GH-469 Implement support for importing and searching for Technic Platform and Solder modpacks

This does not support any custom modpack.jar for 1.6 or newer, it simply uses standard Forge then.
Supports Forge and Fabric, and JAR mods for 1.5 and older.

6 files changed, 682 insertions, 0 deletions

diff --git a/api/logic/modplatform/technic/SingleZipPackInstallTask.cpp b/api/logic/modplatform/technic/SingleZipPackInstallTask.cpp
new file mode 100644
index 00000000..833ac0a2
--- /dev/null
+++ b/api/logic/modplatform/technic/SingleZipPackInstallTask.cpp
@@ -0,0 +1,129 @@
+/* Copyright 2013-2020 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.
+ */
+
+
+#include "SingleZipPackInstallTask.h"
+
+#include "Env.h"
+#include "MMCZip.h"
+#include "TechnicPackProcessor.h"
+
+#include <QtConcurrent>
+
+Technic::SingleZipPackInstallTask::SingleZipPackInstallTask(const QUrl &sourceUrl, const QString &minecraftVersion)
+{
+    m_sourceUrl = sourceUrl;
+    m_minecraftVersion = minecraftVersion;
+}
+
+void Technic::SingleZipPackInstallTask::executeTask()
+{
+    setStatus(tr("Downloading modpack:\n%1").arg(m_sourceUrl.toString()));
+
+    const QString path = m_sourceUrl.host() + '/' + m_sourceUrl.path();
+    auto entry = ENV.metacache()->resolveEntry("general", path);
+    entry->setStale(true);
+    m_filesNetJob.reset(new NetJob(tr("Modpack download")));
+    m_filesNetJob->addNetAction(Net::Download::makeCached(m_sourceUrl, entry));
+    m_archivePath = entry->getFullPath();
+    auto job = m_filesNetJob.get();
+    connect(job, &NetJob::succeeded, this, &Technic::SingleZipPackInstallTask::downloadSucceeded);
+    connect(job, &NetJob::progress, this, &Technic::SingleZipPackInstallTask::downloadProgressChanged);
+    connect(job, &NetJob::failed, this, &Technic::SingleZipPackInstallTask::downloadFailed);
+    m_filesNetJob->start();
+}
+
+void Technic::SingleZipPackInstallTask::downloadSucceeded()
+{
+    setStatus(tr("Extracting modpack"));
+    QDir extractDir(m_stagingPath);
+    qDebug() << "Attempting to create instance from" << m_archivePath;
+
+    // open the zip and find relevant files in it
+    m_packZip.reset(new QuaZip(m_archivePath));
+    if (!m_packZip->open(QuaZip::mdUnzip))
+    {
+        emitFailed(tr("Unable to open supplied modpack zip file."));
+        return;
+    }
+    m_extractFuture = QtConcurrent::run(QThreadPool::globalInstance(), MMCZip::extractSubDir, m_packZip.get(), QString(""), extractDir.absolutePath());
+    connect(&m_extractFutureWatcher, &QFutureWatcher<QStringList>::finished, this, &Technic::SingleZipPackInstallTask::extractFinished);
+    connect(&m_extractFutureWatcher, &QFutureWatcher<QStringList>::canceled, this, &Technic::SingleZipPackInstallTask::extractAborted);
+    m_extractFutureWatcher.setFuture(m_extractFuture);
+    m_filesNetJob.reset();
+}
+
+void Technic::SingleZipPackInstallTask::downloadFailed(QString reason)
+{
+    emitFailed(reason);
+    m_filesNetJob.reset();
+}
+
+void Technic::SingleZipPackInstallTask::downloadProgressChanged(qint64 current, qint64 total)
+{
+    setProgress(current / 2, total);
+}
+
+void Technic::SingleZipPackInstallTask::extractFinished()
+{
+    m_packZip.reset();
+    if (m_extractFuture.result().isEmpty())
+    {
+        emitFailed(tr("Failed to extract modpack"));
+        return;
+    }
+    QDir extractDir(m_stagingPath);
+
+    qDebug() << "Fixing permissions for extracted pack files...";
