From b0d3e4610c36f2ba84ea08125b16bb85f869111d Mon Sep 17 00:00:00 2001
From: Mr-Wiseguy <mrwiseguyromhacking@gmail.com>
Date: Wed, 10 Jul 2024 18:17:32 -0400
Subject: [PATCH] Add duplicate mod detection

---
 librecomp/include/librecomp/mods.hpp | 8 +++++---
 librecomp/src/mod_manifest.cpp       | 9 +++++++++
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/librecomp/include/librecomp/mods.hpp b/librecomp/include/librecomp/mods.hpp
index 954da71..a5a7813 100644
--- a/librecomp/include/librecomp/mods.hpp
+++ b/librecomp/include/librecomp/mods.hpp
@@ -29,9 +29,12 @@ namespace recomp {
             UnrecognizedManifestField,
             IncorrectManifestFieldType,
             MissingManifestField,
-            InnerFileDoesNotExist
+            InnerFileDoesNotExist,
+            DuplicateMod
         };
 
+        std::string error_to_string(ModOpenError);
+
         enum class ModLoadError {
             Good,
             FailedToLoadSyms,
@@ -123,10 +126,9 @@ namespace recomp {
             void add_opened_mod(ModManifest&& manifest);
 
             std::vector<ModHandle> opened_mods;
+            std::unordered_set<std::string> mod_ids;
             std::unordered_set<std::string> enabled_mods;
         };
-
-        std::string error_to_string(ModOpenError);
     }
 };
 
diff --git a/librecomp/src/mod_manifest.cpp b/librecomp/src/mod_manifest.cpp
index 54e8010..302e1c1 100644
--- a/librecomp/src/mod_manifest.cpp
+++ b/librecomp/src/mod_manifest.cpp
@@ -366,6 +366,13 @@ recomp::mods::ModOpenError recomp::mods::ModContext::open_mod(const std::filesys
         }
     }
 
+    // Check for this being a duplicate of another opened mod.
+    if (mod_ids.contains(manifest.mod_id)) {
+        error_param = manifest.mod_id;
+        return ModOpenError::DuplicateMod;
+    }
+    mod_ids.emplace(manifest.mod_id);
+
     ModOpenError validate_error = validate_manifest(manifest, error_param);
     if (validate_error != ModOpenError::Good) {
         return validate_error;
@@ -404,6 +411,8 @@ std::string recomp::mods::error_to_string(ModOpenError error) {
             return "Missing required field in manifest";
         case ModOpenError::InnerFileDoesNotExist:
             return "File inside mod does not exist";
+        case ModOpenError::DuplicateMod:
+            return "Duplicate mod found";
     }
     return "Unknown error " + std::to_string((int)error);
 }