remove unused import

electron/executeUtil.js

@@ -1,20 +1,20 @@
 const childProcess = require("child_process");
 
 const runFile = (folder, file, args, onExit) => {
-    childProcess.execFile(file, args, {
-        cwd: folder
-    }, (_err, _stdout, _stdin) => {
-        if (onExit) onExit();
-    })
-}
+  childProcess.execFile(file, args, {
+    cwd: folder,
+  }, (_err, _stdout, _stdin) => {
+    if (onExit) onExit();
+  });
+};
 
 const runFileDetached = (folder, file, args) => {
-    const subProcess = childProcess.spawn(file + (args ? " " + args : ''), {
-        cwd: folder,
-        detached: true,
-        stdio: 'ignore'
-    });
-    subProcess.unref();
-}
+  const subProcess = childProcess.spawn(file + (args ? " " + args : ""), {
+    cwd: folder,
+    detached: true,
+    stdio: "ignore",
+  });
+  subProcess.unref();
+};
 
-module.exports = { runFile, runFileDetached };
+module.exports = { runFile, runFileDetached };

electron/fileUtil.js

@@ -0,0 +1,15 @@
+const fs = require("fs");
+
+function isWritable(filePath) {
+  let fileAccess = false;
+  try {
+    fs.closeSync(fs.openSync(filePath, "r+"));
+    fileAccess = true;
+  } catch {
+  }
+  return fileAccess;
+}
+
+module.exports = {
+  isWritable,
+};

electron/formattingUtil.js

@@ -1,13 +1,13 @@
 function formatBytes(bytes, decimals = 2) {
-    if (!+bytes) return '0 Bytes'
+  if (!+bytes) return "0 B";
 
-    const k = 1024
-    const dm = decimals < 0 ? 0 : decimals
-    const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']
+  const k = 1024;
+  const dm = decimals < 0 ? 0 : decimals;
+  const sizes = ["B", "KB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"];
 
-    const i = Math.floor(Math.log(bytes) / Math.log(k))
+  const i = Math.floor(Math.log(bytes) / Math.log(k));
 
-    return `${parseFloat((bytes / Math.pow(k, i)).toFixed(dm))}${sizes[i]}`
+  return `${parseFloat((bytes / Math.pow(k, i)).toFixed(dm))}${sizes[i]}`;
 }
 
-module.exports = { formatBytes };
+module.exports = { formatBytes };

electron/logging.js

@@ -0,0 +1,44 @@
+const fs = require("fs");
+const path = require("path");
+
+class Logger {
+  constructor(directory) {
+    this.directory = directory;
+    this.enabled = false;
+  }
+
+  async init() {
+    const filename = `${new Date().toISOString().replace(/:/g, "-")}.log`;
+    this.logPath = path.join(this.directory, filename);
+  }
+
+  async log(message) {
+    if (this.logPath === undefined || this.enabled == false) {
+      return;
+    }
+    if (!fs.existsSync(this.logPath)) {
+      await fs.promises.mkdir(this.directory, { recursive: true });
+      await fs.promises.writeFile(this.logPath, "");
+    }
+    const logMessage = `[${new Date().toISOString()}] LOG: ${message}`;
+    await fs.promises.appendFile(this.logPath, `${logMessage}\n`);
+    console.log(logMessage);
+  }
+
+  async error(message, error) {
+    if (this.logPath === undefined || this.enabled == false) {
+      return;
+    }
+    if (!fs.existsSync(this.logPath)) {
+      await fs.promises.mkdir(this.directory, { recursive: true });
+      await fs.promises.writeFile(this.logPath, "");
+    }
+    const errorMessage = `[${
+      new Date().toISOString()
+    }] ERROR: ${message}\n${error.stack}`;
+    await fs.promises.appendFile(this.logPath, `${errorMessage}\n`);
+    console.error(errorMessage);
+  }
+}
+
+module.exports = Logger;

electron/netUtils.js

@@ -1,8 +1,8 @@
 const { exec } = require("child_process");
 
 async function isNet8Installed() {
-    return new Promise((resolve, reject) => {
-        exec("dotnet --version", (error, stdout, stderr) => {
+    return new Promise((resolve) => {
+        exec("dotnet --list-runtimes", (error, stdout, stderr) => {
             if (error) {
                 resolve(false);
                 return;
@@ -12,7 +12,13 @@ async function isNet8Installed() {
                 return;
             }
             const version = stdout.trim();
-            resolve(version.startsWith("8."));
+            for (const line of version.split('\n')) {
+                if (line.startsWith("Microsoft.WindowsDesktop.App 8.")) {
+                    resolve(true);
+                    break;
+                }
+            }
+            resolve(false);
         })
     });
 }

electron/osuUtil.js

@@ -18,8 +18,8 @@ const gamemodes = {
   4: "osu!(rx)",
   5: "taiko(rx)",
   6: "catch(rx)",
-  8: "osu!(ap)"
-}
+  8: "osu!(ap)",
+};
 const osuEntities = [
   "avcodec-51.dll",
   "avformat-52.dll",
@@ -44,7 +44,7 @@ const osuEntities = [
   "scores.db",
 ];
 
