using System;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

namespace ES3Internal
{
	[Serializable]
	public abstract class ES3SerializableDictionary<TKey, TVal> : Dictionary<TKey, TVal>, ISerializationCallbackReceiver
	{
		[SerializeField]
		private List<TKey> _Keys;

		[SerializeField]
		private List<TVal> _Values;

		protected abstract bool KeysAreEqual(TKey a, TKey b);

		protected abstract bool ValuesAreEqual(TVal a, TVal b);

		public void OnBeforeSerialize()
		{
			_Keys = new List<TKey>();
			_Values = new List<TVal>();
			using Enumerator enumerator = GetEnumerator();
			while (enumerator.MoveNext())
			{
				KeyValuePair<TKey, TVal> current = enumerator.Current;
				try
				{
					_Keys.Add(current.Key);
					_Values.Add(current.Value);
				}
				catch
				{
				}
			}
		}

		public void OnAfterDeserialize()
		{
			if (_Keys == null || _Values == null)
			{
				return;
			}
			if (_Keys.Count != _Values.Count)
			{
				throw new Exception($"Key count is different to value count after deserialising dictionary.");
			}
			Clear();
			for (int i = 0; i < _Keys.Count; i++)
			{
				if (_Keys[i] != null)
				{
					try
					{
						Add(_Keys[i], _Values[i]);
					}
					catch
					{
					}
				}
			}
			_Keys = null;
			_Values = null;
		}

		public int RemoveNullValues()
		{
			List<TKey> list = (from pair in this
				where pair.Value == null
				select pair.Key).ToList();
			foreach (TKey item in list)
			{
				Remove(item);
			}
			return list.Count;
		}

		public bool ChangeKey(TKey oldKey, TKey newKey)
		{
			if (KeysAreEqual(oldKey, newKey))
			{
				return false;
			}
			TVal value = base[oldKey];
			Remove(oldKey);
			base[newKey] = value;
			return true;
		}
	}
}