implement automatic updates

CMakeLists.txt

@@ -69,6 +69,7 @@ add_executable(SppliceCPP
   main.cpp
   globals.cpp
   tools/curl.cpp
+  tools/update.cpp
   tools/qt.cpp
   tools/install.cpp
   tools/package.cpp

globals.cpp

@@ -29,3 +29,6 @@ const std::filesystem::path REPO_PATH = APP_DIR / "repositories.txt";
 int SPPLICE_INSTALL_STATE = 0; // 0 - idle; 1 - installing; 2 - installed
 // TCP communication port between Portal 2 and Spplice (set during runtime)
 int SPPLICE_NETCON_PORT = -1;
+
+// Holds the current version's GitHub tag for automatic updates
+const std::string SPPLICE_VERSION_TAG = "v0.6.3-alpha";

globals.h

@@ -15,5 +15,6 @@ extern std::ofstream LOGFILE;
 extern const std::filesystem::path REPO_PATH;
 extern int SPPLICE_INSTALL_STATE;
 extern int SPPLICE_NETCON_PORT;
+extern const std::string SPPLICE_VERSION_TAG;
 
 #endif

main.cpp

@@ -36,6 +36,7 @@
 #include "tools/install.h"
 #include "tools/package.h"
 #include "tools/repo.h"
+#include "tools/update.h"
 
 // Fetch and display packages from the given repository URL asynchronously
 void displayRepository (const std::string &url, const std::string &last, QVBoxLayout *container) {
@@ -162,6 +163,7 @@ int main (int argc, char *argv[]) {
   }
   // Open the log file
   LOGFILE = std::ofstream(APP_DIR / "log.txt");
+  LOGFILE << "Spplice " << SPPLICE_VERSION_TAG << std::endl;
 
   // Check for a CACHE_DIR override in cache_dir.txt
   checkCacheOverride(APP_DIR / "cache_dir.txt");
@@ -193,6 +195,9 @@ int main (int argc, char *argv[]) {
   // Initialize CURL
   ToolsCURL::init();
 
+  // Check for updates on a separate thread
+  std::thread(ToolsUpdate::installUpdate).detach();
+
   QVBoxLayout *packageContainer = windowUI.PackageListLayout;
 
