using System.Net;
using System.Net.Http;
using System.Runtime.InteropServices;
using CursorLang.Models;
using CursorLang.Services;
using CursorLang.Tests.Infrastructure;

namespace CursorLang.Tests.Services;

/// <summary>
/// Reading the release list of Gitea. The answer of the server is not ours to
/// shape, so what matters is what the app makes of it.
/// </summary>
public sealed class GiteaReleaseFeedTests
{
    private const string Releases = """
        [
          {
            "tag_name": "v1.2.0",
            "draft": false,
            "prerelease": false,
            "html_url": "https://git.alrakis.kz/alrakis/cursor-lang/releases/tag/v1.2.0",
            "assets": [
              {
                "name": "CursorLang-1.2.0.0.msixbundle",
                "browser_download_url": "https://git.alrakis.kz/attachments/CursorLang-1.2.0.0.msixbundle",
                "size": 4096
              }
            ]
          }
        ]
        """;

    [Fact]
    public async Task A_release_is_read_whole()
    {
        ReleaseInfo? release = await Read(Releases);

        Assert.NotNull(release);
        Assert.Equal(new Version(1, 2, 0, 0), release.Version);
        Assert.Equal("v1.2.0", release.Tag);
        Assert.Equal("https://git.alrakis.kz/alrakis/cursor-lang/releases/tag/v1.2.0", release.PageUrl?.ToString());
        Assert.Equal("CursorLang-1.2.0.0.msixbundle", release.Package.FileName);
        Assert.Equal(
            "https://git.alrakis.kz/attachments/CursorLang-1.2.0.0.msixbundle",
            release.Package.Url.ToString());
        Assert.Equal(4096, release.Package.Size);
    }

    // The API of Gitea lives on the server itself, next to the pages of the
    // repository
    [Fact]
    public async Task The_request_goes_to_the_releases_of_the_project()
    {
        var handler = FakeHttpHandler.Json(Releases);
        var feed = new GiteaReleaseFeed(handler.CreateClient(), Options());

        await feed.GetLatestAsync(TestContext.Current.CancellationToken);

        Uri asked = Assert.Single(handler.Requests).RequestUri!;
        Assert.Equal("git.alrakis.kz", asked.Host);
        Assert.StartsWith(
            "/api/v1/repos/alrakis/cursor-lang/releases", asked.AbsolutePath, StringComparison.Ordinal);
    }

    // A server sitting under a path of its own keeps that path: dropping it
    // would send the request to a place that answers nothing
    [Fact]
    public async Task A_server_behind_a_path_keeps_it()
    {
        var handler = FakeHttpHandler.Json(Releases);
        var feed = new GiteaReleaseFeed(
            handler.CreateClient(),
            new UpdateOptions { ServiceUri = new Uri("https://host.example.com/gitea"), Project = "team/app" });

        await feed.GetLatestAsync(TestContext.Current.CancellationToken);

        Uri asked = Assert.Single(handler.Requests).RequestUri!;
        Assert.StartsWith("/gitea/api/v1/repos/team/app/releases", asked.AbsolutePath, StringComparison.Ordinal);
    }

    // «token» is the scheme of Gitea for keys of access
    [Fact]
    public void A_closed_repository_gets_the_token_it_asks_for()
    {
        var feed = new GiteaReleaseFeed(new HttpClient(), Options("secret"));
        using var request = new HttpRequestMessage();

        feed.Authorize(request);

        Assert.Equal("token", request.Headers.Authorization?.Scheme);
        Assert.Equal("secret", request.Headers.Authorization?.Parameter);
    }

    [Fact]
    public void An_open_repository_is_asked_without_a_token()
    {
        var feed = new GiteaReleaseFeed(new HttpClient(), Options());
        using var request = new HttpRequestMessage();

        feed.Authorize(request);

        Assert.Null(request.Headers.Authorization);
    }

    [Theory]
    [InlineData("1.2.3", "1.2.3.0")]
    [InlineData("v1.2.3", "1.2.3.0")]
    [InlineData("V1.2", "1.2.0.0")]
    [InlineData("1.2.3.4", "1.2.3.4")]
    public async Task A_version_is_read_out_of_the_tag(string tag, string expected)
    {
        ReleaseInfo? release = await Read(WithTag(tag));

        Assert.NotNull(release);
        Assert.Equal(Version.Parse(expected), release.Version);
    }

    // A pre-release version is not something the app offers by itself:
    // such a version is asked for on purpose
    [Theory]
    [InlineData("v1.2.3-beta")]
    [InlineData("nightly")]
    [InlineData("release-1")]
    public async Task A_tag_that_is_not_a_version_is_passed_over(string tag)
    {
        Assert.Null(await Read(WithTag(tag)));
    }

    [Fact]
    public async Task A_draft_and_a_pre_release_are_passed_over()
    {
        const string releases = """
            [
              { "tag_name": "v3.0.0", "draft": true, "assets": [
                { "name": "a.msixbundle", "browser_download_url": "https://host/a.msixbundle" } ] },
              { "tag_name": "v2.0.0", "prerelease": true, "assets": [
                { "name": "b.msixbundle", "browser_download_url": "https://host/b.msixbundle" } ] },
              { "tag_name": "v1.0.0", "assets": [
                { "name": "c.msixbundle", "browser_download_url": "https://host/c.msixbundle" } ] }
            ]
            """;

