feat: add modrinth pack downloading

Things that don't work / work poorly (there's more for sure but those
are the evident ones):
    - Icons are broken in the import dialog
    - No way to search for private packs
    - Icons are not downloaded when downloading a mod
    - No support for multiple download URLs
    - Probably a lot more...

7 files changed, 729 insertions, 36 deletions

diff --git a/launcher/CMakeLists.txt b/launcher/CMakeLists.txt
index 7984d3c9..8e75be20 100644
--- a/launcher/CMakeLists.txt
+++ b/launcher/CMakeLists.txt
@@ -778,6 +778,8 @@ SET(LAUNCHER_SOURCES
 
     ui/pages/modplatform/modrinth/ModrinthPage.cpp
     ui/pages/modplatform/modrinth/ModrinthPage.h
+    ui/pages/modplatform/modrinth/ModrinthModel.cpp
+    ui/pages/modplatform/modrinth/ModrinthModel.h
 
     ui/pages/modplatform/technic/TechnicModel.cpp
     ui/pages/modplatform/technic/TechnicModel.h
diff --git a/launcher/modplatform/modrinth/ModrinthPackManifest.cpp b/launcher/modplatform/modrinth/ModrinthPackManifest.cpp
index 2100aaf9..4dcd2fd4 100644
--- a/launcher/modplatform/modrinth/ModrinthPackManifest.cpp
+++ b/launcher/modplatform/modrinth/ModrinthPackManifest.cpp
@@ -14,3 +14,87 @@
  */
 
 #include "ModrinthPackManifest.h"
+#include "Json.h"
+
+#include "minecraft/MinecraftInstance.h"
+#include "minecraft/PackProfile.h"
+
+namespace Modrinth {
+
+void loadIndexedPack(Modpack& pack, QJsonObject& obj)
+{
+    pack.id = Json::ensureString(obj, "project_id");
+
+    pack.name = Json::ensureString(obj, "title");
+    pack.description = Json::ensureString(obj, "description");
+    pack.authors << Json::ensureString(obj, "author");
+    pack.iconName = QString("modrinth_%1").arg(Json::ensureString(obj, "slug"));
+    pack.iconUrl = Json::ensureString(obj, "icon_url");
+}
+
+void loadIndexedInfo(Modpack& pack, QJsonObject& obj)
+{
+    pack.extra.body = Json::ensureString(obj, "body");
+    pack.extra.sourceUrl = Json::ensureString(obj, "source_url");
+    pack.extra.wikiUrl = Json::ensureString(obj, "wiki_url");
+
+    pack.extraInfoLoaded = true;
+}
+
+void loadIndexedVersions(Modpack& pack, QJsonDocument& doc)
+{
+    QVector<ModpackVersion> unsortedVersions;
+
+    auto arr = Json::requireArray(doc);
+
+    for (auto versionIter : arr) {
+        auto obj = Json::requireObject(versionIter);
+        auto file = loadIndexedVersion(obj);
+
+        if(!file.id.isEmpty()) // Heuristic to check if the returned value is valid
+            unsortedVersions.append(file);
+    }
+    auto orderSortPredicate = [](const ModpackVersion& a, const ModpackVersion& b) -> bool {
+        // dates are in RFC 3339 format
+        return a.date > b.date;
+    };
+
+    std::sort(unsortedVersions.begin(), unsortedVersions.end(), orderSortPredicate);
+
+    pack.versions.swap(unsortedVersions);
+
+    pack.versionsLoaded = true;
+}
+
+auto loadIndexedVersion(QJsonObject &obj) -> ModpackVersion
+{
+    ModpackVersion file;
+
+    file.name = Json::requireString(obj, "name");
+    file.version = Json::requireString(obj, "version_number");
+
+    file.id = Json::requireString(obj, "id");
+    file.project_id = Json::requireString(obj, "project_id");
+    
+    file.date = Json::requireString(obj, "date_published");
+
+    auto files = Json::requireArray(obj, "files");
+
+    for (auto file_iter : files) {
+        File indexed_file;
+        auto parent = Json::requireObject(file_iter);
+        if (!Json::ensureBoolean(parent, "primary", false)) {
+            continue;
+        }
+
+        file.download_url = Json::requireString(parent, "url");
+        break;
+    }
+
+    if(file.download_url.isEmpty())
+        return {};
+
+    return file;
+}        
+
+}  // namespace Modrinth
diff --git a/launcher/modplatform/modrinth/ModrinthPackManifest.h b/launcher/modplatform/modrinth/ModrinthPackManifest.h
index 9742aeb2..7dab893c 100644
--- a/launcher/modplatform/modrinth/ModrinthPackManifest.h
+++ b/launcher/modplatform/modrinth/ModrinthPackManifest.h
@@ -15,18 +15,68 @@
 
