// Needed for NET40
#if !NET_4_6
using System;

using LinqInternal.Core;

namespace LinqInternal.Collections
{
    [Serializable]
    internal sealed class ConvertedObserver<TInput, TOutput> : IObserver<TInput>
    {
        private readonly Func<TInput, TOutput> _converter;
        private readonly IObserver<TOutput> _observer;

        public ConvertedObserver(IObserver<TOutput> observer, Func<TInput, TOutput> converter)
        {
            if (observer == null)
            {
                throw new ArgumentNullException("observer");
            }
            _observer = observer;
            if (converter == null)
            {
                throw new ArgumentNullException("converter");
            }
            _converter = converter;
        }

        public void OnCompleted()
        {
            _observer.OnCompleted();
        }

        public void OnError(Exception error)
        {
            _observer.OnError(error);
        }

        public void OnNext(TInput value)
        {
            _observer.OnNext(_converter.Invoke(value));
        }
    }
}
#endif