NOISSUE Wonko is the new Meta

And then Wonko was the Meta.

api/logic/meta/BaseEntity.cpp

@@ -0,0 +1,42 @@
+/* Copyright 2015-2017 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 "BaseEntity.h"
+
+#include "Json.h"
+#include "Util.h"
+
+namespace Meta
+{
+BaseEntity::~BaseEntity()
+{
+}
+
+void BaseEntity::store() const
+{
+	Json::write(serialized(), Meta::localDir().absoluteFilePath(localFilename()));
+}
+
+void BaseEntity::notifyLocalLoadComplete()
+{
+	m_localLoaded = true;
+	store();
+}
+void BaseEntity::notifyRemoteLoadComplete()
+{
+	m_remoteLoaded = true;
+	store();
+}
+}

api/logic/meta/BaseEntity.h

@@ -0,0 +1,53 @@
+/* Copyright 2015-2017 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 <QObject>
+#include <memory>
+
+#include "multimc_logic_export.h"
+
+class Task;
+namespace Meta
+{
+class MULTIMC_LOGIC_EXPORT BaseEntity
+{
+public:
+	virtual ~BaseEntity();
+
+	using Ptr = std::shared_ptr<BaseEntity>;
+
+	virtual std::unique_ptr<Task> remoteUpdateTask() = 0;
+	virtual std::unique_ptr<Task> localUpdateTask() = 0;
+	virtual void merge(const std::shared_ptr<BaseEntity> &other) = 0;
+
+	void store() const;
+	virtual QString localFilename() const = 0;
+	virtual QJsonObject serialized() const = 0;
+
+	bool isComplete() const { return m_localLoaded || m_remoteLoaded; }
+
+	bool isLocalLoaded() const { return m_localLoaded; }
+	bool isRemoteLoaded() const { return m_remoteLoaded; }
+
+	void notifyLocalLoadComplete();
+	void notifyRemoteLoadComplete();
+
+private:
+	bool m_localLoaded = false;
+	bool m_remoteLoaded = false;
+};
+}

api/logic/meta/Index.cpp

@@ -0,0 +1,150 @@
+/* Copyright 2015-2017 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 "Index.h"
+
+#include "VersionList.h"
+#include "tasks/LocalLoadTask.h"
+#include "tasks/RemoteLoadTask.h"
+#include "format/Format.h"
+
+namespace Meta
+{
+Index::Index(QObject *parent)
+	: QAbstractListModel(parent)
+{
+}
+Index::Index(const QVector<VersionListPtr> &lists, QObject *parent)
+	: QAbstractListModel(parent), m_lists(lists)
+{
+	for (int i = 0; i < m_lists.size(); ++i)
+	{
+		m_uids.insert(m_lists.at(i)->uid(), m_lists.at(i));
+		connectVersionList(i, m_lists.at(i));
+	}
+}
+
+QVariant Index::data(const QModelIndex &index, int role) const
+{
+	if (index.parent().isValid() || index.row() < 0 || index.row() >= m_lists.size())
+	{
+		return QVariant();
+	}
+
+	VersionListPtr list = m_lists.at(index.row());
+	switch (role)
+	{
+	case Qt::DisplayRole:
+		switch (index.column())
+		{
+		case 0: return list->humanReadable();
+		default: break;
+		}
+	case UidRole: return list->uid();
+	case NameRole: return list->name();
+	case ListPtrRole: return QVariant::fromValue(list);
+	}
+	return QVariant();
+}
+int Index::rowCount(const QModelIndex &parent) const
+{
+	return m_lists.size();
+}
+int Index::columnCount(const QModelIndex &parent) const
+{
+	return 1;
+}
+QVariant Index::headerData(int section, Qt::Orientation orientation, int role) const
+{
+	if (orientation == Qt::Horizontal && role == Qt::DisplayRole && section == 0)
+	{
+		return tr("Name");
+	}
+	else
+	{
+		return QVariant();
+	}
+}
+
+std::unique_ptr<Task> Index::remoteUpdateTask()
+{
+	return std::unique_ptr<IndexRemoteLoadTask>(new IndexRemoteLoadTask(this, this));
+}
+std::unique_ptr<Task> Index::localUpdateTask()
+{
+	return std::unique_ptr<IndexLocalLoadTask>(new IndexLocalLoadTask(this, this));
+}
+
+QJsonObject Index::serialized() const
+{
+	return Format::serializeIndex(this);
+}
+
+bool Index::hasUid(const QString &uid) const
+{
+	return m_uids.contains(uid);
+}
+VersionListPtr Index::getList(const QString &uid) const
+{
+	return m_uids.value(uid, nullptr);
+}
+VersionListPtr Index::getListGuaranteed(const QString &uid) const
+{
+	return m_uids.value(uid, std::make_shared<VersionList>(uid));
+}
+
+void Index::merge(const Ptr &other)
+{
+	const QVector<VersionListPtr> lists = std::dynamic_pointer_cast<Index>(other)->m_lists;
+	// initial load, no need to merge
+	if (m_lists.isEmpty())
+	{
+		beginResetModel();
+		m_lists = lists;
+		for (int i = 0; i < lists.size(); ++i)
+		{
+			m_uids.insert(lists.at(i)->uid(), lists.at(i));
+			connectVersionList(i, lists.at(i));
+		}
+		endResetModel();
+	}
+	else
+	{
+		for (const VersionListPtr &list : lists)
+		{
+			if (m_uids.contains(list->uid()))
+			{
+				m_uids[list->uid()]->merge(list);
+			}
+			else
+			{
+				beginInsertRows(QModelIndex(), m_lists.size(), m_lists.size());
+				connectVersionList(m_lists.size(), list);
+				m_lists.append(list);
+				m_uids.insert(list->uid(), list);
+				endInsertRows();
+			}
+		}
+	}
+}
+
+void Index::connectVersionList(const int row, const VersionListPtr &list)
+{
+	connect(list.get(), &VersionList::nameChanged, this, [this, row]()
+	{
+		emit dataChanged(index(row), index(row), QVector<int>() << Qt::DisplayRole);
+	});
+}
+}

