refactor: generalize mod models and APIs to resources

Firstly, this abstract away behavior in the mod download models that can
also be applied to other types of resources into a superclass, allowing
other resource types to be implemented without so much code duplication.

For that, this also generalizes the APIs used (currently, ModrinthAPI
and FlameAPI) to be able to make requests to other types of resources.

It also does a general cleanup of both of those. In particular, this
makes use of std::optional instead of invalid values for errors and,
well, optional values :p

This is a squash of some commits that were becoming too interlaced
together to be cleanly separated.

Signed-off-by: flow <flowlnlnln@gmail.com>

27 files changed, 528 insertions, 419 deletions

diff --git a/launcher/modplatform/CheckUpdateTask.h b/launcher/modplatform/CheckUpdateTask.h
index 91922034..932a62d9 100644
--- a/launcher/modplatform/CheckUpdateTask.h
+++ b/launcher/modplatform/CheckUpdateTask.h
@@ -1,18 +1,18 @@
 #pragma once
 
 #include "minecraft/mod/Mod.h"
-#include "modplatform/ModAPI.h"
+#include "modplatform/ResourceAPI.h"
 #include "modplatform/ModIndex.h"
 #include "tasks/Task.h"
 
-class ModDownloadTask;
+class ResourceDownloadTask;
 class ModFolderModel;
 
 class CheckUpdateTask : public Task {
     Q_OBJECT
 
    public:
-    CheckUpdateTask(QList<Mod*>& mods, std::list<Version>& mcVersions, ModAPI::ModLoaderTypes loaders, std::shared_ptr<ModFolderModel> mods_folder)
+    CheckUpdateTask(QList<Mod*>& mods, std::list<Version>& mcVersions, std::optional<ResourceAPI::ModLoaderTypes> loaders, std::shared_ptr<ModFolderModel> mods_folder)
         : Task(nullptr), m_mods(mods), m_game_versions(mcVersions), m_loaders(loaders), m_mods_folder(mods_folder) {};
 
     struct UpdatableMod {
@@ -21,11 +21,11 @@ class CheckUpdateTask : public Task {
         QString old_version;
         QString new_version;
         QString changelog;
-        ModPlatform::Provider provider;
-        ModDownloadTask* download;
+        ModPlatform::ResourceProvider provider;
+        ResourceDownloadTask* download;
 
        public:
-        UpdatableMod(QString name, QString old_h, QString old_v, QString new_v, QString changelog, ModPlatform::Provider p, ModDownloadTask* t)
+        UpdatableMod(QString name, QString old_h, QString old_v, QString new_v, QString changelog, ModPlatform::ResourceProvider p, ResourceDownloadTask* t)
             : name(name), old_hash(old_h), old_version(old_v), new_version(new_v), changelog(changelog), provider(p), download(t)
         {}
     };
@@ -44,7 +44,7 @@ class CheckUpdateTask : public Task {
    protected:
     QList<Mod*>& m_mods;
     std::list<Version>& m_game_versions;
-    ModAPI::ModLoaderTypes m_loaders;
+    std::optional<ResourceAPI::ModLoaderTypes> m_loaders;
     std::shared_ptr<ModFolderModel> m_mods_folder;
 
     std::vector<UpdatableMod> m_updatable;
diff --git a/launcher/modplatform/EnsureMetadataTask.cpp b/launcher/modplatform/EnsureMetadataTask.cpp
index 234330a7..9bf81338 100644
--- a/launcher/modplatform/EnsureMetadataTask.cpp
+++ b/launcher/modplatform/EnsureMetadataTask.cpp
@@ -20,7 +20,7 @@ static ModPlatform::ProviderCapabilities ProviderCaps;
 static ModrinthAPI modrinth_api;
 static FlameAPI flame_api;
 
-EnsureMetadataTask::EnsureMetadataTask(Mod* mod, QDir dir, ModPlatform::Provider prov)
+EnsureMetadataTask::EnsureMetadataTask(Mod* mod, QDir dir, ModPlatform::ResourceProvider prov)
     : Task(nullptr), m_index_dir(dir), m_provider(prov), m_hashing_task(nullptr), m_current_task(nullptr)
 {
     auto hash_task = createNewHash(mod);
@@ -31,7 +31,7 @@ EnsureMetadataTask::EnsureMetadataTask(Mod* mod, QDir dir, ModPlatform::Provider
     hash_task->start();
 }
 
