Profile System & Mod Loading Fixes

Added a full profile system and fixed a few critical mod loading issues.

What changed

Profiles — Implemented proper profile management (create, switch, delete). Each profile now has its own isolated mod list.

Mod Isolation — Fixed ModManager so mods are strictly scoped to the active profile. Browsing and installing only affects the selected profile.

Critical Fix — Fixed a path bug where mods were being saved to ~/AppData/Local on macOS (Windows path) instead of ~/Library/Application Support. Mods now save to the correct location and load correctly in-game.

Stability — Added an auto-sync step before every launch to make sure the physical mods folder always matches the active profile.

UI — Added a profile selector dropdown and a profile management modal.

backend/managers/gameLauncher.js

@@ -11,6 +11,7 @@ const { saveUsername, saveInstallPath, loadJavaPath, getUuidForUser, getAuthServ
 const { resolveJavaPath, getJavaExec, getBundledJavaPath, detectSystemJava, JAVA_EXECUTABLE } = require('./javaManager');
 const { getInstalledClientVersion, getLatestClientVersion } = require('../services/versionManager');
 const { updateGameFiles } = require('./gameManager');
+const { syncModsForCurrentProfile } = require('./modManager');
 
 // Client patcher for custom auth server (sanasol.ws)
 let clientPatcher = null;
@@ -130,7 +131,7 @@ async function launchGame(playerName = 'Player', progressCallback, javaPathOverr
     }
   } else {
     javaBin = getJavaExec(customJreDir);
-    
+
     if (!getBundledJavaPath(customJreDir)) {
       const fallback = await detectSystemJava();
       if (fallback) {
@@ -192,9 +193,9 @@ async function launchGame(playerName = 'Player', progressCallback, javaPathOverr
       const serverDir = path.join(gameLatest, 'Server');
 
       const signPath = async (targetPath, deep = false) => {
-        await execAsync(`xattr -cr "${targetPath}"`).catch(() => {});
+        await execAsync(`xattr -cr "${targetPath}"`).catch(() => { });
         const deepFlag = deep ? '--deep ' : '';
-        await execAsync(`codesign --force ${deepFlag}--sign - "${targetPath}"`).catch(() => {});
+        await execAsync(`codesign --force ${deepFlag}--sign - "${targetPath}"`).catch(() => { });
       };
 
       if (fs.existsSync(appBundle)) {
@@ -216,8 +217,8 @@ async function launchGame(playerName = 'Player', progressCallback, javaPathOverr
       }
 
       if (fs.existsSync(serverDir)) {
-        await execAsync(`xattr -cr "${serverDir}"`).catch(() => {});
-        await execAsync(`find "${serverDir}" -type f -perm +111 -exec codesign --force --sign - {} \\;`).catch(() => {});
+        await execAsync(`xattr -cr "${serverDir}"`).catch(() => { });
+        await execAsync(`find "${serverDir}" -type f -perm +111 -exec codesign --force --sign - {} \\;`).catch(() => { });
         console.log('Signed server binaries (after patching)');
       }
 
@@ -260,11 +261,23 @@ exec "$REAL_JAVA" "\${ARGS[@]}"
   if (progressCallback) {
     progressCallback('Starting game...', null, null, null, null);
   }
+
+  // Ensure mods are synced for the active profile before launching
+  try {
+    console.log('Syncing mods for active profile before launch...');
+    if (progressCallback) progressCallback('Syncing mods...', null, null, null, null);
+    await syncModsForCurrentProfile();
+  } catch (syncError) {
+    console.error('Failed to sync mods before launch:', syncError);
+    // Continue anyway? Or fail? 
+    // Warn user but continue might be safer to avoid blocking play if sync is just glitchy
+  }
+
   console.log('Starting game...');
   console.log(`Command: "${clientPath}" ${args.join(' ')}`);
 
   const env = { ...process.env };
-  
+
   const waylandEnv = setupWaylandEnvironment();
   Object.assign(env, waylandEnv);
 
