using System.Collections;
using System.Reflection;

namespace Connected.Interop.Reflection
{
	public static class ObjectComparer
	{
		public static bool Compare(object left, object right)
		{
			if (left is null || right is null)
				return false;

			if (left.GetType() != right.GetType())
				return false;

			var leftProperties = left.GetType().GetProperties(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance); ;

			foreach (var property in leftProperties)
			{
				if (!Compare(left, right, property))
					return false;
			}

			return true;
		}
		private static bool Compare(object left, object right, PropertyInfo property)
		{
			if (property.PropertyType.IsEnumerable())
			{
				if (!Compare(left as IEnumerable, right as IEnumerable))
					return false;
			}
			else if (property.PropertyType.IsTypePrimitive())
			{
				if (Comparer.DefaultInvariant.Compare(left, right) != 0)
					return false;
			}
			else
			{
				var leftValue = property.GetValue(left);
				var rightValue = property.GetValue(right);

				if (!Compare(leftValue, rightValue))
					return false;
			}

			return true;
		}
		private static bool Compare(IEnumerable left, IEnumerable right)
		{
			var leftEn = left.GetEnumerator();
			var rightEn = right.GetEnumerator();

			while (leftEn.MoveNext())
			{
				if (!rightEn.MoveNext())
					return false;

				if (!Compare(leftEn.Current, rightEn.Current))
					return false;
			}

			if (rightEn.MoveNext())
				return false;

			return true;
		}
	}
}