using System;
using System.Collections.Generic;

namespace UIWidgetsSample
{
    public class EquatableUtils
    {
       // private DeepCollectionEquality _equality = DeepCollectionEquality();

        private int mapPropsToHashCode(List<object> props)
        {
            var value = 0;
            foreach (var prop in props)
            {
                value = _combine(value, prop);
            }
            return _finish(props == null ? 0 : value);
        }
        
        
        
        
        /// Determines whether [list1] and [list2] are equal.
        private bool equals(List<object> list1, List<object> list2)
        {
            if (list1.Equals(list2)) return true;
            if (list1 == null || list2 == null) return false;
            var length = list1.Count;
            if (length != list2.Count) return false;

            for (var i = 0; i < length; i++)
            {
                var unit1 = list1[i];
                var unit2 = list2[i];

                if (_isEquatable(unit1) && _isEquatable(unit2))
                {
                    if (unit1 != unit2) return false;
                }
                else if (unit1 is List<object> || unit1 is Dictionary<object, object>)
                {
                    //if (!_equality.equals(unit1, unit2)) 
                    if(!Equals(unit1,unit2))
                        return false;
                }
                else if (unit1?.GetType() != unit2?.GetType())
                {
                    return false;
                }
                else if (unit1 != unit2)
                {
                    return false;
                }
            }

            return true;
        }

        private bool _isEquatable(object _object)
        {
            return _object is Equatable || _object is EquatableMixin;
        }

        /// Jenkins Hash Functions
        /// https://en.wikipedia.org/wiki/Jenkins_hash_function
        private int _combine(int hash, object _object)
        {
            if (_object is Dictionary<object, object>)
            {
                var Keys = new List<object>();
                foreach (var key in ((Dictionary<object, object>) _object).Keys) Keys.Add(key);
                Keys.Sort((a, b) => a.GetHashCode() - b.GetHashCode());
                foreach (var key in Keys)
                {
                    var value = (object) null;
                    var keyValue = ((Dictionary<object, object>) _object).TryGetValue(key, out value);
                    hash = hash ^ _combine(hash, new Dictionary<object, object> {{key, value}});
                }

                ;
                return hash;
            }

            if (_object is List<object>)
            {
                foreach (var value in (List<object>) _object) hash = hash ^ _combine(hash, value);

                return hash ^ ((List<object>) _object).Count;
            }

            hash = 0x1fffffff & (hash + _object.GetHashCode());
            hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
            return hash ^ (hash >> 6);
        }

        private int _finish(int hash)
        {
            hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
            hash = hash ^ (hash >> 11);
            return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
        }

        /// Returns a string for [props].
        public static string mapPropsToString(Type runtimeType, List<object> props)
        {
            var result = "";
            var results = new List<string>();
            foreach (var prop in props) results.Add(prop.ToString());
            //props.map((prop) => prop.toString()).join(', ')
            return string.Join(",", results);
        }
    }
}