-EnsureMetadataTask::EnsureMetadataTask(QList<Mod*>& mods, QDir dir, ModPlatform::Provider prov)
+EnsureMetadataTask::EnsureMetadataTask(QList<Mod*>& mods, QDir dir, ModPlatform::ResourceProvider prov)
     : Task(nullptr), m_index_dir(dir), m_provider(prov), m_current_task(nullptr)
 {
     m_hashing_task = new ConcurrentTask(this, "MakeHashesTask", 10);
@@ -110,10 +110,10 @@ void EnsureMetadataTask::executeTask()
     NetJob::Ptr version_task;
 
     switch (m_provider) {
-        case (ModPlatform::Provider::MODRINTH):
+        case (ModPlatform::ResourceProvider::MODRINTH):
             version_task = modrinthVersionsTask();
             break;
-        case (ModPlatform::Provider::FLAME):
+        case (ModPlatform::ResourceProvider::FLAME):
             version_task = flameVersionsTask();
             break;
     }
@@ -130,10 +130,10 @@ void EnsureMetadataTask::executeTask()
         NetJob::Ptr project_task;
 
         switch (m_provider) {
-            case (ModPlatform::Provider::MODRINTH):
+            case (ModPlatform::ResourceProvider::MODRINTH):
                 project_task = modrinthProjectsTask();
                 break;
-            case (ModPlatform::Provider::FLAME):
+            case (ModPlatform::ResourceProvider::FLAME):
                 project_task = flameProjectsTask();
                 break;
         }
@@ -212,7 +212,7 @@ void EnsureMetadataTask::emitFail(Mod* m, QString key, RemoveFromList remove)
 
 NetJob::Ptr EnsureMetadataTask::modrinthVersionsTask()
 {
-    auto hash_type = ProviderCaps.hashType(ModPlatform::Provider::MODRINTH).first();
+    auto hash_type = ProviderCaps.hashType(ModPlatform::ResourceProvider::MODRINTH).first();
 
     auto* response = new QByteArray();
     auto ver_task = modrinth_api.currentVersions(m_mods.keys(), hash_type, response);
diff --git a/launcher/modplatform/EnsureMetadataTask.h b/launcher/modplatform/EnsureMetadataTask.h
index a8b0851e..a79e5861 100644
--- a/launcher/modplatform/EnsureMetadataTask.h
+++ b/launcher/modplatform/EnsureMetadataTask.h
@@ -14,8 +14,8 @@ class EnsureMetadataTask : public Task {
     Q_OBJECT
 
    public:
-    EnsureMetadataTask(Mod*, QDir, ModPlatform::Provider = ModPlatform::Provider::MODRINTH);
-    EnsureMetadataTask(QList<Mod*>&, QDir, ModPlatform::Provider = ModPlatform::Provider::MODRINTH);
+    EnsureMetadataTask(Mod*, QDir, ModPlatform::ResourceProvider = ModPlatform::ResourceProvider::MODRINTH);
+    EnsureMetadataTask(QList<Mod*>&, QDir, ModPlatform::ResourceProvider = ModPlatform::ResourceProvider::MODRINTH);
 
     ~EnsureMetadataTask() = default;
 
@@ -57,7 +57,7 @@ class EnsureMetadataTask : public Task {
    private:
     QHash<QString, Mod*> m_mods;
     QDir m_index_dir;
-    ModPlatform::Provider m_provider;
+    ModPlatform::ResourceProvider m_provider;
 
