namespace Testing
{
    public class NewsController_LatestNews
    {
        [Theory]
        [AutoData]
        public void Should_be_news_items_ordered_by_date_descending(IEnumerable<NewsResultItem> newsResultItems)
        {
            var searchContext = Substitute.For<IProviderSearchContext>();
            var queryable = new LuceneProviderQueryableStub(enumerable);
            searchContext.GetQueryable().Returns(queryable);
            var newsController = new NewsController(indexName => searchContext);

            var actual = newsController.LatestNews(5).Model;

            Assert.IsGreater(actual.First().Date, actual.Last().Date);
        }
    }

    public class LuceneProviderQueryableStub<TElement> : IOrderedQueryable<TElement>, IOrderedQueryable, IQueryProvider
    {
        private readonly EnumerableQuery<TElement> innerQueryable;

        public Type ElementType { get { return ((IQueryable)innerQueryable).ElementType; } }

        public Expression Expression { get { return ((IQueryable)innerQueryable).Expression; } }

        public IQueryProvider Provider { get { return this; } }

        public LuceneProviderQueryableStub(IEnumerable<TElement> enumerable)
        {
            innerQueryable = new EnumerableQuery<TElement>(enumerable);
        }

        public LuceneProviderQueryableStub(Expression expression)
        {
            innerQueryable = new EnumerableQuery<TElement>(expression);
        }

        public IQueryable CreateQuery(Expression expression)
        {
            return new LuceneProviderQueryableStub<TElement>((IEnumerable<TElement>)((IQueryProvider)innerQueryable).CreateQuery(expression));
        }

        public IQueryable<TElement1> CreateQuery<TElement1>(Expression expression)
        {
            return (IQueryable<TElement1>)new LuceneProviderQueryableStub<TElement>((IEnumerable<TElement>)((IQueryProvider)innerQueryable).CreateQuery(expression));
        }

        public object Execute(Expression expression)
        {
            throw new NotImplementedException();
        }

        public TResult Execute<TResult>(Expression expression)
        {
            var items = this.ToArray();
            object results = new SearchResults<TElement>(items.Select(s => new SearchHit<TElement>(0, s)), 0);
            return (TResult)results;
        }

        public IEnumerator<TElement> GetEnumerator()
        {
            return ((IEnumerable<TElement>)innerQueryable).GetEnumerator();
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    public class NewsController
    {
        private readonly Func<string, IProviderSearchContext> searchContextFactory;

        public NewsController(Func<string, IProviderSearchContext> searchContextFactory)
        {
            this.searchContextFactory = searchContextFactory;
        }

        public ViewResult LatestNews(int count)
        {
            using (var searchContext = searchContextFactory("news_index"))
            {
                var newsResults = searchContext.GetQueryable<NewsResultItem>().OrderByDescending(x => x.Date).Take(count).GetResults();
                return View("~/Views/LatestNews.cshtml", newsResults);
            }
        }
    }
}