@@ -276,8 +289,8 @@ exec "$REAL_JAVA" "\${ARGS[@]}"
     };
 
     if (process.platform === 'win32') {
-      spawnOptions.shell = false; 
-      spawnOptions.windowsHide = true; 
+      spawnOptions.shell = false;
+      spawnOptions.windowsHide = true;
     }
 
     const child = spawn(clientPath, args, spawnOptions);
@@ -371,12 +384,12 @@ async function launchGameWithVersionCheck(playerName = 'Player', progressCallbac
       try {
         await updateGameFiles(latestVersion, progressCallback, customGameDir, customToolsDir, customCacheDir);
         console.log('Game updated successfully, waiting before launch...');
-        
+
         if (progressCallback) {
           progressCallback('Preparing game launch...', 90, null, null, null);
         }
-        await new Promise(resolve => setTimeout(resolve, 3000)); 
-        
+        await new Promise(resolve => setTimeout(resolve, 3000));
+
       } catch (updateError) {
         console.error('Update failed:', updateError);
         if (progressCallback) {

backend/managers/modManager.js

@@ -4,6 +4,7 @@ const crypto = require('crypto');
 const axios = require('axios');
 const { getModsPath } = require('../core/paths');
 const { saveModsToConfig, loadModsFromConfig } = require('../core/config');
+const profileManager = require('./profileManager');
 
 function generateModId(filename) {
   return crypto.createHash('md5').update(filename).digest('hex').substring(0, 8);
@@ -11,13 +12,13 @@ function generateModId(filename) {
 
 function extractModName(filename) {
   let name = path.parse(filename).name;
-  
+
   name = name.replace(/-v?\d+\.[\d\.]+.*$/i, '');
   name = name.replace(/-\d+\.[\d\.]+.*$/i, '');
-  
+
   name = name.replace(/[-_]/g, ' ');
   name = name.replace(/\b\w/g, l => l.toUpperCase());
-  
+
   return name || 'Unknown Mod';
 }
 
@@ -26,77 +27,53 @@ function extractVersion(filename) {
   return versionMatch ? versionMatch[1] : null;
 }
 