 #pragma once
 
+#include <QMetaType>
+
 #include <QByteArray>
 #include <QCryptographicHash>
 #include <QString>
 #include <QUrl>
 
+class MinecraftInstance;
+
 namespace Modrinth {
+
 struct File
 {
     QString path;
+
     QCryptographicHash::Algorithm hashAlgorithm;
     QByteArray hash;
     // TODO: should this support multiple download URLs, like the JSON does?
     QUrl download;
 };
+
+struct ModpackExtra {
+    QString body;
+
+    QString sourceUrl;
+    QString wikiUrl;
+};
+
+struct ModpackVersion {
+    QString name;
+    QString version;
+
+    QString id;
+    QString project_id;
+
+    QString date;
+
+    QString download_url;
+};
+
+struct Modpack {
+    QString id;
+
+    QString name;
+    QString description;
+    QStringList authors;
+    QString iconName;
+    QUrl    iconUrl;
+
+    bool    versionsLoaded = false;
+    bool    extraInfoLoaded = false;
+
+    ModpackExtra extra;
+    QVector<ModpackVersion> versions;
+};
+
+void loadIndexedPack(Modpack&, QJsonObject&);
+void loadIndexedInfo(Modpack&, QJsonObject&);
+void loadIndexedVersions(Modpack&, QJsonDocument&);
+auto loadIndexedVersion(QJsonObject&) -> ModpackVersion;
+
 }
+
+Q_DECLARE_METATYPE(Modrinth::Modpack);
+Q_DECLARE_METATYPE(Modrinth::ModpackVersion);
diff --git a/launcher/ui/pages/modplatform/modrinth/ModrinthModel.cpp b/launcher/ui/pages/modplatform/modrinth/ModrinthModel.cpp
new file mode 100644
index 00000000..2890e27d
--- /dev/null
+++ b/launcher/ui/pages/modplatform/modrinth/ModrinthModel.cpp
@@ -0,0 +1,274 @@
+#include "ModrinthModel.h"
+
+#include "BuildConfig.h"
+#include "Json.h"
+#include "minecraft/MinecraftInstance.h"
+#include "minecraft/PackProfile.h"
+#include "ui/dialogs/ModDownloadDialog.h"
+
+#include <QMessageBox>
+
+namespace Modrinth {
+
+ModpackListModel::ModpackListModel(ModrinthPage* parent) : QAbstractListModel(parent), m_parent(parent) {}
+
+auto ModpackListModel::debugName() const -> QString
+{
+    return m_parent->debugName();
+}
+
+/******** Make data requests ********/
+
+void ModpackListModel::fetchMore(const QModelIndex& parent)
+{
+    if (parent.isValid())
+        return;
+    if (nextSearchOffset == 0) {
+        qWarning() << "fetchMore with 0 offset is wrong...";
+        return;
+    }
+    performPaginatedSearch();
+}
+
+auto ModpackListModel::data(const QModelIndex& index, int role) const -> QVariant
+{
+    int pos = index.row();
+    if (pos >= modpacks.size() || pos < 0 || !index.isValid()) {
+        return QString("INVALID INDEX %1").arg(pos);
+    }
+
+    Modrinth::Modpack pack = modpacks.at(pos);
+    if (role == Qt::DisplayRole) {
+        return pack.name;
+    } else if (role == Qt::ToolTipRole) {
+        if (pack.description.length() > 100) {
+            // some magic to prevent to long tooltips and replace html linebreaks
+            QString edit = pack.description.left(97);
+            edit = edit.left(edit.lastIndexOf("<br>")).left(edit.lastIndexOf(" ")).append("...");
+            return edit;
+        }
+        return pack.description;
+    } else if (role == Qt::DecorationRole) {
+        // FIXME: help the icons dont have the same size ;-;
+        if (m_logoMap.contains(pack.iconName)) {
+            return (m_logoMap.value(pack.iconName));
+        }
+        QIcon icon = APPLICATION->getThemedIcon("screenshot-placeholder");
