# User Management - Implementation Plan

- [x] 1. Set up backend project structure and dependencies
  - Create Node.js project with Express.js framework
  - Install required dependencies: express, pg, bcrypt, jsonwebtoken, nodemailer, helmet, express-rate-limit
  - Configure project structure with controllers, models, middleware, and routes directories
  - Set up environment configuration with dotenv
  - _Requirements: 7.1, 7.2_

- [x] 2. Create database schema and connection setup
  - Write SQL migration scripts for users and bookmarks tables with proper indexes
  - Implement database connection module with PostgreSQL connection pooling
  - Create database initialization script with table creation and seed data
  - Add database connection error handling and retry logic
  - _Requirements: 7.1, 7.2, 7.5_

- [ ] 3. Implement user authentication service
  - Create User model with bcrypt password hashing functionality
  - Implement user registration with email validation and password strength checking
  - Build login authentication with credential validation and JWT token generation
  - Add password reset functionality with secure token generation and email sending
  - _Requirements: 1.2, 1.3, 2.2, 2.3, 3.1, 3.2, 3.3_

- [ ] 4. Build authentication middleware and security
  - Create JWT token validation middleware for protected routes
  - Implement rate limiting middleware for authentication endpoints
  - Add security headers middleware using helmet.js
  - Create user authorization middleware for bookmark operations
  - _Requirements: 8.1, 8.2, 8.3, 8.6_

- [ ] 5. Create user management API endpoints
  - Implement POST /api/auth/register endpoint with validation and email verification
  - Build POST /api/auth/login endpoint with credential validation and session creation
  - Create POST /api/auth/logout endpoint with session cleanup
  - Add GET /api/user/profile and PUT /api/user/profile endpoints for profile management
  - Implement POST /api/user/change-password endpoint with current password verification
  - _Requirements: 1.1, 1.5, 2.1, 2.3, 4.1, 4.2, 4.5_

- [ ] 6. Implement bookmark data isolation and API endpoints
  - Create Bookmark model with user association and CRUD operations
  - Build GET /api/bookmarks endpoint with user filtering and pagination
  - Implement POST /api/bookmarks endpoint with user association
  - Create PUT /api/bookmarks/:id and DELETE /api/bookmarks/:id endpoints with ownership validation
  - Add bookmark import/export endpoints with user data isolation
  - _Requirements: 5.1, 5.2, 5.3, 5.4, 5.6_

- [ ] 7. Build email service integration
  - Create email service module with nodemailer configuration
  - Implement email verification functionality with secure token generation
  - Build password reset email functionality with time-limited tokens
  - Create email templates for verification and password reset
  - Add email sending error handling and retry logic
  - _Requirements: 1.5, 1.7, 3.1, 3.7_

- [ ] 8. Create frontend authentication pages
  - Build login page with email/password form and validation
  - Create registration page with email, password, and confirmation fields
  - Implement password reset request page with email input
  - Add password reset confirmation page with new password form
  - Create email verification success/error pages
  - _Requirements: 1.1, 2.1, 3.2, 4.1_

- [ ] 9. Integrate authentication with existing frontend
  - Modify existing bookmark manager to check authentication status on load
  - Add user menu to header with profile and logout options
  - Implement automatic token refresh and session management
  - Update all bookmark API calls to include authentication headers
  - Add authentication error handling and redirect to login
  - _Requirements: 2.3, 2.6, 6.1, 6.3, 6.7_

- [ ] 10. Implement data migration functionality
  - Create migration endpoint to import localStorage bookmarks to user account
  - Build frontend migration UI with merge/replace options
  - Add validation for imported bookmark data format
  - Implement conflict resolution for duplicate bookmarks during migration
  - Create post-migration cleanup of localStorage data
  - _Requirements: 9.1, 9.2, 9.3, 9.5, 9.6_

- [ ] 11. Add comprehensive error handling and logging
  - Implement centralized error handling middleware for API endpoints
  - Create logging service with different log levels and rotation
  - Add authentication failure logging for security monitoring
  - Implement database error handling with appropriate user messages
  - Create client-side error boundaries for authentication failures
  - _Requirements: 10.1, 10.2, 10.3, 10.4_

- [ ] 12. Create comprehensive test suite
  - Write unit tests for authentication service functions (password hashing, token generation)
  - Create integration tests for user registration and login flows
  - Build API endpoint tests for all authentication and bookmark endpoints
  - Implement database isolation tests to verify user data separation
  - Add security tests for SQL injection prevention and XSS protection
  - _Requirements: 1.2, 2.2, 5.1, 8.4, 8.5_