quiz-frontend/CORE_INFRASTRUCTURE_SUMMARY.md

Core Infrastructure Setup - Summary

Date: November 12, 2025
Status: ✅ Completed (6 of 7 tasks)
Angular Version: v20 with Standalone Components and Signals

---

Completed Tasks

✅ 1. Environment Configuration

Created:

• src/environments/environment.ts - Production configuration
• src/environments/environment.development.ts - Development configuration

Configuration:

{
  apiUrl: 'http://localhost:3000/api',
  apiTimeout: 30000,
  cacheTimeout: 300000,
  enableLogging: true
}

Updated:

• angular.json - Added fileReplacements for environment switching

---

✅ 2. TypeScript Interfaces & Models

Created 7 comprehensive model files:

1. user.model.ts - User, AuthResponse, AuthState, UserRegistration, UserLogin
2. category.model.ts - Category, CategoryDetail, CategoryStats, QuestionPreview
3. question.model.ts - Question, QuestionFormData, QuestionSearchFilters
4. quiz.model.ts - QuizSession, QuizResults, QuizAnswerSubmission, QuizQuestionResult
5. guest.model.ts - GuestSession, GuestSettings, GuestAnalytics, GuestState
6. dashboard.model.ts - UserDashboard, CategoryPerformance, AdminStatistics
7. index.ts - Barrel export for all models

Total Interfaces: 40+ TypeScript interfaces covering all API models

---

✅ 3. HTTP Interceptors

Created 3 functional interceptors:

1. auth.interceptor.ts

   • Adds JWT Bearer token to authenticated requests
   • Skips auth for guest endpoints
   • Uses functional interceptor pattern (Angular v20)

2. guest.interceptor.ts

   • Adds x-guest-token header for guest user requests
   • Only applies when no auth token exists
   • Handles guest session token management

3. error.interceptor.ts

   • Global HTTP error handling
   • Maps HTTP status codes to user-friendly messages
   • Handles 401 with auto-redirect to login
   • Integrates with ToastService for error notifications
   • Rate limiting (429) handling

Registered in: app.config.ts using withInterceptors()

---

✅ 4. Core Services

Created 4 essential services:

1. storage.service.ts

   • Token management (JWT, Guest)
   • User data persistence
   • Theme preference storage
   • Remember me functionality
   • localStorage/sessionStorage abstraction

2. toast.service.ts

   • Signal-based notification system
   • 4 notification types: success, error, warning, info
   • Auto-dismiss with configurable duration
   • Action buttons support
   • Queue management

3. state.service.ts

   • Signal-based state management utility
   • localStorage/sessionStorage persistence
   • Helper functions for creating persisted signals
   • Loading and error state management

4. loading.service.ts

   • Global loading state with signals
   • Loading counter for concurrent requests
   • Customizable loading messages
   • Force stop functionality

---

✅ 5. Angular Material Setup

Installed: @angular/material@20.2.12

Configuration:

• Theme: Azure Blue
• Typography: Enabled
• Animations: Enabled

Updated Files:

• package.json - Material dependencies added
• src/styles.scss - Material theme imported
• src/index.html - Material fonts and icons

---

✅ 6. Shared UI Components

Created 2 reusable components:

1. LoadingSpinnerComponent

   • Material spinner integration
   • Configurable size and message
   • Overlay mode for full-screen loading
   • Signal-based inputs

   <app-loading-spinner 
     message="Loading data..." 
     size="50" 
     overlay="true">
   </app-loading-spinner>
   

2. ToastContainerComponent

   • Toast notification display
   • 4 notification styles with icons
   • Action button support
   • Auto-dismiss with animations
   • Material icons integration
   • Responsive design (mobile-friendly)

Integrated:

• Toast container added to main app.html
• Ready for app-wide notifications

---

Project Structure

frontend/
├── src/
│   ├── app/
│   │   ├── core/
│   │   │   ├── models/
│   │   │   │   ├── user.model.ts
│   │   │   │   ├── category.model.ts
│   │   │   │   ├── question.model.ts
│   │   │   │   ├── quiz.model.ts
│   │   │   │   ├── guest.model.ts
│   │   │   │   ├── dashboard.model.ts
│   │   │   │   └── index.ts
│   │   │   ├── interceptors/
│   │   │   │   ├── auth.interceptor.ts
│   │   │   │   ├── guest.interceptor.ts
│   │   │   │   ├── error.interceptor.ts
│   │   │   │   └── index.ts
│   │   │   └── services/
│   │   │       ├── storage.service.ts
│   │   │       ├── toast.service.ts
│   │   │       ├── state.service.ts
│   │   │       ├── loading.service.ts
│   │   │       └── index.ts
│   │   ├── shared/
│   │   │   └── components/
│   │   │       ├── loading-spinner/
│   │   │       │   ├── loading-spinner.ts
│   │   │       │   ├── loading-spinner.html
│   │   │       │   └── loading-spinner.scss
│   │   │       └── toast-container/
│   │   │           ├── toast-container.ts
│   │   │           ├── toast-container.html
│   │   │           └── toast-container.scss
│   │   ├── app.config.ts (interceptors configured)
│   │   ├── app.ts (toast container imported)
│   │   └── app.html (toast container added)
│   └── environments/
│       ├── environment.ts
│       └── environment.development.ts
├── angular.json (updated)
└── package.json (Material added)

---

Technologies & Patterns

Angular v20 Features:

• ✅ Standalone components
• ✅ Signals for state management
• ✅ Functional interceptors
• ✅ Signal-based inputs
• ✅ Control flow syntax (@for, @if)
• ✅ Zoneless change detection

Material Design:

• ✅ Azure Blue theme
• ✅ Progress spinner
• ✅ Icons
• ✅ Buttons

State Management:

• ✅ Signal-based reactive state
• ✅ Persistent storage (localStorage/sessionStorage)
• ✅ Loading and error states
• ✅ Toast notifications

---

Next Steps (Remaining Task)

🔲 7. Configure Routing Structure

• Create route guards (auth, admin, guest)
• Set up lazy loading for feature modules
• Configure route paths
• Implement 404 handling
• Add route preloading strategy

---

Usage Examples

Using Storage Service

import { StorageService } from './core/services';

constructor(private storage: StorageService) {}

// Save token
this.storage.setToken('jwt-token', true);

// Get token
const token = this.storage.getToken();

// Check authentication
if (this.storage.isAuthenticated()) {
  // User is logged in
}

Using Toast Service

import { ToastService } from './core/services';

constructor(private toast: ToastService) {}

// Show notifications
this.toast.success('Login successful!');
this.toast.error('Something went wrong');
this.toast.warning('Session expiring soon');
this.toast.info('New feature available');

// With action button
this.toast.showWithAction(
  'Item deleted',
  'Undo',
  () => this.undoDelete(),
  'warning'
);

Using Loading Service

import { LoadingService } from './core/services';

constructor(private loading: LoadingService) {}

// Start loading
this.loading.start('Fetching data...');

// Stop loading
this.loading.stop();

// Check loading state
if (this.loading.getLoadingState()) {
  // Currently loading
}

---

File Statistics

Files Created: 21
Lines of Code: ~2,000+
Interfaces Defined: 40+
Services Created: 4
Interceptors Created: 3
Components Created: 2

---

Quality Checklist

• ✅ TypeScript strict mode enabled
• ✅ All interfaces properly typed
• ✅ Error handling implemented
• ✅ Loading states managed
• ✅ Responsive design ready
• ✅ Material Design integrated
• ✅ Signal-based reactivity
• ✅ Service injection patterns
• ✅ Separation of concerns
• ✅ Reusable components

---

Status: Ready for feature module development!
Next: Authentication Module, Guest Module, Category Module