+        ((ModpackListModel*)this)->requestLogo(pack.iconName, pack.iconUrl.toString());
+        return icon;
+    } else if (role == Qt::UserRole) {
+        QVariant v;
+        v.setValue(pack);
+        return v;
+    }
+
+    return {};
+}
+
+/*
+void ModpackListModel::requestModVersions(ModPlatform::IndexedPack const& current)
+{
+    auto profile = (dynamic_cast<MinecraftInstance*>((dynamic_cast<ModPage*>(parent()))->m_instance))->getPackProfile();
+
+    m_parent->apiProvider()->getVersions(this, { current.addonId.toString(), getMineVersions(), profile->getModLoader() });
+}*/
+
+void ModpackListModel::performPaginatedSearch()
+{
+    // TODO: Move to standalone API
+    NetJob* netJob = new NetJob("Modrinth::SearchModpack", APPLICATION->network());
+    auto searchAllUrl = QString(
+                            "https://staging-api.modrinth.com/v2/search?"
+                            "query=%1&"
+                            "facets=[[\"project_type:modpack\"]]")
+                            .arg(currentSearchTerm);
+
+    netJob->addNetAction(Net::Download::makeByteArray(QUrl(searchAllUrl), &m_all_response));
+
+    QObject::connect(netJob, &NetJob::succeeded, this, [this] {
+        QJsonParseError parse_error_all {};
+
+        QJsonDocument doc_all = QJsonDocument::fromJson(m_all_response, &parse_error_all);
+        if (parse_error_all.error != QJsonParseError::NoError) {
+            qWarning() << "Error while parsing JSON response from " << debugName() << " at " << parse_error_all.offset
+                       << " reason: " << parse_error_all.errorString();
+            qWarning() << m_all_response;
+            return;
+        }
+
+        searchRequestFinished(doc_all);
+    });
+    QObject::connect(netJob, &NetJob::failed, this, &ModpackListModel::searchRequestFailed);
+
+    jobPtr = netJob;
+    jobPtr->start();
+}
+
+void ModpackListModel::refresh()
+{
+    if (jobPtr) {
+        jobPtr->abort();
+        searchState = ResetRequested;
+        return;
+    } else {
+        beginResetModel();
+        modpacks.clear();
+        endResetModel();
+        searchState = None;
+    }
+    nextSearchOffset = 0;
+    performPaginatedSearch();
+}
+
+void ModpackListModel::searchWithTerm(const QString& term, const int sort)
+{
+    if (currentSearchTerm == term && currentSearchTerm.isNull() == term.isNull() && currentSort == sort) {
+        return;
+    }
+
+    currentSearchTerm = term;
+    currentSort = sort;
+
+    refresh();
+}
+
+void ModpackListModel::getLogo(const QString& logo, const QString& logoUrl, LogoCallback callback)
+{
+    if (m_logoMap.contains(logo)) {
+        callback(APPLICATION->metacache()
+                     ->resolveEntry(m_parent->metaEntryBase(), QString("logos/%1").arg(logo.section(".", 0, 0)))
+                     ->getFullPath());
+    } else {
+        requestLogo(logo, logoUrl);
+    }
+}
+
+void ModpackListModel::requestLogo(QString logo, QString url)
+{
+    if (m_loadingLogos.contains(logo) || m_failedLogos.contains(logo)) {
+        return;
+    }
+
+    MetaEntryPtr entry =
+        APPLICATION->metacache()->resolveEntry(m_parent->metaEntryBase(), QString("logos/%1").arg(logo.section(".", 0, 0)));
+    auto job = new NetJob(QString("%1 Icon Download %2").arg(m_parent->debugName()).arg(logo), APPLICATION->network());
+    job->addNetAction(Net::Download::makeCached(QUrl(url), entry));
