[desktop] Add mod importer from folder and zip (#3472)

Closes #3125

Adds buttons to the addons page that imports a mod (or mods) from zip or folder.

Currently known to work with mods that provide proper romfs/exefs things, unsure about cheats and such. Also works on mods that just stuff things into the root of the zip.

TODO:
- [ ] test folder more thoroughly
- [ ] cheats
- [ ] test all sorts of mod pack types

Signed-off-by: crueter <crueter@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3472
Reviewed-by: Lizzie <lizzie@eden-emu.dev>

8 files changed, 292 insertions, 7 deletions

diff --git a/src/yuzu/configuration/addon/mod_select_dialog.cpp b/src/yuzu/configuration/addon/mod_select_dialog.cpp
new file mode 100644
index 0000000000..e6c361b94f
--- /dev/null
+++ b/src/yuzu/configuration/addon/mod_select_dialog.cpp
@@ -0,0 +1,66 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include <QFileInfo>
+#include <qnamespace.h>
+#include "mod_select_dialog.h"
+#include "ui_mod_select_dialog.h"
+
+ModSelectDialog::ModSelectDialog(const QStringList& mods, QWidget* parent)
+    : QDialog(parent), ui(new Ui::ModSelectDialog) {
+    ui->setupUi(this);
+
+    item_model = new QStandardItemModel(ui->treeView);
+    ui->treeView->setModel(item_model);
+
+    // We must register all custom types with the Qt Automoc system so that we are able to use it
+    // with signals/slots. In this case, QList falls under the umbrella of custom types.
+    qRegisterMetaType<QList<QStandardItem*>>("QList<QStandardItem*>");
+
+    for (const auto& mod : mods) {
+        const auto basename = QFileInfo(mod).fileName();
+
+        auto* const first_item = new QStandardItem;
+        first_item->setText(basename);
+        first_item->setData(mod);
+
+        first_item->setCheckable(true);
+        first_item->setCheckState(Qt::Checked);
+
+        item_model->appendRow(first_item);
+    }
+
+    ui->treeView->expandAll();
+    ui->treeView->resizeColumnToContents(0);
+
+    int rows = item_model->rowCount();
+    int height =
+        ui->treeView->contentsMargins().top() * 4 + ui->treeView->contentsMargins().bottom() * 4;
+    int width = 0;
+
+    for (int i = 0; i < rows; ++i) {
+        height += ui->treeView->sizeHintForRow(i);
+        width = qMax(width, item_model->item(i)->sizeHint().width());
+    }
+
+    width += ui->treeView->contentsMargins().left() * 4 + ui->treeView->contentsMargins().right() * 4;
+    ui->treeView->setMinimumHeight(qMin(height, 600));
+    ui->treeView->setMinimumWidth(qMin(width, 700));
+    adjustSize();
+
+    connect(this, &QDialog::accepted, this, [this]() {
+        QStringList selected_mods;
+
+        for (qsizetype i = 0; i < item_model->rowCount(); ++i) {
+            auto* const item = item_model->item(i);
+            if (item->checkState() == Qt::Checked)
+                selected_mods << item->data().toString();
+        }
+
+        emit modsSelected(selected_mods);
+    });
+}
+
+ModSelectDialog::~ModSelectDialog() {
+    delete ui;
+}
diff --git a/src/yuzu/configuration/addon/mod_select_dialog.h b/src/yuzu/configuration/addon/mod_select_dialog.h
new file mode 100644
index 0000000000..d23c435e7a
--- /dev/null
+++ b/src/yuzu/configuration/addon/mod_select_dialog.h
@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#pragma once
+
+#include <QDialog>
+#include <QStandardItemModel>
+
+namespace Ui {
+class ModSelectDialog;
+}
+
+class ModSelectDialog : public QDialog {
+    Q_OBJECT
+
+public:
+    explicit ModSelectDialog(const QStringList &mods, QWidget* parent = nullptr);
+    ~ModSelectDialog();
+
+signals:
+    void modsSelected(const QStringList &mods);
+private:
+    Ui::ModSelectDialog* ui;
+
+    QStandardItemModel* item_model;
+};
diff --git a/src/yuzu/configuration/addon/mod_select_dialog.ui b/src/yuzu/configuration/addon/mod_select_dialog.ui
new file mode 100644
index 0000000000..6e196ecff0
--- /dev/null
+++ b/src/yuzu/configuration/addon/mod_select_dialog.ui
@@ -0,0 +1,99 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>ModSelectDialog</class>
+ <widget class="QDialog" name="ModSelectDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>430</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Dialog</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QLabel" name="label">
+     <property name="text">
+      <string>The specified folder or archive contains the following mods. Select which ones to install.</string>
+     </property>
+     <property name="wordWrap">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QTreeView" name="treeView">
+     <property name="contextMenuPolicy">
+      <enum>Qt::ContextMenuPolicy::NoContextMenu</enum>
+     </property>
+     <property name="editTriggers">
+      <set>QAbstractItemView::EditTrigger::NoEditTriggers</set>
+     </property>
+     <property name="alternatingRowColors">
+      <bool>true</bool>
+     </property>
+     <property name="verticalScrollMode">
+      <enum>QAbstractItemView::ScrollMode::ScrollPerPixel</enum>
+     </property>
+     <property name="uniformRowHeights">
+      <bool>true</bool>
+     </property>
+     <property name="sortingEnabled">
+      <bool>true</bool>
+     </property>
+     <property name="headerHidden">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Orientation::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::StandardButton::Cancel|QDialogButtonBox::StandardButton::Ok</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>ModSelectDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>248</x>
+     <y>254</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>157</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>ModSelectDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>316</x>
+     <y>260</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>286</x>
+     <y>274</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>
diff --git a/src/yuzu/configuration/configure_per_game.cpp b/src/yuzu/configuration/configure_per_game.cpp
index e49978414c..eddb24b952 100644
--- a/src/yuzu/configuration/configure_per_game.cpp
+++ b/src/yuzu/configuration/configure_per_game.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
diff --git a/src/yuzu/configuration/configure_per_game.h b/src/yuzu/configuration/configure_per_game.h
index e4d18f29b9..1e53bf0708 100644
--- a/src/yuzu/configuration/configure_per_game.h
+++ b/src/yuzu/configuration/configure_per_game.h
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: Copyright 2020 yuzu Emulator Project
diff --git a/src/yuzu/configuration/configure_per_game_addons.cpp b/src/yuzu/configuration/configure_per_game_addons.cpp
index ee2db55a5d..3032e4c3d9 100644
--- a/src/yuzu/configuration/configure_per_game_addons.cpp
+++ b/src/yuzu/configuration/configure_per_game_addons.cpp
@@ -1,4 +1,4 @@
-// SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
 // SPDX-License-Identifier: GPL-3.0-or-later
 