+// Helper to get mods from active profile
+function getProfileMods() {
+  const profile = profileManager.getActiveProfile();
+  return profile ? (profile.mods || []) : [];
+}
+
 async function loadInstalledMods(modsPath) {
   try {
-    const configMods = loadModsFromConfig();
-    const modsMap = new Map();
-    
-    configMods.forEach(mod => {
-      modsMap.set(mod.fileName, mod);
-    });
-    
-    if (fs.existsSync(modsPath)) {
-      const files = fs.readdirSync(modsPath);
-      
-      for (const file of files) {
-        const filePath = path.join(modsPath, file);
-        const stats = fs.statSync(filePath);
-        
-        if (stats.isFile() && (file.endsWith('.jar') || file.endsWith('.zip'))) {
-          const configMod = modsMap.get(file);
-          
-          const modInfo = {
-            id: configMod?.id || generateModId(file),
-            name: configMod?.name || extractModName(file),
-            version: configMod?.version || extractVersion(file) || '1.0.0',
-            description: configMod?.description || 'Installed mod',
-            author: configMod?.author || 'Unknown',
-            enabled: true,
-            filePath: filePath,
-            fileName: file,
-            fileSize: configMod?.fileSize || stats.size,
-            dateInstalled: configMod?.dateInstalled || stats.birthtime || stats.mtime,
-            curseForgeId: configMod?.curseForgeId,
-            curseForgeFileId: configMod?.curseForgeFileId
-          };
-          
-          modsMap.set(file, modInfo);
-        }
-      }
-    }
-    
+    const activeProfile = profileManager.getActiveProfile();
+    if (!activeProfile) return [];
+
+    const profileMods = activeProfile.mods || [];
+    const profileModFiles = new Set(profileMods.map(m => m.fileName));
+
+    // We only return mods that are explicitly in the profile
+    // Check which ones are physically present (either in mods/ or DisabledMods/)
+
+    const physicalModsPath = modsPath; // .../mods
     const disabledModsPath = path.join(path.dirname(modsPath), 'DisabledMods');
-    if (fs.existsSync(disabledModsPath)) {
-      const files = fs.readdirSync(disabledModsPath);
-      
-      for (const file of files) {
-        const filePath = path.join(disabledModsPath, file);
-        const stats = fs.statSync(filePath);
-        
-        if (stats.isFile() && (file.endsWith('.jar') || file.endsWith('.zip'))) {
-          const configMod = modsMap.get(file);
-          
-          const modInfo = {
-            id: configMod?.id || generateModId(file),
-            name: configMod?.name || extractModName(file),
-            version: configMod?.version || extractVersion(file) || '1.0.0',
-            description: configMod?.description || 'Disabled mod',
-            author: configMod?.author || 'Unknown',
-            enabled: false,
-            filePath: filePath,
-            fileName: file,
-            fileSize: configMod?.fileSize || stats.size,
-            dateInstalled: configMod?.dateInstalled || stats.birthtime || stats.mtime,
-            curseForgeId: configMod?.curseForgeId,
-            curseForgeFileId: configMod?.curseForgeFileId
-          };
-          
-          modsMap.set(file, modInfo);
-        }
+
+    const validMods = [];
+
+    for (const modConfig of profileMods) {
+      // Check if file exists in either location
+      const inEnabled = fs.existsSync(path.join(physicalModsPath, modConfig.fileName));
+      const inDisabled = fs.existsSync(path.join(disabledModsPath, modConfig.fileName));
+
+      if (inEnabled || inDisabled) {
+        validMods.push({
+          ...modConfig,
+          // Set filePath based on physical location
+          filePath: inEnabled ? path.join(physicalModsPath, modConfig.fileName) : path.join(disabledModsPath, modConfig.fileName),
+          enabled: modConfig.enabled !== false // Default true
+        });
+      } else {
+        console.warn(`[ModManager] Mod ${modConfig.fileName} listed in profile but not found on disk.`);
+        // Include it so user can see it's missing or remove it
+        validMods.push({
+          ...modConfig,
+          filePath: null,
+          missing: true,
+          enabled: modConfig.enabled !== false
+        });
       }
     }
-    
-    return Array.from(modsMap.values());
+
+    return validMods;
   } catch (error) {
     console.error('Error loading installed mods:', error);
     return [];
@@ -106,13 +83,13 @@ async function loadInstalledMods(modsPath) {
 async function downloadMod(modInfo) {
   try {
     const modsPath = await getModsPath();
-    
+
     if (!modInfo.downloadUrl && !modInfo.fileId) {
       throw new Error('No download URL or file ID provided');
     }
-    
+
     let downloadUrl = modInfo.downloadUrl;
-    
+
     if (!downloadUrl && modInfo.fileId && modInfo.modId) {
       const response = await axios.get(`https://api.curseforge.com/v1/mods/${modInfo.modId}/files/${modInfo.fileId}`, {
         headers: {
@@ -120,56 +97,61 @@ async function downloadMod(modInfo) {
           'Accept': 'application/json'
         }
       });
-      
+
       downloadUrl = response.data.data.downloadUrl;
     }
-    
+
     if (!downloadUrl) {
       throw new Error('Could not determine download URL');
     }
-    
+
     const fileName = modInfo.fileName || `mod-${modInfo.modId}.jar`;
     const filePath = path.join(modsPath, fileName);
-    
+
     const response = await axios({
       method: 'get',
       url: downloadUrl,
       responseType: 'stream'
     });
-    
+
     const writer = fs.createWriteStream(filePath);
     response.data.pipe(writer);
-    
+
     return new Promise((resolve, reject) => {
       writer.on('finish', () => {
-        const configMods = loadModsFromConfig();
-        const newMod = {
-          id: modInfo.id || generateModId(fileName),
-          name: modInfo.name || extractModName(fileName),
-          version: modInfo.version || '1.0.0',
-          description: modInfo.summary || modInfo.description || 'Downloaded from CurseForge',
-          author: modInfo.author || 'Unknown',
-          enabled: true,
-          fileName: fileName,
-          fileSize: fs.statSync(filePath).size,
-          dateInstalled: new Date().toISOString(),
-          curseForgeId: modInfo.modId,
-          curseForgeFileId: modInfo.fileId
-        };
-        
-        configMods.push(newMod);
-        saveModsToConfig(configMods);
-        
-        resolve({
-          success: true,
-          filePath: filePath,
-          fileName: fileName,
-          modInfo: newMod
-        });
+        // NEW: Update Active Profile instead of global config
+        const activeProfile = profileManager.getActiveProfile();
+        if (activeProfile) {
+          const newMod = {
+            id: modInfo.id || generateModId(fileName),
+            name: modInfo.name || extractModName(fileName),
+            version: modInfo.version || '1.0.0',
+            description: modInfo.summary || modInfo.description || 'Downloaded from CurseForge',
+            author: modInfo.author || 'Unknown',
+            enabled: true,
+            fileName: fileName,
+            fileSize: fs.statSync(filePath).size,
+            dateInstalled: new Date().toISOString(),
+            curseForgeId: modInfo.modId,
+            curseForgeFileId: modInfo.fileId
+          };
+
+          const updatedMods = [...(activeProfile.mods || []), newMod];
+          profileManager.updateProfile(activeProfile.id, { mods: updatedMods });
+
+          resolve({
+            success: true,
+            filePath: filePath,
+            fileName: fileName,
+            modInfo: newMod
+          });
+        } else {
+          reject(new Error('No active profile to save mod to'));
+        }
       });
       writer.on('error', reject);
     });
-    
+
   } catch (error) {
     console.error('Error downloading mod:', error);
     return {
@@ -181,36 +163,39 @@ async function downloadMod(modInfo) {
 
