From 9662c8ce56a1e33b4c9f00fa7fdb8b0db9493c20 Mon Sep 17 00:00:00 2001
From: mbrucedogs <mbrucedogs@gmail.com>
Date: Sun, 20 Jul 2025 21:33:46 -0500
Subject: [PATCH] Signed-off-by: mbrucedogs <mbrucedogs@gmail.com>

---
 README.md                     | 326 ++++++++++++++++++++++++++++------
 docs/PRD.md                   |  18 ++
 docs/platforms/web/PRD-web.md | 283 +++++++++++++++++++++++++++--
 3 files changed, 557 insertions(+), 70 deletions(-)

diff --git a/README.md b/README.md
index 7959ce4..f984773 100644
--- a/README.md
+++ b/README.md
@@ -1,69 +1,279 @@
-# React + TypeScript + Vite
+# SingSalot AI - Karaoke App
 
-This template provides a minimal setup to get React working in Vite with HMR and some ESLint rules.
+> **Modern React + TypeScript + Ionic + Firebase Realtime Database**
 
-Currently, two official plugins are available:
+A real-time karaoke application designed for in-home party use with multi-user synchronization, admin controls, and comprehensive song management.
 
-- [@vitejs/plugin-react](https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react) uses [Babel](https://babeljs.io/) for Fast Refresh
-- [@vitejs/plugin-react-swc](https://github.com/vitejs/vite-plugin-react/blob/main/packages/plugin-react-swc) uses [SWC](https://swc.rs/) for Fast Refresh
+## 🎯 Features
 
-## Expanding the ESLint configuration
+### **Core Functionality**
+- **Real-time Queue Management** - Synchronized across all connected devices
+- **Multi-User Support** - Admin and user roles with different permissions
+- **Comprehensive Search** - Instant search through song catalog with pagination
+- **Favorites System** - Shared favorites list across all users
+- **History Tracking** - Automatic tracking of played songs
+- **Artist Browsing** - Browse songs by artist with modal views
+- **Song Lists** - Predefined song collections with availability matching
+- **Top Played** - Popular songs based on play history
+- **New Songs** - Recently added songs to the catalog
 
-If you are developing a production application, we recommend updating the configuration to enable type-aware lint rules:
+### **Admin Features**
+- **Queue Control** - Reorder and delete queue items
+- **Playback Control** - Play, pause, stop music
+- **Singer Management** - Add/remove singers
+- **Settings Management** - Configure autoadvance and userpick
+- **Song Management** - Disable/enable songs
 
-```js
-export default tseslint.config([
-  globalIgnores(['dist']),
-  {
-    files: ['**/*.{ts,tsx}'],
-    extends: [
-      // Other configs...
+### **Technical Features**
+- **Real-time Sync** - Firebase Realtime Database synchronization
+- **Performance Optimized** - Memoized components, virtualized lists, pagination
+- **Type Safety** - Full TypeScript implementation
+- **Responsive Design** - Mobile-first with touch-friendly interface
+- **Error Handling** - Graceful degradation and retry patterns
 
-      // Remove tseslint.configs.recommended and replace with this
-      ...tseslint.configs.recommendedTypeChecked,
-      // Alternatively, use this for stricter rules
-      ...tseslint.configs.strictTypeChecked,
-      // Optionally, add this for stylistic rules
-      ...tseslint.configs.stylisticTypeChecked,
+## 🏗️ Architecture
 