api/logic/meta/Index.h

@@ -0,0 +1,72 @@
+/* Copyright 2015-2017 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 <QAbstractListModel>
+#include <memory>
+
+#include "BaseEntity.h"
+
+#include "multimc_logic_export.h"
+
+class Task;
+
+namespace Meta
+{
+using VersionListPtr = std::shared_ptr<class VersionList>;
+
+class MULTIMC_LOGIC_EXPORT Index : public QAbstractListModel, public BaseEntity
+{
+	Q_OBJECT
+public:
+	explicit Index(QObject *parent = nullptr);
+	explicit Index(const QVector<VersionListPtr> &lists, QObject *parent = nullptr);
+
+	enum
+	{
+		UidRole = Qt::UserRole,
+		NameRole,
+		ListPtrRole
+	};
+
+	QVariant data(const QModelIndex &index, int role) const override;
+	int rowCount(const QModelIndex &parent) const override;
+	int columnCount(const QModelIndex &parent) const override;
+	QVariant headerData(int section, Qt::Orientation orientation, int role) const override;
+
+	std::unique_ptr<Task> remoteUpdateTask() override;
+	std::unique_ptr<Task> localUpdateTask() override;
+
+	QString localFilename() const override { return "index.json"; }
+	QJsonObject serialized() const override;
+
+	// queries
+	bool hasUid(const QString &uid) const;
+	VersionListPtr getList(const QString &uid) const;
+	VersionListPtr getListGuaranteed(const QString &uid) const;
+
+	QVector<VersionListPtr> lists() const { return m_lists; }
+
+public: // for usage by parsers only
+	void merge(const BaseEntity::Ptr &other) override;
+
+private:
+	QVector<VersionListPtr> m_lists;
+	QHash<QString, VersionListPtr> m_uids;
+
+	void connectVersionList(const int row, const VersionListPtr &list);
+};
+}

api/logic/meta/Index_test.cpp

@@ -0,0 +1,50 @@
+#include <QTest>
+#include "TestUtil.h"
+
+#include "meta/Index.h"
+#include "meta/VersionList.h"
+#include "Env.h"
+
+class IndexTest : public QObject
+{
+	Q_OBJECT
+private
+slots:
+	void test_isProvidedByEnv()
+	{
+		QVERIFY(ENV.metadataIndex());
+		QCOMPARE(ENV.metadataIndex(), ENV.metadataIndex());
+	}
+
+	void test_providesTasks()
+	{
+		QVERIFY(ENV.metadataIndex()->localUpdateTask() != nullptr);
+		QVERIFY(ENV.metadataIndex()->remoteUpdateTask() != nullptr);
+	}
+
+	void test_hasUid_and_getList()
+	{
+		Meta::Index windex({std::make_shared<Meta::VersionList>("list1"), std::make_shared<Meta::VersionList>("list2"), std::make_shared<Meta::VersionList>("list3")});
+		QVERIFY(windex.hasUid("list1"));
+		QVERIFY(!windex.hasUid("asdf"));
+		QVERIFY(windex.getList("list2") != nullptr);
+		QCOMPARE(windex.getList("list2")->uid(), QString("list2"));
+		QVERIFY(windex.getList("adsf") == nullptr);
+	}
+
+	void test_merge()
+	{
+		Meta::Index windex({std::make_shared<Meta::VersionList>("list1"), std::make_shared<Meta::VersionList>("list2"), std::make_shared<Meta::VersionList>("list3")});
+		QCOMPARE(windex.lists().size(), 3);
+		windex.merge(std::shared_ptr<Meta::Index>(new Meta::Index({std::make_shared<Meta::VersionList>("list1"), std::make_shared<Meta::VersionList>("list2"), std::make_shared<Meta::VersionList>("list3")})));
+		QCOMPARE(windex.lists().size(), 3);
+		windex.merge(std::shared_ptr<Meta::Index>(new Meta::Index({std::make_shared<Meta::VersionList>("list4"), std::make_shared<Meta::VersionList>("list2"), std::make_shared<Meta::VersionList>("list5")})));
+		QCOMPARE(windex.lists().size(), 5);
+		windex.merge(std::shared_ptr<Meta::Index>(new Meta::Index({std::make_shared<Meta::VersionList>("list6")})));
+		QCOMPARE(windex.lists().size(), 6);
+	}
+};
+
+QTEST_GUILESS_MAIN(IndexTest)
+
+#include "Index_test.moc"

api/logic/meta/Reference.cpp

@@ -0,0 +1,48 @@
+/* Copyright 2015-2017 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 "Reference.h"
+
+namespace Meta
+{
+Reference::Reference(const QString &uid)
+	: m_uid(uid)
+{
+}
+
+QString Reference::uid() const
+{
+	return m_uid;
+}
+
+QString Reference::version() const
+{
+	return m_version;
+}
+void Reference::setVersion(const QString &version)
+{
+	m_version = version;
+}
+
+bool Reference::operator==(const Reference &other) const
+{
+	return m_uid == other.m_uid && m_version == other.m_version;
+}
+
+bool Reference::operator!=(const Reference &other) const
+{
+	return m_uid != other.m_uid || m_version != other.m_version;
+}
+}

api/logic/meta/Reference.h

@@ -0,0 +1,44 @@
+/* Copyright 2015-2017 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 <QMetaType>
+
+#include "multimc_logic_export.h"
+
+namespace Meta
+{
+class MULTIMC_LOGIC_EXPORT Reference
+{
+public:
+	Reference() {}
+	explicit Reference(const QString &uid);
+
+	QString uid() const;
+
+	QString version() const;
+	void setVersion(const QString &version);
+
+	bool operator==(const Reference &other) const;
+	bool operator!=(const Reference &other) const;
+
+private:
+	QString m_uid;
+	QString m_version;
+};
+}
+Q_DECLARE_METATYPE(Meta::Reference)

api/logic/meta/Util.cpp

@@ -0,0 +1,50 @@
+/* Copyright 2015-2017 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 "Util.h"
+
+#include <QUrl>
+#include <QDir>
+
+#include "Env.h"
+
+namespace Meta
+{
+QUrl rootUrl()
+{
+	return QUrl("https://meta.multimc.org");
+}
+
+QUrl indexUrl()
+{
+	return rootUrl().resolved(QStringLiteral("index.json"));
+}
+
+QUrl versionListUrl(const QString &uid)
+{
+	return rootUrl().resolved(uid + ".json");
+}
+
+QUrl versionUrl(const QString &uid, const QString &version)
+{
+	return rootUrl().resolved(uid + "/" + version + ".json");
+}
+
+QDir localDir()
+{
+	return QDir("meta");
+}
+
+}