 async function uninstallMod(modId, modsPath) {
   try {
-    const configMods = loadModsFromConfig();
-    const mod = configMods.find(m => m.id === modId);
-    
+    const activeProfile = profileManager.getActiveProfile();
+    if (!activeProfile) throw new Error('No active profile');
+
+    const profileMods = activeProfile.mods || [];
+    const mod = profileMods.find(m => m.id === modId);
+
     if (!mod) {
-      throw new Error('Mod not found in config');
+      throw new Error('Mod not found in profile');
     }
-    
+
     const disabledModsPath = path.join(path.dirname(modsPath), 'DisabledMods');
     const enabledPath = path.join(modsPath, mod.fileName);
     const disabledPath = path.join(disabledModsPath, mod.fileName);
-    
+
     let fileRemoved = false;
+    // Try to remove file from both locations to be safe
     if (fs.existsSync(enabledPath)) {
       fs.unlinkSync(enabledPath);
       fileRemoved = true;
-      console.log('Removed mod from Mods folder:', enabledPath);
-    } else if (fs.existsSync(disabledPath)) {
-      fs.unlinkSync(disabledPath);
-      fileRemoved = true;
-      console.log('Removed mod from DisabledMods folder:', disabledPath);
     }
-    
+    if (fs.existsSync(disabledPath)) {
+      try { fs.unlinkSync(disabledPath); fileRemoved = true; } catch (e) { }
+    }
+
     if (!fileRemoved) {
-      console.warn('Mod file not found on filesystem, removing from config anyway');
+      console.warn('Mod file not found on filesystem, removing from profile anyway');
     }
-    
-    const updatedMods = configMods.filter(m => m.id !== modId);
-    saveModsToConfig(updatedMods);
-    console.log('Mod removed from config.json');
-    
+
+    const updatedMods = profileMods.filter(m => m.id !== modId);
+    profileManager.updateProfile(activeProfile.id, { mods: updatedMods });
+
+    console.log('Mod removed from profile');
+
     return { success: true };
   } catch (error) {
     console.error('Error uninstalling mod:', error);
@@ -223,38 +208,53 @@ async function uninstallMod(modId, modsPath) {
 
 async function toggleMod(modId, modsPath) {
   try {
-    const mods = await loadInstalledMods(modsPath);
-    const mod = mods.find(m => m.id === modId);
-    
-    if (!mod) {
-      throw new Error('Mod not found');
+    const activeProfile = profileManager.getActiveProfile();
+    if (!activeProfile) throw new Error('No active profile');
+
+    const profileMods = activeProfile.mods || [];
+    const modIndex = profileMods.findIndex(m => m.id === modId);
+
+    if (modIndex === -1) {
+      throw new Error('Mod not found in profile');
     }
 