 // SPDX-FileCopyrightText: 2016 Citra Emulator Project
@@ -14,17 +14,21 @@
 #include <QString>
 #include <QTimer>
 #include <QTreeView>
+#include <qstandardpaths.h>
 
 #include "common/fs/fs.h"
 #include "common/fs/path_util.h"
+#include "configuration/addon/mod_select_dialog.h"
 #include "core/core.h"
 #include "core/file_sys/patch_manager.h"
-#include "core/file_sys/xts_archive.h"
 #include "core/loader/loader.h"
+#include "frontend_common/mod_manager.h"
+#include "qt_common/abstract/frontend.h"
+#include "qt_common/config/uisettings.h"
+#include "qt_common/util/mod.h"
 #include "ui_configure_per_game_addons.h"
 #include "yuzu/configuration/configure_input.h"
 #include "yuzu/configuration/configure_per_game_addons.h"
-#include "qt_common/config/uisettings.h"
 
 ConfigurePerGameAddons::ConfigurePerGameAddons(Core::System& system_, QWidget* parent)
     : QWidget(parent), ui{std::make_unique<Ui::ConfigurePerGameAddons>()}, system{system_} {
@@ -66,6 +70,9 @@ ConfigurePerGameAddons::ConfigurePerGameAddons(Core::System& system_, QWidget* p
 
     connect(item_model, &QStandardItemModel::itemChanged,
             [] { UISettings::values.is_game_list_reload_pending.exchange(true); });
+
+    connect(ui->folder, &QAbstractButton::clicked, this, &ConfigurePerGameAddons::InstallModFolder);
+    connect(ui->zip, &QAbstractButton::clicked, this, &ConfigurePerGameAddons::InstallModZip);
 }
 
 ConfigurePerGameAddons::~ConfigurePerGameAddons() = default;
@@ -99,6 +106,68 @@ void ConfigurePerGameAddons::SetTitleId(u64 id) {
     this->title_id = id;
 }
 