api/logic/meta/Util.h

@@ -0,0 +1,31 @@
+/* Copyright 2015-2017 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 "multimc_logic_export.h"
+
+class QUrl;
+class QString;
+class QDir;
+
+namespace Meta
+{
+MULTIMC_LOGIC_EXPORT QUrl rootUrl();
+MULTIMC_LOGIC_EXPORT QUrl indexUrl();
+MULTIMC_LOGIC_EXPORT QUrl versionListUrl(const QString &uid);
+MULTIMC_LOGIC_EXPORT QUrl versionUrl(const QString &uid, const QString &version);
+MULTIMC_LOGIC_EXPORT QDir localDir();
+}

api/logic/meta/Version.cpp

@@ -0,0 +1,105 @@
+/* Copyright 2015-2017 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 "Version.h"
+
+#include <QDateTime>
+
+#include "tasks/LocalLoadTask.h"
+#include "tasks/RemoteLoadTask.h"
+#include "format/Format.h"
+
+namespace Meta
+{
+Version::Version(const QString &uid, const QString &version)
+	: BaseVersion(), m_uid(uid), m_version(version)
+{
+}
+
+QString Version::descriptor()
+{
+	return m_version;
+}
+QString Version::name()
+{
+	return m_version;
+}
+QString Version::typeString() const
+{
+	return m_type;
+}
+
+QDateTime Version::time() const
+{
+	return QDateTime::fromMSecsSinceEpoch(m_time * 1000, Qt::UTC);
+}
+
+std::unique_ptr<Task> Version::remoteUpdateTask()
+{
+	return std::unique_ptr<VersionRemoteLoadTask>(new VersionRemoteLoadTask(this, this));
+}
+std::unique_ptr<Task> Version::localUpdateTask()
+{
+	return std::unique_ptr<VersionLocalLoadTask>(new VersionLocalLoadTask(this, this));
+}
+
+void Version::merge(const std::shared_ptr<BaseEntity> &other)
+{
+	VersionPtr version = std::dynamic_pointer_cast<Version>(other);
+	if (m_type != version->m_type)
+	{
+		setType(version->m_type);
+	}
+	if (m_time != version->m_time)
+	{
+		setTime(version->m_time);
+	}
+	if (m_requires != version->m_requires)
+	{
+		setRequires(version->m_requires);
+	}
+
+	setData(version->m_data);
+}
+
+QString Version::localFilename() const
+{
+	return m_uid + '/' + m_version + ".json";
+}
+QJsonObject Version::serialized() const
+{
+	return Format::serializeVersion(this);
+}
+
+void Version::setType(const QString &type)
+{
+	m_type = type;
+	emit typeChanged();
+}
+void Version::setTime(const qint64 time)
+{
+	m_time = time;
+	emit timeChanged();
+}
+void Version::setRequires(const QVector<Reference> &requires)
+{
+	m_requires = requires;
+	emit requiresChanged();
+}
+void Version::setData(const VersionFilePtr &data)
+{
+	m_data = data;
+}
+}

api/logic/meta/Version.h

@@ -0,0 +1,87 @@
+/* Copyright 2015-2017 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 "BaseVersion.h"
+
+#include <QVector>
+#include <QStringList>
+#include <QJsonObject>
+#include <memory>
+
+#include "minecraft/VersionFile.h"
+
+#include "BaseEntity.h"
+#include "Reference.h"
+
+#include "multimc_logic_export.h"
+
+namespace Meta
+{
+using VersionPtr = std::shared_ptr<class Version>;
+
+class MULTIMC_LOGIC_EXPORT Version : public QObject, public BaseVersion, public BaseEntity
+{
+	Q_OBJECT
+	Q_PROPERTY(QString uid READ uid CONSTANT)
+	Q_PROPERTY(QString version READ version CONSTANT)
+	Q_PROPERTY(QString type READ type NOTIFY typeChanged)
+	Q_PROPERTY(QDateTime time READ time NOTIFY timeChanged)
+	Q_PROPERTY(QVector<Reference> requires READ requires NOTIFY requiresChanged)
+public:
+	explicit Version(const QString &uid, const QString &version);
+
+	QString descriptor() override;
+	QString name() override;
+	QString typeString() const override;
+
+	QString uid() const { return m_uid; }
+	QString version() const { return m_version; }
+	QString type() const { return m_type; }
+	QDateTime time() const;
+	qint64 rawTime() const { return m_time; }
+	QVector<Reference> requires() const { return m_requires; }
+	VersionFilePtr data() const { return m_data; }
+
+	std::unique_ptr<Task> remoteUpdateTask() override;
+	std::unique_ptr<Task> localUpdateTask() override;
+	void merge(const std::shared_ptr<BaseEntity> &other) override;
+
+	QString localFilename() const override;
+	QJsonObject serialized() const override;
+
+public: // for usage by format parsers only
+	void setType(const QString &type);
+	void setTime(const qint64 time);
+	void setRequires(const QVector<Reference> &requires);
+	void setData(const VersionFilePtr &data);
+
+signals:
+	void typeChanged();
+	void timeChanged();
+	void requiresChanged();
+
+private:
+	QString m_uid;
+	QString m_version;
+	QString m_type;
+	qint64 m_time;
+	QVector<Reference> m_requires;
+	VersionFilePtr m_data;
+};
+}
+
+Q_DECLARE_METATYPE(Meta::VersionPtr)