-const ezppLauncherUpdateList = "https://ez-pp.farm/ezpplauncher"
+const ezppLauncherUpdateList = "https://ez-pp.farm/ezpplauncher";
 
 async function isValidOsuFolder(path) {
   const allFiles = await fs.promises.readdir(path);
@@ -184,31 +184,24 @@ function downloadUpdateFiles(osuPath, updateFiles) {
 
   const startDownload = async () => {
     for (const updatePatch of updateFiles) {
-      const fileName = updatePatch.filename;
-      const fileSize = updatePatch.filesize;
-      const fileURL = updatePatch.url_full;
-
-      const axiosDownloadWithProgress = await axios.get(fileURL, {
-        responseType: "stream",
-        onDownloadProgress: (progressEvent) => {
-          const { loaded, total } = progressEvent;
-          eventEmitter.emit("data", {
-            fileName,
-            loaded,
-            total,
-            progress: Math.floor((loaded / total) * 100),
-          });
-        },
-      });
-      axiosDownloadWithProgress.data.on("end", () => {
-        eventEmitter.emit("data", {
-          fileName,
-          loaded: fileSize,
-          total: fileSize,
-          progress: 100,
-        });
-      });
       try {
+        const fileName = updatePatch.filename;
+        const fileSize = updatePatch.filesize;
+        const fileURL = updatePatch.url_full;
+
+        const axiosDownloadWithProgress = await axios.get(fileURL, {
+          responseType: "stream",
+          onDownloadProgress: (progressEvent) => {
+            const { loaded, total } = progressEvent;
+            eventEmitter.emit("data", {
+              fileName,
+              loaded,
+              total,
+              progress: Math.floor((loaded / total) * 100),
+            });
+          },
+        });
+
         if (fs.existsSync(path.join(osuPath, fileName))) {
           await fs.promises.rm(path.join(osuPath, fileName), {
             force: true,
@@ -222,6 +215,7 @@ function downloadUpdateFiles(osuPath, updateFiles) {
         console.log(err);
         eventEmitter.emit("error", {
           fileName,
+          error: err,
         });
       }
     }
@@ -248,10 +242,16 @@ function runOsuWithDevServer(osuPath, serverDomain, onExit) {
 
 async function getEZPPLauncherUpdateFiles(osuPath) {
   const filesToDownload = [];
-  const updateFilesRequest = await fetch(ezppLauncherUpdateList, { method: "PATCH" });
+  const updateFilesRequest = await fetch(ezppLauncherUpdateList, {
+    method: "PATCH",
+  });
   const updateFiles = await updateFilesRequest.json();
   for (const updateFile of updateFiles) {
-    const filePath = path.join(osuPath, ...updateFile.folder.split("/"), updateFile.name);
+    const filePath = path.join(
+      osuPath,
+      ...updateFile.folder.split("/"),
+      updateFile.name,
+    );
     if (fs.existsSync(filePath)) {
       const fileHash = updateFile.md5.toLowerCase();
       const localFileHash = crypto.createHash("md5").update(
@@ -272,22 +272,30 @@ async function downloadEZPPLauncherUpdateFiles(osuPath, updateFiles) {
 
   const startDownload = async () => {
     for (const updateFile of updateFiles) {
-      const filePath = path.join(osuPath, ...updateFile.folder.split("/"), updateFile.name);
-      const folder = path.dirname(filePath);
-      if (!fs.existsSync(folder)) await fs.promises.mkdir(folder, { recursive: true });
-      const axiosDownloadWithProgress = await axios.get(updateFile.url, {
-        responseType: "stream",
-        onDownloadProgress: (progressEvent) => {
-          const { loaded, total } = progressEvent;
-          eventEmitter.emit("data", {
-            fileName: path.basename(filePath),
-            loaded,
-            total,
-            progress: Math.floor((loaded / total) * 100),
-          });
-        },
-      });
       try {
+        const filePath = path.join(
+          osuPath,
+          ...updateFile.folder.split("/"),
+          updateFile.name,
+        );
+        const folder = path.dirname(filePath);
+        if (!fs.existsSync(folder)) {
+          await fs.promises.mkdir(folder, { recursive: true });
+        }
+        const axiosDownloadWithProgress = await axios.get(updateFile.url, {
+          responseType: "stream",
+          onDownloadProgress: (progressEvent) => {
+            const fileSize = updateFile.size;
+            const { loaded } = progressEvent;
+            eventEmitter.emit("data", {
+              fileName: path.basename(filePath),
+              loaded,
+              total: fileSize,
+              progress: Math.floor((loaded / fileSize) * 100),
+            });
+          },
+        });
+
         if (fs.existsSync(filePath)) {
           await fs.promises.rm(filePath, {
             force: true,
@@ -301,10 +309,11 @@ async function downloadEZPPLauncherUpdateFiles(osuPath, updateFiles) {
         console.log(err);
         eventEmitter.emit("error", {
           fileName: path.basename(filePath),
+          error: err,
         });
       }
     }
-  }
+  };
 