-      // Other configs...
-    ],
-    languageOptions: {
-      parserOptions: {
-        project: ['./tsconfig.node.json', './tsconfig.app.json'],
-        tsconfigRootDir: import.meta.dirname,
-      },
-      // other options...
-    },
-  },
-])
+### **Refactored Architecture (Latest)**
+The codebase has been completely refactored for better maintainability and performance:
+
+#### **Domain-Specific Redux Slices**
+- `songsSlice.ts` - Song catalog management
+- `queueSlice.ts` - Queue operations and state
+- `favoritesSlice.ts` - Favorites management
+- `historySlice.ts` - History tracking
+
+#### **Composable Hooks**
+- `useFilteredSongs.ts` - Reusable song filtering logic
+- `usePaginatedData.ts` - Generic pagination with search
+- `useErrorHandler.ts` - Centralized error handling
+- `usePerformanceMonitor.ts` - Performance tracking
+
+#### **Optimized Components**
+- `SongItem.tsx` - Memoized with React.memo and useCallback
+- `ListItem.tsx` - Generic list item with TypeScript support
+- `VirtualizedList.tsx` - High-performance list rendering
+- `ActionButton.tsx` - Reusable action buttons
+
+#### **Performance Optimizations**
+- **React.memo** for component memoization
+- **useMemo/useCallback** for expensive computations
+- **Virtualized rendering** for large datasets
+- **Infinite scroll** with pagination
+- **Optimized Redux selectors**
+
+## 🚀 Quick Start
+
+### **Prerequisites**
+- Node.js 18+ 
+- npm or yarn
+- Firebase project setup
+
+### **Installation**
+```bash
+# Clone the repository
+git clone <repository-url>
+cd singsalot-ai
+
+# Install dependencies
+npm install
+
+# Set up environment variables
+cp env.template .env.local
+# Edit .env.local with your Firebase configuration
+
+# Start development server
+npm run dev
 ```
 
-You can also install [eslint-plugin-react-x](https://github.com/Rel1cx/eslint-react/tree/main/packages/plugins/eslint-plugin-react-x) and [eslint-plugin-react-dom](https://github.com/Rel1cx/eslint-react/tree/main/packages/plugins/eslint-plugin-react-dom) for React-specific lint rules:
-
-```js
-// eslint.config.js
-import reactX from 'eslint-plugin-react-x'
-import reactDom from 'eslint-plugin-react-dom'
-
-export default tseslint.config([
-  globalIgnores(['dist']),
-  {
-    files: ['**/*.{ts,tsx}'],
-    extends: [
-      // Other configs...
-      // Enable lint rules for React
-      reactX.configs['recommended-typescript'],
-      // Enable lint rules for React DOM
-      reactDom.configs.recommended,
-    ],
-    languageOptions: {
-      parserOptions: {
-        project: ['./tsconfig.node.json', './tsconfig.app.json'],
-        tsconfigRootDir: import.meta.dirname,
-      },
-      // other options...
-    },
-  },
-])
+### **Environment Setup**
+Create a `.env.local` file with your Firebase configuration:
+```env
+VITE_FIREBASE_API_KEY=your_api_key
+VITE_FIREBASE_AUTH_DOMAIN=your_project.firebaseapp.com
+VITE_FIREBASE_DATABASE_URL=https://your_project.firebaseio.com
+VITE_FIREBASE_PROJECT_ID=your_project_id
+VITE_FIREBASE_STORAGE_BUCKET=your_project.appspot.com
+VITE_FIREBASE_MESSAGING_SENDER_ID=your_sender_id
+VITE_FIREBASE_APP_ID=your_app_id
 ```
+
+## 📁 Project Structure
+
+```
+src/
+├── components/          # Reusable UI components
+│   ├── Auth/           # Authentication components
+│   ├── common/         # Shared components (SongItem, ActionButton, etc.)
+│   ├── Layout/         # Layout and navigation components
+│   └── Navigation/     # Navigation components
+├── features/           # Feature-specific components
+│   ├── Artists/        # Artist browsing feature
+│   ├── Favorites/      # Favorites management
+│   ├── History/        # Play history
+│   ├── NewSongs/       # New songs feature
+│   ├── Queue/          # Queue management
+│   ├── Search/         # Song search
+│   ├── Settings/       # Settings and admin features
+│   ├── Singers/        # Singer management
+│   ├── SongLists/      # Song lists feature
+│   └── TopPlayed/      # Top played songs
+├── firebase/           # Firebase configuration and services
+├── hooks/              # Custom React hooks (refactored)
+├── redux/              # State management (domain-specific slices)
+├── types/              # TypeScript type definitions
+└── utils/              # Utility functions
+```
+
+## 🛠️ Development
+
+### **Available Scripts**
+```bash
+npm run dev          # Start development server
+npm run build        # Build for production
