Rework the update checking system

2 files changed, 327 insertions, 0 deletions

diff --git a/logic/updater/UpdateChecker.cpp b/logic/updater/UpdateChecker.cpp
new file mode 100644
index 00000000..68c32ae8
--- /dev/null
+++ b/logic/updater/UpdateChecker.cpp
@@ -0,0 +1,234 @@
+/* Copyright 2013 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 "UpdateChecker.h"
+
+#include "MultiMC.h"
+
+#include "config.h"
+#include "logger/QsLog.h"
+
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QJsonValue>
+
+#define API_VERSION 0
+#define CHANLIST_FORMAT 0
+
+UpdateChecker::UpdateChecker()
+{
+	m_currentChannel = VERSION_CHANNEL;
+	m_channelListUrl = CHANLIST_URL;
+	m_updateChecking = false;
+	m_chanListLoading = false;
+	m_checkUpdateWaiting = false;
+	m_chanListLoaded = false;
+}
+
+void UpdateChecker::checkForUpdate()
+{
+	QLOG_DEBUG() << "Checking for updates.";
+
+	// If the channel list hasn't loaded yet, load it and defer checking for updates until later.
+	if (!m_chanListLoaded)
+	{
+		QLOG_DEBUG() << "Channel list isn't loaded yet. Loading channel list and deferring update check.";
+		m_checkUpdateWaiting = true;
+		updateChanList();
+		return;
+	}
+
+	if (m_updateChecking)
+	{
+		QLOG_DEBUG() << "Ignoring update check request. Already checking for updates.";
+		return;
+	}
+
+	m_updateChecking = true;
+
+	// Get the URL for the channel we're using.
+	// TODO: Allow user to select channels. For now, we'll just use the current channel.
+	QString updateChannel = m_currentChannel;
+
+	// Find the desired channel within the channel list and get its repo URL. If if cannot be found, error.
+	m_repoUrl = "";
+	for (ChannelListEntry entry : m_channels)
+	{
+		if (entry.id == updateChannel)
+			m_repoUrl = entry.url;
+	}
+
+	// If we didn't find our channel, error.
+	if (m_repoUrl.isEmpty())
+	{
+		emit updateCheckFailed();
+		return;
+	}
+
+	QUrl indexUrl = QUrl(m_repoUrl).resolved(QUrl("index.json"));
+
+	auto job = new NetJob("GoUpdate Repository Index");
+	job->addNetAction(ByteArrayDownload::make(indexUrl));
+	connect(job, SIGNAL(succeeded()), SLOT(updateCheckFinished()));
+	connect(job, SIGNAL(failed()), SLOT(updateCheckFailed()));
+	indexJob.reset(job);
+	job->start();
+}
+
+void UpdateChecker::updateCheckFinished()
+{
+	QLOG_DEBUG() << "Finished downloading repo index. Checking for new versions.";
+
+	QJsonParseError jsonError;
+	QByteArray data;
+	{
+		ByteArrayDownloadPtr dl = std::dynamic_pointer_cast<ByteArrayDownload>(indexJob->first());
+		data = dl->m_data;
+		indexJob.reset();
+	}
+
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
+	if (jsonError.error != QJsonParseError::NoError || !jsonDoc.isObject())
+	{
+		QLOG_ERROR() << "Failed to parse GoUpdate repository index. JSON error" << jsonError.errorString() << "at offset" << jsonError.offset;
+		return;
+	}
+
+	QJsonObject object = jsonDoc.object();
+
+	bool success = false;
+	int apiVersion = object.value("ApiVersion").toVariant().toInt(&success);
+	if (apiVersion != API_VERSION || !success)
+	{
+		QLOG_ERROR() << "Failed to check for updates. API version mismatch. We're using" << API_VERSION << "server has" << apiVersion;
+		return;
+	}
+
+	QLOG_DEBUG() << "Processing repository version list.";
+	QJsonObject newestVersion;
+	QJsonArray versions = object.value("Versions").toArray();
+	for (QJsonValue versionVal : versions)
+	{
+		QJsonObject version = versionVal.toObject();
+		if (newestVersion.value("Id").toVariant().toInt() < version.value("Id").toVariant().toInt())
+		{
+			QLOG_DEBUG() << "Found newer version with ID" << version.value("Id").toVariant().toInt();
+			newestVersion = version;
+		}
+	}
+
+	// We've got the version with the greatest ID number. Now compare it to our current build number and update if they're different.
+	int newBuildNumber = newestVersion.value("Id").toVariant().toInt();
+	if (newBuildNumber != MMC->version().build)
+	{
+		// Update!
+		emit updateAvailable(m_repoUrl, newestVersion.value("Name").toVariant().toString(), newBuildNumber);
+	}
+
+	m_updateChecking = false;
+}
+
+void UpdateChecker::updateCheckFailed()
+{
+	// TODO: log errors better
+	QLOG_ERROR() << "Update check failed for reasons unknown.";
+}
+
+void UpdateChecker::updateChanList()
+{
+	QLOG_DEBUG() << "Loading the channel list.";
+
+	if (m_channelListUrl.isEmpty())
+	{
+		QLOG_ERROR() << "Failed to update channel list. No channel list URL set."
