fix: implement atomic writes and hardened VDF provisioning for robust Steam integration on fresh installs

frontend/electron/services/steam-client.ts

@@ -26,14 +26,16 @@ class SteamClientService {
     if (platform === 'win32') {
       const possiblePaths = [
         'C:\\Program Files (x86)\\Steam',
-        'C:\\Program Files\\Steam'
+        'C:\\Program Files\\Steam',
+        path.join(process.env.APPDATA || '', 'Steam'),
       ];
       this.steamPath = possiblePaths.find(p => fs.existsSync(p)) || null;
     } else if (platform === 'linux') {
       const possiblePaths = [
         path.join(home, '.steam/steam'),
         path.join(home, '.local/share/Steam'),
-        path.join(home, '.var/app/com.valvesoftware.Steam/.steam/steam')
+        path.join(home, '.var/app/com.valvesoftware.Steam/.steam/steam'), // Flatpak
+        path.join(home, 'snap/steam/common/.steam/steam'), // Snap
       ];
       this.steamPath = possiblePaths.find(p => fs.existsSync(p)) || null;
     }
@@ -53,13 +55,36 @@ class SteamClientService {
     return path.join(this.steamPath, 'config', 'config.vdf');
   }
 
+  /**
+   * Safe Atomic Write: Writes to a temp file and renames it.
+   * This prevents file corruption if the app crashes during write.
+   */
+  private safeWriteVdf(filePath: string, data: any) {
+    const tempPath = `${filePath}.tmp_${Date.now()}`;
+    const dir = path.dirname(filePath);
+    
+    try {
+      if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
+      const vdfContent = stringify(data);
+      fs.writeFileSync(tempPath, vdfContent, 'utf-8');
+      
+      // Atomic rename
+      fs.renameSync(tempPath, filePath);
+    } catch (e: any) {
+      console.error(`[SteamClient] Atomic write failed for ${filePath}: ${e.message}`);
+      if (fs.existsSync(tempPath)) fs.unlinkSync(tempPath);
+      throw e;
+    }
+  }
+
   public startWatching(callback: (accounts: LocalSteamAccount[]) => void) {
     this.onAccountsChanged = callback;
     const loginUsersPath = this.getLoginUsersPath();
 
     if (loginUsersPath && fs.existsSync(loginUsersPath)) {
       this.readLocalAccounts();
-      chokidar.watch(loginUsersPath, { persistent: true }).on('change', () => {
+      chokidar.watch(loginUsersPath, { persistent: true, ignoreInitial: true }).on('change', () => {
+        console.log(`[SteamClient] loginusers.vdf changed, re-scanning...`);
         this.readLocalAccounts();
       });
     }
@@ -71,16 +96,20 @@ class SteamClientService {
 
     try {
       const content = fs.readFileSync(filePath, 'utf-8');
+      if (!content.trim()) return; // Empty file
+
       const data = parse(content) as any;
       if (!data || !data.users) return;
 
       const accounts: LocalSteamAccount[] = [];
       for (const [steamId64, userData] of Object.entries(data.users)) {
         const user = userData as any;
+        if (!user || !user.AccountName) continue;
+        
         accounts.push({
           steamId: steamId64,
           accountName: user.AccountName,
-          personaName: user.PersonaName,
+          personaName: user.PersonaName || user.AccountName,
           timestamp: parseInt(user.Timestamp) || 0
         });
       }
@@ -98,35 +127,39 @@ class SteamClientService {
     try {
       const content = fs.readFileSync(configPath, 'utf-8');
       const data = parse(content) as any;
-      
       const accounts = data?.InstallConfigStore?.Software?.Valve?.Steam?.Accounts;
-      if (accounts && accounts[accountName]) {
+      return (accounts && accounts[accountName]) ? accounts[accountName] : null;
-        return accounts[accountName];
-      }
     } catch (e) {
       console.error('[SteamClient] Failed to extract config.vdf data');
+      return null;
     }
-    return null;
   }
 
   public injectAccountConfig(accountName: string, accountData: any) {
     const configPath = this.getConfigVdfPath();
     if (!configPath) return;
 
-    // Create directory if it doesn't exist
+    let data: any = { 
-    const configDir = path.dirname(configPath);
+      InstallConfigStore: { 
-    if (!fs.existsSync(configDir)) fs.mkdirSync(configDir, { recursive: true });
+        Software: { 
-
+          Valve: { 
-    let data: any = { InstallConfigStore: { Software: { Valve: { Steam: { Accounts: {} } } } } };
+            Steam: { 
+              Accounts: {} 
+            } 
+          } 
+        } 
+      } 
+    };
 
     if (fs.existsSync(configPath)) {
       try {
         const content = fs.readFileSync(configPath, 'utf-8');
-        data = parse(content) as any;
+        const parsed = parse(content) as any;
+        if (parsed && typeof parsed === 'object') data = parsed;
       } catch (e) { }
     }
 