+npm run preview      # Preview production build
+npm run lint         # Run ESLint
+npm run type-check   # Run TypeScript type checking
+```
+
+### **Key Development Patterns**
+
+#### **Adding New Features**
+1. Create feature component in `src/features/`
+2. Add corresponding Redux slice if needed
+3. Create custom hooks for business logic
+4. Add TypeScript types in `src/types/`
+
+#### **Component Guidelines**
+- Use `React.memo` for performance-critical components
+- Implement `useMemo` and `useCallback` for expensive operations
+- Follow the established prop patterns for consistency
+
+#### **State Management**
+- Use domain-specific Redux slices for related functionality
+- Implement async thunks for Firebase operations
+- Use memoized selectors for performance
+
+## 🔧 Firebase Configuration
+
+### **Database Structure**
+The app uses Firebase Realtime Database with the following structure:
+```json
+{
+  "controllers": {
+    "[controllerName]": {
+      "favorites": {},
+      "history": {},
+      "topPlayed": {},
+      "newSongs": {},
+      "disabledSongs": {},
+      "player": {
+        "queue": {},
+        "settings": {},
+        "singers": {},
+        "state": {}
+      },
+      "songList": {},
+      "songs": {}
+    }
+  }
+}
+```
+
+### **Security Rules**
+The app uses client-side validation with permissive Firebase rules for real-time synchronization.
+
+## 📱 User Experience
+
+### **Authentication**
+- Login requires Party ID and singer name
+- Admin access is a privileged mode
+- Session state managed in app (lost on reload)
+
+### **Queue Management**
+- Real-time synchronization across all clients
+- Sequential numerical keys (0, 1, 2, ...)
+- Admin-only reordering and deletion
+- First item protection during playback
+
+### **Search & Discovery**
+- Instant search with debouncing
+- Paginated results with infinite scroll
+- Multiple entry points (search, history, favorites, etc.)
+- Context-aware actions for each song
+
+## 🧪 Testing
+
+### **Current Testing Status**
+- ✅ TypeScript compilation
+- ✅ ESLint validation
+- ✅ Build process
+- 🔄 Unit tests (planned)
+- 🔄 Integration tests (planned)
+
+### **Testing Strategy**
+- Unit tests for business logic and hooks
+- Integration tests for Firebase operations
+- Component testing with React Testing Library
+- Performance testing for large datasets
+
+## 🚀 Deployment
+
+### **Build Process**
+```bash
+npm run build
+```
+
+The build process:
+- Compiles TypeScript
+- Bundles with Vite
+- Optimizes for production
+- Generates static assets
+
+### **Deployment Options**
+- **Firebase Hosting** - Recommended for Firebase integration
+- **Vercel** - Easy deployment with automatic builds
+- **Netlify** - Static site hosting with CI/CD
+- **Traditional hosting** - Any static file server
+
+## 📚 Documentation
+
+### **Related Documents**
+- [`docs/PRD.md`](docs/PRD.md) - Product Requirements Document
+- [`docs/platforms/web/PRD-web.md`](docs/platforms/web/PRD-web.md) - Web-specific implementation guide
+- [`docs/firebase_schema.json`](docs/firebase_schema.json) - Firebase database schema
+
+### **Design Assets**
+- [`docs/platforms/web/design/`](docs/platforms/web/design/) - UI/UX design mockups and assets
+
+## 🤝 Contributing
+
+### **Development Workflow**
+1. Create feature branch from main
+2. Implement changes following established patterns
+3. Ensure TypeScript compilation passes
+4. Run linting and type checking
+5. Test functionality manually
+6. Submit pull request
+
+### **Code Standards**
+- Follow TypeScript best practices
+- Use established component patterns
+- Maintain performance optimizations
+- Add appropriate error handling
+- Update documentation as needed
+
+## 📄 License
+
+This project is proprietary software. All rights reserved.
+
+## 🆘 Support
+
+For technical support or questions about the implementation:
+- Check the documentation in the `docs/` folder
+- Review the TypeScript types for API contracts
+- Examine the Firebase schema for data structure
+- Refer to the platform-specific PRD for implementation details
+
+---
+
+**Built with ❤️ using React, TypeScript, Ionic, and Firebase**
diff --git a/docs/PRD.md b/docs/PRD.md
index e2093a3..84cb17b 100644
--- a/docs/PRD.md
+++ b/docs/PRD.md
@@ -493,6 +493,15 @@ controllers: {
 - **Data Models** shared across all layers
 - **Firebase Integration** abstracted through service layer
 
