using System;
using System.ComponentModel;
using System.Linq;
using UnityEngine;

namespace UIWidgets
{
	[Serializable]
	public class TreeNode<TItem> : IObservable, IDisposable, INotifyPropertyChanged
	{
		public bool PauseObservation;

		[SerializeField]
		private bool isVisible = true;

		[SerializeField]
		private bool isExpanded;

		[SerializeField]
		private TItem item;

		[SerializeField]
		private IObservableList<TreeNode<TItem>> nodes;

		public int UsedNodesCount;

		private WeakReference parent;

		private bool disposed;

		public bool IsVisible
		{
			get
			{
				return isVisible;
			}
			set
			{
				isVisible = value;
				Changed("IsVisible");
			}
		}

		public bool IsExpanded
		{
			get
			{
				return isExpanded;
			}
			set
			{
				isExpanded = value;
				Changed("IsExpanded");
			}
		}

		public TItem Item
		{
			get
			{
				return item;
			}
			set
			{
				item = value;
				Changed("Item");
			}
		}

		public IObservableList<TreeNode<TItem>> Nodes
		{
			get
			{
				return nodes;
			}
			set
			{
				if (nodes != null)
				{
					nodes.OnChange -= Changed;
					nodes.OnCollectionChange -= CollectionChanged;
				}
				nodes = value;
				if (nodes != null)
				{
					nodes.OnChange += Changed;
					nodes.OnCollectionChange += CollectionChanged;
					CollectionChanged();
				}
				Changed("Nodes");
			}
		}

		public int TotalNodesCount
		{
			get
			{
				if (nodes == null)
				{
					return 1;
				}
				return nodes.Sum((TreeNode<TItem> x) => x.TotalNodesCount) + 1;
			}
		}

		public int AllUsedNodesCount
		{
			get
			{
				if (!isVisible)
				{
					return 0;
				}
				if (!isExpanded)
				{
					return UsedNodesCount;
				}
				if (nodes == null)
				{
					return UsedNodesCount;
				}
				return nodes.Sum((TreeNode<TItem> x) => x.AllUsedNodesCount) + UsedNodesCount;
			}
		}

		public TreeNode<TItem> Parent
		{
			get
			{
				if (parent != null && parent.IsAlive)
				{
					return parent.Target as TreeNode<TItem>;
				}
				return null;
			}
			set
			{
				SetParentValue(value);
			}
		}

		public event OnChange OnChange;

		public event PropertyChangedEventHandler PropertyChanged;

		public TreeNode(TItem nodeItem, IObservableList<TreeNode<TItem>> nodeNodes = null, bool nodeIsExpanded = false, bool nodeIsVisible = true)
		{
			item = nodeItem;
			nodes = nodeNodes;
			isExpanded = nodeIsExpanded;
			isVisible = nodeIsVisible;
			if (nodes != null)
			{
				nodes.OnChange += Changed;
				nodes.OnCollectionChange += CollectionChanged;
				CollectionChanged();
			}
		}

		public bool IsParentOfNode(TreeNode<TItem> node)
		{
			TreeNode<TItem> treeNode = node.Parent;
			while (treeNode != null)
			{
				if (treeNode == this)
				{
					return true;
				}
				treeNode = treeNode.Parent;
			}
			return false;
		}

		public bool CanBeParent(TreeNode<TItem> newParent)
		{
			if (this == newParent)
			{
				return false;
			}
			return !IsParentOfNode(newParent);
		}

		private void SetParentValue(TreeNode<TItem> newParent)
		{
			TreeNode<TItem> treeNode = ((parent == null || !parent.IsAlive) ? null : (parent.Target as TreeNode<TItem>));
			if (treeNode == newParent)
			{
				return;
			}
			if (newParent != null)
			{
				if (newParent == this)
				{
					throw new ArgumentException("Node cannot be own parent.");
				}
				if (IsParentOfNode(newParent))
				{
					throw new ArgumentException("Own child node cannot be parent node.");
				}
			}
			if (treeNode != null)
			{
				treeNode.nodes.OnCollectionChange -= treeNode.CollectionChanged;
				treeNode.nodes.Remove(this);
				treeNode.nodes.OnCollectionChange += treeNode.CollectionChanged;
			}
			parent = new WeakReference(newParent);
			if (newParent != null)
			{
				if (newParent.nodes == null)
				{
					newParent.nodes = new ObservableList<TreeNode<TItem>>();
					newParent.nodes.OnChange += newParent.Changed;
					newParent.nodes.OnCollectionChange += newParent.CollectionChanged;
				}
				newParent.nodes.OnCollectionChange -= newParent.CollectionChanged;
				newParent.nodes.Add(this);
				newParent.nodes.OnCollectionChange += newParent.CollectionChanged;
			}
		}

		private void CollectionChanged()
		{
			if (nodes != null)
			{
				nodes.ForEach(SetParent);
			}
		}

		private void SetParent(TreeNode<TItem> node)
		{
			if (node.Parent != null && node.Parent != this)
			{
				node.Parent.nodes.Remove(node);
			}
			node.parent = new WeakReference(this);
		}

		private void Changed()
		{
			Changed("Nodes");
		}

		private void Changed(string propertyName)
		{
			if (!PauseObservation)
			{
				if (this.OnChange != null)
				{
					this.OnChange();
				}
				if (this.PropertyChanged != null)
				{
					this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
				}
			}
		}

		public override bool Equals(object obj)
		{
			TreeNode<TItem> treeNode = obj as TreeNode<TItem>;
			if (treeNode == null)
			{
				return this == null;
			}
			if (this == null)
			{
				return false;
			}
			return item.Equals(treeNode.item);
		}

		public override int GetHashCode()
		{
			return base.GetHashCode();
		}

		public static bool operator ==(TreeNode<TItem> a, TreeNode<TItem> b)
		{
			bool flag = object.ReferenceEquals(null, a);
			bool flag2 = object.ReferenceEquals(null, b);
			if (flag && flag2)
			{
				return true;
			}
			if (flag != flag2)
			{
				return false;
			}
			bool flag3 = object.ReferenceEquals(null, a.item);
			bool flag4 = object.ReferenceEquals(null, b.item);
			if (flag3 && flag4)
			{
				return true;
			}
			if (flag3 != flag4)
			{
				return false;
			}
			return a.item.Equals(b.item);
		}

		public static bool operator !=(TreeNode<TItem> a, TreeNode<TItem> b)
		{
			bool flag = object.ReferenceEquals(null, a);
			bool flag2 = object.ReferenceEquals(null, b);
			if (flag && flag2)
			{
				return false;
			}
			if (flag != flag2)
			{
				return true;
			}
			bool flag3 = object.ReferenceEquals(null, a.item);
			bool flag4 = object.ReferenceEquals(null, b.item);
			if (flag3 && flag4)
			{
				return false;
			}
			if (flag3 != flag4)
			{
				return true;
			}
			return !a.item.Equals(b.item);
		}

		public void Dispose()
		{
			Dispose(true);
			GC.SuppressFinalize(this);
		}

		private void DisposeItem(TreeNode<TItem> node)
		{
			node.OnChange -= Changed;
			node.Dispose();
		}

		protected virtual void Dispose(bool disposing)
		{
			if (!disposed)
			{
				if (disposing)
				{
				}
				if (Nodes != null)
				{
					Nodes.BeginUpdate();
					Nodes.ForEach(DisposeItem);
					Nodes.EndUpdate();
					Nodes = null;
				}
				disposed = true;
			}
		}

		~TreeNode()
		{
			Dispose(false);
		}
	}
}