   // Connect the "Settings" button

tools/update.cpp

@@ -0,0 +1,129 @@
+#include <iostream>
+#include <QJsonDocument>
+#include <QJsonObject>
+#include <QJsonArray>
+#include <QMessageBox>
+
+#ifdef TARGET_WINDOWS
+  #include <windows.h>
+#else
+  #include <unistd.h>
+  #include <limits.h>
+#endif
+
+#include "curl.h" // ToolsCURL
+#include "../globals.h" // Project globals
+
+// Definitions for this source file
+#include "update.h"
+
+#ifndef TARGET_WINDOWS
+  const std::string updateBinary = "SppliceCPP";
+#else
+  const std::string updateBinary = "autoupdate";
+#endif
+
+std::filesystem::path getExecutablePath () {
+
+#ifdef TARGET_WINDOWS
+  wchar_t buffer[MAX_PATH];
+  DWORD size = GetModuleFileNameW(NULL, buffer, MAX_PATH);
+  if (size == 0 || size == MAX_PATH) return std::filesystem::path();
+#else
+  char buffer[PATH_MAX];
+  ssize_t size = readlink("/proc/self/exe", buffer, sizeof(buffer) - 1);
+  if (size == -1) return std::filesystem::path();
+  buffer[size] = '\0';
+#endif
+
+  return std::filesystem::path(buffer);
+
+}
+
+void ToolsUpdate::installUpdate () {
+
+  // Download the GitHub releases manifest containing one item
+  std::string releasesString = ToolsCURL::downloadString("https://api.github.com/repos/p2r3/spplice-cpp/releases?per_page=1");
+  // If the download failed, do nothing
+  if (releasesString == "") {
+    LOGFILE << "[E] Failed to download GitHub releases list" << std::endl;
+    return;
+  }
+
+  // Parse the JSON to get an array of releases
+  QJsonDocument doc = QJsonDocument::fromJson(QString::fromStdString(releasesString).toUtf8());
+  QJsonArray releases = doc.array();
+  // Get the latest (pre)release
+  QJsonObject latest = releases[0].toObject();
+
+  // If we're up to date, do nothing
+  const std::string latestTag = latest["tag_name"].toString().toStdString();
+  if (SPPLICE_VERSION_TAG == latestTag) return;
+  LOGFILE << "[I] Update required (" << SPPLICE_VERSION_TAG << " -> " << latestTag << ")" << std::endl;
+
+  // Parse the assets array
+  QJsonArray assets = latest["assets"].toArray();
+  // Find the right binary for this platform
+  QJsonObject asset;
+  bool foundUpdateBinary = false;
+  for (const QJsonValue &curr : assets) {
+    asset = curr.toObject();
+    if (asset["name"].toString().toStdString() == updateBinary) {
+      foundUpdateBinary = true;
+      break;
+    }
+  }
+  // If no matching update binary was found, request a manual update
+  if (!foundUpdateBinary) {
+    QMessageBox::information(nullptr, "Spplice Update",
+      "This version of Spplice is obsolete and requires a manual update.\nGo to p2r3.com/spplice to download the latest version.");
+    return;
+  }
+
+  // Download the binary
+  const std::string url = asset["browser_download_url"].toString().toStdString();
+  LOGFILE << "[I] Downloading update from \"" << url << '"' << std::endl;
+
+  const std::filesystem::path updatePath = CACHE_DIR / "update_binary";
+  bool success = ToolsCURL::downloadFile(url, updatePath);
+  // If the download failed, do nothing
+  if (!success) {
+    LOGFILE << "[E] Failed to download update from \"" << url << '"' << std::endl;
+    return;
+  }
+
+  // Get the path of the currently running executable
+  const std::filesystem::path executablePath = getExecutablePath();
+  // If this failed, do nothing
+  if (executablePath.empty()) {
+    LOGFILE << "[E] Failed to find own executable." << std::endl;
+    return;
+  }
+  LOGFILE << "[I] Found own executable at " << executablePath << std::endl;
+
+  // Swap the running executable with the one we just downloaded
+#ifdef TARGET_WINDOWS
+  // If on Windows, defer replacing until next reboot to avoid conflicts
+  if (MoveFileExW(updatePath.c_str(), executablePath.c_str(), MOVEFILE_DELAY_UNTIL_REBOOT)) {
+    LOGFILE << "[I] Scheduled update file replacement for next reboot" << std::endl;
+  } else {
+    LOGFILE << "[E] Failed to schedule update file replacement. ERRNO: " << GetLastError() << std::endl;
+    return;
+  }
+  QMessageBox::information(nullptr, "Spplice Update",
+    "Spplice has been updated.\nChanges will take effect after a system reboot.");
+#else
+  // If on Linux, replace the executable right away
+  try {
+    std::filesystem::remove(executablePath);
+    std::filesystem::rename(updatePath, executablePath);
+    LOGFILE << "[I] Replaced " << executablePath << " with " << updatePath << std::endl;
+  } catch (const std::filesystem::filesystem_error& e) {
+    LOGFILE << "[E] Failed to replace executable post-update: " << e.what() << std::endl;
+    return;
+  }
+  QMessageBox::information(nullptr, "Spplice Update",
+    "Spplice has been updated.\nRestart Spplice to apply the changes.");
+#endif
+
+}

tools/update.h

@@ -0,0 +1,9 @@
+#ifndef TOOLS_UPDATE_H
+#define TOOLS_UPDATE_H
+
+class ToolsUpdate {
+  public:
+    static void installUpdate ();
+};
+
+#endif