+### **Architecture Principles:**
+- **Separation of Concerns** - UI components handle presentation, business logic in services
+- **Reusable Business Logic** - Business rules implemented in platform-agnostic services
+- **Testable Code** - Business logic separated from UI for easy testing
+- **Maintainability** - Changes to logic don't affect UI
+- **Performance** - Optimized data access and state management
+- **Type Safety** - Strong typing throughout the codebase
+- **Single Responsibility** - Each file has one clear purpose
+
 ### **Platform Implementation:**
 - **Web:** See `platforms/web/PRD-web.md#codebase-organization` for React/Ionic structure
 - **iOS:** See `platforms/ios/PRD-ios.md#codebase-organization` (future)
@@ -542,6 +551,15 @@ controllers: {
 - **Caching strategy** for frequently accessed data
 - **Memory management** for large datasets
 
+### **Performance Requirements:**
+- **Real-time synchronization** with minimal latency
+- **Efficient data loading** with pagination and infinite scroll
+- **Optimized state management** to prevent unnecessary re-renders
+- **Caching strategy** for frequently accessed data
+- **Memory management** for large datasets
+- **Component optimization** for expensive UI operations
+- **Data filtering and search** with efficient algorithms
+
 ### **Platform Implementation:**
 - **Web:** See `platforms/web/PRD-web.md#performance` for React/Ionic optimization
 - **iOS:** See `platforms/ios/PRD-ios.md#performance` (future)
diff --git a/docs/platforms/web/PRD-web.md b/docs/platforms/web/PRD-web.md
index 93011d9..ef61547 100644
--- a/docs/platforms/web/PRD-web.md
+++ b/docs/platforms/web/PRD-web.md
@@ -12,14 +12,200 @@ This document contains **web-specific implementation details** for the Karaoke A
 | Section | Purpose |
 |---------|---------|
 | [UI/UX Behavior](#uiux-behavior) | Web-specific UI patterns and interactions |
+| [Refactored Architecture](#refactored-architecture) | Latest architecture improvements and patterns |
 | [Component Architecture](#component-architecture) | React/Ionic component structure |
 | [State Management](#state-management) | Redux Toolkit implementation |
+| [Performance Optimizations](#performance-optimizations) | Web-specific performance strategies |
 | [Development Setup](#development-setup) | Web project configuration |
 | [Design Assets](#design-assets) | Web-specific visual references |
 | [Toolset Choices](#toolset-choices) | Web technology rationale |
 