+    const mod = profileMods[modIndex];
+    const newEnabled = !mod.enabled; // Toggle
+
+    // Update Profile First
+    const updatedMods = [...profileMods];
+    updatedMods[modIndex] = { ...mod, enabled: newEnabled };
+    profileManager.updateProfile(activeProfile.id, { mods: updatedMods });
+
+    // Manually move the file to reflect the new state
     const disabledModsPath = path.join(path.dirname(modsPath), 'DisabledMods');
-    if (!fs.existsSync(disabledModsPath)) {
-      fs.mkdirSync(disabledModsPath, { recursive: true });
-    }
+    if (!fs.existsSync(disabledModsPath)) fs.mkdirSync(disabledModsPath, { recursive: true });
 
-    const currentPath = mod.filePath;
-    let newPath, newEnabled;
+    const currentPath = mod.enabled ? path.join(modsPath, mod.fileName) : path.join(disabledModsPath, mod.fileName);
 
-    if (mod.enabled) {
-      newPath = path.join(disabledModsPath, path.basename(currentPath));
-      newEnabled = false;
+    // Determine target paths
+
+    const targetDir = newEnabled ? modsPath : disabledModsPath;
+    const targetPath = path.join(targetDir, mod.fileName);
+
+    if (fs.existsSync(currentPath)) {
+      fs.renameSync(currentPath, targetPath);
     } else {
-      newPath = path.join(modsPath, path.basename(currentPath));
-      newEnabled = true;
+      // Fallback: check if it's already in target?
+
+
+      if (fs.existsSync(targetPath)) {
+        // It's already there, maybe just state was wrong.
+
+        console.log(`[ModManager] Mod ${mod.fileName} is already in the correct state`);
+
+      } else {
+        // Try finding it
+        const altPath = mod.enabled ? path.join(disabledModsPath, mod.fileName) : path.join(modsPath, mod.fileName);
+        if (fs.existsSync(altPath)) fs.renameSync(altPath, targetPath);
+      }
     }
 
-    fs.renameSync(currentPath, newPath);
-    
-    const configMods = loadModsFromConfig();
-    const configModIndex = configMods.findIndex(m => m.id === modId);
-    if (configModIndex !== -1) {
-      configMods[configModIndex].enabled = newEnabled;
-      saveModsToConfig(configMods);
-    }
-    
     return { success: true, enabled: newEnabled };
   } catch (error) {
     console.error('Error toggling mod:', error);
@@ -265,11 +265,69 @@ async function toggleMod(modId, modsPath) {
   }
 }
 