        ReleaseInfo? release = await Read(releases);

        Assert.NotNull(release);
        Assert.Equal(new Version(1, 0, 0, 0), release.Version);
    }

    // The order of the releases belongs to the server, the highest number to
    // the app: a fix to an older branch can be the freshest release
    [Fact]
    public async Task The_highest_version_wins_over_the_order_of_the_answer()
    {
        const string releases = """
            [
              { "tag_name": "v1.0.5", "assets": [
                { "name": "a.msixbundle", "browser_download_url": "https://host/a.msixbundle" } ] },
              { "tag_name": "v2.0.0", "assets": [
                { "name": "b.msixbundle", "browser_download_url": "https://host/b.msixbundle" } ] }
            ]
            """;

        ReleaseInfo? release = await Read(releases);

        Assert.NotNull(release);
        Assert.Equal(new Version(2, 0, 0, 0), release.Version);
    }

    [Fact]
    public async Task A_release_without_a_package_is_passed_over()
    {
        const string releases = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "notes.txt", "browser_download_url": "https://host/notes.txt" } ] },
              { "tag_name": "v1.0.0", "assets": [
                { "name": "a.msixbundle", "browser_download_url": "https://host/a.msixbundle" } ] }
            ]
            """;

        ReleaseInfo? release = await Read(releases);

        Assert.NotNull(release);
        Assert.Equal(new Version(1, 0, 0, 0), release.Version);
    }

    // The signature is what Windows checks, but a package offered over an open
    // connection is not worth downloading in the first place
    [Fact]
    public async Task A_package_offered_over_an_open_connection_is_passed_over()
    {
        const string releases = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "a.msixbundle", "browser_download_url": "http://host/a.msixbundle" } ] }
            ]
            """;

        Assert.Null(await Read(releases));
    }

    [Fact]
    public async Task A_bundle_wins_over_the_packages_of_single_architectures()
    {
        const string releases = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "CursorLang-2.0.0.0-x64.msix", "browser_download_url": "https://host/x64.msix" },
                { "name": "CursorLang-2.0.0.0.msixbundle", "browser_download_url": "https://host/all.msixbundle" } ] }
            ]
            """;

        ReleaseInfo? release = await Read(releases);

        Assert.NotNull(release);
        Assert.Equal("https://host/all.msixbundle", release.Package.Url.ToString());
    }

    [Fact]
    public async Task Out_of_several_packages_the_one_for_this_machine_is_taken()
    {
        const string releases = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "CursorLang-2.0.0.0-arm64.msix", "browser_download_url": "https://host/arm64.msix" },
                { "name": "CursorLang-2.0.0.0-x64.msix", "browser_download_url": "https://host/x64.msix" } ] }
            ]
            """;

        string expected = RuntimeInformation.ProcessArchitecture == Architecture.Arm64
            ? "https://host/arm64.msix"
            : "https://host/x64.msix";

        ReleaseInfo? release = await Read(releases);

        Assert.NotNull(release);
        Assert.Equal(expected, release.Package.Url.ToString());
    }

    // Without the architecture in the name there is no telling which package is
    // for this machine — unless it is the only one there
    [Fact]
    public async Task A_package_without_an_architecture_is_taken_only_when_alone()
    {
        const string alone = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "CursorLang.msix", "browser_download_url": "https://host/one.msix" } ] }
            ]
            """;

        const string ambiguous = """
            [
              { "tag_name": "v2.0.0", "assets": [
                { "name": "CursorLang.msix", "browser_download_url": "https://host/one.msix" },
                { "name": "CursorLang-other.msix", "browser_download_url": "https://host/other.msix" } ] }
            ]
            """;

        Assert.NotNull(await Read(alone));
        Assert.Null(await Read(ambiguous));
    }

    [Fact]
    public async Task An_empty_list_of_releases_means_nothing_to_offer()
    {
        Assert.Null(await Read("[]"));
    }

    // A server answering with something else is no reason to fail
    [Fact]
    public async Task An_answer_that_is_not_a_list_leaves_the_app_with_nothing()
    {
        Assert.Null(await Read("""{ "message": "Not Found" }"""));
    }

    [Fact]
    public async Task A_refusal_of_the_server_is_raised()
    {
        var handler = FakeHttpHandler.Status(HttpStatusCode.Unauthorized);
        var feed = new GiteaReleaseFeed(handler.CreateClient(), Options());

        await Assert.ThrowsAsync<HttpRequestException>(
            () => feed.GetLatestAsync(TestContext.Current.CancellationToken));
    }

    private static string WithTag(string tag) => $$"""
        [
          { "tag_name": "{{tag}}", "assets": [
            { "name": "CursorLang.msixbundle", "browser_download_url": "https://host/a.msixbundle" } ] }
        ]
        """;

    private static UpdateOptions Options(string? token = null) => new()
    {
        ServiceUri = new Uri("https://git.alrakis.kz/"),
        Project = "alrakis/cursor-lang",
        AccessToken = token,
    };

    private static Task<ReleaseInfo?> Read(string json) =>
        new GiteaReleaseFeed(FakeHttpHandler.Json(json).CreateClient(), Options())
            .GetLatestAsync(TestContext.Current.CancellationToken);
}