+
+    auto fullPath = entry->getFullPath();
+    QObject::connect(job, &NetJob::succeeded, this, [this, logo, fullPath, job] {
+        job->deleteLater();
+        emit logoLoaded(logo, QIcon(fullPath));
+        if (waitingCallbacks.contains(logo)) {
+            waitingCallbacks.value(logo)(fullPath);
+        }
+    });
+
+    QObject::connect(job, &NetJob::failed, this, [this, logo, job] {
+        job->deleteLater();
+        emit logoFailed(logo);
+    });
+
+    job->start();
+    m_loadingLogos.append(logo);
+}
+
+/******** Request callbacks ********/
+
+void ModpackListModel::logoLoaded(QString logo, QIcon out)
+{
+    m_loadingLogos.removeAll(logo);
+    m_logoMap.insert(logo, out);
+    for (int i = 0; i < modpacks.size(); i++) {
+        if (modpacks[i].iconName == logo) {
+            emit dataChanged(createIndex(i, 0), createIndex(i, 0), { Qt::DecorationRole });
+        }
+    }
+}
+
+void ModpackListModel::logoFailed(QString logo)
+{
+    m_failedLogos.append(logo);
+    m_loadingLogos.removeAll(logo);
+}
+
+void ModpackListModel::searchRequestFinished(QJsonDocument& doc_all)
+{
+    jobPtr.reset();
+
+    QList<Modrinth::Modpack> newList;
+
+    auto packs_all = doc_all.object().value("hits").toArray();
+    for (auto packRaw : packs_all) {
+        auto packObj = packRaw.toObject();
+
+        Modrinth::Modpack pack;
+        try {
+            Modrinth::loadIndexedPack(pack, packObj);
+            newList.append(pack);
+        } catch (const JSONValidationError& e) {
+            qWarning() << "Error while loading mod from " << m_parent->debugName() << ": " << e.cause();
+            continue;
+        }
+    }
+    
+    if (packs_all.size() < 25) {
+        searchState = Finished;
+    } else {
+        nextSearchOffset += 25;
+        searchState = CanPossiblyFetchMore;
+    }
+
+    beginInsertRows(QModelIndex(), modpacks.size(), modpacks.size() + newList.size() - 1);
+    modpacks.append(newList);
+    endInsertRows();
+}
+
+void ModpackListModel::searchRequestFailed(QString reason)
+{
+    if (!jobPtr->first()->m_reply) {
+        // Network error
+        QMessageBox::critical(nullptr, tr("Error"), tr("A network error occurred. Could not load mods."));
+    } else if (jobPtr->first()->m_reply && jobPtr->first()->m_reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt() == 409) {
+        // 409 Gone, notify user to update
+        QMessageBox::critical(nullptr, tr("Error"),
+                              //: %1 refers to the launcher itself
+                              QString("%1 %2")
+                                  .arg(m_parent->displayName())
+                                  .arg(tr("API version too old!\nPlease update %1!").arg(BuildConfig.LAUNCHER_NAME)));
+    }
+    jobPtr.reset();
+
+    if (searchState == ResetRequested) {
+        beginResetModel();
+        modpacks.clear();
+        endResetModel();
+
+        nextSearchOffset = 0;
+        performPaginatedSearch();
+    } else {
+        searchState = Finished;
+    }
+}
+
+void ModpackListModel::versionRequestSucceeded(QJsonDocument doc, QString id)
+{
+    auto& current = m_parent->getCurrent();
+    if (id != current.id) {
+        return;
+    }
+
+    auto arr = doc.isObject() ? Json::ensureArray(doc.object(), "data") : doc.array();
+
+    try {
+        // loadIndexedPackVersions(current, arr);