+    QDirIterator it(extractDir, QDirIterator::Subdirectories);
+    while (it.hasNext())
+    {
+        auto filepath = it.next();
+        QFileInfo file(filepath);
+        auto permissions = QFile::permissions(filepath);
+        auto origPermissions = permissions;
+        if (file.isDir())
+        {
+            // Folder +rwx for current user
+            permissions |= QFileDevice::Permission::ReadUser | QFileDevice::Permission::WriteUser | QFileDevice::Permission::ExeUser;
+        }
+        else
+        {
+            // File +rw for current user
+            permissions |= QFileDevice::Permission::ReadUser | QFileDevice::Permission::WriteUser;
+        }
+        if (origPermissions != permissions)
+        {
+            if (!QFile::setPermissions(filepath, permissions))
+            {
+                logWarning(tr("Could not fix permissions for %1").arg(filepath));
+            }
+            else
+            {
+                qDebug() << "Fixed" << filepath;
+            }
+        }
+    }
+
+    shared_qobject_ptr<Technic::TechnicPackProcessor> packProcessor = new Technic::TechnicPackProcessor();
+    connect(packProcessor.get(), &Technic::TechnicPackProcessor::succeeded, this, &Technic::SingleZipPackInstallTask::emitSucceeded);
+    connect(packProcessor.get(), &Technic::TechnicPackProcessor::failed, this, &Technic::SingleZipPackInstallTask::emitFailed);
+    packProcessor->run(m_globalSettings, m_instName, m_instIcon, m_stagingPath, m_minecraftVersion);
+}
+
+void Technic::SingleZipPackInstallTask::extractAborted()
+{
+    emitFailed(tr("Instance import has been aborted."));
+}
diff --git a/api/logic/modplatform/technic/SingleZipPackInstallTask.h b/api/logic/modplatform/technic/SingleZipPackInstallTask.h
new file mode 100644
index 00000000..929476bb
--- /dev/null
+++ b/api/logic/modplatform/technic/SingleZipPackInstallTask.h
@@ -0,0 +1,64 @@
+/* Copyright 2013-2020 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
+
+#ifndef TECHNIC_SINGLEZIPPACKINSTALLTASK_H
+#define TECHNIC_SINGLEZIPPACKINSTALLTASK_H
+
+#include "InstanceTask.h"
+#include "net/NetJob.h"
+#include "multimc_logic_export.h"
+
+#include "quazip.h"
+
+#include <QFutureWatcher>
+#include <QStringList>
+#include <QUrl>
+
+namespace Technic {
+
+class MULTIMC_LOGIC_EXPORT SingleZipPackInstallTask : public InstanceTask
+{
+    Q_OBJECT
+
+public:
+    SingleZipPackInstallTask(const QUrl &sourceUrl, const QString &minecraftVersion);
+
+protected:
+    void executeTask() override;
+
+
+private slots:
+    void downloadSucceeded();
+    void downloadFailed(QString reason);
+    void downloadProgressChanged(qint64 current, qint64 total);
+    void extractFinished();
+    void extractAborted();
+
+private:
+    QUrl m_sourceUrl;
+    QString m_minecraftVersion;
+    QString m_archivePath;
+    NetJobPtr m_filesNetJob;
+    std::unique_ptr<QuaZip> m_packZip;
+    QFuture<QStringList> m_extractFuture;
+    QFutureWatcher<QStringList> m_extractFutureWatcher;
+};
+
+} // namespace Technic
+
+#endif // TECHNIC_SINGLEZIPPACKINSTALLTASK_H
diff --git a/api/logic/modplatform/technic/SolderPackInstallTask.cpp b/api/logic/modplatform/technic/SolderPackInstallTask.cpp
new file mode 100644
index 00000000..cb440e84
--- /dev/null
+++ b/api/logic/modplatform/technic/SolderPackInstallTask.cpp
@@ -0,0 +1,194 @@
+/* Copyright 2013-2020 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.
