using System;
using System.IO;
using System.Linq;
using Xunit;

namespace ytLive.Tests;

/// <summary>
/// The shipped binary is <c>LlamaCasty.exe</c> (renamed 2026-11-01, before the first Steam
/// depot). Two things have to agree for that to be true, and neither fails the build when it
/// doesn't:
///
/// <list type="number">
/// <item>The assembly name comes from <c>ytLive.csproj</c> and silently reverting it produces
/// <c>ytLive.exe</c> again — which is why the rename lands before a depot upload rather than
/// after (Steamworks: renaming a live exe is painful).</item>
/// <item>Assembly-qualified WPF pack URIs (<c>/Assembly;component/path</c>) resolve by that
/// same name. A stale <c>/ytLive;component/…</c> compiles, runs, and then fails <b>silently</b>
/// the moment that particular view opens — a blank window icon, a missing logo in the overlay
/// host. Nobody notices until a dialog is opened at the wrong time, so the rename is exactly the
/// kind of change that needs a source-level guard.</item>
/// </list>
///
/// <para>The C# namespaces stay <c>ytLive</c>: they are not user-visible, and the file churn
/// would buy nothing. Only the assembly name and the URIs that quote it move.</para>
/// </summary>
public class AssemblyIdentityTests
{
    private const string ShipName = "LlamaCasty";
    private const string LegacyName = "ytLive";

    [Fact]
    public void The_assembly_is_LlamaCasty_and_no_pack_uri_still_names_the_legacy_assembly()
    {
        Assert.Equal(ShipName, typeof(MainWindow).Assembly.GetName().Name);

        var root = RepoRoot();
        var stale = Directory.EnumerateFiles(root, "*.xaml", SearchOption.AllDirectories)
            .Where(path => !IsBuildOutput(path))
            .Where(path => File.ReadAllText(path).Contains("/" + LegacyName + ";component/", StringComparison.Ordinal))
            .Select(path => Path.GetRelativePath(root, path))
            .ToArray();

        Assert.True(stale.Length == 0,
            "These XAML files still point at the legacy assembly name in a pack URI, which " +
            "fails silently at runtime: " + string.Join(", ", stale));
    }

    /// <summary>Walks up from the test output directory to the repo root (the folder holding
    /// <c>ytLive.csproj</c>).</summary>
    private static string RepoRoot()
    {
        var dir = new DirectoryInfo(AppContext.BaseDirectory);
        while (dir != null)
        {
            if (File.Exists(Path.Combine(dir.FullName, "ytLive.csproj"))) return dir.FullName;
            dir = dir.Parent;
        }
        throw new InvalidOperationException("Could not locate the repo root from " + AppContext.BaseDirectory);
    }

    /// <summary>Publish and compile output carry copies of the XAML (and old generated XAML);
    /// only the source tree is the thing under test.</summary>
    private static bool IsBuildOutput(string path)
    {
        var parts = path.Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar);
        return parts.Any(part => part.Equals("bin", StringComparison.OrdinalIgnoreCase)
                              || part.Equals("obj", StringComparison.OrdinalIgnoreCase)
                              || part.Equals("artifacts", StringComparison.OrdinalIgnoreCase));
    }
}