From c5091bfe00c241b6432367aeaea020d4e3d40d28 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Sat, 22 Dec 2018 21:28:56 -0500
Subject: [PATCH] patch_manager: Add support for loading cheats lists Uses
 load/<title_id>/<mod_name>/cheats as root dir, file name is all upper or
 lower hex first 8 bytes build ID.

---
 src/core/file_sys/patch_manager.cpp | 52 +++++++++++++++++++++++++++++
 src/core/file_sys/patch_manager.h   |  4 +++
 2 files changed, 56 insertions(+)

diff --git a/src/core/file_sys/patch_manager.cpp b/src/core/file_sys/patch_manager.cpp
index 61706966e..f0fb28e2f 100644
--- a/src/core/file_sys/patch_manager.cpp
+++ b/src/core/file_sys/patch_manager.cpp
@@ -7,6 +7,7 @@
 #include <cstddef>
 #include <cstring>
 
+#include "common/file_util.h"
 #include "common/hex_util.h"
 #include "common/logging/log.h"
 #include "core/file_sys/content_archive.h"
@@ -232,6 +233,57 @@ bool PatchManager::HasNSOPatch(const std::array<u8, 32>& build_id_) const {
     return !CollectPatches(patch_dirs, build_id).empty();
 }
 
+static std::optional<CheatList> ReadCheatFileFromFolder(u64 title_id,
+                                                        const std::array<u8, 0x20>& build_id_,
+                                                        const VirtualDir& base_path, bool upper) {
+    const auto build_id_raw = Common::HexArrayToString(build_id_, upper);
+    const auto build_id = build_id_raw.substr(0, sizeof(u64) * 2);
+    const auto file = base_path->GetFile(fmt::format("{}.txt", build_id));
+
+    if (file == nullptr) {
+        LOG_INFO(Common_Filesystem, "No cheats file found for title_id={:016X}, build_id={}",
+                 title_id, build_id);
+        return std::nullopt;
+    }
+
+    std::vector<u8> data(file->GetSize());
+    if (file->Read(data.data(), data.size()) != data.size()) {
+        LOG_INFO(Common_Filesystem, "Failed to read cheats file for title_id={:016X}, build_id={}",
+                 title_id, build_id);
+        return std::nullopt;
+    }
+
+    TextCheatParser parser;
+    return parser.Parse(data);
+}
+
+std::vector<CheatList> PatchManager::CreateCheatList(const std::array<u8, 32>& build_id_) const {
+    std::vector<CheatList> out;
+
+    const auto load_dir = Service::FileSystem::GetModificationLoadRoot(title_id);
+    auto patch_dirs = load_dir->GetSubdirectories();
+    std::sort(patch_dirs.begin(), patch_dirs.end(),
+              [](const VirtualDir& l, const VirtualDir& r) { return l->GetName() < r->GetName(); });
+
+    out.reserve(patch_dirs.size());
+    for (const auto& subdir : patch_dirs) {
+        auto cheats_dir = subdir->GetSubdirectory("cheats");
+        if (cheats_dir != nullptr) {
+            auto res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, true);
+            if (res.has_value()) {
+                out.push_back(std::move(*res));
+                continue;
+            }
+
+            res = ReadCheatFileFromFolder(title_id, build_id_, cheats_dir, false);
+            if (res.has_value())
+                out.push_back(std::move(*res));
+        }
+    }
+
+    return out;
+}
+
 static void ApplyLayeredFS(VirtualFile& romfs, u64 title_id, ContentRecordType type) {
     const auto load_dir = Service::FileSystem::GetModificationLoadRoot(title_id);
     if ((type != ContentRecordType::Program && type != ContentRecordType::Data) ||
diff --git a/src/core/file_sys/patch_manager.h b/src/core/file_sys/patch_manager.h
index b8a1652fd..3e3ac6aca 100644
--- a/src/core/file_sys/patch_manager.h
+++ b/src/core/file_sys/patch_manager.h
@@ -8,6 +8,7 @@
 #include <memory>
 #include <string>
 #include "common/common_types.h"
+#include "core/file_sys/cheat_engine.h"
 #include "core/file_sys/nca_metadata.h"
 #include "core/file_sys/vfs.h"
 
@@ -45,6 +46,9 @@ public:
     // Used to prevent expensive copies in NSO loader.
     bool HasNSOPatch(const std::array<u8, 0x20>& build_id) const;
 
+    // Creates a CheatList object with all
+    std::vector<CheatList> CreateCheatList(const std::array<u8, 0x20>& build_id) const;
+
     // Currently tracked RomFS patches:
     // - Game Updates
     // - LayeredFS