using LehrerApp.Data;
using LehrerApp.Sync.Crypto;
using Xunit;

namespace LehrerApp.Sync.Tests;

public sealed class AttachmentSyncerTests
{
    private static LiteDbContext NewInMemoryContext() => new(new MemoryStream());
    private static readonly byte[] Key = SyncCrypto.GenerateKey();

    [Fact]
    public async Task UploadPendingAsync_LaedtVerschluesselteBytesHochUndMarkiertAlsErledigt()
    {
        using var temp = new TempEventQueue();
        using var db = NewInMemoryContext();
        var storageId = Guid.NewGuid().ToString("N");
        db.Attachments.Upload(storageId, "brief.pdf", new MemoryStream([1, 2, 3, 4]));
        temp.Queue.QueueAttachmentUpload(storageId);
        // Bytes MÜSSEN synchron innerhalb des Handler-Callbacks gelesen werden: AttachmentSyncer
        // disposed sein ByteArrayContent direkt nach dem PostAsync-Aufruf (eigenes "using"),
        // ein Zugriff auf request.Content danach würde ObjectDisposedException werfen.
        byte[]? uploadedEncrypted = null;
        var handler = new FakeHttpMessageHandler(req =>
        {
            uploadedEncrypted = req.Content!.ReadAsByteArrayAsync().GetAwaiter().GetResult();
            return new HttpResponseMessage(System.Net.HttpStatusCode.OK);
        });
        var http = new HttpClient(handler) { BaseAddress = new Uri("https://example.invalid") };
        var syncer = new AttachmentSyncer(db, http, Key);

        await syncer.UploadPendingAsync(temp.Queue);

        var request = Assert.Single(handler.Requests);
        Assert.Equal(HttpMethod.Post, request.Method);
        Assert.Equal($"/api/sync/attachments/{storageId}", request.RequestUri!.AbsolutePath);
        Assert.NotNull(uploadedEncrypted);
        Assert.Equal([1, 2, 3, 4], SyncCrypto.Decrypt(uploadedEncrypted!, Key));
        Assert.Empty(temp.Queue.GetPendingAttachmentUploads());
    }

    [Fact]
    public async Task UploadPendingAsync_LokalNichtMehrVorhandenerAnhang_WirdOhneUploadAlsErledigtMarkiert()
    {
        using var temp = new TempEventQueue();
        using var db = NewInMemoryContext();
        temp.Queue.QueueAttachmentUpload("laengst-geloescht");
        var handler = new FakeHttpMessageHandler(_ => new HttpResponseMessage(System.Net.HttpStatusCode.OK));
        var http = new HttpClient(handler) { BaseAddress = new Uri("https://example.invalid") };
        var syncer = new AttachmentSyncer(db, http, Key);

        await syncer.UploadPendingAsync(temp.Queue);

        Assert.Empty(handler.Requests);
        Assert.Empty(temp.Queue.GetPendingAttachmentUploads());
    }

    private sealed class TempEventQueue : IDisposable
    {
        private readonly string _directory = Path.Combine(
            Path.GetTempPath(), $"lehrerapp-sync-tests-attachments-{Guid.NewGuid():N}");
        public EventQueue Queue { get; }

        public TempEventQueue()
        {
            Directory.CreateDirectory(_directory);
            Queue = new EventQueue(Path.Combine(_directory, "queue.db"));
        }

        public void Dispose()
        {
            Queue.Dispose();
            if (Directory.Exists(_directory)) Directory.Delete(_directory, recursive: true);
        }
    }
}