# Implementation Plan

## Phase 1: Core Infrastructure
- [ ] 1. Implement the UserAuthenticationService
  - [ ] 1.1 Create project structure and setup configuration
  - [ ] 1.2 Implement core UserAuthenticationService class in `src/services/auth/UserAuthenticationService.py`
  - [ ] 1.3 Add user registration and validation methods
  - [ ] 1.4 Implement JWT token generation and validation
  - [ ] 1.5 Add password hashing with bcrypt
  - [ ] 1.6 Create user repository interface and implementation
  - [ ] 1.7 Write unit tests for UserAuthenticationService
  - [ ] 1.8 Create integration tests for authentication flow
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 7.1, 7.2_

- [ ] 2. Implement the TaskManagementEngine
  - [ ] 2.1 Create TaskManagementEngine class in `src/services/tasks/TaskManagementEngine.py`
  - [ ] 2.2 Implement task CRUD operations (create, read, update, delete)
  - [ ] 2.3 Add task assignment and status change methods
  - [ ] 2.4 Implement task filtering and search functionality
  - [ ] 2.5 Create task repository interface and implementation
  - [ ] 2.6 Add input validation and business rules
  - [ ] 2.7 Write unit tests for task operations
  - [ ] 2.8 Create performance tests for task queries
  - _Requirements: 2.1, 2.2, 2.3, 2.4, 6.1, 7.3_

## Phase 2: Data Layer and Storage
- [ ] 3. Setup Database Infrastructure
  - [ ] 3.1 Configure PostgreSQL database connection
  - [ ] 3.2 Create database migration scripts for schema
  - [ ] 3.3 Implement users table with proper constraints
  - [ ] 3.4 Create tasks table with foreign key relationships
  - [ ] 3.5 Setup projects table and member relationships
  - [ ] 3.6 Add indexes for performance optimization
  - [ ] 3.7 Create database backup and recovery procedures
  - [ ] 3.8 Write database integration tests
  - _Requirements: 1.1, 2.1, 3.1, 3.2, 3.3, 3.4, 7.4_

- [ ] 4. Implement the ProjectOrganizer
  - [ ] 4.1 Create ProjectOrganizer class in `src/services/projects/ProjectOrganizer.py`
  - [ ] 4.2 Implement project creation and management methods
  - [ ] 4.3 Add team member invitation and permission system
  - [ ] 4.4 Create project repository interface and implementation
  - [ ] 4.5 Implement role-based access control for projects
  - [ ] 4.6 Add project archiving and deletion functionality
  - [ ] 4.7 Write unit tests for project operations
  - [ ] 4.8 Create tests for permission validation
  - _Requirements: 3.1, 3.2, 3.3, 3.4_

## Phase 3: Communication Layer
- [ ] 5. Implement the NotificationService
  - [ ] 5.1 Create NotificationService class in `src/services/notifications/NotificationService.py`
  - [ ] 5.2 Setup WebSocket manager for real-time communications
  - [ ] 5.3 Implement email service integration with SMTP
  - [ ] 5.4 Create notification templates and formatting
  - [ ] 5.5 Add notification queue and retry mechanisms
  - [ ] 5.6 Implement notification preferences and filtering
  - [ ] 5.7 Write tests for real-time notification delivery
  - [ ] 5.8 Create email notification tests
  - _Requirements: 4.1, 4.2, 4.3, 4.4, 6.4_

- [ ] 6. REST API Implementation
  - [ ] 6.1 Create Flask/FastAPI application structure
  - [ ] 6.2 Implement authentication middleware and decorators
  - [ ] 6.3 Create user endpoints (register, login, profile)
  - [ ] 6.4 Implement task CRUD endpoints with proper validation
  - [ ] 6.5 Add project management endpoints
  - [ ] 6.6 Create API documentation with OpenAPI/Swagger
  - [ ] 6.7 Add rate limiting and request validation
  - [ ] 6.8 Write comprehensive API tests
  - _Requirements: 1.2, 2.1, 2.2, 3.1, 7.3_

## Phase 4: Business Intelligence
- [ ] 7. Implement the ReportingModule
  - [ ] 7.1 Create ReportingModule class in `src/services/reports/ReportingModule.py`
  - [ ] 7.2 Implement task completion rate calculations
  - [ ] 7.3 Create productivity analytics and dashboards
  - [ ] 7.4 Add overdue task identification and impact analysis
  - [ ] 7.5 Implement project performance metrics
  - [ ] 7.6 Create report generation and export functionality
  - [ ] 7.7 Add caching for frequently accessed reports
  - [ ] 7.8 Write tests for report accuracy and performance
  - _Requirements: 5.1, 5.2, 5.3, 5.4, 6.2_