api/logic/meta/VersionList.cpp

@@ -0,0 +1,288 @@
+/* Copyright 2015-2017 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 "VersionList.h"
+
+#include <QDateTime>
+
+#include "Version.h"
+#include "tasks/RemoteLoadTask.h"
+#include "tasks/LocalLoadTask.h"
+#include "format/Format.h"
+#include "Reference.h"
+
+namespace Meta
+{
+
+class WVLLoadTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit WVLLoadTask(VersionList *list, QObject *parent = nullptr)
+		: Task(parent), m_list(list)
+	{
+	}
+
+	bool canAbort() const override
+	{
+		return !m_currentTask || m_currentTask->canAbort();
+	}
+	bool abort() override
+	{
+		return m_currentTask->abort();
+	}
+
+private:
+	void executeTask() override
+	{
+		if (!m_list->isLocalLoaded())
+		{
+			m_currentTask = m_list->localUpdateTask();
+			connect(m_currentTask.get(), &Task::succeeded, this, &WVLLoadTask::next);
+		}
+		else
+		{
+			m_currentTask = m_list->remoteUpdateTask();
+			connect(m_currentTask.get(), &Task::succeeded, this, &WVLLoadTask::emitSucceeded);
+		}
+		connect(m_currentTask.get(), &Task::status, this, &WVLLoadTask::setStatus);
+		connect(m_currentTask.get(), &Task::progress, this, &WVLLoadTask::setProgress);
+		connect(m_currentTask.get(), &Task::failed, this, &WVLLoadTask::emitFailed);
+		m_currentTask->start();
+	}
+
+	void next()
+	{
+		m_currentTask = m_list->remoteUpdateTask();
+		connect(m_currentTask.get(), &Task::status, this, &WVLLoadTask::setStatus);
+		connect(m_currentTask.get(), &Task::progress, this, &WVLLoadTask::setProgress);
+		connect(m_currentTask.get(), &Task::succeeded, this, &WVLLoadTask::emitSucceeded);
+		m_currentTask->start();
+	}
+
+	VersionList *m_list;
+	std::unique_ptr<Task> m_currentTask;
+};
+
+VersionList::VersionList(const QString &uid, QObject *parent)
+	: BaseVersionList(parent), m_uid(uid)
+{
+	setObjectName("Version list: " + uid);
+}
+
+Task *VersionList::getLoadTask()
+{
+	return new WVLLoadTask(this);
+}
+
+bool VersionList::isLoaded()
+{
+	return isLocalLoaded() && isRemoteLoaded();
+}
+
+const BaseVersionPtr VersionList::at(int i) const
+{
+	return m_versions.at(i);
+}
+int VersionList::count() const
+{
+	return m_versions.size();
+}
+
+void VersionList::sortVersions()
+{
+	beginResetModel();
+	std::sort(m_versions.begin(), m_versions.end(), [](const VersionPtr &a, const VersionPtr &b)
+	{
+		return *a.get() < *b.get();
+	});
+	endResetModel();
+}
+
+QVariant VersionList::data(const QModelIndex &index, int role) const
+{
+	if (!index.isValid() || index.row() < 0 || index.row() >= m_versions.size() || index.parent().isValid())
+	{
+		return QVariant();
+	}
+
+	VersionPtr version = m_versions.at(index.row());
+
+	switch (role)
+	{
+	case VersionPointerRole: return QVariant::fromValue(std::dynamic_pointer_cast<BaseVersion>(version));
+	case VersionRole:
+	case VersionIdRole:
+		return version->version();
+	case ParentGameVersionRole:
+	{
+		const auto end = version->requires().end();
+		const auto it = std::find_if(version->requires().begin(), end,
+									 [](const Reference &ref) { return ref.uid() == "net.minecraft"; });
+		if (it != end)
+		{
+			return (*it).version();
+		}
+		return QVariant();
+	}
+	case TypeRole: return version->type();
+
+	case UidRole: return version->uid();
+	case TimeRole: return version->time();
+	case RequiresRole: return QVariant::fromValue(version->requires());
+	case SortRole: return version->rawTime();
+	case VersionPtrRole: return QVariant::fromValue(version);
+	case RecommendedRole: return version == getRecommended();
+	case LatestRole: return version == getLatestStable();
+	default: return QVariant();
+	}
+}
+
+BaseVersionList::RoleList VersionList::providesRoles() const
+{
+	return {VersionPointerRole, VersionRole, VersionIdRole, ParentGameVersionRole,
+				TypeRole, UidRole, TimeRole, RequiresRole, SortRole,
+				RecommendedRole, LatestRole, VersionPtrRole};
+}
+
+QHash<int, QByteArray> VersionList::roleNames() const
+{
+	QHash<int, QByteArray> roles = BaseVersionList::roleNames();
+	roles.insert(UidRole, "uid");
+	roles.insert(TimeRole, "time");
+	roles.insert(SortRole, "sort");
+	roles.insert(RequiresRole, "requires");
+	return roles;
+}
+
+std::unique_ptr<Task> VersionList::remoteUpdateTask()
+{
+	return std::unique_ptr<VersionListRemoteLoadTask>(new VersionListRemoteLoadTask(this, this));
+}
+std::unique_ptr<Task> VersionList::localUpdateTask()
+{
+	return std::unique_ptr<VersionListLocalLoadTask>(new VersionListLocalLoadTask(this, this));
+}
+
+QString VersionList::localFilename() const
+{
+	return m_uid + ".json";
+}
+QJsonObject VersionList::serialized() const
+{
+	return Format::serializeVersionList(this);
+}
+
+QString VersionList::humanReadable() const
+{
+	return m_name.isEmpty() ? m_uid : m_name;
+}
+
+bool VersionList::hasVersion(const QString &version) const
+{
+	return m_lookup.contains(version);
+}
+VersionPtr VersionList::getVersion(const QString &version) const
+{
+	return m_lookup.value(version);
+}
+
+void VersionList::setName(const QString &name)
+{
+	m_name = name;
+	emit nameChanged(name);
+}
+void VersionList::setVersions(const QVector<VersionPtr> &versions)
+{
+	beginResetModel();
+	m_versions = versions;
+	std::sort(m_versions.begin(), m_versions.end(), [](const VersionPtr &a, const VersionPtr &b)
+	{
+		return a->rawTime() > b->rawTime();
+	});
+	for (int i = 0; i < m_versions.size(); ++i)
+	{
+		m_lookup.insert(m_versions.at(i)->version(), m_versions.at(i));
+		setupAddedVersion(i, m_versions.at(i));
+	}
+
+	m_latest = m_versions.isEmpty() ? nullptr : m_versions.first();
+	auto recommendedIt = std::find_if(m_versions.constBegin(), m_versions.constEnd(), [](const VersionPtr &ptr) { return ptr->type() == "release"; });
+	m_recommended = recommendedIt == m_versions.constEnd() ? nullptr : *recommendedIt;
+	endResetModel();
+}
+
+void VersionList::merge(const BaseEntity::Ptr &other)
+{
+	const VersionListPtr list = std::dynamic_pointer_cast<VersionList>(other);
+	if (m_name != list->m_name)
+	{
+		setName(list->m_name);
+	}
+
+	if (m_versions.isEmpty())
+	{
+		setVersions(list->m_versions);
+	}
+	else
+	{
+		for (const VersionPtr &version : list->m_versions)
+		{
+			if (m_lookup.contains(version->version()))
+			{
+				m_lookup.value(version->version())->merge(version);
+			}
+			else
+			{
+				beginInsertRows(QModelIndex(), m_versions.size(), m_versions.size());
+				setupAddedVersion(m_versions.size(), version);
+				m_versions.append(version);
+				m_lookup.insert(version->uid(), version);
+				endInsertRows();
+
+				if (!m_latest || version->rawTime() > m_latest->rawTime())
+				{
+					m_latest = version;
+					emit dataChanged(index(0), index(m_versions.size() - 1), QVector<int>() << LatestRole);
+				}
+				if (!m_recommended || (version->type() == "release" && version->rawTime() > m_recommended->rawTime()))
+				{
+					m_recommended = version;
+					emit dataChanged(index(0), index(m_versions.size() - 1), QVector<int>() << RecommendedRole);
+				}
+			}
+		}
+	}
+}
+
+void VersionList::setupAddedVersion(const int row, const VersionPtr &version)
+{
+	connect(version.get(), &Version::requiresChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << RequiresRole); });
+	connect(version.get(), &Version::timeChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << TimeRole << SortRole); });
+	connect(version.get(), &Version::typeChanged, this, [this, row]() { emit dataChanged(index(row), index(row), QVector<int>() << TypeRole); });
+}
+
+BaseVersionPtr VersionList::getLatestStable() const
+{
+	return m_latest;
+}
+BaseVersionPtr VersionList::getRecommended() const
+{
+	return m_recommended;
+}
+
+}
+
+#include "VersionList.moc"

