using System.Net;
using System.Text;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc.Testing;
using Microsoft.AspNetCore.TestHost;
using Microsoft.Extensions.DependencyInjection;
using SQLInsight.Updates;
using SQLInsight.Updates.Tests;

namespace SQLInsight.Community.Tests;

/// <summary>The site against a signed test feed (a folder) and a stubbed Discourse forum.</summary>
public sealed class SiteTests : IDisposable
{
    private const string LatestJson = """
        { "topic_list": { "topics": [
          { "id": 1, "title": "Velkommen", "slug": "velkommen", "posts_count": 1, "bumped_at": "2026-09-01T10:00:00Z", "pinned": true },
          { "id": 7, "title": "Hvad skal MAXDOP være?", "slug": "maxdop", "posts_count": 3, "bumped_at": "2026-09-28T10:00:00Z", "pinned": false, "has_accepted_answer": true }
        ] } }
        """;

    private readonly TestFeed _feed = new();
    private readonly StubHandler _forum = new(LatestJson);

    public void Dispose()
    {
        _feed.Dispose();
        _forum.Dispose();
    }

    [Theory]
    [InlineData("/")]
    [InlineData("/funktioner")]
    [InlineData("/download")]
    [InlineData("/dokumentation")]
    [InlineData("/dokumentation/installation")]
    [InlineData("/sql-server-versioner")]
    [InlineData("/regler")]
    [InlineData("/support")]
    [InlineData("/health")]
    public async Task Pages_render(string path)
    {
        using var factory = Site();
        using var client = factory.CreateClient();

        using var response = await client.GetAsync(new Uri(path, UriKind.Relative), CancellationToken.None);

        Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        Assert.Contains("default-src 'self'", response.Headers.GetValues("Content-Security-Policy").Single(), StringComparison.Ordinal);
    }

    [Theory]
    [InlineData("/findes-ikke")]
    [InlineData("/dokumentation/findes-ikke")]
    [InlineData("/dokumentation/hub")]
    public async Task Unknown_pages_are_404(string path)
    {
        using var factory = Site();
        using var client = factory.CreateClient();

        using var response = await client.GetAsync(new Uri(path, UriKind.Relative), CancellationToken.None);

        Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
        Assert.Contains("findes ikke", await response.Content.ReadAsStringAsync(CancellationToken.None), StringComparison.OrdinalIgnoreCase);
    }

    [Fact]
    public async Task Download_lists_signed_releases_with_hashes()
    {
        var release = _feed.MsiRelease("1.2.0");
        _feed.Publish("stable", release: release);
        using var factory = Site();

        var html = await Get(factory, "/download");

        Assert.Contains("SQLInsight Pro 1.2.0", html, StringComparison.Ordinal);
        Assert.Contains("SQLInsight-Pro-1.2.0-x64.msi", html, StringComparison.Ordinal);
        foreach (var asset in release.Assets)
        {
            Assert.Contains(asset.File.Sha256.ToLowerInvariant(), html, StringComparison.Ordinal);
        }
    }

    [Fact]
    public async Task A_folder_feed_links_downloads_to_the_public_address()
    {
        _feed.Publish("stable", release: _feed.MsiRelease("1.2.0"));
        using var factory = Site(downloadUrl: "https://hub.example/updates/");

        var html = await Get(factory, "/download");

        Assert.Contains("href=\"https://hub.example/updates/releases/SQLInsight-Pro-1.2.0-x64.msi\"", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task A_manifest_with_a_bad_signature_is_not_shown()
    {
        _feed.Publish("stable", release: _feed.MsiRelease("1.2.0"));
        var path = Path.Combine(_feed.FeedDirectory, "stable", UpdateFeed.ManifestFile);
        var token = await File.ReadAllTextAsync(path, CancellationToken.None);
        var parts = token.Split('.');
        var payload = parts[1].ToCharArray();
        payload[payload.Length / 2] = payload[payload.Length / 2] == 'A' ? 'B' : 'A';
        parts[1] = new string(payload);
        await File.WriteAllTextAsync(path, string.Join('.', parts), CancellationToken.None);
        using var factory = Site();

        var html = await Get(factory, "/download");

        Assert.DoesNotContain("1.2.0", html, StringComparison.Ordinal);
        Assert.Contains("ingen udgivelser", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task A_manifest_signed_with_an_unknown_key_is_not_shown()
    {
        _feed.Publish("stable", release: _feed.MsiRelease("1.2.0"));
        using var factory = Site(trustKey: false);

        var html = await Get(factory, "/download");

