selForeground);
				RegisterForRedraw ();
			}
		}

		protected void raiseSelectedItemChanged(){
			SelectedItemChanged.Raise (this, new SelectionChangeEventArgs (SelectedItem));
		}


		public virtual void AddItem(GraphicObject g){
			items.AddChild (g);
			g.LogicalParent = this;
			NotifyValueChanged ("HasChildren", true);
		}
		public virtual void RemoveItem(GraphicObject g)
		{
			g.LogicalParent = null;
			items.RemoveChild (g);
			if (items.Children.Count == 0)
				NotifyValueChanged ("HasChildren", false);
		}

		public virtual void ClearItems()
		{
			_selectedIndex = -1;
			NotifyValueChanged ("SelectedIndex", _selectedIndex);
			NotifyValueChanged ("SelectedItem", null);

			items.ClearChildren ();
			NotifyValueChanged ("HasChildren", false);
		}


		#region GraphicObject overrides
		public override GraphicObject FindByName (string nameToFind)
		{
			if (Name == nameToFind)
				return this;

			foreach (GraphicObject w in Items) {
				GraphicObject r = w.FindByName (nameToFind);
				if (r != null)
					return r;
			}
			return null;
		}
		public override bool Contains (GraphicObject goToFind)
		{
			foreach (GraphicObject w in Items) {
				if (w == goToFind)
					return true;
				if (w.Contains (goToFind))
					return true;
			}
			return base.Contains(goToFind);
		}
//		public override void ClearBinding ()
//		{
//			if (items != null)
//				items.ClearBinding ();
//
//			base.ClearBinding ();
//		}
//		public override void ResolveBindings ()
//		{
//			base.ResolveBindings ();
//			if (items != null)
//				items.ResolveBindings ();
//		}
		#endregion

		void loading(){
			if (ItemTemplates == null)
				ItemTemplates = new Dictionary<string, ItemTemplate> ();
			if (!ItemTemplates.ContainsKey ("default"))
				ItemTemplates ["default"] = Interface.GetItemTemplate (ItemTemplate);

			for (int i = 1; i <= (data.Count / itemPerPage) + 1; i++) {
				if ((bool)loadingThread?.cancelRequested) {
					this.Dispose ();
					return;
				}
				loadPage (i);
				Thread.Sleep (1);
			}
		}
		void cancelLoadingThread(){
			if (loadingThread != null)
				loadingThread.Cancel ();
		}
		void loadPage(int pageNum)
		{
			#if DEBUG_LOAD
			Stopwatch loadingTime = new Stopwatch ();
			loadingTime.Start ();
			#endif

			Group page;
			if (typeof(Wrapper).IsAssignableFrom (items.GetType ())) {
				page = items;
				itemPerPage = int.MaxValue;
			} else if (typeof(GenericStack).IsAssignableFrom (items.GetType ())) {
				GenericStack gs = new GenericStack ();
				gs.CurrentInterface = items.CurrentInterface;
				gs.Initialize ();
				gs.Orientation = (items as GenericStack).Orientation;
				gs.Width = items.Width;
				gs.Height = items.Height;
				gs.VerticalAlignment = items.VerticalAlignment;
				gs.HorizontalAlignment = items.HorizontalAlignment;
				page = gs;
				page.Name = "page" + pageNum;
				isPaged = true;
			} else {
				page = Activator.CreateInstance (items.GetType ()) as Group;
				page.Name = "page" + pageNum;
				isPaged = true;
			}

			for (int i = (pageNum - 1) * itemPerPage; i < pageNum * itemPerPage; i++) {
				if (i >= data.Count)
					break;
				if ((bool)loadingThread?.cancelRequested) {
					page.Dispose ();
					return;
				}

				loadItem (i, page);
			}

			if (page == items)
				return;
			lock (CurrentInterface.LayoutMutex)
				items.AddChild (page);

			#if DEBUG_LOAD
			loadingTime.Stop ();
			Console.WriteLine("Listbox {2} Loading: {0} ticks \t, {1} ms",
			loadingTime.ElapsedTicks,
			loadingTime.ElapsedMilliseconds, this.ToString());
			#endif
		}
		string getItempKey(Type dataType, object o){
			try {
				return dataType.GetProperty (_dataTest).GetGetMethod ().Invoke (o, null).ToString();
			} catch  {
				return dataType.FullName;
			}
		}
		protected void loadItem(int i, Group page){
			if (data [i] == null)//TODO:surely a threading sync problem
				return;
			GraphicObject g = null;
			ItemTemplate iTemp = null;
			Type dataType = data [i].GetType ();
			string itempKey = dataType.FullName;

			if (_dataTest != "TypeOf")
				itempKey = getItempKey (dataType, data [i]);

			if (ItemTemplates.ContainsKey (itempKey))
				iTemp = ItemTemplates [itempKey];
			else {
				foreach (string it in ItemTemplates.Keys) {
					Type t = Type.GetType (it);
					if (t == null) {
						Assembly a = Assembly.GetEntryAssembly ();
						foreach (Type expT in a.GetExportedTypes ()) {
							if (expT.Name == it) {
								t = expT;
								break;
							}
						}
					}
					if (t == null)
						continue;
					if (t.IsAssignableFrom (dataType)) {//TODO:types could be cached
						iTemp = ItemTemplates [it];
						break;
					}
				}
				if (iTemp == null)
					iTemp = ItemTemplates ["default"];
			}

			lock (CurrentInterface.LayoutMutex) {
				g = iTemp.CreateInstance(CurrentInterface);
				page.AddChild (g);
				//g.LogicalParent = this;
				registerItemClick (g);
			}

			if (iTemp.Expand != null && g is Expandable) {
				(g as Expandable).Expand += iTemp.Expand;
				(g as Expandable).GetIsExpandable = iTemp.HasSubItems;
			}

			g.DataSource = data [i];
		}
		protected virtual void registerItemClick(GraphicObject g){
			g.MouseClick += itemClick;
		}
//		protected void _list_LayoutChanged (object sender, LayoutingEventArgs e)
//		{
//			#if DEBUG_LAYOUTING
//			Console.WriteLine("list_LayoutChanged");
//			#endif
//			if (_gsList.Orientation == Orientation.Horizontal) {
//				if (e.LayoutType == LayoutingType.Width)
//					_gsList.Width = approxSize;
//			} else if (e.LayoutType == LayoutingType.Height)
//				_gsList.Height = approxSize;
//		}
		int approxSize
		{
			get {
				if (data == null)
					return -1;
				GenericStack page1 = items.FindByName ("page1") as GenericStack;
				if (page1 == null)
					return -1;

				return page1.Orientation == Orientation.Horizontal ?
					data.Count < itemPerPage ?
					-1:
					(int)Math.Ceiling ((double)page1.Slot.Width / (double)itemPerPage * (double)(data.Count+1)):
					data.Count < itemPerPage ?
					-1:
					(int)Math.Ceiling ((double)page1.Slot.Height / (double)itemPerPage * (double)(data.Count+1));
			}
		}
		internal virtual void itemClick(object sender, MouseButtonEventArgs e){
			SelectedIndex = data.IndexOf((sender as GraphicObject).DataSource);
		}

		protected override void Dispose (bool disposing)
		{
			if (disposing && loadingThread != null)
				loadingThread.Cancel ();
			base.Dispose (disposing);
		}
	}
}