api/logic/meta/VersionList.h

@@ -0,0 +1,95 @@
+/* Copyright 2015-2017 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 "BaseVersionList.h"
+#include "BaseEntity.h"
+#include <memory>
+
+namespace Meta
+{
+using VersionPtr = std::shared_ptr<class Version>;
+using VersionListPtr = std::shared_ptr<class VersionList>;
+
+class MULTIMC_LOGIC_EXPORT VersionList : public BaseVersionList, public BaseEntity
+{
+	Q_OBJECT
+	Q_PROPERTY(QString uid READ uid CONSTANT)
+	Q_PROPERTY(QString name READ name NOTIFY nameChanged)
+public:
+	explicit VersionList(const QString &uid, QObject *parent = nullptr);
+
+	enum Roles
+	{
+		UidRole = Qt::UserRole + 100,
+		TimeRole,
+		RequiresRole,
+		VersionPtrRole
+	};
+
+	Task *getLoadTask() override;
+	bool isLoaded() override;
+	const BaseVersionPtr at(int i) const override;
+	int count() const override;
+	void sortVersions() override;
+
+	BaseVersionPtr getLatestStable() const override;
+	BaseVersionPtr getRecommended() const override;
+
+	QVariant data(const QModelIndex &index, int role) const override;
+	RoleList providesRoles() const override;
+	QHash<int, QByteArray> roleNames() const override;
+
+	std::unique_ptr<Task> remoteUpdateTask() override;
+	std::unique_ptr<Task> localUpdateTask() override;
+
+	QString localFilename() const override;
+	QJsonObject serialized() const override;
+
+	QString uid() const { return m_uid; }
+	QString name() const { return m_name; }
+	QString humanReadable() const;
+
+	bool hasVersion(const QString &version) const;
+	VersionPtr getVersion(const QString &version) const;
+
+	QVector<VersionPtr> versions() const { return m_versions; }
+
+public: // for usage only by parsers
+	void setName(const QString &name);
+	void setVersions(const QVector<VersionPtr> &versions);
+	void merge(const BaseEntity::Ptr &other) override;
+
+signals:
+	void nameChanged(const QString &name);
+
+protected slots:
+	void updateListData(QList<BaseVersionPtr>) override {}
+
+private:
+	QVector<VersionPtr> m_versions;
+	QHash<QString, VersionPtr> m_lookup;
+	QString m_uid;
+	QString m_name;
+
+	VersionPtr m_recommended;
+	VersionPtr m_latest;
+
+	void setupAddedVersion(const int row, const VersionPtr &version);
+};
+
+}
+Q_DECLARE_METATYPE(Meta::VersionListPtr)

api/logic/meta/format/Format.cpp

@@ -0,0 +1,84 @@
+/* Copyright 2015-2017 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 "Format.h"
+
+#include "FormatV1.h"
+
+#include "meta/Index.h"
+#include "meta/Version.h"
+#include "meta/VersionList.h"
+
+namespace Meta
+{
+
+static int formatVersion(const QJsonObject &obj)
+{
+	if (!obj.contains("formatVersion")) {
+		throw ParseException(QObject::tr("Missing required field: 'formatVersion'"));
+	}
+	if (!obj.value("formatVersion").isDouble()) {
+		throw ParseException(QObject::tr("Required field has invalid type: 'formatVersion'"));
+	}
+	return obj.value("formatVersion").toInt();
+}
+
+void Format::parseIndex(const QJsonObject &obj, Index *ptr)
+{
+	const int version = formatVersion(obj);
+	switch (version) {
+	case 1:
+		ptr->merge(FormatV1().parseIndexInternal(obj));
+		break;
+	default:
+		throw ParseException(QObject::tr("Unknown formatVersion: %1").arg(version));
+	}
+}
+void Format::parseVersion(const QJsonObject &obj, Version *ptr)
+{
+	const int version = formatVersion(obj);
+	switch (version) {
+	case 1:
+		ptr->merge(FormatV1().parseVersionInternal(obj));
+		break;
+	default:
+		throw ParseException(QObject::tr("Unknown formatVersion: %1").arg(version));
+	}
+}
+void Format::parseVersionList(const QJsonObject &obj, VersionList *ptr)
+{
+	const int version = formatVersion(obj);
+	switch (version) {
+	case 10:
+		ptr->merge(FormatV1().parseVersionListInternal(obj));
+		break;
+	default:
+		throw ParseException(QObject::tr("Unknown formatVersion: %1").arg(version));
+	}
+}
+
+QJsonObject Format::serializeIndex(const Index *ptr)
+{
+	return FormatV1().serializeIndexInternal(ptr);
+}
+QJsonObject Format::serializeVersion(const Version *ptr)
+{
+	return FormatV1().serializeVersionInternal(ptr);
+}
+QJsonObject Format::serializeVersionList(const VersionList *ptr)
+{
+	return FormatV1().serializeVersionListInternal(ptr);
+}
+}