     QHash<QString, ModPlatform::IndexedVersion> m_temp_versions;
     ConcurrentTask* m_hashing_task;
diff --git a/launcher/modplatform/ModAPI.h b/launcher/modplatform/ModAPI.h
deleted file mode 100644
index 703de143..00000000
--- a/launcher/modplatform/ModAPI.h
+++ /dev/null
@@ -1,118 +0,0 @@
-// SPDX-License-Identifier: GPL-3.0-only
-/*
- *  PolyMC - Minecraft Launcher
- *  Copyright (C) 2022 Sefa Eyeoglu <contact@scrumplex.net>
- *
- *  This program is free software: you can redistribute it and/or modify
- *  it under the terms of the GNU General Public License as published by
- *  the Free Software Foundation, version 3.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
- *
- * This file incorporates work covered by the following copyright and
- * permission notice:
- *
- *      Copyright 2013-2021 MultiMC Contributors
- *
- *      Licensed under the Apache License, Version 2.0 (the "License");
- *      you may not use this file except in compliance with the License.
- *      You may obtain a copy of the License at
- *
- *          http://www.apache.org/licenses/LICENSE-2.0
- *
- *      Unless required by applicable law or agreed to in writing, software
- *      distributed under the License is distributed on an "AS IS" BASIS,
- *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *      See the License for the specific language governing permissions and
- *      limitations under the License.
- */
-
-#pragma once
-
-#include <QString>
-#include <QList>
-#include <list>
-
-#include "../Version.h"
-#include "net/NetJob.h"
-
-namespace ModPlatform {
-class ListModel;
-struct IndexedPack;
-}
-
-class ModAPI {
-   protected:
-    using CallerType = ModPlatform::ListModel;
-
-   public:
-    virtual ~ModAPI() = default;
-
-    enum ModLoaderType {
-        Unspecified = 0,
-        Forge = 1 << 0,
-        Cauldron = 1 << 1,
-        LiteLoader = 1 << 2,
-        Fabric = 1 << 3,
-        Quilt = 1 << 4
-    };
-    Q_DECLARE_FLAGS(ModLoaderTypes, ModLoaderType)
-
-    struct SearchArgs {
-        int offset;
-        QString search;
-        QString sorting;
-        ModLoaderTypes loaders;
-        std::list<Version> versions;
-    };
-
-    virtual void searchMods(CallerType* caller, SearchArgs&& args) const = 0;
-    virtual void getModInfo(ModPlatform::IndexedPack& pack, std::function<void(QJsonDocument&, ModPlatform::IndexedPack&)> callback) = 0;
-
-    virtual auto getProject(QString addonId, QByteArray* response) const -> NetJob* = 0;
-    virtual auto getProjects(QStringList addonIds, QByteArray* response) const -> NetJob* = 0;
-
-
-    struct VersionSearchArgs {
-        QString addonId;
-        std::list<Version> mcVersions;
-        ModLoaderTypes loaders;
-    };
-
-    virtual void getVersions(VersionSearchArgs&& args, std::function<void(QJsonDocument&, QString)> callback) const = 0;
-
-    static auto getModLoaderString(ModLoaderType type) -> const QString {
-        switch (type) {
-            case Unspecified:
-                break;
-            case Forge:
-                return "forge";
-            case Cauldron:
-                return "cauldron";
-            case LiteLoader:
-                return "liteloader";
-            case Fabric:
-                return "fabric";
-            case Quilt:
-                return "quilt";
-        }
-        return "";
-    }
-
-   protected:
-    inline auto getGameVersionsString(std::list<Version> mcVersions) const -> QString
-    {
-        QString s;
-        for(auto& ver : mcVersions){
-            s += QString("\"%1\",").arg(ver.toString());
-        }
-        s.remove(s.length() - 1, 1); //remove last comma
-        return s;
-    }
-};
diff --git a/launcher/modplatform/ModIndex.cpp b/launcher/modplatform/ModIndex.cpp
index 34fd9f30..6a507caf 100644
--- a/launcher/modplatform/ModIndex.cpp
+++ b/launcher/modplatform/ModIndex.cpp
@@ -24,47 +24,47 @@
 
 namespace ModPlatform {
 
-auto ProviderCapabilities::name(Provider p) -> const char*
+auto ProviderCapabilities::name(ResourceProvider p) -> const char*
 {
     switch (p) {
-        case Provider::MODRINTH:
+        case ResourceProvider::MODRINTH:
             return "modrinth";
-        case Provider::FLAME:
+        case ResourceProvider::FLAME:
             return "curseforge";
     }
     return {};
 }
-auto ProviderCapabilities::readableName(Provider p) -> QString
+auto ProviderCapabilities::readableName(ResourceProvider p) -> QString
 {
     switch (p) {
-        case Provider::MODRINTH:
+        case ResourceProvider::MODRINTH:
             return "Modrinth";
-        case Provider::FLAME:
+        case ResourceProvider::FLAME:
             return "CurseForge";
     }
     return {};
 }
-auto ProviderCapabilities::hashType(Provider p) -> QStringList
+auto ProviderCapabilities::hashType(ResourceProvider p) -> QStringList
 {
     switch (p) {
-        case Provider::MODRINTH:
+        case ResourceProvider::MODRINTH:
             return { "sha512", "sha1" };
-        case Provider::FLAME:
+        case ResourceProvider::FLAME:
             // Try newer formats first, fall back to old format
             return { "sha1", "md5", "murmur2" };
     }
     return {};
 }
 
