From dec395616777f7a39dfd4771c648bfa280abb287 Mon Sep 17 00:00:00 2001
From: Chomp <dev@dev.sp-tarkov.com>
Date: Sun, 9 Feb 2025 11:33:28 +0000
Subject: [PATCH] Expanded `ModDllLoader` implementation

---
 Libraries/Core/Models/Spt/Mod/SptMod.cs |  4 +-
 Server/ModDllLoader.cs                  | 55 +++++++++++++++++++------
 2 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/Libraries/Core/Models/Spt/Mod/SptMod.cs b/Libraries/Core/Models/Spt/Mod/SptMod.cs
index 33873231..ce471de2 100644
--- a/Libraries/Core/Models/Spt/Mod/SptMod.cs
+++ b/Libraries/Core/Models/Spt/Mod/SptMod.cs
@@ -6,14 +6,14 @@ namespace Core.Models.Spt.Mod;
 public class SptMod
 {
     [JsonPropertyName("PackageJson")]
-    public PackageJsonData PackageJson
+    public PackageJsonData? PackageJson
     {
         get;
         set;
     }
 
     [JsonPropertyName("Assembly")]
-    public Assembly Assembly
+    public Assembly? Assembly
     {
         get;
         set;
diff --git a/Server/ModDllLoader.cs b/Server/ModDllLoader.cs
index a7dd39dc..34c7cd87 100644
--- a/Server/ModDllLoader.cs
+++ b/Server/ModDllLoader.cs
@@ -23,10 +23,9 @@ public class ModDllLoader
         // load both
         // if either is missing Throw Warning and skip
 
-        var modDirectories = GetSortedModDirectories();
-
-        // TODO: Handle package.json 'Dependencies' property
+        var modDirectories = Directory.GetDirectories(ModPath);
 
+        // Load mods found in dir
         foreach (var modDirectory in modDirectories)
         {
             try
@@ -39,15 +38,46 @@ public class ModDllLoader
             }
         }
 
+        ValidateModDependencies(mods);
+
+        // Sort by mods LoadBefore/LoadAfter collections
+        SortMods(mods);
+
         return mods;
     }
 
-    private static string[] GetSortedModDirectories()
+    /// <summary>
+    /// Ensure all mods have their dependencies
+    /// </summary>
+    /// <param name="mods">Mods to check dependencies of</param>
+    private static void ValidateModDependencies(List<SptMod> mods)
     {
-        // TODO: add system to read from package.json and order mod paths by their LoadBefore/LoadAfter properties
-        return Directory.GetDirectories(ModPath);
+        foreach (var sptMod in mods)
+        {
+            if (sptMod.PackageJson?.Dependencies?.Count > 0)
+            {
+                // Has deps, validate they exist
+                foreach (var dependency in sptMod.PackageJson.Dependencies
+                             .Where(dependency => !mods.Exists(x => x.PackageJson.Name.ToLower() == dependency.Key)))
+                {
+                    // TODO: also check version passes semver check
+                    throw new Exception($"Mod: {sptMod.PackageJson.Name} is unable to load as it cannot find another mod it needs: {dependency.Key} version: {dependency.Value}");
+                }
+            }
+        }
     }
 
+    private static void SortMods(List<SptMod> mods)
+    {
+        //TODO: implement
+        Console.WriteLine($"NOT IMPLEMENTED: SortMods");
+    }
+
+    /// <summary>
+    /// Check the provided directory path for a dll and .json file, load into memory
+    /// </summary>
+    /// <param name="path">Directory path that contains mod files</param>
+    /// <returns>SptMod</returns>
     private static SptMod LoadMod(string path)
     {
         var result = new SptMod();
@@ -59,10 +89,9 @@ public class ModDllLoader
             {
                 packCount++;
 
-                // deal with package.json
-                var jjson = File.ReadAllText(file.FullName);
-                var json = JsonSerializer.Deserialize<PackageJsonData>(jjson);
-                result.PackageJson = json;
+                // Handle package.json
+                var rawJson = File.ReadAllText(file.FullName);
+                result.PackageJson = JsonSerializer.Deserialize<PackageJsonData>(rawJson);
                 if (packCount > 1)
                 {
                     throw new Exception($"More than one package.json file found in path: {path}");
@@ -76,14 +105,14 @@ public class ModDllLoader
                 result.Assembly = Assembly.LoadFile(Path.GetFullPath(file.FullName));
                 if (asmCount > 1)
                 {
-                    throw new Exception($"More than one Assembly found in {path}");
+                    throw new Exception($"More than one Assembly found in: {path}");
                 }
             }
         }
 
         if (asmCount == 0 && packCount == 0)
         {
-            throw new Exception($"No Assembly or package.json found in {Path.GetFullPath(path)}");
+            throw new Exception($"No Assembly or package.json found in: {Path.GetFullPath(path)}");
         }
 
         if (packCount == 0)
@@ -98,7 +127,7 @@ public class ModDllLoader
 
         if (result.Assembly is not null && result.PackageJson is not null)
         {
-            Console.WriteLine($"Loaded {result.PackageJson.Name} mod by {result.PackageJson.Author}");
+            Console.WriteLine($"Loaded: {result.PackageJson.Name} Version: {result.PackageJson.Version} by: {result.PackageJson.Author}");
         }
 
         return result;