api/logic/meta/format/Format.h

@@ -0,0 +1,57 @@
+/* Copyright 2015-2017 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 <QJsonObject>
+#include <memory>
+
+#include "Exception.h"
+#include "meta/BaseEntity.h"
+
+namespace Meta
+{
+class Index;
+class Version;
+class VersionList;
+
+class ParseException : public Exception
+{
+public:
+	using Exception::Exception;
+};
+
+class Format
+{
+public:
+	virtual ~Format() {}
+
+	static void parseIndex(const QJsonObject &obj, Index *ptr);
+	static void parseVersion(const QJsonObject &obj, Version *ptr);
+	static void parseVersionList(const QJsonObject &obj, VersionList *ptr);
+
+	static QJsonObject serializeIndex(const Index *ptr);
+	static QJsonObject serializeVersion(const Version *ptr);
+	static QJsonObject serializeVersionList(const VersionList *ptr);
+
+protected:
+	virtual BaseEntity::Ptr parseIndexInternal(const QJsonObject &obj) const = 0;
+	virtual BaseEntity::Ptr parseVersionInternal(const QJsonObject &obj) const = 0;
+	virtual BaseEntity::Ptr parseVersionListInternal(const QJsonObject &obj) const = 0;
+	virtual QJsonObject serializeIndexInternal(const Index *ptr) const = 0;
+	virtual QJsonObject serializeVersionInternal(const Version *ptr) const = 0;
+	virtual QJsonObject serializeVersionListInternal(const VersionList *ptr) const = 0;
+};
+}

api/logic/meta/format/FormatV1.cpp

@@ -0,0 +1,161 @@
+/* Copyright 2015-2017 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 "FormatV1.h"
+#include <minecraft/onesix/OneSixVersionFormat.h>
+
+#include "Json.h"
+
+#include "meta/Index.h"
+#include "meta/Version.h"
+#include "meta/VersionList.h"
+#include "Env.h"
+
+using namespace Json;
+
+namespace Meta
+{
+static VersionPtr parseCommonVersion(const QString &uid, const QJsonObject &obj)
+{
+	const QVector<QJsonObject> requiresRaw = obj.contains("requires") ? requireIsArrayOf<QJsonObject>(obj, "requires") : QVector<QJsonObject>();
+	QVector<Reference> requires;
+	requires.reserve(requiresRaw.size());
+	std::transform(requiresRaw.begin(), requiresRaw.end(), std::back_inserter(requires), [](const QJsonObject &rObj)
+	{
+		Reference ref(requireString(rObj, "uid"));
+		ref.setVersion(ensureString(rObj, "version", QString()));
+		return ref;
+	});
+
+	VersionPtr version = std::make_shared<Version>(uid, requireString(obj, "version"));
+	if (obj.value("time").isString())
+	{
+		version->setTime(QDateTime::fromString(requireString(obj, "time"), Qt::ISODate).toMSecsSinceEpoch() / 1000);
+	}
+	else
+	{
+		version->setTime(requireInteger(obj, "time"));
+	}
+	version->setType(ensureString(obj, "type", QString()));
+	version->setRequires(requires);
+	return version;
+}
+static void serializeCommonVersion(const Version *version, QJsonObject &obj)
+{
+	QJsonArray requires;
+	for (const Reference &ref : version->requires())
+	{
+		if (ref.version().isEmpty())
+		{
+			QJsonObject out;
+			out["uid"] = ref.uid();
+			requires.append(out);
+		}
+		else
+		{
+			QJsonObject out;
+			out["uid"] = ref.uid();
+			out["version"] = ref.version();
+			requires.append(out);
+		}
+	}
+
+	obj.insert("version", version->version());
+	obj.insert("type", version->type());
+	obj.insert("time", version->time().toString(Qt::ISODate));
+	obj.insert("requires", requires);
+}
+
+BaseEntity::Ptr FormatV1::parseIndexInternal(const QJsonObject &obj) const
+{
+	const QVector<QJsonObject> objects = requireIsArrayOf<QJsonObject>(obj, "index");
+	QVector<VersionListPtr> lists;
+	lists.reserve(objects.size());
+	std::transform(objects.begin(), objects.end(), std::back_inserter(lists), [](const QJsonObject &obj)
+	{
+		VersionListPtr list = std::make_shared<VersionList>(requireString(obj, "uid"));
+		list->setName(ensureString(obj, "name", QString()));
+		return list;
+	});
+	return std::make_shared<Index>(lists);
+}
+BaseEntity::Ptr FormatV1::parseVersionInternal(const QJsonObject &obj) const
+{
+	VersionPtr version = parseCommonVersion(requireString(obj, "uid"), obj);
+
+	version->setData(OneSixVersionFormat::versionFileFromJson(QJsonDocument(obj),
+										   QString("%1/%2.json").arg(version->uid(), version->version()),
+										   obj.contains("order")));
+	return version;
+}
+BaseEntity::Ptr FormatV1::parseVersionListInternal(const QJsonObject &obj) const
+{
+	const QString uid = requireString(obj, "uid");
+
+	const QVector<QJsonObject> versionsRaw = requireIsArrayOf<QJsonObject>(obj, "versions");
+	QVector<VersionPtr> versions;
+	versions.reserve(versionsRaw.size());
+	std::transform(versionsRaw.begin(), versionsRaw.end(), std::back_inserter(versions), [this, uid](const QJsonObject &vObj)
+	{ return parseCommonVersion(uid, vObj); });
+
+	VersionListPtr list = std::make_shared<VersionList>(uid);
+	list->setName(ensureString(obj, "name", QString()));
+	list->setVersions(versions);
+	return list;
+}
+
+QJsonObject FormatV1::serializeIndexInternal(const Index *ptr) const
+{
+	QJsonArray index;
+	for (const VersionListPtr &list : ptr->lists())
+	{
+		QJsonObject out;
+		out["uid"] = list->uid();
+		out["version"] = list->name();
+		index.append(out);
+	}
+	QJsonObject out;
+	out["formatVersion"] = 1;
+	out["index"] = index;
+	return out;
+}
+QJsonObject FormatV1::serializeVersionInternal(const Version *ptr) const
+{
+	QJsonObject obj = OneSixVersionFormat::versionFileToJson(ptr->data(), true).object();
+	serializeCommonVersion(ptr, obj);
+	obj.insert("formatVersion", 1);
+	obj.insert("uid", ptr->uid());
+	// TODO: the name should be looked up in the UI based on the uid
+	obj.insert("name", ENV.metadataIndex()->getListGuaranteed(ptr->uid())->name());
+
+	return obj;
+}
+QJsonObject FormatV1::serializeVersionListInternal(const VersionList *ptr) const
+{
+	QJsonArray versions;
+	for (const VersionPtr &version : ptr->versions())
+	{
+		QJsonObject obj;
+		serializeCommonVersion(version.get(), obj);
+		versions.append(obj);
+	}
+	QJsonObject out;
+	out["formatVersion"] = 10;
+	out["uid"] = ptr->uid();
+	out["name"] = ptr->name().isNull() ? QJsonValue() : ptr->name();
+	out["versions"] = versions;
+	return out;
+}
+}