 ---
 
+## Refactored Architecture
+
+### **Overview**
+The web implementation has been completely refactored to improve maintainability, performance, and developer experience. This section documents the latest architecture patterns and implementation details.
+
+### **Key Architectural Improvements**
+
+#### **1. Domain-Specific Redux Slices**
+Replaced the monolithic `controllerSlice` with focused, domain-specific slices:
+
+```typescript
+// Before: Monolithic controllerSlice
+src/redux/controllerSlice.ts (1000+ lines)
+
+// After: Domain-specific slices
+src/redux/songsSlice.ts      // Song catalog management
+src/redux/queueSlice.ts      // Queue operations and state
+src/redux/favoritesSlice.ts  // Favorites management
+src/redux/historySlice.ts    // History tracking
+```
+
+**Benefits:**
+- **Better Performance** - Smaller slices mean faster state updates
+- **Easier Testing** - Isolated business logic for each domain
+- **Improved Maintainability** - Clear separation of concerns
+- **Reduced Bundle Size** - Only load necessary slice logic
+
+#### **2. Composable Hooks**
+Extracted common patterns into reusable, composable hooks:
+
+```typescript
+// Reusable filtering logic
+useFilteredSongs(songs, searchTerm, disabledSongs)
+
+// Generic pagination with search
+usePaginatedData(data, pageSize, searchTerm)
+
+// Centralized error handling
+useErrorHandler(operation, fallbackMessage)
+
+// Performance monitoring
+usePerformanceMonitor(componentName, props)
+```
+
+**Benefits:**
+- **Code Reuse** - Common patterns shared across features
+- **Performance Optimized** - Each hook can be optimized independently
+- **Type Safety** - Full TypeScript support with proper typing
+- **Easier Testing** - Isolated business logic
+
+#### **3. Optimized Components**
+Enhanced components with performance optimizations:
+
+```typescript
+// Memoized SongItem with optimized rendering
+const SongItem = React.memo<SongItemProps>(({ song, context, ...props }) => {
+  const isInQueue = useMemo(() => /* expensive computation */, [queue, song.path]);
+  const handleAddToQueue = useCallback(() => /* action */, [handleAddToQueue, song]);
+  
+  return <IonItem>...</IonItem>;
+});
+
+// Generic ListItem for any data type
+const ListItem = React.memo<GenericListItemProps>(({ 
+  primaryText, secondaryText, onClick, ...props 
+}) => {
+  return <IonItem>...</IonItem>;
+});
+
+// High-performance virtualized list
+const VirtualizedList = <T,>({ 
+  items, renderItem, itemHeight, ...props 
+}: VirtualizedListProps<T>) => {
+  // Only renders visible items
+  return <div>...</div>;
+};
+```
+
+**Benefits:**
+- **React.memo** - Prevents unnecessary re-renders
+- **Generic Components** - Reusable across different data types
+- **Virtualized Rendering** - Handles large datasets efficiently
+- **Performance Monitoring** - Built-in tracking capabilities
+
+### **Implementation Patterns**
+
+#### **State Management Pattern**
+```typescript
+// Domain-specific slice
+export const songsSlice = createSlice({
+  name: 'songs',
+  initialState,
+  reducers: { /* domain-specific actions */ },
+  extraReducers: (builder) => {
+    builder.addCase(fetchSongs.fulfilled, (state, action) => {
+      // Handle async operations
+    });
+  },
+});
+
+// Composable hook using the slice
+export const useSongs = () => {
+  const dispatch = useAppDispatch();
+  const songs = useAppSelector(selectSongs);
+  
+  const fetchSongs = useCallback(async () => {
+    try {
+      await dispatch(fetchSongsThunk());
+    } catch (error) {
+      // Error handling
+    }
+  }, [dispatch]);
+  
+  return { songs, fetchSongs };
+};
+```
+
+#### **Component Pattern**
+```typescript
+// Feature component using composable hooks
+const Search: React.FC = () => {
+  const { songs, loading, error } = useSongs();
+  const { filteredSongs, searchTerm, setSearchTerm } = useFilteredSongs(songs);
+  const { paginatedData, hasMore, loadMore } = usePaginatedData(filteredSongs);
+  
+  return (
+    <div>
+      <SearchInput value={searchTerm} onChange={setSearchTerm} />
+      <VirtualizedList
+        items={paginatedData}
+        renderItem={(song) => <SongItem song={song} context="search" />}
+        hasMore={hasMore}
+        onLoadMore={loadMore}
+      />
+    </div>
+  );
+};
+```
+
+### **Performance Optimizations**
+
+#### **Component-Level Optimizations**
+- **React.memo** - Prevents re-renders when props haven't changed
+- **useMemo** - Memoizes expensive computations
+- **useCallback** - Memoizes event handlers and functions
+- **Virtualized Lists** - Only renders visible items for large datasets
+
+#### **State Management Optimizations**
+- **Domain-Specific Slices** - Smaller, focused state management
+- **Memoized Selectors** - Efficient state access with reselect
+- **Lazy Loading** - Load components and data only when needed
+- **Incremental Updates** - Target specific Firebase nodes for efficiency
+
+#### **Data Handling Optimizations**
+- **Pagination** - Load data in chunks to prevent UI blocking
+- **Search Debouncing** - Reduce unnecessary API calls during typing
+- **Filtering Optimization** - Efficient algorithms for large datasets
+- **Memory Management** - Proper cleanup of listeners and subscriptions
+
+### **Development Guidelines**
+
+#### **Adding New Features**
+1. **Create domain-specific slice** if needed
+2. **Implement composable hooks** for business logic
+3. **Build optimized components** with React.memo and useCallback
+4. **Add TypeScript types** for type safety
+5. **Implement error handling** using useErrorHandler
+
+#### **Performance Best Practices**
+- **Use React.memo** for expensive components
+- **Implement useMemo/useCallback** for expensive operations
+- **Leverage virtualized lists** for large datasets
+- **Optimize Redux selectors** with memoization
+- **Monitor performance** with usePerformanceMonitor
+
+#### **Code Organization**
+- **Domain-specific slices** in `/redux/`
+- **Composable hooks** in `/hooks/`
+- **Generic components** in `/components/common/`
+- **Feature components** in `/features/`
+- **TypeScript types** in `/types/`
+
+---
+
 ## UI/UX Behavior
 