   return {
     eventEmitter,
@@ -316,7 +325,11 @@ async function replaceUIFiles(osuPath, revert) {
   if (!revert) {
     const ezppUIFile = path.join(osuPath, "EZPPLauncher", "ezpp!ui.dll");
     const oldOsuUIFile = path.join(osuPath, "osu!ui.dll");
-    const ezppGameplayFile = path.join(osuPath, "EZPPLauncher", "ezpp!gameplay.dll");
+    const ezppGameplayFile = path.join(
+      osuPath,
+      "EZPPLauncher",
+      "ezpp!gameplay.dll",
+    );
     const oldOsuGameplayFile = path.join(osuPath, "osu!gameplay.dll");
 
     await fs.promises.rename(
@@ -334,7 +347,11 @@ async function replaceUIFiles(osuPath, revert) {
     const oldOsuUIFile = path.join(osuPath, "osu!ui.dll");
     const ezppUIFile = path.join(osuPath, "EZPPLauncher", "ezpp!ui.dll");
     const oldOsuGameplayFile = path.join(osuPath, "osu!gameplay.dll");
-    const ezppGameplayFile = path.join(osuPath, "EZPPLauncher", "ezpp!gameplay.dll");
+    const ezppGameplayFile = path.join(
+      osuPath,
+      "EZPPLauncher",
+      "ezpp!gameplay.dll",
+    );
 
     await fs.promises.rename(oldOsuUIFile, ezppUIFile);
     await fs.promises.rename(
@@ -413,5 +430,5 @@ module.exports = {
   runOsuUpdater,
   getEZPPLauncherUpdateFiles,
   downloadEZPPLauncherUpdateFiles,
-  gamemodes
+  gamemodes,
 };

electron/richPresence.js

@@ -35,7 +35,9 @@ module.exports = {
       richPresence = new DiscordRPC.AutoClient({ transport: "ipc" });
       richPresence.endlessLogin({ clientId });
       richPresence.once("ready", () => {
-        console.log("connected presence with user " + richPresence.user.username);
+        console.log(
+          "connected presence with user " + richPresence.user.username,
+        );
         richPresence.setActivity(currentStatus);
         intervalId = setInterval(() => {
           richPresence.setActivity(currentStatus);

main.js

@@ -20,7 +20,6 @@ const {
   runOsuWithDevServer,
   replaceUIFiles,
   findOsuInstallation,
-  updateOsuConfigHashes,
   runOsuUpdater,
   gamemodes,
   getEZPPLauncherUpdateFiles,
@@ -38,6 +37,8 @@ const { updateAvailable, releasesUrl } = require("./electron/updateCheck");
 const fkill = require("fkill");
 const { checkImageExists } = require("./electron/imageUtil");
 const { isNet8Installed } = require("./electron/netUtils");
+const Logger = require("./electron/logging");
+const { isWritable } = require("./electron/fileUtil");
 
 // Keep a global reference of the window object, if you don't, the window will
 // be closed automatically when the JavaScript object is garbage collected.
@@ -46,6 +47,13 @@ let osuCheckInterval;
 let userOsuPath;
 let osuLoaded = false;
 let patch = false;
+let logger = new Logger(path.join(
+  process.platform == "win32"
+    ? process.env["LOCALAPPDATA"]
+    : process.env["HOME"],
+  "EZPPLauncher",
+  "logs",
+));
 
 let currentUser = undefined;
 
@@ -66,10 +74,18 @@ function startOsuStatus() {
         osuLoaded = true;
 
         try {
-          const currentUserInfo = await fetch(`https://api.ez-pp.farm/get_player_info?name=${currentUser.username}&scope=info`);
+          const currentUserInfo = await fetch(
+            `https://api.ez-pp.farm/get_player_info?name=${currentUser.username}&scope=info`,
+          );
           const currentUserInfoJson = await currentUserInfo.json();
-          if ("player" in currentUserInfoJson && currentUserInfoJson.player != null) {
-            if ("info" in currentUserInfoJson.player && currentUserInfoJson.player.info != null) {
+          if (
+            "player" in currentUserInfoJson &&
+            currentUserInfoJson.player != null
+          ) {
+            if (
+              "info" in currentUserInfoJson.player &&
+              currentUserInfoJson.player.info != null
+            ) {
               const id = currentUserInfoJson.player.info.id;
               const username = currentUserInfoJson.player.info.name;
               richPresence.updateUser({
@@ -80,7 +96,6 @@ function startOsuStatus() {
             }
           }
         } catch {
-
         }
 
         setTimeout(() => {
@@ -112,7 +127,8 @@ function startOsuStatus() {
       const currentModeString = gamemodes[currentMode];
 
       const currentInfoRequest = await fetch(
-        "https://api.ez-pp.farm/get_player_info?name=" + currentUser.username + "&scope=all",
+        "https://api.ez-pp.farm/get_player_info?name=" + currentUser.username +
+          "&scope=all",
       );
       const currentInfo = await currentInfoRequest.json();
       let currentUsername = currentInfo.player.info.name;
@@ -192,7 +208,7 @@ function startOsuStatus() {
       richPresence.updateUser({
         username: currentUsername,
         id: currentId,
-      })
+      });
 