-    // Ensure structure exists
+    // Ensure safe nesting
     if (!data.InstallConfigStore) data.InstallConfigStore = {};
     if (!data.InstallConfigStore.Software) data.InstallConfigStore.Software = {};
     if (!data.InstallConfigStore.Software.Valve) data.InstallConfigStore.Software.Valve = {};
@@ -136,11 +169,9 @@ class SteamClientService {
     data.InstallConfigStore.Software.Valve.Steam.Accounts[accountName] = accountData;
 
     try {
-      fs.writeFileSync(configPath, stringify(data));
+      this.safeWriteVdf(configPath, data);
-      console.log(`[SteamClient] Injected login config for ${accountName} into config.vdf`);
+      console.log(`[SteamClient] Safely injected session for ${accountName}`);
-    } catch (e) {
+    } catch (e) { }
-      console.error('[SteamClient] Failed to write config.vdf');
-    }
   }
 
   public async setAutoLoginUser(accountName: string, accountConfig?: any, steamId?: string): Promise<boolean> {
@@ -148,14 +179,12 @@ class SteamClientService {
     const loginUsersPath = this.getLoginUsersPath();
 
     if (loginUsersPath) {
-      const configDir = path.dirname(loginUsersPath);
-      if (!fs.existsSync(configDir)) fs.mkdirSync(configDir, { recursive: true });
-
       let data: any = { users: {} };
       if (fs.existsSync(loginUsersPath)) {
         try {
           const content = fs.readFileSync(loginUsersPath, 'utf-8');
-          data = parse(content) as any;
+          const parsed = parse(content) as any;
+          if (parsed && parsed.users) data = parsed;
         } catch (e) { }
       }
 
@@ -164,7 +193,7 @@ class SteamClientService {
       let found = false;
       for (const [id, user] of Object.entries(data.users)) {
         const u = user as any;
-        if (u.AccountName.toLowerCase() === accountName.toLowerCase()) {
+        if (u.AccountName?.toLowerCase() === accountName.toLowerCase()) {
           u.mostrecent = "1";
           u.RememberPassword = "1";
           u.AllowAutoLogin = "1";
@@ -177,8 +206,8 @@ class SteamClientService {
         }
       }
 
-      if (!found && steamId) {
+      if (!found && steamId && accountName) {
-        console.log(`[SteamClient] Provisioning user ${accountName} into loginusers.vdf`);
+        console.log(`[SteamClient] Provisioning new user profile for ${accountName}`);
         data.users[steamId] = {
           AccountName: accountName,
           PersonaName: accountName,
@@ -193,16 +222,15 @@ class SteamClientService {
       }
 
       try {
-        fs.writeFileSync(loginUsersPath, stringify(data));
+        this.safeWriteVdf(loginUsersPath, data);
-      } catch (e) {
+      } catch (e) { }
-        console.error('[SteamClient] Failed to write loginusers.vdf');
-      }
     }
 
-    if (accountConfig) {
+    if (accountConfig && accountName) {
       this.injectAccountConfig(accountName, accountConfig);
     }
 
+    // --- Linux Registry / Registry.vdf Hardening ---
     if (platform === 'linux') {
       const regLocations = [
         path.join(os.homedir(), '.steam', 'registry.vdf'),
@@ -210,36 +238,40 @@ class SteamClientService {
       ];
 
       for (const regPath of regLocations) {
-        let regData: any = { Registry: { HKCU: { Software: { Valve: { Steam: {} } } } } };
+        if (!fs.existsSync(path.dirname(regPath))) continue;
+
+        let regData: any = { Registry: { HKCU: { Software: { Valve: { Steam: { 
+          AutoLoginUser: "",
+          RememberPassword: "1",
+          AlreadyLoggedIn: "1"
+        } } } } } };
         
         if (fs.existsSync(regPath)) {
           try {
             const content = fs.readFileSync(regPath, 'utf-8');
-            regData = parse(content) as any;
+            const parsed = parse(content) as any;
+            if (parsed && typeof parsed === 'object') regData = parsed;
           } catch (e) { }
-        } else {
-          const regDir = path.dirname(regPath);
-          if (!fs.existsSync(regDir)) fs.mkdirSync(regDir, { recursive: true });
         }
 
-        const setPath = (obj: any, keys: string[], val: string) => {
+        // Deep merge helper
+        const ensurePath = (obj: any, keys: string[]) => {
           let curr = obj;
-          for (let i = 0; i < keys.length - 1; i++) {
+          for (const key of keys) {
-            if (!curr[keys[i]!]) curr[keys[i]!] = {};
+            if (!curr[key] || typeof curr[key] !== 'object') curr[key] = {};
-            curr = curr[keys[i]!];
+            curr = curr[key];
           }
-          curr[keys[keys.length - 1]!] = val;
+          return curr;
         };
 
-        const steamReg = ['Registry', 'HKCU', 'Software', 'Valve', 'Steam'];
+        const steamKey = ensurePath(regData, ['Registry', 'HKCU', 'Software', 'Valve', 'Steam']);
-        setPath(regData, [...steamReg, 'AutoLoginUser'], accountName);
+        steamKey.AutoLoginUser = accountName;
-        setPath(regData, [...steamReg, 'RememberPassword'], "1");
+        steamKey.RememberPassword = "1";
-        setPath(regData, [...steamReg, 'AlreadyLoggedIn'], "1");
+        steamKey.AlreadyLoggedIn = "1";
-        setPath(regData, [...steamReg, 'WantsOfflineMode'], "0");
+        steamKey.WantsOfflineMode = "0";
 
         try {
-          fs.writeFileSync(regPath, stringify(regData));
+          this.safeWriteVdf(regPath, regData);
-          console.log(`[SteamClient] Registry updated: ${regPath}`);
         } catch (e) { }
       }
     }