-auto ProviderCapabilities::hash(Provider p, QIODevice* device, QString type) -> QString
+auto ProviderCapabilities::hash(ResourceProvider p, QIODevice* device, QString type) -> QString
 {
     QCryptographicHash::Algorithm algo = QCryptographicHash::Sha1;
     switch (p) {
-        case Provider::MODRINTH: {
+        case ResourceProvider::MODRINTH: {
             algo = (type == "sha1") ? QCryptographicHash::Sha1 : QCryptographicHash::Sha512;
             break;
         }
-        case Provider::FLAME:
+        case ResourceProvider::FLAME:
             algo = (type == "sha1") ? QCryptographicHash::Sha1 : QCryptographicHash::Md5;
             break;
     }
diff --git a/launcher/modplatform/ModIndex.h b/launcher/modplatform/ModIndex.h
index 518fed7c..f65a6a4b 100644
--- a/launcher/modplatform/ModIndex.h
+++ b/launcher/modplatform/ModIndex.h
@@ -28,17 +28,16 @@ class QIODevice;
 
 namespace ModPlatform {
 
-enum class Provider {
-    MODRINTH,
-    FLAME
-};
+enum class ResourceProvider { MODRINTH, FLAME };
+
+enum class ResourceType { MOD, RESOURCE_PACK };
 
 class ProviderCapabilities {
    public:
-    auto name(Provider) -> const char*;
-    auto readableName(Provider) -> QString;
-    auto hashType(Provider) -> QStringList;
-    auto hash(Provider, QIODevice*, QString type = "") -> QString;
+    auto name(ResourceProvider) -> const char*;
+    auto readableName(ResourceProvider) -> QString;
+    auto hashType(ResourceProvider) -> QStringList;
+    auto hash(ResourceProvider, QIODevice*, QString type = "") -> QString;
 };
 
 struct ModpackAuthor {
@@ -81,7 +80,7 @@ struct ExtraPackData {
 
 struct IndexedPack {
     QVariant addonId;
-    Provider provider;
+    ResourceProvider provider;
     QString name;
     QString slug;
     QString description;
@@ -101,4 +100,4 @@ struct IndexedPack {
 }  // namespace ModPlatform
 