 ### **Web-Specific Requirements:**
@@ -55,7 +241,7 @@ This document contains **web-specific implementation details** for the Karaoke A
 
 ## Codebase Organization & File Structure
 
-### **Web Project Structure:**
+### **Refactored Web Project Structure (Latest):**
 ```
 src/
 ├── components/          # Reusable UI components
@@ -78,28 +264,55 @@ src/
 │   ├── config.ts       # Firebase configuration
 │   ├── services.ts     # Firebase service layer
 │   └── useFirebase.ts  # Firebase hooks
-├── hooks/              # Custom React hooks
+├── hooks/              # Custom React hooks (refactored)
+│   ├── useFilteredSongs.ts    # Reusable song filtering logic
+│   ├── usePaginatedData.ts    # Generic pagination with search
+│   ├── useErrorHandler.ts     # Centralized error handling
+│   ├── usePerformanceMonitor.ts # Performance tracking
 │   ├── useQueue.ts     # Queue management hooks
 │   ├── useSearch.ts    # Search functionality hooks
 │   ├── useFavorites.ts # Favorites management hooks
 │   └── ...            # Other feature hooks
-├── redux/              # State management
+├── redux/              # State management (domain-specific slices)
 │   ├── store.ts        # Redux store configuration
-│   ├── slices/         # Redux slices
+│   ├── songsSlice.ts   # Song catalog management
+│   ├── queueSlice.ts   # Queue operations and state
+│   ├── favoritesSlice.ts # Favorites management
+│   ├── historySlice.ts # History tracking
 │   ├── selectors.ts    # Memoized selectors
 │   └── hooks.ts        # Redux hooks
 ├── types/              # TypeScript type definitions
 └── utils/              # Utility functions
 ```
 
+### **Refactored Architecture Benefits:**
+
+#### **Domain-Specific Redux Slices:**
+- **Modular Design** - Each slice handles a specific domain (songs, queue, favorites, history)
+- **Better Performance** - Smaller slices mean faster state updates and re-renders
+- **Easier Testing** - Isolated business logic for each domain
+- **Improved Maintainability** - Clear separation of concerns
+
+#### **Composable Hooks:**
+- **Reusable Logic** - Common patterns extracted into reusable hooks
+- **Performance Optimized** - Each hook can be optimized independently
+- **Type Safety** - Full TypeScript support with proper typing
+- **Error Handling** - Centralized error management across the app
+
+#### **Optimized Components:**
+- **React.memo** - Prevents unnecessary re-renders for expensive components
+- **Generic Components** - Reusable across different data types (ListItem, VirtualizedList)
+- **Performance Monitoring** - Built-in performance tracking
+- **Error Boundaries** - Graceful error handling and recovery
+
 ### **File Organization Rules:**
 | Folder | Purpose | Key Files | Import Pattern |
 |--------|---------|-----------|----------------|
-| `/components` | Reusable UI components | `SongItem.tsx`, `ActionButton.tsx` | `import { SongItem } from '../components/common'` |
+| `/components` | Reusable UI components | `SongItem.tsx`, `ActionButton.tsx`, `ListItem.tsx` | `import { SongItem } from '../components/common'` |
 | `/features` | Feature-specific pages | `Queue.tsx`, `Search.tsx` | `import { Queue } from '../features/Queue'` |
 | `/firebase` | Firebase integration | `services.ts`, `config.ts` | `import { queueService } from '../firebase/services'` |
-| `/hooks` | Custom business logic | `useQueue.ts`, `useSearch.ts` | `import { useQueue } from '../hooks/useQueue'` |
-| `/redux` | State management | `controllerSlice.ts`, `authSlice.ts`, `selectors.ts` | `import { useAppDispatch, selectQueue } from '../redux'` |
+| `/hooks` | Composable business logic | `useFilteredSongs.ts`, `usePaginatedData.ts` | `import { useFilteredSongs } from '../hooks'` |
+| `/redux` | Domain-specific state | `songsSlice.ts`, `queueSlice.ts` | `import { songsSlice } from '../redux'` |
 | `/types` | TypeScript definitions | `index.ts` (extends docs/types.ts) | `import type { Song, QueueItem } from '../types'` |
 