api/logic/meta/format/FormatV1.h

@@ -0,0 +1,33 @@
+/* Copyright 2015-2017 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 "Format.h"
+
+namespace Meta
+{
+class FormatV1 : public Format
+{
+public:
+	BaseEntity::Ptr parseIndexInternal(const QJsonObject &obj) const override;
+	BaseEntity::Ptr parseVersionInternal(const QJsonObject &obj) const override;
+	BaseEntity::Ptr parseVersionListInternal(const QJsonObject &obj) const override;
+
+	QJsonObject serializeIndexInternal(const Index *ptr) const override;
+	QJsonObject serializeVersionInternal(const Version *ptr) const override;
+	QJsonObject serializeVersionListInternal(const VersionList *ptr) const override;
+};
+}

api/logic/meta/tasks/LocalLoadTask.cpp

@@ -0,0 +1,123 @@
+/* Copyright 2015-2017 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 "LocalLoadTask.h"
+
+#include <QFile>
+
+#include "meta/format/Format.h"
+#include "meta/Util.h"
+#include "meta/Index.h"
+#include "meta/Version.h"
+#include "meta/VersionList.h"
+#include "Env.h"
+#include "Json.h"
+
+namespace Meta
+{
+LocalLoadTask::LocalLoadTask(BaseEntity *entity, QObject *parent)
+	: Task(parent), m_entity(entity)
+{
+}
+
+void LocalLoadTask::executeTask()
+{
+	const QString fname = Meta::localDir().absoluteFilePath(filename());
+	if (!QFile::exists(fname))
+	{
+		emitFailed(tr("File doesn't exist"));
+		return;
+	}
+
+	setStatus(tr("Reading %1...").arg(name()));
+	setProgress(0, 0);
+
+	try
+	{
+		parse(Json::requireObject(Json::requireDocument(fname, name()), name()));
+		m_entity->notifyLocalLoadComplete();
+		emitSucceeded();
+	}
+	catch (Exception &e)
+	{
+		emitFailed(tr("Unable to parse file %1: %2").arg(fname, e.cause()));
+	}
+}
+
+
+// INDEX
+IndexLocalLoadTask::IndexLocalLoadTask(Index *index, QObject *parent)
+	: LocalLoadTask(index, parent)
+{
+}
+QString IndexLocalLoadTask::filename() const
+{
+	return "index.json";
+}
+QString IndexLocalLoadTask::name() const
+{
+	return tr("Metadata Index");
+}
+void IndexLocalLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseIndex(obj, dynamic_cast<Index *>(entity()));
+}
+
+
+// VERSION LIST
+VersionListLocalLoadTask::VersionListLocalLoadTask(VersionList *list, QObject *parent)
+	: LocalLoadTask(list, parent)
+{
+}
+QString VersionListLocalLoadTask::filename() const
+{
+	return list()->uid() + ".json";
+}
+QString VersionListLocalLoadTask::name() const
+{
+	return tr("Version List for %1").arg(list()->humanReadable());
+}
+void VersionListLocalLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseVersionList(obj, list());
+}
+VersionList *VersionListLocalLoadTask::list() const
+{
+	return dynamic_cast<VersionList *>(entity());
+}
+
+
+// VERSION
+VersionLocalLoadTask::VersionLocalLoadTask(Version *version, QObject *parent)
+	: LocalLoadTask(version, parent)
+{
+}
+QString VersionLocalLoadTask::filename() const
+{
+	return version()->uid() + "/" + version()->version() + ".json";
+}
+QString VersionLocalLoadTask::name() const
+{
+	return tr(" Version for %1").arg(version()->name());
+}
+void VersionLocalLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseVersion(obj, version());
+}
+Version *VersionLocalLoadTask::version() const
+{
+	return dynamic_cast<Version *>(entity());
+}
+}

api/logic/meta/tasks/LocalLoadTask.h

@@ -0,0 +1,84 @@
+/* Copyright 2015-2017 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 "tasks/Task.h"
+#include <memory>
+
+namespace Meta
+{
+class BaseEntity;
+class Index;
+class VersionList;
+class Version;
+
+class LocalLoadTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit LocalLoadTask(BaseEntity *entity, QObject *parent = nullptr);
+
+protected:
+	virtual QString filename() const = 0;
+	virtual QString name() const = 0;
+	virtual void parse(const QJsonObject &obj) const = 0;
+
+	BaseEntity *entity() const { return m_entity; }
+
+private:
+	void executeTask() override;
+
+	BaseEntity *m_entity;
+};
+
+class IndexLocalLoadTask : public LocalLoadTask
+{
+	Q_OBJECT
+public:
+	explicit IndexLocalLoadTask(Index *index, QObject *parent = nullptr);
+
+private:
+	QString filename() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+};
+class VersionListLocalLoadTask : public LocalLoadTask
+{
+	Q_OBJECT
+public:
+	explicit VersionListLocalLoadTask(VersionList *list, QObject *parent = nullptr);
+
+private:
+	QString filename() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+
+	VersionList *list() const;
+};
+class VersionLocalLoadTask : public LocalLoadTask
+{
+	Q_OBJECT
+public:
+	explicit VersionLocalLoadTask(Version *version, QObject *parent = nullptr);
+
+private:
+	QString filename() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+
+	Version *version() const;
+};
+}

