1 files changed, 109 insertions, 0 deletions
diff --git a/Jellyfin.Server/ServerSetupApp/StartupUiRenderer.cs b/Jellyfin.Server/ServerSetupApp/StartupUiRenderer.cs
new file mode 100644
index 0000000000..db07b9d8c1
--- /dev/null
+++ b/Jellyfin.Server/ServerSetupApp/StartupUiRenderer.cs
@@ -0,0 +1,109 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using MediaBrowser.Model.IO;
+using Microsoft.Extensions.Logging;
+using Morestachio;
+using Morestachio.Framework.IO.SingleStream;
+using Morestachio.Rendering;
+
+namespace Jellyfin.Server.ServerSetupApp;
+
+/// <summary>
+/// Compiles and renders the startup UI Morestachio template.
+/// Shared by the live <see cref="SetupServer"/> and the standalone startup UI preview tool so both
+/// exercise the exact same template and formatters.
+/// </summary>
+public sealed class StartupUiRenderer
+{
+    private readonly IRenderer _renderer;
+
+    private StartupUiRenderer(IRenderer renderer)
+    {
+        _renderer = renderer;
+    }
+
+    /// <summary>
+    /// Compiles the startup UI template located at <paramref name="templatePath"/>.
+    /// </summary>
+    /// <param name="templatePath">The full path to the <c>index.mstemplate.html</c> template.</param>
+    /// <returns>A ready to use <see cref="StartupUiRenderer"/>.</returns>
+    public static async Task<StartupUiRenderer> CreateAsync(string templatePath)
+    {
+        var fileTemplate = await File.ReadAllTextAsync(templatePath).ConfigureAwait(false);
+        var renderer = (await ParserOptionsBuilder.New()
+            .WithTemplate(fileTemplate)
+            .WithFormatter(
+            (Version version, int arg) =>
+            {
+                // version type does not for some stupid reason implement IFormattable which morestachio relies on for ToString support therefor we need to do it manually.
+                return version.ToString(arg);
+            },
+            "ToString")
+            .WithFormatter(
+                (StartupLogTopic logEntry, IEnumerable<StartupLogTopic> children) =>
+                {
+                    if (children.Any())
+                    {
+                        var maxLevel = logEntry.LogLevel;
+                        var stack = new Stack<StartupLogTopic>(children);
+
+                        while (maxLevel != LogLevel.Error && stack.Count > 0 && (logEntry = stack.Pop()) is not null) // error is the highest inherted error level.
+                        {
+                            maxLevel = maxLevel < logEntry.LogLevel ? logEntry.LogLevel : maxLevel;
+                            foreach (var child in logEntry.Children)
+                            {
+                                stack.Push(child);
+                            }
+                        }
+
+                        return maxLevel;
+                    }
+
+                    return logEntry.LogLevel;
+                },
+                "FormatLogLevel")
+            .WithFormatter(
+                (LogLevel logLevel) =>
+                {
+                    switch (logLevel)
+                    {
+                        case LogLevel.Trace:
+                        case LogLevel.Debug:
+                        case LogLevel.None:
+                            return "success";
+                        case LogLevel.Information:
+                            return "info";
+                        case LogLevel.Warning:
+                            return "warn";
+                        case LogLevel.Error:
+                            return "danger";
+                        case LogLevel.Critical:
+                            return "danger-strong";
+                    }
+
+                    return string.Empty;
+                },
+                "ToString")
+            .BuildAndParseAsync()
+            .ConfigureAwait(false))
+            .CreateCompiledRenderer();
+
+        return new StartupUiRenderer(renderer);
+    }
+
+    /// <summary>
+    /// Renders the template with the provided model into the target stream.
+    /// </summary>
+    /// <param name="model">The values made available to the template.</param>
+    /// <param name="output">The stream the rendered HTML is written to.</param>
+    /// <returns>A Task.</returns>
+    public Task RenderAsync(IDictionary<string, object> model, Stream output)
+    {
+        return _renderer.RenderAsync(
+            model,
+            new ByteCounterStream(output, IODefaults.FileStreamBufferSize, true, _renderer.ParserOptions));
+    }
+}