       richPresence.updateStatus({
         details,
@@ -211,9 +227,19 @@ function stopOsuStatus() {
 
 function registerIPCPipes() {
   ipcMain.handle("ezpplauncher:login", async (e, args) => {
-    const hwid = getHwId();
+    let hwid = "";
+    try {
+      hwid = getHwId();
+    } catch (err) {
+      logger.error(`Failed to get HWID.`, err);
+      return {
+        code: 500,
+        message: "Failed to get HWID.",
+      };
+    }
     const timeout = new AbortController();
     const timeoutId = setTimeout(() => timeout.abort(), 8000);
+    logger.log(`Logging in with user ${args.username}...`);
     try {
       const fetchResult = await fetch("https://ez-pp.farm/login/check", {
         signal: timeout.signal,
@@ -238,14 +264,20 @@ function registerIPCPipes() {
           }
           currentUser = args;
           config.remove("guest");
-        }
+          logger.log(`Logged in as user ${args.username}!`);
+        } else logger.log(`Login failed for user ${args.username}.`);
         return result;
       }
+      logger.log(
+        `Login failed for user ${username}.\nResponse:\n${await fetchResult
+          .text()}`,
+      );
       return {
         code: 500,
         message: "Something went wrong while logging you in.",
       };
     } catch (err) {
+      logger.error("Error while logging in:", err);
       return {
         code: 500,
         message: "Something went wrong while logging you in.",
@@ -275,6 +307,7 @@ function registerIPCPipes() {
     }
     const timeout = new AbortController();
     const timeoutId = setTimeout(() => timeout.abort(), 8000);
+    logger.log(`Logging in with user ${username}...`);
     try {
       const fetchResult = await fetch("https://ez-pp.farm/login/check", {
         signal: timeout.signal,
@@ -297,16 +330,23 @@ function registerIPCPipes() {
             username: username,
             password: password,
           };
-        }
+          logger.log(`Logged in as user ${username}!`);
+        } else logger.log(`Login failed for user ${username}.`);
+
         return result;
       } else {
         config.remove("password");
       }
+      logger.log(
+        `Login failed for user ${username}.\nResponse:\n${await fetchResult
+          .text()}`,
+      );
       return {
         code: 500,
         message: "Something went wrong while logging you in.",
       };
     } catch (err) {
+      logger.error("Error while logging in:", err);
       return {
         code: 500,
         message: "Something went wrong while logging you in.",
@@ -319,6 +359,7 @@ function registerIPCPipes() {
     config.remove("password");
     config.set("guest", "1");
     currentUser = undefined;
+    logger.log("Logged in as guest user.");
   });
 
   ipcMain.handle("ezpplauncher:logout", (e) => {
@@ -326,6 +367,7 @@ function registerIPCPipes() {
     config.remove("password");
     config.remove("guest");
     currentUser = undefined;
+    logger.log("Loging out.");
     return true;
   });
 
@@ -342,6 +384,10 @@ function registerIPCPipes() {
         else richPresence.connect();
       }
 
+      if (key == "logging") {
+        logger.enabled = logging;
+      }
+
       if (typeof value == "boolean") {
         config.set(key, value ? "true" : "false");
       } else {
@@ -391,100 +437,78 @@ function registerIPCPipes() {
   });
 