 Q_DECLARE_METATYPE(ModPlatform::IndexedPack)
-Q_DECLARE_METATYPE(ModPlatform::Provider)
+Q_DECLARE_METATYPE(ModPlatform::ResourceProvider)
diff --git a/launcher/modplatform/ResourceAPI.h b/launcher/modplatform/ResourceAPI.h
new file mode 100644
index 00000000..d18a2caa
--- /dev/null
+++ b/launcher/modplatform/ResourceAPI.h
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  PolyMC - Minecraft Launcher
+ *  Copyright (C) 2022 Sefa Eyeoglu <contact@scrumplex.net>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * This file incorporates work covered by the following copyright and
+ * permission notice:
+ *
+ *      Copyright 2013-2021 MultiMC Contributors
+ *
+ *      Licensed under the Apache License, Version 2.0 (the "License");
+ *      you may not use this file except in compliance with the License.
+ *      You may obtain a copy of the License at
+ *
+ *          http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *      Unless required by applicable law or agreed to in writing, software
+ *      distributed under the License is distributed on an "AS IS" BASIS,
+ *      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *      See the License for the specific language governing permissions and
+ *      limitations under the License.
+ */
+
+#pragma once
+
+#include <QList>
+#include <QString>
+
+#include <list>
+
+#include "../Version.h"
+
+#include "modplatform/ModIndex.h"
+#include "net/NetJob.h"
+
+/* Simple class with a common interface for interacting with APIs */
+class ResourceAPI {
+   public:
+    virtual ~ResourceAPI() = default;
+
+    enum ModLoaderType { Forge = 1 << 0, Cauldron = 1 << 1, LiteLoader = 1 << 2, Fabric = 1 << 3, Quilt = 1 << 4 };
+    Q_DECLARE_FLAGS(ModLoaderTypes, ModLoaderType)
+
+    struct SearchArgs {
+        ModPlatform::ResourceType type{};
+        int offset = 0;
+
+        std::optional<QString> search;
+        std::optional<QString> sorting;
+        std::optional<ModLoaderTypes> loaders;
+        std::optional<std::list<Version> > versions;
+    };
+    struct SearchCallbacks {
+        std::function<void(QJsonDocument&)> on_succeed;
+        std::function<void(QString const& reason, int network_error_code)> on_fail;
+        std::function<void()> on_abort;
+    };
+
+    struct VersionSearchArgs {
+        QString addonId;
+
+        std::optional<std::list<Version> > mcVersions;
+        std::optional<ModLoaderTypes> loaders;
+    };
+    struct VersionSearchCallbacks {
+        std::function<void(QJsonDocument&, QString)> on_succeed;
+    };
+
+    struct ProjectInfoArgs {
+        ModPlatform::IndexedPack& pack;
+
+        void operator=(ProjectInfoArgs other) { pack = other.pack; }
+    };
+    struct ProjectInfoCallbacks {
+        std::function<void(QJsonDocument&, ModPlatform::IndexedPack&)> on_succeed;
+    };
+
+   public slots:
+    [[nodiscard]] virtual NetJob::Ptr searchProjects(SearchArgs&&, SearchCallbacks&&) const
+    {
+        qWarning() << "TODO";
+        return nullptr;
+    }
+    [[nodiscard]] virtual NetJob::Ptr getProject(QString addonId, QByteArray* response) const
+    {
+        qWarning() << "TODO";
+        return nullptr;
+    }
+    [[nodiscard]] virtual NetJob::Ptr getProjects(QStringList addonIds, QByteArray* response) const
+    {
+        qWarning() << "TODO";
+        return nullptr;
+    }
+
+    [[nodiscard]] virtual NetJob::Ptr getProjectInfo(ProjectInfoArgs&&, ProjectInfoCallbacks&&) const
+    {
+        qWarning() << "TODO";
+        return nullptr;
+    }
+    [[nodiscard]] virtual NetJob::Ptr getProjectVersions(VersionSearchArgs&&, VersionSearchCallbacks&&) const
+    {
+        qWarning() << "TODO";
+        return nullptr;
+    }
+
+    static auto getModLoaderString(ModLoaderType type) -> const QString
+    {
+        switch (type) {
+            case Forge:
+                return "forge";
+            case Cauldron:
+                return "cauldron";
+            case LiteLoader:
+                return "liteloader";
+            case Fabric:
+                return "fabric";
+            case Quilt:
+                return "quilt";
+            default:
+                break;
+        }
+        return "";
+    }
+
+   protected:
+    [[nodiscard]] inline QString debugName() const { return "External resource API"; }
+
+    [[nodiscard]] inline auto getGameVersionsString(std::list<Version> mcVersions) const -> QString
+    {
+        QString s;
+        for (auto& ver : mcVersions) {
+            s += QString("\"%1\",").arg(ver.toString());
+        }
+        s.remove(s.length() - 1, 1);  // remove last comma
+        return s;
+    }
+};
diff --git a/launcher/modplatform/flame/FlameAPI.cpp b/launcher/modplatform/flame/FlameAPI.cpp
index 4d71da21..ae401399 100644
--- a/launcher/modplatform/flame/FlameAPI.cpp
+++ b/launcher/modplatform/flame/FlameAPI.cpp
@@ -106,13 +106,19 @@ auto FlameAPI::getModDescription(int modId) -> QString
 
 auto FlameAPI::getLatestVersion(VersionSearchArgs&& args) -> ModPlatform::IndexedVersion
 {
+    auto versions_url_optional = getVersionsURL(args);
+    if (!versions_url_optional.has_value())
+        return {};
+
+    auto versions_url = versions_url_optional.value();
+
     QEventLoop loop;
 
     auto netJob = new NetJob(QString("Flame::GetLatestVersion(%1)").arg(args.addonId), APPLICATION->network());
     auto response = new QByteArray();
     ModPlatform::IndexedVersion ver;
 
-    netJob->addNetAction(Net::Download::makeByteArray(getVersionsURL(args), response));
+    netJob->addNetAction(Net::Download::makeByteArray(versions_url, response));
 