+ */
+
+
+#include "SolderPackInstallTask.h"
+
+#include <FileSystem.h>
+#include <Json.h>
+#include <QtConcurrentRun>
+#include <MMCZip.h>
+#include "TechnicPackProcessor.h"
+
+Technic::SolderPackInstallTask::SolderPackInstallTask(const QUrl &sourceUrl, const QString &minecraftVersion)
+{
+    m_sourceUrl = sourceUrl;
+    m_minecraftVersion = minecraftVersion;
+}
+
+void Technic::SolderPackInstallTask::executeTask()
+{
+    setStatus(tr("Finding recommended version:\n%1").arg(m_sourceUrl.toString()));
+    m_filesNetJob.reset(new NetJob(tr("Finding recommended version")));
+    m_filesNetJob->addNetAction(Net::Download::makeByteArray(m_sourceUrl, &m_response));
+    auto job = m_filesNetJob.get();
+    connect(job, &NetJob::succeeded, this, &Technic::SolderPackInstallTask::versionSucceeded);
+    connect(job, &NetJob::failed, this, &Technic::SolderPackInstallTask::downloadFailed);
+    m_filesNetJob->start();
+}
+
+void Technic::SolderPackInstallTask::versionSucceeded()
+{
+    try
+    {
+        QJsonDocument doc = Json::requireDocument(m_response);
+        QJsonObject obj = Json::requireObject(doc);
+        QString version = Json::requireString(obj, "recommended", "__placeholder__");
+        m_sourceUrl = m_sourceUrl.toString() + '/' + version;
+    }
+    catch (const JSONValidationError &e)
+    {
+        emitFailed(e.cause());
+        m_filesNetJob.reset();
+        return;
+    }
+
+    setStatus(tr("Resolving modpack files:\n%1").arg(m_sourceUrl.toString()));
+    m_filesNetJob.reset(new NetJob(tr("Resolving modpack files")));
+    m_filesNetJob->addNetAction(Net::Download::makeByteArray(m_sourceUrl, &m_response));
+    auto job = m_filesNetJob.get();
+    connect(job, &NetJob::succeeded, this, &Technic::SolderPackInstallTask::fileListSucceeded);
+    connect(job, &NetJob::failed, this, &Technic::SolderPackInstallTask::downloadFailed);
+    m_filesNetJob->start();
+}
+
+void Technic::SolderPackInstallTask::fileListSucceeded()
+{
+    setStatus(tr("Downloading modpack:"));
+    QStringList modUrls;
+    try
+    {
+        QJsonDocument doc = Json::requireDocument(m_response);
+        QJsonObject obj = Json::requireObject(doc);
+        QString minecraftVersion = Json::ensureString(obj, "minecraft", QString(), "__placeholder__");
+        if (!minecraftVersion.isEmpty())
+            m_minecraftVersion = minecraftVersion;
+        QJsonArray mods = Json::requireArray(obj, "mods", "'mods'");
+        for (auto mod: mods)
+        {
+            QJsonObject modObject = Json::requireObject(mod);
+            modUrls.append(Json::requireString(modObject, "url", "'url'"));
+        }
+    }
+    catch (const JSONValidationError &e)
+    {
+        emitFailed(e.cause());
+        m_filesNetJob.reset();
+        return;
+    }
+    m_filesNetJob.reset(new NetJob(tr("Downloading modpack")));
+    int i = 0;
+    for (auto &modUrl: modUrls)
+    {
+        m_filesNetJob->addNetAction(Net::Download::makeFile(modUrl, m_outputDir.filePath(QString("%1").arg(i))));
+        i++;
+    }
+
+    m_modCount = modUrls.size();
+
+    connect(m_filesNetJob.get(), &NetJob::succeeded, this, &Technic::SolderPackInstallTask::downloadSucceeded);
+    connect(m_filesNetJob.get(), &NetJob::progress, this, &Technic::SolderPackInstallTask::downloadProgressChanged);
+    connect(m_filesNetJob.get(), &NetJob::failed, this, &Technic::SolderPackInstallTask::downloadFailed);
+    m_filesNetJob->start();
+}
+
+void Technic::SolderPackInstallTask::downloadSucceeded()
+{
+    setStatus(tr("Extracting modpack"));
+    m_filesNetJob.reset();
+    m_extractFuture = QtConcurrent::run([this]()
+    {
+        int i = 0;
+        QString extractDir = FS::PathCombine(m_stagingPath, ".minecraft");
+        FS::ensureFolderPathExists(extractDir);
+
+        while (m_modCount > i)
+        {
+            if (MMCZip::extractDir(m_outputDir.filePath(QString("%1").arg(i)), extractDir).isEmpty())
+            {
+                return false;
+            }
+            i++;
+        }
+        return true;
+    });
+    connect(&m_extractFutureWatcher, &QFutureWatcher<QStringList>::finished, this, &Technic::SolderPackInstallTask::extractFinished);