   ipcMain.handle("ezpplauncher:launch", async (e) => {
-    const configPatch = config.get("patch");
-    patch = configPatch != undefined ? configPatch == "true" : true;
-    mainWindow.webContents.send("ezpplauncher:launchstatus", {
-      status: "Checking osu! directory...",
-    });
-    await new Promise((res) => setTimeout(res, 1000));
-    const osuPath = config.get("osuPath");
-    userOsuPath = osuPath;
-    if (osuPath == undefined) {
-      mainWindow.webContents.send("ezpplauncher:launchabort");
-      mainWindow.webContents.send("ezpplauncher:alert", {
-        type: "error",
-        message: "osu! path not set!",
-      });
-      mainWindow.webContents.send("ezpplauncher:open-settings");
-      return;
-    }
-    if (!(await isValidOsuFolder(osuPath))) {
-      mainWindow.webContents.send("ezpplauncher:launchabort");
-      mainWindow.webContents.send("ezpplauncher:alert", {
-        type: "error",
-        message: "invalid osu! path!",
-      });
-      return;
-    }
-    if (patch) {
-      if (!(await isNet8Installed())) {
-        mainWindow.webContents.send("ezpplauncher:launchabort");
+    try {
+      const osuWindowTitle = windowName.getWindowText("osu!.exe");
+      if (osuWindowTitle.length > 0) {
         mainWindow.webContents.send("ezpplauncher:alert", {
           type: "error",
-          message: ".NET 8 is not installed.",
+          message: "osu! is running, please exit.",
         });
-        //open .net 8 download in browser
-        shell.openExternal('https://dotnet.microsoft.com/en-us/download/dotnet/thank-you/runtime-desktop-8.0.4-windows-x64-installer');
-      }
-    }
-    mainWindow.webContents.send("ezpplauncher:launchstatus", {
-      status: "Checking for osu! updates...",
-    });
-    await new Promise((res) => setTimeout(res, 1000));
-    const releaseStream = await getGlobalConfig(osuPath).get("_ReleaseStream");
-    const latestFiles = await getUpdateFiles(releaseStream);
-    const updateFiles = await getFilesThatNeedUpdate(osuPath, latestFiles);
-    if (updateFiles.length > 0) {
-      const updateDownloader = downloadUpdateFiles(osuPath, updateFiles);
-      let errored = false;
-      updateDownloader.eventEmitter.on("error", (data) => {
-        const filename = data.fileName;
-        errored = true;
-        mainWindow.webContents.send("ezpplauncher:alert", {
-          type: "error",
-          message:
-            `Failed to download/replace ${filename}!\nMaybe try to restart EZPPLauncher.`,
-        });
-      });
-      updateDownloader.eventEmitter.on("data", (data) => {
-        mainWindow.webContents.send("ezpplauncher:launchprogress", {
-          progress: Math.ceil(data.progress),
-        });
-        mainWindow.webContents.send("ezpplauncher:launchstatus", {
-          status: `Downloading ${data.fileName}(${formatBytes(data.loaded)}/${formatBytes(data.total)
-            })...`,
-        });
-      });
-      await updateDownloader.startDownload();
-      mainWindow.webContents.send("ezpplauncher:launchprogress", {
-        progress: -1,
-      });
-      if (errored) {
         mainWindow.webContents.send("ezpplauncher:launchabort");
         return;
       }
-      mainWindow.webContents.send("ezpplauncher:launchstatus", {
-        status: "osu! is now up to date!",
-      });
-      await new Promise((res) => setTimeout(res, 1000));
-    } else {
-      mainWindow.webContents.send("ezpplauncher:launchstatus", {
-        status: "osu! is up to date!",
-      });
-      await new Promise((res) => setTimeout(res, 1000));
-    }
 
-    if (patch) {
+      logger.log("Preparing launch...");
+      const configPatch = config.get("patch");
+      patch = configPatch != undefined ? configPatch == "true" : true;
       mainWindow.webContents.send("ezpplauncher:launchstatus", {
-        status: "Looking for patcher updates...",
+        status: "Checking osu! directory...",
       });
       await new Promise((res) => setTimeout(res, 1000));
-      const patchFiles = await getEZPPLauncherUpdateFiles(osuPath);
-      if (patchFiles.length > 0) {
-        const patcherDownloader = await downloadEZPPLauncherUpdateFiles(osuPath, patchFiles);
+      const osuPath = config.get("osuPath");
+      userOsuPath = osuPath;
+      if (osuPath == undefined) {
+        mainWindow.webContents.send("ezpplauncher:launchabort");
+        mainWindow.webContents.send("ezpplauncher:alert", {
+          type: "error",
+          message: "osu! path not set!",
+        });
+        mainWindow.webContents.send("ezpplauncher:open-settings");
+        logger.log("osu! path is not set.");
+        return;
+      }
+      if (!(await isValidOsuFolder(osuPath))) {
+        mainWindow.webContents.send("ezpplauncher:launchabort");
+        mainWindow.webContents.send("ezpplauncher:alert", {
+          type: "error",
+          message: "invalid osu! path!",
+        });
+        logger.log("osu! path is invalid.");
+        return;
+      }
+      if (patch) {
+        if (!(await isNet8Installed())) {
+          mainWindow.webContents.send("ezpplauncher:launchabort");
+          mainWindow.webContents.send("ezpplauncher:alert", {
+            type: "error",
+            message: ".NET 8 is not installed.",
+          });
+          //open .net 8 download in browser
+          shell.openExternal(
+            "https://dotnet.microsoft.com/en-us/download/dotnet/thank-you/runtime-desktop-8.0.4-windows-x64-installer",
+          );
+          logger.log(".NET 8 is not installed.");
+        }
+      }
+      mainWindow.webContents.send("ezpplauncher:launchstatus", {
+        status: "Checking for osu! updates...",
+      });
+      await new Promise((res) => setTimeout(res, 1000));
+      const releaseStream = await getGlobalConfig(osuPath).get(
+        "_ReleaseStream",
+      );
+      const latestFiles = await getUpdateFiles(releaseStream);
+      const updateFiles = await getFilesThatNeedUpdate(osuPath, latestFiles);
+      if (updateFiles.length > 0) {
+        logger.log("osu! updates found.");
+        const updateDownloader = downloadUpdateFiles(osuPath, updateFiles);
         let errored = false;
-        patcherDownloader.eventEmitter.on("error", (data) => {
+        updateDownloader.eventEmitter.on("error", (data) => {
           const filename = data.fileName;
+          logger.error(
+            `Failed to download/replace ${filename}!`,
+            data.error,
+          );
           errored = true;
           mainWindow.webContents.send("ezpplauncher:alert", {
             type: "error",
@@ -492,16 +516,20 @@ function registerIPCPipes() {
               `Failed to download/replace ${filename}!\nMaybe try to restart EZPPLauncher.`,
           });
         });
-        patcherDownloader.eventEmitter.on("data", (data) => {
+        updateDownloader.eventEmitter.on("data", (data) => {
+          if (data.progress >= 100) {
+            logger.log(`Downloaded ${data.fileName} successfully.`);
+          }
           mainWindow.webContents.send("ezpplauncher:launchprogress", {
             progress: Math.ceil(data.progress),
           });
           mainWindow.webContents.send("ezpplauncher:launchstatus", {
-            status: `Downloading ${data.fileName}(${formatBytes(data.loaded)}/${formatBytes(data.total)
-              })...`,
+            status: `Downloading ${data.fileName}(${formatBytes(data.loaded)}/${
+              formatBytes(data.total)
+            })...`,
           });
         });
-        await patcherDownloader.startDownload();
+        await updateDownloader.startDownload();
         mainWindow.webContents.send("ezpplauncher:launchprogress", {
           progress: -1,
         });
@@ -510,119 +538,206 @@ function registerIPCPipes() {
           return;
         }
         mainWindow.webContents.send("ezpplauncher:launchstatus", {
-          status: "Patcher is now up to date!",
+          status: "osu! is now up to date!",
         });
+        await new Promise((res) => setTimeout(res, 1000));
       } else {
         mainWindow.webContents.send("ezpplauncher:launchstatus", {
-          status: "Patcher is up to date!",
+          status: "osu! is up to date!",
         });
+        await new Promise((res) => setTimeout(res, 1000));
       }
-      await new Promise((res) => setTimeout(res, 1000));
-    }
-    if (updateFiles.length > 0) {
-      mainWindow.webContents.send("ezpplauncher:launchstatus", {
-        status: "Launching osu! updater to verify updates...",
-      });
-      await new Promise((res) => setTimeout(res, 1000));
 
