Added a simply utility to build mods.json files, so that launchers ca…

…n support launching from raw mods folders without requiring code to actually generate a mods.json. This is always discouraged.

Util/ModJsonBuilder.cs

@@ -0,0 +1,66 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.Json;
+using Andraste.Shared.ModManagement;
+using Andraste.Shared.ModManagement.Json;
+
+namespace Andraste.Shared.Util
+{
+    #nullable enable
+    [Obsolete("This is only a utility for a transition period/simple launchers. " +
+              "Always prefer building the mods.json with your dedicated launcher")]
+    public static class ModJsonBuilder
+    {
+        /// <summary>
+        /// In case we didn't have a mods.json passed in, we're generating one on the fly.
+        /// </summary>
+        public static byte[]? WriteModsJson(string modsFolder)
+        {
+            var settings = new ModSettings();
+            var enabledMods = new List<ModSetting>();
+
+            foreach (var mod in PotentialModEnumerator.FindAllPotentialMods(modsFolder))
+            {
+                var modInfo = ModInformationParser.ParseString(File.ReadAllText(Path.Combine(mod, "mod.json")));
+                Console.WriteLine($"Found a potential mod in {mod}: {modInfo.Slug ?? "Could not load mod.json"}");
+                if (modInfo.Slug != null)
+                {
+                    Console.WriteLine($"Enabling {modInfo.Name} by {string.Join(", ", modInfo.Authors)}");
+                    // TODO: if mod has more than one configuration, check if one is called default etc.
+
+                    string active;
+                    if (modInfo.Configurations.Count == 1)
+                    {
+                        active = modInfo.Configurations.First().Key;
+                    }
+                    else
+                    {
+                        if (modInfo.Configurations.ContainsKey("default"))
+                        {
+                            active = "default";
+                        }
+                        else
+                        {
+                            Console.Error.WriteLine($"{modInfo.Slug} has {modInfo.Configurations.Count} configurations, " +
+                                                    "but none of it is called `default`. Manually picking one is TODO");
+                            return null;
+                        }
+                    }
+
+                    enabledMods.Add(new ModSetting
+                    {
+                        ModPath = mod,
+                        ActiveConfiguration = active
+                    });
+                }
+            }
+
+            // TODO: Do things with the features to resolve conflicts
+            settings.EnabledMods = enabledMods.ToArray();
+            return JsonSerializer.SerializeToUtf8Bytes(settings, new JsonSerializerOptions { WriteIndented = true });
+        }
+    }
+    #nullable restore
+}