     QObject::connect(netJob, &NetJob::succeeded, [response, args, &ver] {
         QJsonParseError parse_error{};
@@ -161,7 +167,7 @@ auto FlameAPI::getLatestVersion(VersionSearchArgs&& args) -> ModPlatform::Indexe
     return ver;
 }
 
-auto FlameAPI::getProjects(QStringList addonIds, QByteArray* response) const -> NetJob*
+NetJob::Ptr FlameAPI::getProjects(QStringList addonIds, QByteArray* response) const
 {
     auto* netJob = new NetJob(QString("Flame::GetProjects"), APPLICATION->network());
 
@@ -178,13 +184,13 @@ auto FlameAPI::getProjects(QStringList addonIds, QByteArray* response) const ->
 
     netJob->addNetAction(Net::Upload::makeByteArray(QString("https://api.curseforge.com/v1/mods"), response, body_raw));
 
-    QObject::connect(netJob, &NetJob::finished, [response, netJob] { delete response; netJob->deleteLater(); });
+    QObject::connect(netJob, &NetJob::finished, [response] { delete response; });
     QObject::connect(netJob, &NetJob::failed, [body_raw] { qDebug() << body_raw; });
 
     return netJob;
 }
 
-auto FlameAPI::getFiles(const QStringList& fileIds, QByteArray* response) const -> NetJob*
+NetJob::Ptr FlameAPI::getFiles(const QStringList& fileIds, QByteArray* response) const
 {
     auto* netJob = new NetJob(QString("Flame::GetFiles"), APPLICATION->network());
 
@@ -201,7 +207,7 @@ auto FlameAPI::getFiles(const QStringList& fileIds, QByteArray* response) const
 
     netJob->addNetAction(Net::Upload::makeByteArray(QString("https://api.curseforge.com/v1/mods/files"), response, body_raw));
 
-    QObject::connect(netJob, &NetJob::finished, [response, netJob] { delete response; netJob->deleteLater(); });
+    QObject::connect(netJob, &NetJob::finished, [response] { delete response; });
     QObject::connect(netJob, &NetJob::failed, [body_raw] { qDebug() << body_raw; });
 
     return netJob;
diff --git a/launcher/modplatform/flame/FlameAPI.h b/launcher/modplatform/flame/FlameAPI.h
index 4c6ca64c..114a2716 100644
--- a/launcher/modplatform/flame/FlameAPI.h
+++ b/launcher/modplatform/flame/FlameAPI.h
@@ -1,21 +1,21 @@
 #pragma once
 
 #include "modplatform/ModIndex.h"
-#include "modplatform/helpers/NetworkModAPI.h"
+#include "modplatform/helpers/NetworkResourceAPI.h"
 
-class FlameAPI : public NetworkModAPI {
+class FlameAPI : public NetworkResourceAPI {
    public:
-    auto matchFingerprints(const QList<uint>& fingerprints, QByteArray* response) -> NetJob::Ptr;
     auto getModFileChangelog(int modId, int fileId) -> QString;
     auto getModDescription(int modId) -> QString;
 
     auto getLatestVersion(VersionSearchArgs&& args) -> ModPlatform::IndexedVersion;
 
-    auto getProjects(QStringList addonIds, QByteArray* response) const -> NetJob* override;
-    auto getFiles(const QStringList& fileIds, QByteArray* response) const -> NetJob*;
+    NetJob::Ptr getProjects(QStringList addonIds, QByteArray* response) const override;
+    NetJob::Ptr matchFingerprints(const QList<uint>& fingerprints, QByteArray* response);
+    NetJob::Ptr getFiles(const QStringList& fileIds, QByteArray* response) const;
 
    private:
-    inline auto getSortFieldInt(QString sortString) const -> int
+    static int getSortFieldInt(QString const& sortString)
     {
         return sortString == "Featured"         ? 1
                : sortString == "Popularity"     ? 2
@@ -28,48 +28,16 @@ class FlameAPI : public NetworkModAPI {
                                                 : 1;
     }
 