-      await new Promise((res) => {
-        runOsuUpdater(osuPath, async () => {
-          await new Promise((res) => setTimeout(res, 500));
-          const terminationThread = setInterval(async () => {
-            const osuWindowTitle = windowName.getWindowText("osu!.exe");
-            if (osuWindowTitle.length < 0) {
-              return;
-            }
-            const firstInstance = osuWindowTitle[0];
-            if (firstInstance) {
-              const processId = firstInstance.processId;
-              await fkill(processId, { force: true, silent: true });
-              clearInterval(terminationThread);
-              res();
-            }
-          }, 500);
+      if (patch) {
+        mainWindow.webContents.send("ezpplauncher:launchstatus", {
+          status: "Looking for patcher updates...",
         });
-      });
-    }
-
-    await new Promise((res) => setTimeout(res, 1000));
-
-    mainWindow.webContents.send("ezpplauncher:launchstatus", {
-      status: "Preparing launch...",
-    });
-
-    await updateOsuConfigHashes(osuPath);
-    await replaceUIFiles(osuPath, false);
-
-    const forceUpdateFiles = [
-      ".require_update",
-      "help.txt",
-      "_pending",
-    ];
-
-    try {
-      for (const updateFileName of forceUpdateFiles) {
-        const updateFile = path.join(osuPath, updateFileName);
-        if (fs.existsSync(updateFile)) {
-          await fs.promises.rm(updateFile, {
-            force: true,
-            recursive: (await fs.promises.lstat(updateFile)).isDirectory,
+        await new Promise((res) => setTimeout(res, 1000));
+        const patchFiles = await getEZPPLauncherUpdateFiles(osuPath);
+        if (patchFiles.length > 0) {
+          logger.log("EZPPLauncher updates found.");
+          const patcherDownloader = await downloadEZPPLauncherUpdateFiles(
+            osuPath,
+            patchFiles,
+          );
+          let errored = false;
+          patcherDownloader.eventEmitter.on("error", (data) => {
+            const filename = data.fileName;
+            logger.error(`Failed to download/replace ${filename}!`, data.error);
+            errored = true;
+            mainWindow.webContents.send("ezpplauncher:alert", {
+              type: "error",
+              message:
+                `Failed to download/replace ${filename}!\nMaybe try to restart EZPPLauncher.`,
+            });
+          });
+          patcherDownloader.eventEmitter.on("data", (data) => {
+            if (data.progress >= 100) {
+              logger.log(`Downloaded ${data.fileName} successfully.`);
+            }
+            mainWindow.webContents.send("ezpplauncher:launchprogress", {
+              progress: Math.ceil(data.progress),
+            });
+            mainWindow.webContents.send("ezpplauncher:launchstatus", {
+              status: `Downloading ${data.fileName}(${
+                formatBytes(data.loaded)
+              }/${formatBytes(data.total)})...`,
+            });
+          });
+          await patcherDownloader.startDownload();
+          mainWindow.webContents.send("ezpplauncher:launchprogress", {
+            progress: -1,
+          });
+          if (errored) {
+            mainWindow.webContents.send("ezpplauncher:launchabort");
+            return;
+          }
+          mainWindow.webContents.send("ezpplauncher:launchstatus", {
+            status: "Patcher is now up to date!",
+          });
+        } else {
+          mainWindow.webContents.send("ezpplauncher:launchstatus", {
+            status: "Patcher is up to date!",
           });
         }
+        await new Promise((res) => setTimeout(res, 1000));
       }
-    } catch { }
+      if (updateFiles.length > 0) {
+        mainWindow.webContents.send("ezpplauncher:launchstatus", {
+          status: "Launching osu! updater to verify updates...",
+        });
+        await new Promise((res) => setTimeout(res, 1000));
 
