using System.Xml.Linq;
using DeepDrftModels.DTOs;
using DeepDrftModels.Enums;
using DeepDrftPublic.Client.Common;
using DeepDrftPublic.Seo;

namespace DeepDrftTests;

/// <summary>
/// Unit tests for <see cref="SitemapXml"/> — the pure sitemaps.org urlset composition (Phase 23 wave 23.2).
/// The document is parsed back to an <see cref="XDocument"/> so each assertion checks real structure, not a
/// substring: that every <c>&lt;loc&gt;</c> is absolute and built through <see cref="ReleaseRoutes"/> (so it
/// equals the page canonical), that <c>&lt;lastmod&gt;</c> tracks the release date, that the static roots are
/// present and FramePlayer is absent, and that empty input still yields a well-formed roots-only document.
/// </summary>
[TestFixture]
public class SitemapXmlTests
{
    private const string BaseUrl = "https://deepdrft.com";
    private static readonly XNamespace Ns = "http://www.sitemaps.org/schemas/sitemap/0.9";

    private static ReleaseDto Release(string entryKey, ReleaseMedium medium, DateOnly? releaseDate = null) => new()
    {
        EntryKey = entryKey,
        Title = "Title",
        Artist = "Artist",
        Medium = medium,
        ReleaseDate = releaseDate,
    };

    private static List<string> Locs(string xml)
    {
        var doc = XDocument.Parse(xml);
        return doc.Root!.Elements(Ns + "url")
            .Select(u => u.Element(Ns + "loc")!.Value)
            .ToList();
    }

    [Test]
    public void Build_EmptyReleases_YieldsWellFormedRootsOnlyDocument()
    {
        var xml = SitemapXml.Build(BaseUrl, []);

        var locs = Locs(xml);
        Assert.Multiple(() =>
        {
            Assert.That(locs, Has.Count.EqualTo(SitemapXml.StaticRoots.Count));
            Assert.That(locs, Does.Contain("https://deepdrft.com/"));
            Assert.That(locs, Does.Contain("https://deepdrft.com/about"));
            Assert.That(locs, Does.Contain("https://deepdrft.com/cuts"));
            Assert.That(locs, Does.Contain("https://deepdrft.com/sessions"));
            Assert.That(locs, Does.Contain("https://deepdrft.com/mixes"));
            Assert.That(locs, Does.Contain("https://deepdrft.com/archive"));
        });
    }

    [Test]
    public void Build_IsWellFormedUrlsetWithSitemapsOrgNamespace()
    {
        var xml = SitemapXml.Build(BaseUrl, []);
        var doc = XDocument.Parse(xml);

        Assert.Multiple(() =>
        {
            Assert.That(doc.Root!.Name, Is.EqualTo(Ns + "urlset"));
            Assert.That(xml, Does.Contain("utf-8").IgnoreCase);
        });
    }

    [Test]
    public void Build_FramePlayerIsNeverAStaticRoot()
    {
        var xml = SitemapXml.Build(BaseUrl, []);

        Assert.That(Locs(xml), Has.None.Contains("FramePlayer"));
    }

    [TestCase(ReleaseMedium.Cut, "https://deepdrft.com/cuts/key-1")]
    [TestCase(ReleaseMedium.Session, "https://deepdrft.com/sessions/key-1")]
    [TestCase(ReleaseMedium.Mix, "https://deepdrft.com/mixes/key-1")]
    public void Build_ReleaseLoc_IsAbsoluteAndResolvedThroughReleaseRoutes(ReleaseMedium medium, string expectedLoc)
    {
        var xml = SitemapXml.Build(BaseUrl, [Release("key-1", medium)]);

        // The loc must equal BaseUrl + ReleaseRoutes.DetailHref — i.e. the page's SeoHead canonical, by construction.
        var expected = BaseUrl + ReleaseRoutes.DetailHref("key-1", medium);
        Assert.Multiple(() =>
        {
            Assert.That(expected, Is.EqualTo(expectedLoc));
            Assert.That(Locs(xml), Does.Contain(expectedLoc));
        });
    }

    [Test]
    public void Build_AllReleasesEnumerated_AppendedAfterStaticRoots()
    {
        var releases = new[]
        {
            Release("a", ReleaseMedium.Cut),
            Release("b", ReleaseMedium.Mix),
            Release("c", ReleaseMedium.Session),
        };

        var xml = SitemapXml.Build(BaseUrl, releases);

        Assert.That(Locs(xml), Has.Count.EqualTo(SitemapXml.StaticRoots.Count + releases.Length));
    }

    [Test]
    public void Build_ReleaseWithDate_EmitsW3CLastmod()
    {
        var xml = SitemapXml.Build(BaseUrl, [Release("key-1", ReleaseMedium.Cut, new DateOnly(2026, 5, 12))]);

        var doc = XDocument.Parse(xml);
        var releaseUrl = doc.Root!.Elements(Ns + "url")
            .Single(u => u.Element(Ns + "loc")!.Value.EndsWith("/cuts/key-1"));

        Assert.That(releaseUrl.Element(Ns + "lastmod")!.Value, Is.EqualTo("2026-05-12"));
    }

    [Test]
    public void Build_ReleaseWithoutDate_OmitsLastmod()
    {
        var xml = SitemapXml.Build(BaseUrl, [Release("key-1", ReleaseMedium.Cut)]);

        var doc = XDocument.Parse(xml);
        var releaseUrl = doc.Root!.Elements(Ns + "url")
            .Single(u => u.Element(Ns + "loc")!.Value.EndsWith("/cuts/key-1"));

        Assert.That(releaseUrl.Element(Ns + "lastmod"), Is.Null);
    }

    [Test]
    public void Build_StaticRoots_NeverCarryLastmod()
    {
        var xml = SitemapXml.Build(BaseUrl, []);

        var doc = XDocument.Parse(xml);
        Assert.That(doc.Root!.Elements(Ns + "url").All(u => u.Element(Ns + "lastmod") is null), Is.True);
    }

    [Test]
    public void Build_TrimsTrailingSlashOnBaseUrl()
    {
        var xml = SitemapXml.Build("https://deepdrft.com/", [Release("key-1", ReleaseMedium.Cut)]);

        Assert.Multiple(() =>
        {
            // No doubled slash on the root or the release URL.
            Assert.That(Locs(xml), Does.Contain("https://deepdrft.com/"));
            Assert.That(Locs(xml), Does.Contain("https://deepdrft.com/cuts/key-1"));
        });
    }
}