+void ConfigurePerGameAddons::InstallMods(const QStringList& mods) {
+    QStringList failed;
+    for (const auto& mod : mods) {
+        if (FrontendCommon::InstallMod(mod.toStdString(), title_id, true) ==
+            FrontendCommon::Failed) {
+            failed << QFileInfo(mod).baseName();
+        }
+    }
+
+    if (failed.empty()) {
+        QtCommon::Frontend::Information(tr("Mod Install Succeeded"),
+                                        tr("Successfully installed all mods."));
+
+        item_model->removeRows(0, item_model->rowCount());
+        list_items.clear();
+        LoadConfiguration();
+
+        UISettings::values.is_game_list_reload_pending.exchange(true);
+    } else {
+        QtCommon::Frontend::Critical(
+            tr("Mod Install Failed"),
+            tr("Failed to install the following mods:\n\t%1\nCheck the log for details.")
+                .arg(failed.join(QStringLiteral("\n\t"))));
+    }
+}
+
+void ConfigurePerGameAddons::InstallModPath(const QString& path) {
+    const auto mods = QtCommon::Mod::GetModFolders(path, {});
+
+    if (mods.size() > 1) {
+        ModSelectDialog* dialog = new ModSelectDialog(mods, this);
+        connect(dialog, &ModSelectDialog::modsSelected, this, &ConfigurePerGameAddons::InstallMods);
+        dialog->show();
+    } else {
+        InstallMods(mods);
+    }
+}
+
+void ConfigurePerGameAddons::InstallModFolder() {
+    const auto path = QtCommon::Frontend::GetExistingDirectory(
+        tr("Mod Folder"), QStandardPaths::writableLocation(QStandardPaths::DownloadLocation));
+    if (path.isEmpty()) {
+        return;
+    }
+
+    InstallModPath(path);
+}
+
+void ConfigurePerGameAddons::InstallModZip() {
+    const auto path = QtCommon::Frontend::GetOpenFileName(
+        tr("Zipped Mod Location"),
+        QStandardPaths::writableLocation(QStandardPaths::DownloadLocation),
+        tr("Zipped Archives (*.zip)"));
+    if (path.isEmpty()) {
+        return;
+    }
+
+    const QString extracted = QtCommon::Mod::ExtractMod(path);
+    if (!extracted.isEmpty())
+        InstallModPath(extracted);
+}
+
 void ConfigurePerGameAddons::changeEvent(QEvent* event) {
     if (event->type() == QEvent::LanguageChange) {
         RetranslateUI();
diff --git a/src/yuzu/configuration/configure_per_game_addons.h b/src/yuzu/configuration/configure_per_game_addons.h
index 32dc5dde62..8b698b5bec 100644
--- a/src/yuzu/configuration/configure_per_game_addons.h
+++ b/src/yuzu/configuration/configure_per_game_addons.h
@@ -1,3 +1,6 @@
+// SPDX-FileCopyrightText: Copyright 2026 Eden Emulator Project
+// SPDX-License-Identifier: GPL-3.0-or-later
+
 // SPDX-FileCopyrightText: 2016 Citra Emulator Project
 // SPDX-License-Identifier: GPL-2.0-or-later
 
@@ -7,6 +10,7 @@
 #include <vector>
 
 #include <QList>
+#include <QWidget>
 
 #include "core/file_sys/vfs/vfs_types.h"
 
@@ -38,6 +42,13 @@ public:
 
     void SetTitleId(u64 id);
 
+public slots:
+    void InstallMods(const QStringList &mods);
+    void InstallModPath(const QString& path);
+
+    void InstallModFolder();
+    void InstallModZip();
+
 private:
     void changeEvent(QEvent* event) override;
     void RetranslateUI();
diff --git a/src/yuzu/configuration/configure_per_game_addons.ui b/src/yuzu/configuration/configure_per_game_addons.ui
index f9cf6f2c31..632f9d422b 100644
--- a/src/yuzu/configuration/configure_per_game_addons.ui
+++ b/src/yuzu/configuration/configure_per_game_addons.ui
@@ -17,7 +17,21 @@
    <string>Add-Ons</string>
   </property>
   <layout class="QGridLayout" name="gridLayout">
-   <item row="0" column="0">
+   <item row="1" column="0">
+    <widget class="QPushButton" name="zip">
+     <property name="text">
+      <string>Import Mod from ZIP</string>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="1">
+    <widget class="QPushButton" name="folder">
+     <property name="text">
+      <string>Import Mod from Folder</string>
+     </property>
+    </widget>
+   </item>
+   <item row="0" column="0" colspan="2">
     <widget class="QScrollArea" name="scrollArea">
      <property name="widgetResizable">
       <bool>true</bool>
@@ -28,7 +42,7 @@
         <x>0</x>
         <y>0</y>
         <width>380</width>
-        <height>280</height>
+        <height>249</height>
        </rect>
       </property>
      </widget>