-    const userConfig = getUserConfig(osuPath);
-    if (richPresence.hasPresence) {
-      await userConfig.set("DiscordRichPresence", "0");
-    }
-    await userConfig.set("ShowInterfaceDuringRelax", "1");
-    if (currentUser) {
-      await userConfig.set("CredentialEndpoint", "ez-pp.farm");
-      await userConfig.set("SavePassword", "1");
-      await userConfig.set("SaveUsername", "1");
-      await userConfig.set("Username", currentUser.username);
-      await userConfig.set("Password", currentUser.password);
-    }
+        await new Promise((res) => {
+          runOsuUpdater(osuPath, async () => {
+            await new Promise((res) => setTimeout(res, 500));
+            const terminationThread = setInterval(async () => {
+              const osuWindowTitle = windowName.getWindowText("osu!.exe");
+              if (osuWindowTitle.length < 0) {
+                return;
+              }
+              const firstInstance = osuWindowTitle[0];
+              if (firstInstance) {
+                const processId = firstInstance.processId;
+                await fkill(processId, { force: true, silent: true });
+                clearInterval(terminationThread);
+                res();
+              }
+            }, 500);
+          });
+        });
+      }
 
-    mainWindow.webContents.send("ezpplauncher:launchstatus", {
-      status: "Launching osu!...",
-    });
+      await new Promise((res) => setTimeout(res, 1000));
 
-    const onExitHook = () => {
-      mainWindow.show();
-      mainWindow.focus();
-      stopOsuStatus();
-      richPresence.updateUser({
-        username: "  ",
-        id: undefined
-      });
-      richPresence.updateStatus({
-        state: "Idle in Launcher...",
-        details: undefined,
-      });
-      richPresence.update();
       mainWindow.webContents.send("ezpplauncher:launchstatus", {
-        status: "Waiting for cleanup...",
+        status: "Preparing launch...",
       });
 
-      setTimeout(async () => {
-        await replaceUIFiles(osuPath, true);
+      /* await updateOsuConfigHashes(osuPath); */
+      logger.log("Replacing UI files...");
+      try {
+        await replaceUIFiles(osuPath, false);
+        logger.log("UI files replaced successfully.");
+      } catch (err) {
+        logger.error("Failed to replace UI files:", err);
+        mainWindow.webContents.send("ezpplauncher:alert", {
+          type: "error",
+          message: "Failed to replace UI files. try restarting EZPPLauncher.",
+        });
         mainWindow.webContents.send("ezpplauncher:launchabort");
-        osuLoaded = false;
-      }, 5000);
-    };
-    runOsuWithDevServer(osuPath, "ez-pp.farm", onExitHook);
-    mainWindow.hide();
-    startOsuStatus();
+        return;
+      }
 
-    /* mainWindow.webContents.send("ezpplauncher:launchprogress", {
-      progress: 0,
-    });
-    mainWindow.webContents.send("ezpplauncher:launchprogress", {
-      progress: 100,
-    }); */
-    return true;
+      const forceUpdateFiles = [
+        ".require_update",
+        "help.txt",
+        "_pending",
+      ];
+
+      try {
+        for (const updateFileName of forceUpdateFiles) {
+          const updateFile = path.join(osuPath, updateFileName);
+          if (fs.existsSync(updateFile)) {
+            await fs.promises.rm(updateFile, {
+              force: true,
+              recursive: (await fs.promises.lstat(updateFile)).isDirectory,
+            });
+          }
+        }
+      } catch (err) {
+        logger.error("Failed to remove force update files:", err);
+      }
+
+      const userConfig = getUserConfig(osuPath);
+      if (richPresence.hasPresence) {
+        await userConfig.set("DiscordRichPresence", "0");
+      }
+      await userConfig.set("ShowInterfaceDuringRelax", "1");
+      if (currentUser) {
+        await userConfig.set("CredentialEndpoint", "ez-pp.farm");
+        await userConfig.set("SavePassword", "1");
+        await userConfig.set("SaveUsername", "1");
+        await userConfig.set("Username", currentUser.username);
+        await userConfig.set("Password", currentUser.password);
+      }
+
+      mainWindow.webContents.send("ezpplauncher:launchstatus", {
+        status: "Launching osu!...",
+      });
+
+      await new Promise((res) => setTimeout(res, 1000));
+
+      logger.log("Launching osu!...");
+
+      const onExitHook = () => {
+        logger.log("osu! has exited.");
+        mainWindow.show();
+        mainWindow.focus();
+        stopOsuStatus();
+        richPresence.updateUser({
+          username: "  ",
+          id: undefined,
+        });
+        richPresence.updateStatus({
+          state: "Idle in Launcher...",
+          details: undefined,
+        });
+        richPresence.update();
+        mainWindow.webContents.send("ezpplauncher:launchstatus", {
+          status: "Waiting for cleanup...",
+        });
+        const timeStart = performance.now();
+        logger.log("Waiting for cleanup...");
+
+        const cleanup = setInterval(async () => {
+          const osuUIFile = path.join(osuPath, "osu!ui.dll");
+          const osuGameplayFile = path.join(osuPath, "osu!gameplay.dll");
+          if (isWritable(osuUIFile) && isWritable(osuGameplayFile)) {
+            logger.log(
+              `Cleanup complete, took ${
+                ((performance.now() - timeStart) / 1000).toFixed(3)
+              } seconds.`,
+            );
+            clearInterval(cleanup);
+            await replaceUIFiles(osuPath, true);
+            mainWindow.webContents.send("ezpplauncher:launchabort");
+            osuLoaded = false;
+          }
+        }, 1000);
+      };
+      runOsuWithDevServer(osuPath, "ez-pp.farm", onExitHook);
+      mainWindow.hide();
+      startOsuStatus();
+      return true;
+    } catch (err) {
+      logger.error("Failed to launch", err);
+      mainWindow.webContents.send("ezpplauncher:alert", {
+        type: "error",
+        message: "Failed to launch osu!. Please try again.",
+      });
+      mainWindow.webContents.send("ezpplauncher:launchabort");
+    }
   });
 }
 