+    connect(&m_extractFutureWatcher, &QFutureWatcher<QStringList>::canceled, this, &Technic::SolderPackInstallTask::extractAborted);
+    m_extractFutureWatcher.setFuture(m_extractFuture);
+}
+
+void Technic::SolderPackInstallTask::downloadFailed(QString reason)
+{
+    emitFailed(reason);
+    m_filesNetJob.reset();
+}
+
+void Technic::SolderPackInstallTask::downloadProgressChanged(qint64 current, qint64 total)
+{
+    setProgress(current / 2, total);
+}
+
+void Technic::SolderPackInstallTask::extractFinished()
+{
+    if (!m_extractFuture.result())
+    {
+        emitFailed(tr("Failed to extract modpack"));
+        return;
+    }
+    QDir extractDir(m_stagingPath);
+
+    qDebug() << "Fixing permissions for extracted pack files...";
+    QDirIterator it(extractDir, QDirIterator::Subdirectories);
+    while (it.hasNext())
+    {
+        auto filepath = it.next();
+        QFileInfo file(filepath);
+        auto permissions = QFile::permissions(filepath);
+        auto origPermissions = permissions;
+        if(file.isDir())
+        {
+            // Folder +rwx for current user
+            permissions |= QFileDevice::Permission::ReadUser | QFileDevice::Permission::WriteUser | QFileDevice::Permission::ExeUser;
+        }
+        else
+        {
+            // File +rw for current user
+            permissions |= QFileDevice::Permission::ReadUser | QFileDevice::Permission::WriteUser;
+        }
+        if(origPermissions != permissions)
+        {
+            if(!QFile::setPermissions(filepath, permissions))
+            {
+                logWarning(tr("Could not fix permissions for %1").arg(filepath));
+            }
+            else
+            {
+                qDebug() << "Fixed" << filepath;
+            }
+        }
+    }
+
+    shared_qobject_ptr<Technic::TechnicPackProcessor> packProcessor = new Technic::TechnicPackProcessor();
+    connect(packProcessor.get(), &Technic::TechnicPackProcessor::succeeded, this, &Technic::SolderPackInstallTask::emitSucceeded);
+    connect(packProcessor.get(), &Technic::TechnicPackProcessor::failed, this, &Technic::SolderPackInstallTask::emitFailed);
+    packProcessor->run(m_globalSettings, m_instName, m_instIcon, m_stagingPath, m_minecraftVersion, true); // TODO: pass the minecraft version down
+}
+
+void Technic::SolderPackInstallTask::extractAborted()
+{
+    emitFailed(tr("Instance import has been aborted."));
+    return;
+}
+
diff --git a/api/logic/modplatform/technic/SolderPackInstallTask.h b/api/logic/modplatform/technic/SolderPackInstallTask.h
new file mode 100644
index 00000000..d3a1d0fd
--- /dev/null
+++ b/api/logic/modplatform/technic/SolderPackInstallTask.h
@@ -0,0 +1,57 @@
+/* Copyright 2013-2020 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 <InstanceTask.h>
+#include <net/NetJob.h>
+#include <tasks/Task.h>
+
+#include <QUrl>
+
+
+namespace Technic
+{
+    class MULTIMC_LOGIC_EXPORT SolderPackInstallTask : public InstanceTask
+    {
+        Q_OBJECT
+    public:
+        explicit SolderPackInstallTask(const QUrl &sourceUrl, const QString &minecraftVersion);
+
+    protected:
+        //! Entry point for tasks.
+        virtual void executeTask() override;
+
+    private slots:
+        void versionSucceeded();
+        void fileListSucceeded();
+        void downloadSucceeded();
+        void downloadFailed(QString reason);
+        void downloadProgressChanged(qint64 current, qint64 total);
+        void extractFinished();
+        void extractAborted();
+
+    private:
+        NetJobPtr m_filesNetJob;
+        QUrl m_sourceUrl;
+        QString m_minecraftVersion;
+        QByteArray m_response;
+        QTemporaryDir m_outputDir;
+        int m_modCount;
+        QFuture<bool> m_extractFuture;
+        QFutureWatcher<bool> m_extractFutureWatcher;
+    };
+}
diff --git a/api/logic/modplatform/technic/TechnicPackProcessor.cpp b/api/logic/modplatform/technic/TechnicPackProcessor.cpp
new file mode 100644
index 00000000..f986a529
--- /dev/null
+++ b/api/logic/modplatform/technic/TechnicPackProcessor.cpp
@@ -0,0 +1,201 @@
+/* Copyright 2020 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.