+    } catch (const JSONValidationError& e) {
+        qDebug() << doc;
+        qWarning() << "Error while reading " << debugName() << " mod version: " << e.cause();
+    }
+
+    // m_parent->updateModVersions();
+}
+
+}  // namespace Modrinth
+
+/******** Helpers ********/
diff --git a/launcher/ui/pages/modplatform/modrinth/ModrinthModel.h b/launcher/ui/pages/modplatform/modrinth/ModrinthModel.h
new file mode 100644
index 00000000..1fdbe278
--- /dev/null
+++ b/launcher/ui/pages/modplatform/modrinth/ModrinthModel.h
@@ -0,0 +1,81 @@
+#pragma once
+
+#include <QAbstractListModel>
+
+#include "modplatform/modrinth/ModrinthPackManifest.h"
+#include "ui/pages/modplatform/modrinth/ModrinthPage.h"
+
+class ModPage;
+class Version;
+
+namespace Modrinth {
+
+using LogoMap = QMap<QString, QIcon>;
+using LogoCallback = std::function<void (QString)>;
+
+class ModpackListModel : public QAbstractListModel {
+    Q_OBJECT
+
+   public:
+    ModpackListModel(ModrinthPage* parent);
+    ~ModpackListModel() override = default;
+
+    inline auto rowCount(const QModelIndex& parent) const -> int override { return modpacks.size(); };
+    inline auto columnCount(const QModelIndex& parent) const -> int override { return 1; };
+    inline auto flags(const QModelIndex& index) const -> Qt::ItemFlags override { return QAbstractListModel::flags(index); };
+
+    auto debugName() const -> QString;
+
+    /* Retrieve information from the model at a given index with the given role */
+    auto data(const QModelIndex& index, int role) const -> QVariant override;
+
+    inline void setActiveJob(NetJob::Ptr ptr) { jobPtr = ptr; }
+
+    /* Ask the API for more information */
+    void fetchMore(const QModelIndex& parent) override;
+    void refresh();
+    void searchWithTerm(const QString& term, const int sort);
+
+    void getLogo(const QString& logo, const QString& logoUrl, LogoCallback callback);
+
+    inline auto canFetchMore(const QModelIndex& parent) const -> bool override { return searchState == CanPossiblyFetchMore; };
+
+   public slots:
+    void searchRequestFinished(QJsonDocument& doc_all);
+    void searchRequestFailed(QString reason);
+
+    void versionRequestSucceeded(QJsonDocument doc, QString addonId);
+
+   protected slots:
+
+    void logoFailed(QString logo);
+    void logoLoaded(QString logo, QIcon out);
+
+    void performPaginatedSearch();
+
+   protected:
+    void requestLogo(QString file, QString url);
+
+    inline auto getMineVersions() const -> std::list<Version>;
+
+   protected:
+    ModrinthPage* m_parent;
+
+    QList<Modrinth::Modpack> modpacks;
+
+    LogoMap m_logoMap;
+    QMap<QString, LogoCallback> waitingCallbacks;
+    QStringList m_failedLogos;
+    QStringList m_loadingLogos;
+
+    QString currentSearchTerm;
+    int currentSort = 0;
+    int nextSearchOffset = 0;
+    enum SearchState { None, CanPossiblyFetchMore, ResetRequested, Finished } searchState = None;
+
+    NetJob::Ptr jobPtr;
+
+    QByteArray m_all_response;
+    QByteArray m_specific_response;
+};
+}  // namespace ModPlatform
diff --git a/launcher/ui/pages/modplatform/modrinth/ModrinthPage.cpp b/launcher/ui/pages/modplatform/modrinth/ModrinthPage.cpp
index 0d65ef16..68805316 100644
--- a/launcher/ui/pages/modplatform/modrinth/ModrinthPage.cpp
+++ b/launcher/ui/pages/modplatform/modrinth/ModrinthPage.cpp
@@ -34,14 +34,41 @@
  */
 