+async function syncModsForCurrentProfile() {
+  try {
+    const activeProfile = profileManager.getActiveProfile();
+    if (!activeProfile) {
+      console.warn('No active profile found during mod sync');
+      return;
+    }
+
+    console.log(`[ModManager] Syncing mods for profile: ${activeProfile.name}`);
+
+    const modsPath = await getModsPath();
+    const disabledModsPath = path.join(path.dirname(modsPath), 'DisabledMods');
+
+    if (!fs.existsSync(disabledModsPath)) {
+      fs.mkdirSync(disabledModsPath, { recursive: true });
+    }
+
+    // Get all physical files from both folders
+    const enabledFiles = fs.existsSync(modsPath) ? fs.readdirSync(modsPath).filter(f => f.endsWith('.jar') || f.endsWith('.zip')) : [];
+    const disabledFiles = fs.existsSync(disabledModsPath) ? fs.readdirSync(disabledModsPath).filter(f => f.endsWith('.jar') || f.endsWith('.zip')) : [];
+
+    const allFiles = new Set([...enabledFiles, ...disabledFiles]);
+
+    // Profile.mods contains the list of ALL mods for that profile, with their enabled state.
+
+    const profileMods = activeProfile.mods || [];
+
+    for (const fileName of allFiles) {
+      const modConfig = profileMods.find(m => m.fileName === fileName);
+      const shouldBeEnabled = modConfig && modConfig.enabled !== false; // Default to true if in list, unless explicitly false
+
+      // Logic:
+      // If it should be enabled -> Move to mods/
+      // If it should be disabled -> Move to DisabledMods/
+
+      const currentPath = enabledFiles.includes(fileName) ? path.join(modsPath, fileName) : path.join(disabledModsPath, fileName);
+      const targetDir = shouldBeEnabled ? modsPath : disabledModsPath;
+      const targetPath = path.join(targetDir, fileName);
+
+      if (path.dirname(currentPath) !== targetDir) {
+        console.log(`[Mod Sync] Moving ${fileName} to ${shouldBeEnabled ? 'Enabled' : 'Disabled'}`);
+        try {
+          fs.renameSync(currentPath, targetPath);
+        } catch (err) {
+          console.error(`Failed to move ${fileName}: ${err.message}`);
+        }
+      }
+    }
+
+    return { success: true };
+
+  } catch (error) {
+    console.error('[ModManager] Error syncing mods:', error);
+    return { success: false, error: error.message };
+  }
+}
+
 module.exports = {
   loadInstalledMods,
   downloadMod,
   uninstallMod,
   toggleMod,
+  syncModsForCurrentProfile,
   generateModId,
   extractModName,
   extractVersion

