#if UNITY_5_3_OR_NEWER
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEngine;

namespace RocketUtils
{
    [Serializable]
    public class ObservableDict<TKey, TValue> : IDictionary<TKey, TValue>, ISerializationCallbackReceiver
    {
        public event Action Changed;

        [SerializeField] private Dictionary<TKey, TValue> _dict;

        #region IDictionary Properties
        public ICollection<TKey> Keys
        {
            get { return _dict.Keys; }
        }

        public ICollection<TValue> Values
        {
            get { return _dict.Values; }
        }

        public int Count
        {
            get { return _dict.Count; }
        }

        public bool IsReadOnly
        {
            get { return false; }
        }

        public TValue this[TKey key]
        {
            get { return _dict[key]; }
            set
            {
                _dict[key] = value;
                RaiseChangedEvent();
            }
        }
        #endregion

        public ObservableDict()
        {
            _dict = new Dictionary<TKey, TValue>();
        }

        public ObservableDict(ObservableDict<TKey, TValue> other)
        {
            _dict = new Dictionary<TKey, TValue>();

            var keys = other.Keys.ToList();

            for (int i = 0; i < keys.Count; i++)
            {
                var value = other[keys[i]];
                _dict.Add(keys[i], value);

                IObservableModel observableItem = value as IObservableModel;

                if (observableItem != null)
                    observableItem.PropertyChanged += RaiseChangedEvent;
            }
        }

        ~ObservableDict()
        {
            Clear();
        }

		private void RaiseChangedEvent()
		{
			if (Changed != null)
				Changed.Invoke();
		}

        #region IDictionary Methods
        public void Add(TKey key, TValue value)
        {
            try
            {
                _dict.Add(key, value);
            }
            catch (ArgumentException e)
            {
                throw e;
            }

            RaiseChangedEvent();

            IObservableModel observableItem = value as IObservableModel;
            if (observableItem != null)
                observableItem.PropertyChanged += RaiseChangedEvent;
        }

        public bool ContainsKey(TKey key)
        {
            return _dict.ContainsKey(key);
        }

        public bool Remove(TKey key)
        {
            if (_dict.ContainsKey(key))
            {
                var value = _dict[key];

                IObservableModel observableItem = value as IObservableModel;
                if (observableItem != null)
                    observableItem.PropertyChanged -= RaiseChangedEvent;

                _dict.Remove(key);
                RaiseChangedEvent();
                return true;
            }

            return false;
        }

        public bool TryGetValue(TKey key, out TValue value)
        {
            return _dict.TryGetValue(key, out value);
        }

        public void Add(KeyValuePair<TKey, TValue> item)
        {
            try
            {
                Add(item.Key, item.Value);
            }
            catch (ArgumentException e)
            {
                throw e;
            }
        }

		public void Clear()
		{
			if (_dict == null)
			{
				return;
			}

			foreach (var pair in _dict)
			{
				IObservableModel observableItem = pair.Value as IObservableModel;
				if (observableItem != null)
					observableItem.PropertyChanged -= RaiseChangedEvent;
			}

			_dict.Clear();

			RaiseChangedEvent();
		}

		public bool Contains(KeyValuePair<TKey, TValue> item)
        {
            return _dict.ContainsKey(item.Key) && _dict[item.Key].Equals(item.Value);
        }

        public void CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex)
        {
            throw new NotImplementedException();
        }

        public bool Remove(KeyValuePair<TKey, TValue> item)
        {
            throw new NotImplementedException();
        }

        public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator()
        {
            return _dict.GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return _dict.GetEnumerator();
        }
        #endregion

        #region Serialization Callbacks
        [SerializeField] private TKey[] _keys;
        [SerializeField] private TValue[] _values;

        public void OnAfterDeserialize()
        {
            if (_keys != null && _values != null)
            {
                if (_dict == null) _dict = new Dictionary<TKey, TValue>(_keys.Length);
                else _dict.Clear();
                for (int i = 0; i < _keys.Length; i++)
                {
                    if (i < _values.Length)
                        _dict[_keys[i]] = _values[i];
                    else
                        _dict[_keys[i]] = default(TValue);
                }
            }

            _keys = null;
            _values = null;
        }

        public void OnBeforeSerialize()
        {
            if (_dict == null || _dict.Count == 0)
            {
                _keys = null;
                _values = null;
            }
            else
            {
                int cnt = _dict.Count;
                _keys = new TKey[cnt];
                _values = new TValue[cnt];
                int i = 0;
                var e = _dict.GetEnumerator();
                while (e.MoveNext())
                {
                    _keys[i] = e.Current.Key;
                    _values[i] = e.Current.Value;
                    i++;
                }

                e.Dispose();
            }
        }
        #endregion
    }
}
#endif