 #include "ModrinthPage.h"
-
 #include "ui_ModrinthPage.h"
 
+#include "ModrinthModel.h"
+
+#include "InstanceImportTask.h"
+#include "Json.h"
+
+#include <HoeDown.h>
+
+#include <QComboBox>
 #include <QKeyEvent>
+#include <QPushButton>
 
-ModrinthPage::ModrinthPage(NewInstanceDialog *dialog, QWidget *parent) : QWidget(parent), ui(new Ui::ModrinthPage), dialog(dialog)
+ModrinthPage::ModrinthPage(NewInstanceDialog* dialog, QWidget* parent) : QWidget(parent), ui(new Ui::ModrinthPage), dialog(dialog)
 {
     ui->setupUi(this);
+
+    connect(ui->searchButton, &QPushButton::clicked, this, &ModrinthPage::triggerSearch);
+    ui->searchEdit->installEventFilter(this);
+    m_model = new Modrinth::ModpackListModel(this);
+    ui->packView->setModel(m_model);
+
+    ui->versionSelectionBox->view()->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
+    ui->versionSelectionBox->view()->parentWidget()->setMaximumHeight(300);
+
+    ui->sortByBox->addItem(tr("Sort by Featured"));
+    ui->sortByBox->addItem(tr("Sort by Popularity"));
+    ui->sortByBox->addItem(tr("Sort by Last Updated"));
+    ui->sortByBox->addItem(tr("Sort by Name"));
+    ui->sortByBox->addItem(tr("Sort by Author"));
+    ui->sortByBox->addItem(tr("Sort by Total Downloads"));
+
+    connect(ui->sortByBox, SIGNAL(currentIndexChanged(int)), this, SLOT(triggerSearch()));
+    connect(ui->packView->selectionModel(), &QItemSelectionModel::currentChanged, this, &ModrinthPage::onSelectionChanged);
+    connect(ui->versionSelectionBox, &QComboBox::currentTextChanged, this, &ModrinthPage::onVersionSelectionChanged);
 }
 
 ModrinthPage::~ModrinthPage()
@@ -60,10 +87,10 @@ void ModrinthPage::openedImpl()
     triggerSearch();
 }
 
-bool ModrinthPage::eventFilter(QObject *watched, QEvent *event)
+bool ModrinthPage::eventFilter(QObject* watched, QEvent* event)
 {
     if (watched == ui->searchEdit && event->type() == QEvent::KeyPress) {
-        auto *keyEvent = reinterpret_cast<QKeyEvent *>(event);
+        auto* keyEvent = reinterpret_cast<QKeyEvent*>(event);
         if (keyEvent->key() == Qt::Key_Return) {
             this->triggerSearch();
             keyEvent->accept();
@@ -73,6 +100,176 @@ bool ModrinthPage::eventFilter(QObject *watched, QEvent *event)
     return QObject::eventFilter(watched, event);
 }
 
-void ModrinthPage::triggerSearch() {
+void ModrinthPage::onSelectionChanged(QModelIndex first, QModelIndex second)
+{
+    ui->versionSelectionBox->clear();
+
+    if (!first.isValid()) {
+        if (isOpened) {
+            dialog->setSuggestedPack();
+        }
+        return;
+    }
+
+    current = m_model->data(first, Qt::UserRole).value<Modrinth::Modpack>();
+    auto name = current.name;
+
+    if (!current.extraInfoLoaded) {
+        qDebug() << "Loading modrinth modpack information";
+
+        auto netJob = new NetJob(QString("Modrinth::PackInformation(%1)").arg(current.name), APPLICATION->network());
+        auto response = new QByteArray();
+
+        QString id = current.id;
 
