From ee44f575350cf137420a2f9a0ec9e2c778528436 Mon Sep 17 00:00:00 2001
From: Kaede <malchanceux@protonmail.com>
Date: Fri, 10 Nov 2023 01:04:30 +0200
Subject: [PATCH] Add support for patch-specific logging that is not a
 Console.Writeline in the patch itself.

---
 Marsey/MarseyPatcher.cs        |  2 ++
 Marsey/PatchAssemblyManager.cs | 36 ++++++++++++++++++++++++++++------
 Marsey/Utility.cs              | 28 ++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 6 deletions(-)

diff --git a/Marsey/MarseyPatcher.cs b/Marsey/MarseyPatcher.cs
index c7f69a2..5d5a961 100644
--- a/Marsey/MarseyPatcher.cs
+++ b/Marsey/MarseyPatcher.cs
@@ -30,6 +30,8 @@ public static void Boot(Assembly? robClientAssembly)
 
         FileHandler.LoadAssemblies(new []{"Marsey", "Enabled"});
 
+        PatchAssemblyManager.InitLogger();
+
         GameAssemblyManager.PatchProc();
     }
 }
diff --git a/Marsey/PatchAssemblyManager.cs b/Marsey/PatchAssemblyManager.cs
index 743674d..16534f7 100644
--- a/Marsey/PatchAssemblyManager.cs
+++ b/Marsey/PatchAssemblyManager.cs
@@ -20,14 +20,12 @@ public abstract class PatchAssemblyManager
     /// Initializes a given assembly, validates its structure, and adds it to the list of patch assemblies
     /// </summary>
     /// <param name="assembly">The assembly to initialize</param>
-    /// <exception cref="Exception">Excepts if MarseyPatch is not present in the assembly</exception>
-    /// <exception cref="Exception">Excepts if "TargetAssembly" is present in the assembly MarseyPatch type"</exception>
-    /// <exception cref="Exception">Excepts if GetPatchAssemblyFields returns null</exception>
+    /// <exception cref="PatchAssemblyException">Excepts if MarseyPatch is not present in the assembly</exception>
+    /// <exception cref="PatchAssemblyException">Excepts if "TargetAssembly" is present in the assembly MarseyPatch type"</exception>
+    /// <exception cref="PatchAssemblyException">Excepts if GetPatchAssemblyFields returns null</exception>
     public static void InitAssembly(Assembly assembly)
     {
-        Type marseyPatchType = assembly.GetType("MarseyPatch") ?? throw new PatchAssemblyException("Loaded assembly does not have MarseyPatch type.");
-
-        if (marseyPatchType.GetField("TargetAssembly") != null) throw new PatchAssemblyException($"{assembly.FullName} cannot be loaded because it uses an outdated patch!");
+        Type marseyPatchType = assembly.GetType("MarseyPatch") ?? throw new PatchAssemblyException("Loaded assembly does not have MarseyPatch type. Most likely because MarseyPatch is under a namespace, or you provided a non-patch dll.");
 
         List<FieldInfo> targets = GetPatchAssemblyFields(marseyPatchType) ?? throw new PatchAssemblyException($"Couldn't get assembly fields on {assembly.FullName}.");
 
@@ -51,6 +49,32 @@ public static void InitAssembly(Assembly assembly)
 
     }
 
+    /// <summary>
+    /// Initializes logger class in patches that have it.
+    /// Executed only by the loader.
+    /// MarseyLogger example can be found in the Rethemer MarseyPatch example.
+    /// </summary>
+    public static void InitLogger()
+    {
+        foreach (MarseyPatch patch in _patchAssemblies)
+        {
+            Assembly assembly = patch.Asm;
+
+            // Check for a logger class
+            Type? marseyLoggerType = assembly.GetType("MarseyLogger");
+
+            if (marseyLoggerType != null)
+            {
+                //Utility.Log(Utility.LogType.DEBG, $"{assembly.GetName().Name} has a MarseyLogger class");
+                Utility.SetupLogger(assembly);
+            }
+            else
+            {
+                Utility.Log(Utility.LogType.DEBG, $"{assembly.GetName().Name} has no MarseyLogger class");
+            }
+        }
+    }
+
     /// <summary>
     /// Obtains fields for each of the game's assemblies.
     /// Returns null if any of the fields is null.
diff --git a/Marsey/Utility.cs b/Marsey/Utility.cs
index ba11c31..3bca045 100644
--- a/Marsey/Utility.cs
+++ b/Marsey/Utility.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Reflection;
 
 namespace Marsey;
 
@@ -11,8 +12,35 @@ public enum LogType
         FATL,
         DEBG
     }
+
+    // Loader logs
     public static void Log(LogType logType, string message)
     {
         Console.WriteLine($"[MARSEY] [{logType.ToString()}] {message}");
     }
+
+    // Patch logs
+    public static void Log(AssemblyName asm, string message)
+    {
+        Console.WriteLine($"[{asm.Name}] {message}");
+    }
+
+    /// <summary>
+    /// Sets patch delegate to Utility::Log(AssemblyName, string)
+    /// Executed only by the Loader.
+    /// </summary>
+    /// <see cref="PatchAssemblyManager.InitLogger"/>
+    /// <param name="patch">Assembly from MarseyPatch</param>
+    public static void SetupLogger(Assembly patch)
+    {
+        Type marseyLoggerType = patch.GetType("MarseyLogger")!;
+
+        Type logDelegateType = marseyLoggerType.GetNestedType("Forward", BindingFlags.Public)!;
+
+        MethodInfo logMethod = typeof(Utility).GetMethod("Log", new []{typeof(AssemblyName), typeof(string)})!;
+
+        Delegate logDelegate = Delegate.CreateDelegate(logDelegateType, null, logMethod);
+
+        marseyLoggerType.GetField("logDelegate", BindingFlags.Public | BindingFlags.Static).SetValue(null, logDelegate);
+    }
 }