init mod

src/Util/ModCatalogSource.cs

@@ -0,0 +1,46 @@
+using System;
+using System.Collections.Generic;
+
+namespace Mods.ModManager
+{
+    /// <summary>
+    /// Presentation helpers for catalog provenance. The manager shows where a mod
+    /// comes from without cluttering the tile: a short host label plus the full
+    /// URL list in the tooltip, and a "+N" marker when several catalogs publish
+    /// the same build.
+    /// </summary>
+    public static class ModCatalogSource
+    {
+        /// <summary>First source URL, or null when there are none.</summary>
+        public static string FirstUrl(IReadOnlyList<string> urls)
+            => urls != null && urls.Count > 0 ? urls[0] : null;
+
+        /// <summary>Host of a URL (fallback: the raw string when it does not parse).</summary>
+        public static string Host(string url)
+        {
+            if (string.IsNullOrWhiteSpace(url))
+                return null;
+
+            if (Uri.TryCreate(url, UriKind.Absolute, out var uri) && !string.IsNullOrEmpty(uri.Host))
+                return uri.Host;
+
+            return url;
+        }
+
+        /// <summary>Short label: host plus "+N" for extra catalogs, or null when unknown.</summary>
+        public static string Label(IReadOnlyList<string> urls)
+        {
+            var first = FirstUrl(urls);
+            if (first == null)
+                return null;
+
+            var host = Host(first);
+            var extra = urls.Count - 1;
+            return extra > 0 ? $"{host} +{extra}" : host;
+        }
+
+        /// <summary>Newline-joined full URL list for tooltips.</summary>
+        public static string Tooltip(IReadOnlyList<string> urls)
+            => urls == null || urls.Count == 0 ? null : string.Join("\n", urls);
+    }
+}