-   private:
-    inline auto getModSearchURL(SearchArgs& args) const -> QString override
-    {
-        auto gameVersionStr = args.versions.size() != 0 ? QString("gameVersion=%1").arg(args.versions.front().toString()) : QString();
-
-        return QString(
-                   "https://api.curseforge.com/v1/mods/search?"
-                   "gameId=432&"
-                   "classId=6&"
-
-                   "index=%1&"
-                   "pageSize=25&"
-                   "searchFilter=%2&"
-                   "sortField=%3&"
-                   "sortOrder=desc&"
-                   "modLoaderType=%4&"
-                   "%5")
-            .arg(args.offset)
-            .arg(args.search)
-            .arg(getSortFieldInt(args.sorting))
-            .arg(getMappedModLoader(args.loaders))
-            .arg(gameVersionStr);
-    };
-
-    inline auto getModInfoURL(QString& id) const -> QString override
+    static int getClassId(ModPlatform::ResourceType type)
     {
-        return QString("https://api.curseforge.com/v1/mods/%1").arg(id);
-    };
-
-    inline auto getVersionsURL(VersionSearchArgs& args) const -> QString override
-    {
-        QString gameVersionQuery = args.mcVersions.size() == 1 ? QString("gameVersion=%1&").arg(args.mcVersions.front().toString()) : "";
-        QString modLoaderQuery = QString("modLoaderType=%1&").arg(getMappedModLoader(args.loaders));
-
-        return QString("https://api.curseforge.com/v1/mods/%1/files?pageSize=10000&%2%3")
-            .arg(args.addonId)
-            .arg(gameVersionQuery)
-            .arg(modLoaderQuery);
-    };
+        switch (type) {
+            default:
+            case ModPlatform::ResourceType::MOD:
+                return 6;
+        }
+    }
 
-   public:
-    static auto getMappedModLoader(const ModLoaderTypes loaders) -> int
+    static int getMappedModLoader(ModLoaderTypes loaders)
     {
         // https://docs.curseforge.com/?http#tocS_ModLoaderType
         if (loaders & Forge)
@@ -81,4 +49,43 @@ class FlameAPI : public NetworkModAPI {
             return 4;  // Quilt would probably be 5
         return 0;
     }
+
+   private:
+    [[nodiscard]] std::optional<QString> getSearchURL(SearchArgs const& args) const override
+    {
+        auto gameVersionStr = args.versions.has_value() ? QString("gameVersion=%1").arg(args.versions.value().front().toString()) : QString();
+
+        QStringList get_arguments;
+        get_arguments.append(QString("classId=%1").arg(getClassId(args.type)));
+        get_arguments.append(QString("index=%1").arg(args.offset));
+        get_arguments.append("pageSize=25");
+        if (args.search.has_value())
+            get_arguments.append(QString("searchFilter=%1").arg(args.search.value()));
+        if (args.sorting.has_value())
+            get_arguments.append(QString("sortField=%1").arg(getSortFieldInt(args.sorting.value())));
+        get_arguments.append("sortOrder=desc");
+        if (args.loaders.has_value())
+            get_arguments.append(QString("modLoaderType=%1").arg(getMappedModLoader(args.loaders.value())));
+        get_arguments.append(gameVersionStr);
+
+        return "https://api.curseforge.com/v1/mods/search?gameId=432&" + get_arguments.join('&');
+    };
+
+    [[nodiscard]] std::optional<QString> getInfoURL(QString const& id) const override
+    {
+        return QString("https://api.curseforge.com/v1/mods/%1").arg(id);
+    };
+
+    [[nodiscard]] std::optional<QString> getVersionsURL(VersionSearchArgs const& args) const override
+    {
+        QString url{QString("https://api.curseforge.com/v1/mods/%1/files?pageSize=10000&").arg(args.addonId)};
+
+        QStringList get_parameters;
+        if (args.mcVersions.has_value())
+            get_parameters.append(QString("gameVersion=%1").arg(args.mcVersions.value().front().toString()));
+        if (args.loaders.has_value())
+            get_parameters.append(QString("modLoaderType=%1").arg(getMappedModLoader(args.loaders.value())));
+
+        return url + get_parameters.join('&');
+    };
 };
diff --git a/launcher/modplatform/flame/FlameCheckUpdate.cpp b/launcher/modplatform/flame/FlameCheckUpdate.cpp
index 8dd3a846..285fa49f 100644
--- a/launcher/modplatform/flame/FlameCheckUpdate.cpp
+++ b/launcher/modplatform/flame/FlameCheckUpdate.cpp
@@ -7,7 +7,10 @@