@@ -678,6 +793,13 @@ function createWindow() {
       richPresence.connect();
     }
   }
+
+  logger.init();
+
+  const loggingEnabled = config.get("logging");
+  if (loggingEnabled && loggingEnabled == "true") {
+    logger.enabled = true;
+  }
   // Uncomment the following line of code when app is ready to be packaged.
   // loadURL(mainWindow);
 

src/pages/Settings.svelte

@@ -1,7 +1,7 @@
 <script lang="ts">
   import { Button, ButtonGroup, Input, Toggle } from "flowbite-svelte";
   import { FileSearchSolid, FolderSolid } from "flowbite-svelte-icons";
-  import { patch, presence } from "./../storage/localStore";
+  import { patch, presence, logging } from "./../storage/localStore";
 
   let folderPath: string = "";
 
@@ -12,8 +12,10 @@
     const settingPresence = settings.find(
       (setting) => setting.key == "presence"
     );
+    const settingLogging = settings.find((setting) => setting.key == "logging");
     patch.set(settingPatch ? settingPatch.val == "true" : true);
     presence.set(settingPresence ? settingPresence.val == "true" : true);
+    logging.set(settingLogging ? settingLogging.val == "true" : false);
     folderPath = osuPath ? osuPath.val : "";
   });
   window.dispatchEvent(new CustomEvent("settings-get"));
@@ -39,19 +41,18 @@
       new CustomEvent("setting-update", { detail: { presence: $presence } })
     );
   };
+
+  const toggleLogging = () => {
+    logging.set(!$logging);
+    window.dispatchEvent(
+      new CustomEvent("setting-update", { detail: { logging: $logging } })
+    );
+  };
 </script>
 
 <main
   class="h-[265px] flex flex-col justify-start p-3 animate-fadeIn opacity-0"
 >
-  <div class="flex flex-col gap-2 p-3">
-    <Toggle class="w-fit" bind:checked={$presence} on:click={togglePresence}
-      >Discord Presence</Toggle
-    >
-    <Toggle class="w-fit" bind:checked={$patch} on:click={togglePatching}
-      >Patching</Toggle
-    >
-  </div>
   <div
     class="container flex flex-col items-center justify-center gap-5 rounded-lg p-3"
   >
@@ -77,4 +78,15 @@
       </Button>
     </ButtonGroup>
   </div>
+  <div class="flex flex-col gap-2 p-3">
+    <Toggle class="w-fit" bind:checked={$presence} on:click={togglePresence}
+      >Discord Presence</Toggle
+    >
+    <Toggle class="w-fit" bind:checked={$patch} on:click={togglePatching}
+      >Patching</Toggle
+    >
+    <Toggle class="w-fit" bind:checked={$logging} on:click={toggleLogging}
+      >Debug Logging</Toggle
+    >
+  </div>
 </main>

src/storage/localStore.ts

@@ -7,8 +7,11 @@ export const updateAvailable = writable(false);
 export const launching = writable(false);
 export const launchStatus = writable("Waiting...");
 export const launchPercentage = writable(-1);
+
+export const currentUser: Writable<undefined | User> = writable(undefined);
+export const currentPage = writable(Page.Login);
+
 export const osuPath: Writable<undefined | string> = writable(undefined);
 export const patch = writable(true);
 export const presence = writable(true);
-export const currentUser: Writable<undefined | User> = writable(undefined);
-export const currentPage = writable(Page.Login);
+export const logging = writable(false);