using System.Net;
using System.Text.Json;
using System.Text.Json.Nodes;
using Microsoft.Extensions.DependencyInjection;
using MoShiro.Backend.Application;
using MoShiro.Protocol;

namespace MoShiro.Backend.Tests;

public sealed class BackendUpdateTests : IAsyncLifetime
{
    private const string Digest = "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
    private readonly BackendFixture _backend = new();

    public async ValueTask InitializeAsync()
    {
        await _backend.InitializeAsync();
        _backend.Services.GetRequiredService<BackendOptions>().UpdateChannel = "dev";
    }

    public ValueTask DisposeAsync() => _backend.DisposeAsync();

    [Theory]
    [InlineData("moshiro-dev", "dev")]
    [InlineData("registry.example/team/moshiro-dev", "dev")]
    [InlineData("moshiro", "release")]
    [InlineData("registry.example/team/moshiro", "release")]
    public void AutoChannel_FollowsTheConfiguredImageRepository(string imageNamespace, string expected)
    {
        Assert.Equal(expected, BackendUpdates.ChannelOf(new BackendOptions { UpdateChannel = "auto", ImageNamespace = imageNamespace }));
    }

    private async Task<HttpResponseMessage> PublishAsync(long seq, string channel = "dev")
    {
        string manifest = $$"""{"component":"backend","channel":"{{channel}}","image":"registry.example/moshiro-{{channel}}/moshiro-backend","digest":"{{Digest}}","tag":"{{channel}}-{{seq}}","version":"0.1.1","seq":{{seq}}}""";
        return await _backend.Admin.PostAsync("/api/admin/releases", BackendFixture.Json(new JsonObject { ["manifest"] = manifest, ["signature"] = "MEUC" }));
    }

    private Task<JsonNode> ViewAsync() => _backend.GetJsonAsync(_backend.Admin, "/api/admin/backend/update");

    private async Task VerifiedAsync(long seq)
    {
        string directory = Path.Combine(_backend.DataDirectory, "update-status");
        Directory.CreateDirectory(directory);
        var status = new UpdateStatus
        {
            State = "available",
            Current = "sha256:" + new string('b', 64),
            Available = new UpdateAvailable { Seq = seq, Digest = Digest, Tag = "dev-" + seq, Version = "0.1.1" },
        };
        await File.WriteAllTextAsync(Path.Combine(directory, "status.json"), JsonSerializer.Serialize(status, MoShiroJsonContext.Default.UpdateStatus));
    }

    [Fact]
    public async Task Webhook_PreservesChannels_AndNeverConfirmsAnUpdateByItself()
    {
        using HttpResponseMessage dev = await PublishAsync(1);
        using HttpResponseMessage release = await PublishAsync(1, "release");
        Assert.Equal(HttpStatusCode.Created, dev.StatusCode);
        Assert.Equal(HttpStatusCode.Created, release.StatusCode);
        JsonNode view = await ViewAsync();
        Assert.Equal("dev", view["channel"]!.GetValue<string>());
        Assert.Equal("dev-1", view["available"]!["tag"]!.GetValue<string>());
        string requestDirectory = Path.Combine(_backend.DataDirectory, "update");
        Assert.False(File.Exists(Path.Combine(requestDirectory, "apply.request")));
        Assert.Contains("\"channel\":\"dev\"", await File.ReadAllTextAsync(Path.Combine(requestDirectory, "offer.manifest")), StringComparison.Ordinal);
        ReleaseOffer? stable = await _backend.Services.GetRequiredService<ReleaseService>().GetBackendAsync("release", default);
        Assert.Equal("release-1", stable!.Tag);
        using HttpResponseMessage replay = await PublishAsync(1);
        Assert.Equal(HttpStatusCode.Conflict, replay.StatusCode);
    }

    [Fact]
    public async Task Confirm_RequiresHostVerification_AndRejectsASupersededSequence()
    {
        using HttpResponseMessage first = await PublishAsync(10);
        Assert.Equal(HttpStatusCode.Created, first.StatusCode);
        using HttpResponseMessage unverified = await _backend.Admin.PostAsync("/api/admin/backend/update", BackendFixture.Json(new JsonObject { ["seq"] = 10 }));
        Assert.Equal(HttpStatusCode.PreconditionFailed, unverified.StatusCode);
        await VerifiedAsync(10);
        using HttpResponseMessage accepted = await _backend.Admin.PostAsync("/api/admin/backend/update", BackendFixture.Json(new JsonObject { ["seq"] = 10 }));
        Assert.Equal(HttpStatusCode.NoContent, accepted.StatusCode);
        string path = Path.Combine(_backend.DataDirectory, "update", "apply.request");
        Assert.Equal("10", await File.ReadAllTextAsync(path));
        Assert.Equal("requested", (await ViewAsync())["state"]!.GetValue<string>());
        using HttpResponseMessage second = await PublishAsync(11);
        Assert.Equal(HttpStatusCode.Created, second.StatusCode);
        using HttpResponseMessage stale = await _backend.Admin.PostAsync("/api/admin/backend/update", BackendFixture.Json(new JsonObject { ["seq"] = 10 }));
        Assert.Equal(HttpStatusCode.PreconditionFailed, stale.StatusCode);
        Assert.Equal("10", await File.ReadAllTextAsync(path)); // 新 webhook 不会把确认请求悄悄改成 11
        await VerifiedAsync(11);
        using HttpResponseMessage newConfirmation = await _backend.Admin.PostAsync("/api/admin/backend/update", BackendFixture.Json(new JsonObject { ["seq"] = 11 }));
        Assert.Equal(HttpStatusCode.NoContent, newConfirmation.StatusCode);
        Assert.Equal("11", await File.ReadAllTextAsync(path));
    }

    [Fact]
    public async Task Live_PushesCurrentChannel_AndAnonymousCannotReadOrConfirm()
    {
        using HttpResponseMessage denied = await _backend.Anonymous.GetAsync("/api/admin/backend/update");
        Assert.Equal(HttpStatusCode.Unauthorized, denied.StatusCode);
        using HttpResponseMessage cannotConfirm = await _backend.Anonymous.PostAsync("/api/admin/backend/update", BackendFixture.Json(new JsonObject { ["seq"] = 1 }));
        Assert.Equal(HttpStatusCode.Unauthorized, cannotConfirm.StatusCode);
        await using SseClient live = await SseClient.ConnectAsync(_backend.Admin, "/api/admin/backend/update/live");
        await live.WaitForAsync(e => e.Name == "backend_update");
        using HttpResponseMessage release = await PublishAsync(20);
        Assert.Equal(HttpStatusCode.Created, release.StatusCode);
        SseEvent updated = await live.WaitForAsync(e => e.Name == "backend_update" && e.Data?["available"]?["seq"]?.GetValue<long>() == 20);
        Assert.Equal("dev", updated.Data!["channel"]!.GetValue<string>());
        Assert.False(File.Exists(Path.Combine(_backend.DataDirectory, "update", "apply.request")));
    }
}