api/logic/meta/tasks/RemoteLoadTask.cpp

@@ -0,0 +1,132 @@
+/* Copyright 2015-2017 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 "RemoteLoadTask.h"
+
+#include "net/Download.h"
+#include "net/HttpMetaCache.h"
+#include "net/NetJob.h"
+#include "meta/format/Format.h"
+#include "meta/Util.h"
+#include "meta/Index.h"
+#include "meta/Version.h"
+#include "meta/VersionList.h"
+#include "Env.h"
+#include "Json.h"
+
+namespace Meta
+{
+
+RemoteLoadTask::RemoteLoadTask(BaseEntity *entity, QObject *parent)
+	: Task(parent), m_entity(entity)
+{
+}
+
+void RemoteLoadTask::executeTask()
+{
+	NetJob *job = new NetJob(name());
+
+	auto entry = ENV.metacache()->resolveEntry("meta", url().toString());
+	entry->setStale(true);
+	m_dl = Net::Download::makeCached(url(), entry);
+	job->addNetAction(m_dl);
+	connect(job, &NetJob::failed, this, &RemoteLoadTask::emitFailed);
+	connect(job, &NetJob::succeeded, this, &RemoteLoadTask::networkFinished);
+	connect(job, &NetJob::status, this, &RemoteLoadTask::setStatus);
+	connect(job, &NetJob::progress, this, &RemoteLoadTask::setProgress);
+	job->start();
+}
+
+void RemoteLoadTask::networkFinished()
+{
+	setStatus(tr("Parsing..."));
+	setProgress(0, 0);
+
+	try
+	{
+		parse(Json::requireObject(Json::requireDocument(m_dl->getTargetFilepath(), name()), name()));
+		m_entity->notifyRemoteLoadComplete();
+		emitSucceeded();
+	}
+	catch (Exception &e)
+	{
+		emitFailed(tr("Unable to parse response: %1").arg(e.cause()));
+	}
+}
+
+// INDEX
+IndexRemoteLoadTask::IndexRemoteLoadTask(Index *index, QObject *parent)
+	: RemoteLoadTask(index, parent)
+{
+}
+QUrl IndexRemoteLoadTask::url() const
+{
+	return Meta::indexUrl();
+}
+QString IndexRemoteLoadTask::name() const
+{
+	return tr("Metadata Index");
+}
+void IndexRemoteLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseIndex(obj, dynamic_cast<Index *>(entity()));
+}
+
+
+// VERSION LIST
+VersionListRemoteLoadTask::VersionListRemoteLoadTask(VersionList *list, QObject *parent)
+	: RemoteLoadTask(list, parent)
+{
+}
+QUrl VersionListRemoteLoadTask::url() const
+{
+	return Meta::versionListUrl(list()->uid());
+}
+QString VersionListRemoteLoadTask::name() const
+{
+	return tr("Version List for %1").arg(list()->humanReadable());
+}
+void VersionListRemoteLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseVersionList(obj, list());
+}
+VersionList* Meta::VersionListRemoteLoadTask::list() const
+{
+	return dynamic_cast<VersionList *>(entity());
+}
+
+
+// VERSION
+VersionRemoteLoadTask::VersionRemoteLoadTask(Version *version, QObject *parent)
+	: RemoteLoadTask(version, parent)
+{
+}
+QUrl VersionRemoteLoadTask::url() const
+{
+	return Meta::versionUrl(version()->uid(), version()->version());
+}
+QString VersionRemoteLoadTask::name() const
+{
+	return tr("Meta Version for %1").arg(version()->name());
+}
+void VersionRemoteLoadTask::parse(const QJsonObject &obj) const
+{
+	Format::parseVersion(obj, version());
+}
+Version *VersionRemoteLoadTask::version() const
+{
+	return dynamic_cast<Version *>(entity());
+}
+}

api/logic/meta/tasks/RemoteLoadTask.h

@@ -0,0 +1,95 @@
+/* Copyright 2015-2017 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 "tasks/Task.h"
+#include <memory>
+
+namespace Net
+{
+class Download;
+}
+
+namespace Meta
+{
+class BaseEntity;
+class Index;
+class VersionList;
+class Version;
+
+class RemoteLoadTask : public Task
+{
+	Q_OBJECT
+public:
+	explicit RemoteLoadTask(BaseEntity *entity, QObject *parent = nullptr);
+
+protected:
+	virtual QUrl url() const = 0;
+	virtual QString name() const = 0;
+	virtual void parse(const QJsonObject &obj) const = 0;
+
+	BaseEntity *entity() const { return m_entity; }
+
+private slots:
+	void networkFinished();
+
+private:
+	void executeTask() override;
+
+	BaseEntity *m_entity;
+	std::shared_ptr<Net::Download> m_dl;
+};
+
+class IndexRemoteLoadTask : public RemoteLoadTask
+{
+	Q_OBJECT
+public:
+	explicit IndexRemoteLoadTask(Index *index, QObject *parent = nullptr);
+
+private:
+	QUrl url() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+};
+
+class VersionListRemoteLoadTask : public RemoteLoadTask
+{
+	Q_OBJECT
+public:
+	explicit VersionListRemoteLoadTask(VersionList *list, QObject *parent = nullptr);
+
+private:
+	QUrl url() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+
+	VersionList *list() const;
+};
+
+class VersionRemoteLoadTask : public RemoteLoadTask
+{
+	Q_OBJECT
+public:
+	explicit VersionRemoteLoadTask(Version *version, QObject *parent = nullptr);
+
+private:
+	QUrl url() const override;
+	QString name() const override;
+	void parse(const QJsonObject &obj) const override;
+
+	Version *version() const;
+};
+}