+ */
+
+
+#include "TechnicPackProcessor.h"
+
+#include <FileSystem.h>
+#include <Json.h>
+#include <minecraft/MinecraftInstance.h>
+#include <minecraft/PackProfile.h>
+#include <quazip.h>
+#include <quazipdir.h>
+#include <quazipfile.h>
+#include <settings/INISettingsObject.h>
+
+#include <memory>
+
+
+void Technic::TechnicPackProcessor::run(SettingsObjectPtr globalSettings, const QString &instName, const QString &instIcon, const QString &stagingPath, const QString &minecraftVersion, const bool isSolder)
+{
+    QString minecraftPath = FS::PathCombine(stagingPath, ".minecraft");
+    QString configPath = FS::PathCombine(stagingPath, "instance.cfg");
+    auto instanceSettings = std::make_shared<INISettingsObject>(configPath);
+    instanceSettings->registerSetting("InstanceType", "Legacy");
+    instanceSettings->set("InstanceType", "OneSix");
+    MinecraftInstance instance(globalSettings, instanceSettings, stagingPath);
+
+    instance.setName(instName);
+
+    if (instIcon != "default")
+    {
+        instance.setIconKey(instIcon);
+    }
+
+    auto components = instance.getPackProfile();
+    components->buildingFromScratch();
+
+    QByteArray data;
+
+    QString modpackJar = FS::PathCombine(minecraftPath, "bin", "modpack.jar");
+    QString versionJson = FS::PathCombine(minecraftPath, "bin", "version.json");
+    QString fmlMinecraftVersion;
+    if (QFile::exists(modpackJar))
+    {
+        QuaZip zipFile(modpackJar);
+        if (!zipFile.open(QuaZip::mdUnzip))
+        {
+            emit failed(tr("Unable to open \"bin/modpack.jar\" file!"));
+            return;
+        }
+        QuaZipDir zipFileRoot(&zipFile, "/");
+        if (zipFileRoot.exists("/version.json"))
+        {
+            if (zipFileRoot.exists("/fmlversion.properties"))
+            {
+                zipFile.setCurrentFile("fmlversion.properties");
+                QuaZipFile file(&zipFile);
+                if (!file.open(QIODevice::ReadOnly))
+                {
+                    emit failed(tr("Unable to open \"fmlversion.properties\"!"));
+                    return;
+                }
+                QByteArray fmlVersionData = file.readAll();
+                file.close();
+                INIFile iniFile;
+                iniFile.loadFile(fmlVersionData);
+                // If not present, this evaluates to a null string
+                fmlMinecraftVersion = iniFile["fmlbuild.mcversion"].toString();
+            }
+            zipFile.setCurrentFile("version.json", QuaZip::csSensitive);
+            QuaZipFile file(&zipFile);
+            if (!file.open(QIODevice::ReadOnly))
+            {
+                emit failed(tr("Unable to open \"version.json\"!"));
+                return;
+            }
+            data = file.readAll();
+            file.close();
+        }
+        else
+        {
+            if (minecraftVersion.isEmpty())
+                emit failed(tr("Could not find \"version.json\" inside \"bin/modpack.jar\", but minecraft version is unknown"));
+            components->setComponentVersion("net.minecraft", minecraftVersion, true);
+            components->installJarMods({modpackJar});
+
+            // Forge for 1.4.7 and for 1.5.2 require extra libraries.
