using FluentAssertions;
using MongoDB.Driver;
using NSubstitute;
using Robware.Blog;
using Robware.Blog.Data.MongoDB.State;
using System;
using System.Threading.Tasks;
using Xunit;

namespace Robware.Data.MongoDB.Tests {
	public class BlogRepositoryTests {
		[Fact]
		public async Task SavePost_WithNewPost_GetsNewIdAndSetsTimestampAndSavesAsync() {
			var collection = Substitute.For<IMongoCollection<BlogPostState>>();
			collection.CountDocumentsAsync(Arg.Any<FilterDefinition<BlogPostState>>()).Returns(10);
			var database = Substitute.For<IMongoDatabase>();
			database.GetCollection<BlogPostState>("blog").Returns(collection);

			var repo = new BlogRepository(database);
			var post = new BlogPost();
			await repo.SavePost(post);
			post.Id.Should().Be(11);
			post.Timestamp.Should().BeCloseTo(DateTime.Now);
			await collection.Received(1).InsertOneAsync(Arg.Any<BlogPostState>());
		}

		[Fact]
		public async Task SavePost_WithExistingPost_DoesNotSetTimestampAndSavesAsync() {
			var collection = Substitute.For<IMongoCollection<BlogPostState>>();
			var database = Substitute.For<IMongoDatabase>();
			database.GetCollection<BlogPostState>("blog").Returns(collection);

			var repo = new BlogRepository(database);
			var post = new BlogPost() {
				Id = 1
			};
			await repo.SavePost(post);
			post.Id.Should().Be(1);
			post.Timestamp.Should().Be(new DateTime());
			await collection.Received(1).InsertOneAsync(Arg.Any<BlogPostState>());
		}

		[Fact]
		public async Task GetCountAsync_ReturnsCountFromDatabase() {
			var collection = Substitute.For<IMongoCollection<BlogPostState>>();
			collection.CountDocumentsAsync(Arg.Any<FilterDefinition<BlogPostState>>()).Returns(10);
			var database = Substitute.For<IMongoDatabase>();
			database.GetCollection<BlogPostState>("blog").Returns(collection);

			var repo = new BlogRepository(database);
			(await repo.GetCountAsync()).Should().Be(10);
		}
	}
}