SocialPub/PrivaPub.Tests/Domain/MediaFlowTests.cs

using PrivaPub.Models.Federation;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Caching.Memory;

using MongoDB.Entities;

using NetVips;

using PrivaPub.Domain.Media;
using PrivaPub.Domain.Statuses;
using PrivaPub.Federation.Rendering;
using PrivaPub.Models.Media;
using PrivaPub.Tests.Support;

namespace PrivaPub.Tests.Domain
{
	[Trait("Category", "Integration")]
	public sealed class MediaFlowTests : IAsyncLifetime
	{
		Harness _harness;

		public async ValueTask InitializeAsync()
		{
			Assert.SkipUnless(MongoFixture.Enabled, MongoFixture.Skip);
			_harness = await Harness.Start();
		}

		public async ValueTask DisposeAsync()
		{
			if (_harness != default)
				await _harness.DisposeAsync();
		}

		static byte[] Png(int width, int height)
		{
			using var image = (Image.Black(width, height, bands: 3) + new double[] { 10, 120, 200 }).Cast(Enums.BandFormat.Uchar);
			return image.WriteToBuffer(".png");
		}

		static IFormFile Upload(byte[] bytes, string contentType) =>
			new FormFile(new MemoryStream(bytes), 0, bytes.Length, "file", "picture") { Headers = new HeaderDictionary(), ContentType = contentType };

		[Fact]
		public async Task An_upload_is_attached_once_and_federated_with_its_alt_text()
		{
			var token = TestContext.Current.CancellationToken;
			var (_, alice) = await _harness.Persona("alice");
			var (_, mallory) = await _harness.Persona("mallory");

			var upload = await _harness.Media.Upload(alice, Upload(Png(300, 200), "image/png"), "a blue square", "0.25,-0.5", false, token);
			Assert.True(upload.Ok);
			Assert.True(File.Exists(Path.Combine(_harness.Media.Root, upload.Attachment.FilePath)));

			var stolen = await _harness.Statuses.Publish(mallory, new StatusDraft { Text = "mine", MediaIds = new[] { upload.Attachment.ID } }, token);
			Assert.False(stolen.Ok);

			var posted = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "look", MediaIds = new[] { upload.Attachment.ID } }, token);
			Assert.True(posted.Ok);
			Assert.Equal(posted.Post.ID, (await DB.Default.Find<MediaAttachment>().OneAsync(upload.Attachment.ID, token)).PostId);

			var note = ActivityPubRenderer.Note(posted.Post, alice, default, default);
			var attachment = note["attachment"]![0]!;
			Assert.Equal("a blue square", attachment["name"]!.GetValue<string>());
			Assert.Equal(300, attachment["width"]!.GetValue<int>());
			Assert.Equal(-0.5f, attachment["focalPoint"]![1]!.GetValue<float>());
			Assert.StartsWith("https://privapub.test/media/files/", attachment["url"]!.GetValue<string>());

			var reused = await _harness.Statuses.Publish(alice, new StatusDraft { Text = "again", MediaIds = new[] { upload.Attachment.ID } }, token);
			Assert.False(reused.Ok);
		}

		[Fact]
		public async Task Unsupported_files_are_refused()
		{
			var (_, alice) = await _harness.Persona("alice");

			var outcome = await _harness.Media.Upload(alice, Upload(System.Text.Encoding.UTF8.GetBytes("<svg/>"), "image/svg+xml"), default, default, false, TestContext.Current.CancellationToken);

			Assert.False(outcome.Ok);
			Assert.Equal(422, outcome.Status);
		}

		[Fact]
		public async Task The_proxy_serves_signed_remote_media_and_nothing_else()
		{
			var token = TestContext.Current.CancellationToken;
			var path = $"/files/{Guid.NewGuid():N}.png";
			_harness.Peer.ServeFile(path, Png(10, 10), "image/png");
			var proxy = new MediaProxy(_harness.Local, Peer.Http(), _harness.Media, new StaticOptions<MediaOptions>(new MediaOptions()));

			var wrapped = proxy.Wrap(_harness.Peer.A + path);
			var parts = new Uri(wrapped).AbsolutePath.Split('/');
			var (file, contentType) = await proxy.Fetch(parts[3], parts[4], token);
			var (tampered, _) = await proxy.Fetch(parts[3].Replace(parts[3][0], parts[3][0] == 'A' ? 'B' : 'A'), parts[4], token);

			Assert.StartsWith("https://privapub.test/media/proxy/", wrapped);
			Assert.Equal("image/png", contentType);
			Assert.True(File.Exists(file));
			Assert.StartsWith(_harness.Media.ProxyRoot, file);
			Assert.Null(tampered);
		}

		// nothing of a suspended server, or of one whose media are rejected, is proxied; blocking one purges what was cached
		[Fact]
		public async Task A_blocked_servers_media_are_not_proxied_and_their_cache_goes()
		{
			var token = TestContext.Current.CancellationToken;
			var path = $"/files/{Guid.NewGuid():N}.png";
			_harness.Peer.ServeFile(path, Png(10, 10), "image/png");
			var remote = _harness.Peer.A + path;
			var host = new Uri(remote).Host;
			var blocks = new Blocks();
			var proxy = new MediaProxy(_harness.Local, Peer.Http(), _harness.Media, new StaticOptions<MediaOptions>(new MediaOptions()), blocks);
			Assert.Equal(ProxyOutcome.Cached, (await proxy.Download(remote, token)).Outcome);

			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Silence, RejectMedia = true };
			Assert.True(proxy.Refuses(remote));
			Assert.True(proxy.Purge(host) >= 1);
			Assert.Equal(default, proxy.Cached(remote));

			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Silence };
			Assert.False(proxy.Refuses(remote));
			blocks.Blocked[host] = new DomainBlock { Domain = host, Severity = DomainBlockSeverity.Suspend };
			Assert.True(proxy.Refuses(remote));
		}

		sealed class Blocks : PrivaPub.Federation.Moderation.IDomainBlocks
		{
			public Dictionary<string, DomainBlock> Blocked { get; } = new();
			public DomainBlock Find(string host) => Blocked.GetValueOrDefault(host);
			public bool IsSuspended(string host) => Find(host)?.Severity == DomainBlockSeverity.Suspend;
			public Task Reload(CancellationToken token) => Task.CompletedTask;
		}
	}
}