+            // Figure out the forge version and add it as a component
+            // (the code still comes from the jar mod installed above)
+            if (zipFileRoot.exists("/forgeversion.properties"))
+            {
+                zipFile.setCurrentFile("forgeversion.properties", QuaZip::csSensitive);
+                QuaZipFile file(&zipFile);
+                if (!file.open(QIODevice::ReadOnly))
+                {
+                    // Really shouldn't happen, but error handling shall not be forgotten
+                    emit failed(tr("Unable to open \"forgeversion.properties\""));
+                    return;
+                }
+                QByteArray forgeVersionData = file.readAll();
+                file.close();
+                INIFile iniFile;
+                iniFile.loadFile(forgeVersionData);
+                QString major, minor, revision, build;
+                major = iniFile["forge.major.number"].toString();
+                minor = iniFile["forge.minor.number"].toString();
+                revision = iniFile["forge.revision.number"].toString();
+                build = iniFile["forge.build.number"].toString();
+
+                if (major.isEmpty() || minor.isEmpty() || revision.isEmpty() || build.isEmpty())
+                {
+                    emit failed(tr("Invalid \"forgeversion.properties\"!"));
+                    return;
+                }
+
+                components->setComponentVersion("net.minecraftforge", major + '.' + minor + '.' + revision + '.' + build);
+            }
+
+            components->saveNow();
+            emit succeeded();
+            return;
+        }
+    }
+    else if (QFile::exists(versionJson))
+    {
+        QFile file(versionJson);
+        if (!file.open(QIODevice::ReadOnly))
+        {
+            emit failed(tr("Unable to open \"version.json\"!"));
+            return;
+        }
+        data = file.readAll();
+        file.close();
+    }
+    else
+    {
+        // This is the "Vanilla" modpack, excluded by the search code
+        emit failed(tr("Unable to find a \"version.json\"!"));
+        return;
+    }
+
+    try
+    {
+        QJsonDocument doc = Json::requireDocument(data);
+        QJsonObject root = Json::requireObject(doc, "version.json");
+        QString minecraftVersion = Json::ensureString(root, "inheritsFrom", QString(), "");
+        if (minecraftVersion.isEmpty())
+        {
+            if (fmlMinecraftVersion.isEmpty())
+            {
+                emit failed(tr("Could not understand \"version.json\":\ninheritsFrom is missing"));
+                return;
+            }
+            minecraftVersion = fmlMinecraftVersion;
+        }
+        components->setComponentVersion("net.minecraft", minecraftVersion, true);
+        for (auto library: Json::ensureArray(root, "libraries", {}))
+        {
+            if (!library.isObject())
+            {
+                continue;
+            }
+
+            auto libraryObject = Json::ensureObject(library, {}, "");
+            auto libraryName = Json::ensureString(libraryObject, "name", "", "");
+
+            if (libraryName.startsWith("net.minecraftforge:forge:") && libraryName.contains('-'))
+            {
+                components->setComponentVersion("net.minecraftforge", libraryName.section('-', 1));
+            }
+            else if (libraryName.startsWith("net.minecraftforge:minecraftforge:"))
+            {
+                components->setComponentVersion("net.minecraftforge", libraryName.section(':', 2));
+            }
+            else if (libraryName.startsWith("net.fabricmc:fabric-loader:"))
+            {
+                components->setComponentVersion("net.fabricmc.fabric-loader", libraryName.section(':', 2));
+            }
+        }
+    }
+    catch (const JSONValidationError &e)
+    {
+        emit failed(tr("Could not understand \"version.json\":\n") + e.cause());
+        return;
+    }
+
+    components->saveNow();
+    emit succeeded();
+}
diff --git a/api/logic/modplatform/technic/TechnicPackProcessor.h b/api/logic/modplatform/technic/TechnicPackProcessor.h
new file mode 100644
index 00000000..49d046a5
--- /dev/null
+++ b/api/logic/modplatform/technic/TechnicPackProcessor.h
@@ -0,0 +1,37 @@
+/* Copyright 2020 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 "settings/SettingsObject.h"
+
+
+namespace Technic
+{
+    // not exporting it, only used in SingleZipPackInstallTask, InstanceImportTask and SolderPackInstallTask
+    class TechnicPackProcessor : public QObject
+    {
+        Q_OBJECT
+
+    signals:
+        void succeeded();
+        void failed(QString reason);
+
+    public:
+        void run(SettingsObjectPtr globalSettings, const QString &instName, const QString &instIcon, const QString &stagingPath, const QString &minecraftVersion=QString(), const bool isSolder = false);
+    };
+}