+					 << "If you'd like to use MultiMC's update system, please pass the channel list URL to CMake at compile time.";
+		return;
+	}
+
+	m_chanListLoading = true;
+	NetJob* job = new NetJob("Update System Channel List");
+	job->addNetAction(ByteArrayDownload::make(QUrl(m_channelListUrl)));
+	QObject::connect(job, &NetJob::succeeded, this, &UpdateChecker::chanListDownloadFinished);
+	QObject::connect(job, &NetJob::failed, this, &UpdateChecker::chanListDownloadFailed);
+	chanListJob.reset(job);
+	job->start();
+}
+
+void UpdateChecker::chanListDownloadFinished()
+{
+	QByteArray data;
+	{
+		ByteArrayDownloadPtr dl = std::dynamic_pointer_cast<ByteArrayDownload>(chanListJob->first());
+		data = dl->m_data;
+		chanListJob.reset();
+	}
+
+	QJsonParseError jsonError;
+	QJsonDocument jsonDoc = QJsonDocument::fromJson(data, &jsonError);
+	if (jsonError.error != QJsonParseError::NoError)
+	{
+		// TODO: Report errors to the user.
+		QLOG_ERROR() << "Failed to parse channel list JSON:" << jsonError.errorString() << "at" << jsonError.offset;
+		return;
+	}
+	
+	QJsonObject object = jsonDoc.object();
+
+	bool success = false;
+	int formatVersion = object.value("format_version").toVariant().toInt(&success);
+	if (formatVersion != CHANLIST_FORMAT || !success)
+	{
+		QLOG_ERROR() << "Failed to check for updates. Channel list format version mismatch. We're using" << CHANLIST_FORMAT << "server has" << formatVersion;
+		return;
+	}
+
+	// Load channels into a temporary array.
+	QList<ChannelListEntry> loadedChannels;
+	QJsonArray channelArray = object.value("channels").toArray();
+	for (QJsonValue chanVal : channelArray)
+	{
+		QJsonObject channelObj = chanVal.toObject();
+		ChannelListEntry entry{
+				channelObj.value("id").toVariant().toString(),
+				channelObj.value("name").toVariant().toString(),
+				channelObj.value("description").toVariant().toString(),
+				channelObj.value("url").toVariant().toString()
+			};
+		if (entry.id.isEmpty() || entry.name.isEmpty() || entry.url.isEmpty())
+		{
+			QLOG_ERROR() << "Channel list entry with empty ID, name, or URL. Skipping.";
+			continue;
+		}
+		loadedChannels.append(entry);
+	}
+
+	// Swap  the channel list we just loaded into the object's channel list.
+	m_channels.swap(loadedChannels);
+
+	m_chanListLoading = false;
+	m_chanListLoaded = true;
+	QLOG_INFO() << "Successfully loaded UpdateChecker channel list.";
+
+	// If we're waiting to check for updates, do that now.
+	if (m_checkUpdateWaiting)
+		checkForUpdate();
+}
+
+void UpdateChecker::chanListDownloadFailed()
+{
+	m_chanListLoading = false;
+	QLOG_ERROR() << "Failed to download channel list.";
+}
+
diff --git a/logic/updater/UpdateChecker.h b/logic/updater/UpdateChecker.h
new file mode 100644
index 00000000..829f7303
--- /dev/null
+++ b/logic/updater/UpdateChecker.h
@@ -0,0 +1,93 @@
+/* Copyright 2013 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 "logic/net/NetJob.h"
+
+#include <QUrl>
+
+class UpdateChecker : public QObject
+{
+	Q_OBJECT
+
+public:
+signals:
+	//! Signal emitted when an update is available. Passes the URL for the repo and the ID and name for the version.
+	void updateAvailable(QString repoUrl, QString versionName, int versionId);
+
+private slots:
+	void updateCheckFinished();
+	void updateCheckFailed();
+
+	void chanListDownloadFinished();
+	void chanListDownloadFailed();
+
+public:
+	UpdateChecker();
+	void checkForUpdate();
+
+	/*!
+	 * Causes the update checker to download the channel list from the URL specified in config.h (generated by CMake).
+	 * If this isn't called before checkForUpdate(), it will automatically be called.
+	 */
+	void updateChanList();
+
+	/*!
+	 * An entry in the channel list.
+	 */
+	struct ChannelListEntry
+	{
+		QString id;
+		QString name;
+		QString description;
+		QString url;
+	};
+
+private:
+	NetJobPtr indexJob;
+	NetJobPtr chanListJob;
+
+	QString m_repoUrl;
+
+	QString m_channelListUrl;
+	QString m_currentChannel;
+
+	QList<ChannelListEntry> m_channels;
+
+	/*!
+	 * True while the system is checking for updates.
+	 * If checkForUpdate is called while this is true, it will be ignored.
+	 */
+	bool m_updateChecking;
+
+	/*!
+	 * True if the channel list has loaded.
+	 * If this is false, trying to check for updates will call updateChanList first.
+	 */
+	bool m_chanListLoaded;
+
+	/*!
+	 * Set to true while the channel list is currently loading.
+	 */
+	bool m_chanListLoading;
+
+	/*!
+	 * Set to true when checkForUpdate is called while the channel list isn't loaded.
+	 * When the channel list finishes loading, if this is true, the update checker will check for updates.
+	 */
+	bool m_checkUpdateWaiting;
+};
+