## Phase 5: Testing and Quality Assurance
- [ ] 8. Comprehensive Testing Suite
  - [ ] 8.1 Complete unit test coverage for all components (target: 90%+)
  - [ ] 8.2 Create integration tests for component interactions
  - [ ] 8.3 Implement end-to-end tests for critical user flows
  - [ ] 8.4 Add performance testing and load testing
  - [ ] 8.5 Create security testing and vulnerability scanning
  - [ ] 8.6 Implement automated testing in CI/CD pipeline
  - [ ] 8.7 Add user acceptance testing scenarios
  - [ ] 8.8 Create test data management and cleanup procedures
  - _Requirements: 6.1, 6.2, 6.3, 6.4_

- [ ] 9. Security Implementation
  - [ ] 9.1 Configure HTTPS/TLS for all communications
  - [ ] 9.2 Implement secure password storage and hashing
  - [ ] 9.3 Add input validation and sanitization
  - [ ] 9.4 Create security headers and CSP policies
  - [ ] 9.5 Implement audit logging for sensitive operations
  - [ ] 9.6 Add rate limiting and DDoS protection
  - [ ] 9.7 Create security monitoring and alerting
  - [ ] 9.8 Write security tests and penetration testing
  - _Requirements: 7.1, 7.2, 7.3, 7.4_

## Phase 6: Deployment and Operations
- [ ] 10. Production Deployment
  - [ ] 10.1 Setup production environment and infrastructure
  - [ ] 10.2 Configure application servers and load balancers
  - [ ] 10.3 Implement database clustering and backup strategies
  - [ ] 10.4 Setup monitoring and logging infrastructure
  - [ ] 10.5 Create deployment scripts and CI/CD pipeline
  - [ ] 10.6 Configure environment-specific settings
  - [ ] 10.7 Implement health checks and monitoring alerts
  - [ ] 10.8 Create disaster recovery and rollback procedures
  - _Requirements: 5.1, 5.2_

- [ ] 11. Documentation and Training
  - [ ] 11.1 Create comprehensive API documentation
  - [ ] 11.2 Write user guides and documentation
  - [ ] 11.3 Create administrator and deployment guides
  - [ ] 11.4 Document system architecture and design decisions
  - [ ] 11.5 Create troubleshooting and maintenance guides
  - [ ] 11.6 Develop training materials for end users
  - [ ] 11.7 Record video tutorials and walkthroughs
  - [ ] 11.8 Create knowledge base and FAQ resources
  - _Requirements: 5.1, 5.2_

## Phase 7: Performance Optimization
- [ ] 12. Performance Tuning
  - [ ] 12.1 Optimize database queries and add query caching
  - [ ] 12.2 Implement Redis caching for frequently accessed data
  - [ ] 12.3 Add connection pooling and optimize resource usage
  - [ ] 12.4 Optimize API response times and implement pagination
  - [ ] 12.5 Add asynchronous processing for long-running tasks
  - [ ] 12.6 Implement content delivery network for static assets
  - [ ] 12.7 Monitor and optimize memory usage
  - [ ] 12.8 Create performance benchmarks and monitoring
  - _Requirements: 6.1, 6.2, 6.3, 6.4_

## Final Acceptance Criteria
- [ ] 13. System Integration and Validation
  - [ ] 13.1 Validate all acceptance criteria from requirements document
  - [ ] 13.2 Run complete traceability validation using automated script
  - [ ] 13.3 Perform full system integration testing
  - [ ] 13.4 Conduct security audit and penetration testing
  - [ ] 13.5 Validate performance under expected load
  - [ ] 13.6 Confirm all user workflows function correctly
  - [ ] 13.7 Complete user acceptance testing with stakeholders
  - [ ] 13.8 Finalize documentation and prepare for launch
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 2.1, 2.2, 2.3, 2.4, 3.1, 3.2, 3.3, 3.4, 4.1, 4.2, 4.3, 4.4, 5.1, 5.2, 5.3, 5.4, 6.1, 6.2, 6.3, 6.4, 7.1, 7.2, 7.3, 7.4_