 ### **Import Patterns:**
@@ -709,11 +922,55 @@ const Queue: React.FC = () => {
 ```
 
 ### **Performance Optimizations:**
-- **React.memo** for expensive components
-- **useMemo** and **useCallback** for expensive calculations
-- **Redux selectors** with memoization
-- **Lazy loading** for route-based code splitting
-- **Service worker** for PWA caching
+
+#### **Component-Level Optimizations:**
+- **React.memo** - Prevents unnecessary re-renders for expensive components like `SongItem`
+- **useMemo/useCallback** - Memoizes expensive computations and event handlers
+- **Virtualized Lists** - `VirtualizedList` component renders only visible items for large datasets
+- **Generic Components** - `ListItem` component works with any data type for reusability
+
+#### **State Management Optimizations:**
+- **Domain-Specific Slices** - Smaller, focused Redux slices (songs, queue, favorites, history)
+- **Composable Hooks** - Reusable logic (`useFilteredSongs`, `usePaginatedData`, `useErrorHandler`)
+- **Optimized Selectors** - Memoized Redux selectors for efficient state access
+- **Lazy Loading** - Components and data loaded only when needed
+
+#### **Data Handling Optimizations:**
+- **Pagination** - `usePaginatedData` hook loads data in chunks to prevent UI blocking
+- **Search Debouncing** - Reduces unnecessary API calls during typing
+- **Filtering Optimization** - `useFilteredSongs` hook provides efficient filtering algorithms
+- **Memory Management** - Proper cleanup of listeners and subscriptions
+
+#### **Performance Monitoring:**
+- **Built-in Performance Hooks** - `usePerformanceMonitor` tracks component render times
+- **Error Tracking** - Centralized error handling with performance impact monitoring
+- **Bundle Analysis** - Optimized bundle size with code splitting
+
+#### **Specific Optimizations:**
+- **SongItem Component** - Fully memoized with React.memo, useMemo, and useCallback
+- **ListItem Component** - Generic component supporting multiple data types
+- **VirtualizedList Component** - High-performance list rendering with windowing
+- **ActionButton Component** - Reusable buttons with consistent styling and behavior
+
+### **Refactoring Benefits & Migration Notes:**
+
+#### **Architecture Improvements:**
+- **Modular Redux Slices** - Replaced monolithic `controllerSlice` with domain-specific slices
+- **Composable Hooks** - Extracted common patterns into reusable hooks
+- **Performance Optimizations** - Added React.memo, useMemo, useCallback throughout
+- **Type Safety** - Enhanced TypeScript support with strict typing
+
+#### **Component Enhancements:**
+- **Generic ListItem** - Replaced song-specific component with generic, reusable component
+- **VirtualizedList** - Added high-performance list rendering for large datasets
+- **Performance Monitoring** - Built-in performance tracking with `usePerformanceMonitor`
+- **Error Boundaries** - Centralized error handling across the application
+
+#### **Development Experience:**
+- **Better Maintainability** - Clear separation of concerns with domain-specific slices
+- **Easier Testing** - Isolated business logic for each domain
+- **Improved Performance** - Optimized rendering and state management
+- **Enhanced Type Safety** - Full TypeScript coverage with proper typing
 
 ### **Critical Implementation Rules:**
 - **Never import directly from slice files** - always use the main redux index
@@ -721,6 +978,8 @@ const Queue: React.FC = () => {
 - **Implement business logic in hooks**, not components
 - **Use memoization** for expensive operations
 - **Handle loading and error states** in all async operations
+- **Use React.memo** for performance-critical components
+- **Leverage composable hooks** for reusable business logic
 
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