+        netJob->addNetAction(Net::Download::makeByteArray(QString("https://staging-api.modrinth.com/v2/project/%1").arg(id), response));
+
+        QObject::connect(netJob, &NetJob::succeeded, this, [this, response, id] {
+            if (id != current.id) {
+                return;  // wrong request?
+            }
+
+            QJsonParseError parse_error;
+            QJsonDocument doc = QJsonDocument::fromJson(*response, &parse_error);
+            if (parse_error.error != QJsonParseError::NoError) {
+                qWarning() << "Error while parsing JSON response from Modrinth at " << parse_error.offset
+                           << " reason: " << parse_error.errorString();
+                qWarning() << *response;
+                return;
+            }
+
+            auto obj = Json::requireObject(doc);
+
+            try {
+                Modrinth::loadIndexedInfo(current, obj);
+            } catch (const JSONValidationError& e) {
+                qDebug() << *response;
+                qWarning() << "Error while reading modrinth modpack version: " << e.cause();
+            }
+
+            updateUI();
+            suggestCurrent();
+        });
+        QObject::connect(netJob, &NetJob::finished, this, [response, netJob] {
+            netJob->deleteLater();
+            delete response;
+        });
+        netJob->start();
+    } else
+        updateUI();
+
+    if (!current.versionsLoaded) {
+        qDebug() << "Loading modrinth modpack versions";
+
+        auto netJob = new NetJob(QString("Modrinth::PackVersions(%1)").arg(current.name), APPLICATION->network());
+        auto response = new QByteArray();
+
+        QString id = current.id;
+
+        netJob->addNetAction(
+            Net::Download::makeByteArray(QString("https://staging-api.modrinth.com/v2/project/%1/version").arg(id), response));
+
+        QObject::connect(netJob, &NetJob::succeeded, this, [this, response, id] {
+            if (id != current.id) {
+                return;  // wrong request?
+            }
+
+            QJsonParseError parse_error;
+            QJsonDocument doc = QJsonDocument::fromJson(*response, &parse_error);
+            if (parse_error.error != QJsonParseError::NoError) {
+                qWarning() << "Error while parsing JSON response from Modrinth at " << parse_error.offset
+                           << " reason: " << parse_error.errorString();
+                qWarning() << *response;
+                return;
+            }
+
+            try {
+                Modrinth::loadIndexedVersions(current, doc);
+            } catch (const JSONValidationError& e) {
+                qDebug() << *response;
+                qWarning() << "Error while reading modrinth modpack version: " << e.cause();
+            }
+
+            for (auto version : current.versions) {
+                ui->versionSelectionBox->addItem(version.version, QVariant(version.id));
+            }
+
+            updateVersionsUI();
+            suggestCurrent();
+        });
+        QObject::connect(netJob, &NetJob::finished, this, [response, netJob] {
+            netJob->deleteLater();
+            delete response;
+        });
+        netJob->start();
+
+    } else {
+        for (auto version : current.versions) {
+            ui->versionSelectionBox->addItem(QString("%1 - %2").arg(version.name, version.version), QVariant(version.id));
+        }
+
+        suggestCurrent();
+    }
+}
+
+void ModrinthPage::updateUI()
+{
+    QString text = "";
+
+    if (current.extra.sourceUrl.isEmpty())
+        text = current.name;
+    else
+        text = "<a href=\"" + current.extra.sourceUrl + "\">" + current.name + "</a>";
+
+    if (!current.authors.empty()) {
+        // TODO: Implement multiple authors with links
+        text += "<br>" + tr(" by ") + current.authors.at(0);
+    }
+
+    text += "<br>";
+
+    HoeDown h;
+    text += h.process(current.extra.body.toUtf8());
+
+    ui->packDescription->setHtml(text + current.description);
+}
+
+void ModrinthPage::updateVersionsUI()
+{
+    // idk
+}
+
+void ModrinthPage::suggestCurrent()
+{
+    if (!isOpened) {
+        return;
+    }
+
+    if (selectedVersion.isEmpty()) {
+        dialog->setSuggestedPack();
+        return;
+    }
+
+    for (auto& ver : current.versions) {
+        if (ver.id == selectedVersion) {
+            dialog->setSuggestedPack(current.name, new InstanceImportTask(ver.download_url));
+
+            break;
+        }
+    }
+}
+
+void ModrinthPage::triggerSearch()
+{
+    m_model->searchWithTerm(ui->searchEdit->text(), ui->sortByBox->currentIndex());
+}
+
+void ModrinthPage::onVersionSelectionChanged(QString data)
+{
+    if (data.isNull() || data.isEmpty()) {
+        selectedVersion = "";
+        return;
+    }
+    selectedVersion = ui->versionSelectionBox->currentData().toString();
+    suggestCurrent();
 }
diff --git a/launcher/ui/pages/modplatform/modrinth/ModrinthPage.h b/launcher/ui/pages/modplatform/modrinth/ModrinthPage.h
index 562049b4..f72a5071 100644
--- a/launcher/ui/pages/modplatform/modrinth/ModrinthPage.h
+++ b/launcher/ui/pages/modplatform/modrinth/ModrinthPage.h
@@ -39,48 +39,53 @@
 #include "ui/dialogs/NewInstanceDialog.h"
 #include "ui/pages/BasePage.h"
 
