URL Shortener

Project Specification: URL Shortening Service

Objective: Develop a robust, user-friendly URL shortening service with advanced features and a responsive design.

Technology Stack: HTML5, CSS3, JavaScript (with modern frameworks/libraries), backend API (RESTful), database (SQL or NoSQL)

Key Features and Functionality:

1. Frontend Design:

   • Clean, intuitive user interface with a prominent, wide input field
   • Responsive layout for optimal user experience on all devices (desktop, mobile, tablet)
   • Consistent visual style and branding
   • Clear calls-to-action for key functions

2. URL Processing:

   • Input validation: Check for empty fields, valid URL format, and maximum length
   • URL sanitization: Remove non-alphanumeric characters, trailing slashes, etc.
   • URL canonicalization: Convert relative URLs to absolute form
   • Support for long and complex URLs

3. URL Shortening:

   • Automatic generation of short, unique URL aliases
   • Option to enter a custom alias (with validation for uniqueness and format)
   • Alias suggestion if custom input is invalid or occupied

4. QR Code Generation:

   • Automatic generation of QR codes for shortened URLs
   • Download option for the QR code image
   • Display of a readable URL below the QR code

5. Link Expiration:

   • Option to set an expiration date for shortened links
   • Expiration date validation (cannot be in the past)
   • Link deactivation upon expiration

6. Password Protection:

   • Option to add a password to sensitive URLs
   • Password strength validation
   • Secure password storage (hashed and salted)
   • Separate password prompt page

7. Click Tracking and Analytics:

   • Automatic tracking of all URL clicks
   • Display click count and timestamp for each shortened link
   • Simple, intuitive analytics dashboard
   • Search and filter functionality for URLs in the history

8. Copy-to-Clipboard:

   • Single-click copy of the shortened URL to clipboard
   • Confirmation message after successful copy
   • Fallback option for systems without clipboard API

9. Backend API:

   • RESTful API endpoints for all core functions
   • Secure authentication and authorization (JWT, sessions, or API keys)
   • Rate limiting to prevent abuse
   • Scalable architecture for high traffic

Constraints and Requirements:

• Database should support rapid read/write operations
• API responses should be JSON, with consistent field naming
• Frontend should have minimal load times and be SEO-friendly
• Security measures: input validation, output encoding, CSRF protection
• Error handling: clear error messages, redirection on errors
• Accessibility: follow Web Content Accessibility Guidelines (WCAG)
• Performance: optimize images, minify code, lazy-load content

Timeline: Design and development should be completed within 4-6 weeks.

Deliverables: Complete source code, documentation, and deployment instructions.

Please provide a detailed project plan, including architecture diagrams, database schema, and specific API endpoints.