backend/managers/profileManager.js

@@ -0,0 +1,209 @@
+const path = require('path');
+const fs = require('fs');
+const { v4: uuidv4 } = require('uuid');
+const { 
+  loadConfig, 
+  saveConfig, 
+  getModsPath 
+} = require('../core/config');
+
+// We'll lazy-load modManager to avoid circular dependencies if possible, 
+// or carefully structure our imports. 
+// For now, we might need to access mod paths directly or use helper functions.
+
+class ProfileManager {
+  constructor() {
+    this.initialized = false;
+  }
+
+  init() {
+    if (this.initialized) return;
+
+    const config = loadConfig();
+    
+    // Migration: specific check to see if we have profiles yet
+    if (!config.profiles || Object.keys(config.profiles).length === 0) {
+      this.migrateLegacyConfig(config);
+    }
+    
+    this.initialized = true;
+    console.log('[ProfileManager] Initialized');
+  }
+
+  migrateLegacyConfig(config) {
+    console.log('[ProfileManager] Migrating legacy config to profile system...');
+    
+    // Create a default profile with current settings
+    const defaultProfileId = 'default';
+    const defaultProfile = {
+      id: defaultProfileId,
+      name: 'Default',
+      created: new Date().toISOString(),
+      lastUsed: new Date().toISOString(),
+      
+      // settings specific to this profile
+      // If global settings existed, we copy them here
+      mods: config.installedMods || [], // Legacy mods are now part of default profile
+      javaPath: config.javaPath || '',
+      gameOptions: {
+        minMemory: '1G',
+        maxMemory: '4G',
+        args: []
+      }
+    };
+
+    const updates = {
+      profiles: {
+        [defaultProfileId]: defaultProfile
+      },
+      activeProfileId: defaultProfileId,
+      // We keep a global registry of "known" mods if we want, 
+      // but for now the current implementation implies 
+      // mods are just files in folders.
+      // We'll use the profile "mods" array to track ENABLED/KNOWN mods for that profile.
+    };
+
+    saveConfig(updates);
+    console.log('[ProfileManager] Migration complete. Created Default profile.');
+  }
+
+  createProfile(name) {
+    if (!name || typeof name !== 'string') {
+      throw new Error('Invalid profile name');
+    }
+
+    const config = loadConfig();
+    const id = uuidv4();
+    
+    const newProfile = {
+      id,
+      name: name.trim(),
+      created: new Date().toISOString(),
+      lastUsed: null,
+      mods: [], // Start with no mods enabled
+      javaPath: '', 
+      gameOptions: {
+        minMemory: '1G',
+        maxMemory: '4G',
+        args: []
+      }
+    };
+
+    const profiles = config.profiles || {};
+    profiles[id] = newProfile;
+
+    saveConfig({ profiles });
+    
+    console.log(`[ProfileManager] Created new profile: "${name}" (${id})`);
+    return newProfile;
+  }
+
+  getProfiles() {
+    const config = loadConfig();
+    return Object.values(config.profiles || {});
+  }
+
+  getProfile(id) {
+    const config = loadConfig();
+    return (config.profiles && config.profiles[id]) || null;
+  }
+
+  getActiveProfile() {
+    const config = loadConfig();
+    const activeId = config.activeProfileId;
+    if (!activeId || !config.profiles || !config.profiles[activeId]) {
+      // Fallback if something is corrupted
+      return this.getProfiles()[0] || null; 
+    }
+    return config.profiles[activeId];
+  }
+
+  async activateProfile(id) {
+    const config = loadConfig();
+    if (!config.profiles || !config.profiles[id]) {
+        throw new Error(`Profile not found: ${id}`);
+    }
+
+    if (config.activeProfileId === id) {
+        console.log(`[ProfileManager] Profile ${id} is already active.`);
+        return config.profiles[id];
+    }
+
+    console.log(`[ProfileManager] Switching to profile: ${config.profiles[id].name} (${id})`);
+    
+    // 1. Update config first
+    config.profiles[id].lastUsed = new Date().toISOString();
+    saveConfig({ 
+        activeProfileId: id,
+        profiles: config.profiles 
+    });
+
+    // 2. Trigger Mod Sync
+    // We need to require this here to ensure it uses the *newly saved* active profile ID
+    const { syncModsForCurrentProfile } = require('./modManager');
+    await syncModsForCurrentProfile();
+
+    return config.profiles[id];
+  }
+
+  deleteProfile(id) {
+    const config = loadConfig();
+    const profiles = config.profiles || {};
+    
+    if (!profiles[id]) {
+      throw new Error('Profile not found');
+    }
+
+    if (config.activeProfileId === id) {
+       throw new Error('Cannot delete the active profile');
+    }
+
+    // Don't allow deleting the last profile
+    if (Object.keys(profiles).length <= 1) {
+        throw new Error('Cannot delete the only remaining profile');
+    }
+
+    delete profiles[id];
+    saveConfig({ profiles });
+    console.log(`[ProfileManager] Deleted profile: ${id}`);
+    
+    return true;
+  }
+
+  updateProfile(id, updates) {
+    const config = loadConfig();
+    const profiles = config.profiles || {};
+    
+    if (!profiles[id]) {
+        throw new Error('Profile not found');
+    }
+
+    // Safety checks on updates
+    const allowedFields = ['name', 'javaPath', 'gameOptions', 'mods'];
+    const sanitizedUpdates = {};
+    
+    Object.keys(updates).forEach(key => {
+        if (allowedFields.includes(key)) {
+            sanitizedUpdates[key] = updates[key];
+        }
+    });
+
+    profiles[id] = { ...profiles[id], ...sanitizedUpdates };
+    
+    saveConfig({ profiles });
+    console.log(`[ProfileManager] Updated profile: ${id}`);
+    
+    // If we updated mods for the *active* profile, we might need to sync immediately
+    if (config.activeProfileId === id && updates.mods) {
+         // Optionally trigger sync? 
+         // Usually updates come from "Enabling/Disabling" a single mod, 
+         // which might call a more specific method. 
+         // But if we bulk update, we should sync.
+         // Let's leave sync invoke to the caller or specific methods for now.
+    }
+
+    return profiles[id];
+  }
+}
+
+module.exports = new ProfileManager();