+#include "modplatform/modrinth/ModrinthPackManifest.h"
+
 #include <QWidget>
 
-namespace Ui
-{
-    class ModrinthPage;
+namespace Ui {
+class ModrinthPage;
+}
+
+namespace Modrinth {
+class ModpackListModel;
 }
 
-class ModrinthPage : public QWidget, public BasePage
-{
+class ModrinthPage : public QWidget, public BasePage {
     Q_OBJECT
 
-public:
-    explicit ModrinthPage(NewInstanceDialog *dialog, QWidget *parent = nullptr);
+   public:
+    explicit ModrinthPage(NewInstanceDialog* dialog, QWidget* parent = nullptr);
     ~ModrinthPage() override;
 
-    QString displayName() const override
-    {
-        return tr("Modrinth");
-    }
-    QIcon icon() const override
-    {
-        return APPLICATION->getThemedIcon("modrinth");
-    }
-    QString id() const override
-    {
-        return "modrinth";
-    }
-
-    virtual QString helpPage() const override
-    {
-        return "Modrinth-platform";
-    }
-    void retranslate() override;
+    QString displayName() const override { return tr("Modrinth"); }
+    QIcon icon() const override { return APPLICATION->getThemedIcon("modrinth"); }
+    QString id() const override { return "modrinth"; }
+    QString helpPage() const override { return "Modrinth-platform"; }
 
-    void openedImpl() override;
+    inline auto debugName() const -> QString { return "Modrinth"; }
+    inline auto metaEntryBase() const -> QString { return "ModrinthModpacks"; };
 
-    bool eventFilter(QObject *watched, QEvent *event) override;
+    auto getCurrent() -> Modrinth::Modpack& { return current; }
+    void suggestCurrent();
 
-private slots:
+    void updateUI();
+    void updateVersionsUI();
+
+    void retranslate() override;
+    void openedImpl() override;
+    bool eventFilter(QObject* watched, QEvent* event) override;
+
+   private slots:
+    void onSelectionChanged(QModelIndex first, QModelIndex second);
+    void onVersionSelectionChanged(QString data);
     void triggerSearch();
 
-private:
-    Ui::ModrinthPage *ui;
-    NewInstanceDialog *dialog;
+   private:
+    Ui::ModrinthPage* ui;
+    NewInstanceDialog* dialog;
+    Modrinth::ModpackListModel* m_model;
+
+    Modrinth::Modpack current;
+    QString selectedVersion;
 };