        Assert.DoesNotContain("SQLInsight Pro 1.2.0", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Front_page_shows_forum_topics_without_pinned_ones()
    {
        using var factory = Site();

        var html = await Get(factory, "/");

        Assert.Contains("Hvad skal MAXDOP være?", html, StringComparison.Ordinal);
        Assert.Contains("https://forum.example/t/maxdop/7", html, StringComparison.Ordinal);
        Assert.Contains("Løst", html, StringComparison.Ordinal);
        Assert.DoesNotContain(">Velkommen<", html, StringComparison.Ordinal);
        Assert.EndsWith("/latest.json", _forum.Requests.Single().AbsolutePath, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Front_page_works_when_the_forum_is_down()
    {
        _forum.Fail = true;
        using var factory = Site();

        var html = await Get(factory, "/");

        Assert.Contains("SQL Server-overvågning", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Versions_page_uses_the_newest_signed_rule_pack()
    {
        _feed.Publish("stable", rulePack: _feed.RulePack(new Version(2099, 1, 1)));
        using var factory = Site();

        var html = await Get(factory, "/sql-server-versioner");

        Assert.Contains("2099.1.1", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Docs_are_rendered_with_rewritten_links()
    {
        using var factory = Site();

        var html = await Get(factory, "/dokumentation/installation");

        Assert.Contains("href=\"/dokumentation/opdatering", html, StringComparison.Ordinal);
        Assert.Contains("https://git.example/seo/sqlinsight-pro/src/branch/main/db/permissions/grant-least-privilege.sql", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Rules_page_lists_built_in_and_community_rules()
    {
        using var factory = Site();

        var html = await Get(factory, "/regler");

        Assert.Contains("SQLI-CFG-004", html, StringComparison.Ordinal);
        Assert.Contains("COM-SEC-001", html, StringComparison.Ordinal);
    }

    [Fact]
    public async Task Forum_shortcut_redirects_to_the_forum()
    {
        using var factory = Site();
        using var client = factory.CreateClient(new WebApplicationFactoryClientOptions { AllowAutoRedirect = false });

        using var response = await client.GetAsync(new Uri("/forum", UriKind.Relative), CancellationToken.None);

        Assert.Equal(HttpStatusCode.Redirect, response.StatusCode);
        Assert.Equal(new Uri("https://forum.example/"), response.Headers.Location);
    }

    private WebApplicationFactory<Program> Site(bool trustKey = true, string? downloadUrl = null)
    {
        var settings = new Dictionary<string, string?>
        {
            ["SQLInsight:Community:Feed"] = _feed.FeedDirectory,
            ["SQLInsight:Community:ForumUrl"] = "https://forum.example/",
            ["SQLInsight:Community:SourceUrl"] = "https://git.example/seo/sqlinsight-pro",
        };
        if (downloadUrl is not null)
        {
            settings["SQLInsight:Community:DownloadUrl"] = downloadUrl;
        }

        if (trustKey)
        {
            settings[$"SQLInsight:Community:TrustedKeys:{TestFeed.KeyId}"] = _feed.PublicKey;
        }

        return new WebApplicationFactory<Program>().WithWebHostBuilder(builder =>
        {
            builder.UseEnvironment("Production");
            foreach (var (key, value) in settings)
            {
                builder.UseSetting(key, value);
            }

            builder.ConfigureTestServices(services =>
                services.AddHttpClient("forum").ConfigurePrimaryHttpMessageHandler(() => new NonDisposing(_forum)));
        });
    }

    private static async Task<string> Get(WebApplicationFactory<Program> factory, string path)
    {
        using var client = factory.CreateClient();
        return await client.GetStringAsync(new Uri(path, UriKind.Relative), CancellationToken.None);
    }

    private sealed class StubHandler(string body) : HttpMessageHandler
    {
        public List<Uri> Requests { get; } = [];
        public bool Fail { get; set; }

        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
        {
            Requests.Add(request.RequestUri!);
            return Fail
                ? throw new HttpRequestException("forum nede")
                : Task.FromResult(new HttpResponseMessage(HttpStatusCode.OK) { Content = new StringContent(body, Encoding.UTF8, "application/json") });
        }

        public Task<HttpResponseMessage> Forward(HttpRequestMessage request, CancellationToken cancellationToken) => SendAsync(request, cancellationToken);
    }

    /// <summary>Lets the handler factory dispose its wrapper without disposing the shared stub.</summary>
    private sealed class NonDisposing(StubHandler inner) : HttpMessageHandler
    {
        protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) => inner.Forward(request, cancellationToken);
    }
}