# Implementation Plan: Tag-Based Filtering

## Overview

This implementation plan breaks down the tag-based filtering feature into discrete coding tasks that build incrementally. Each task focuses on specific functionality while ensuring integration with the existing plugin architecture.

## Tasks

- [ ] 1. Create core tag filtering data models and utilities
  - Create `TagFilter`, `TagFilterSet`, and `FilterResult` data classes
  - Implement tag matching logic for key-value and key-only filters
  - Add validation methods for filter syntax and combinations
  - _Requirements: 1.1, 1.2, 1.3, 2.5_

- [ ] 1.1 Write property test for tag filter matching
  - **Property 1: Tag Filter Matching**
  - **Validates: Requirements 1.1, 1.2, 1.3**

- [ ] 2. Implement Tag Filter Parser for CLI integration
  - Create `TagFilterParser` class to parse CLI arguments
  - Support `--tag`, `--tag-key`, `--exclude-tag`, `--exclude-tag-key` options
  - Add `--tag-logic` option for AND/OR operations
  - Add `--service-tag` option for service-specific filtering
  - _Requirements: 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7_

- [ ] 2.1 Write property test for CLI argument parsing
  - **Property 7: CLI Argument Parsing**
  - **Validates: Requirements 5.2, 5.3, 5.4, 5.5, 5.6, 5.7**

- [ ] 3. Create Tag Filter Engine as central coordinator
  - Implement `TagFilterEngine` class with core filtering logic
  - Add methods for applying filters to resource collections
  - Implement logical operations (AND/OR) for multiple filters
  - Add include/exclude filter precedence handling
  - _Requirements: 2.1, 2.2, 2.3, 2.4_

- [ ] 3.1 Write property test for logical operations consistency
  - **Property 2: Logical Operations Consistency**
  - **Validates: Requirements 2.1, 2.2, 2.3**

- [ ] 3.2 Write property test for include-exclude filter precedence
  - **Property 3: Include-Exclude Filter Precedence**
  - **Validates: Requirements 2.4**

- [ ] 4. Extend plugin base class with tag filtering interface
  - Add `supports_tag_filtering()` method to `AWSServicePlugin`
  - Add `apply_tag_filters()` method for filter application
  - Add `get_resource_tags()` method for tag extraction
  - Add `filter_resources_by_tags()` method for resource filtering
  - _Requirements: 10.1, 10.2_

- [ ] 4.1 Write property test for plugin interface consistency
  - **Property 10: Plugin Interface Consistency**
  - **Validates: Requirements 10.1, 10.2, 10.3, 10.4, 10.5**

- [ ] 5. Implement tag filtering in EC2 plugin
  - Add tag filtering support to EC2Plugin class
  - Filter EC2 instances, VPCs, subnets, and security groups by tags
  - Implement service-specific filtering logic
  - Preserve relationships between filtered EC2 resources
  - _Requirements: 3.2, 3.4_

- [ ] 5.1 Write property test for service isolation in filtering
  - **Property 4: Service Isolation in Filtering**
  - **Validates: Requirements 3.1, 3.3, 4.1**

- [ ] 5.2 Write property test for relationship preservation
  - **Property 5: Relationship Preservation**
  - **Validates: Requirements 1.5, 4.4**

- [ ] 6. Implement tag filtering in Organizations plugin
  - Add tag filtering support to OrganizationsPlugin class
  - Filter accounts based on account-level tags
  - Handle organizational units with tag-based account filtering
  - Maintain organization hierarchy after filtering
  - _Requirements: 4.2_

- [ ] 7. Implement tag filtering in Identity Center plugin
  - Add tag filtering support to IdentityCenterPlugin class
  - Filter permission sets and assignments based on tags where applicable
  - Handle cases where Identity Center resources may not have tags
  - _Requirements: 4.3_

- [ ] 7.1 Write property test for graceful service degradation
  - **Property 12: Graceful Service Degradation**
  - **Validates: Requirements 3.5, 6.3**

- [ ] 8. Create Preset Manager for saved configurations
  - Implement `PresetManager` class for filter configuration management
  - Add methods to save, load, list, and delete filter presets
  - Store presets in JSON format for version control compatibility
  - Support preset overrides while maintaining base configuration
  - _Requirements: 8.1, 8.2, 8.3, 8.4, 8.5_

- [ ] 8.1 Write property test for preset operations
  - **Property 9: Preset Operations**
  - **Validates: Requirements 8.1, 8.2, 8.3, 8.4, 8.5**

- [ ] 9. Integrate tag filtering with CLI interface
  - Update `reverse_diagrams.py` to support tag filtering arguments
  - Add argument parsing for all tag filter options
  - Integrate TagFilterEngine with plugin execution
  - Add validation and error handling for filter arguments
  - _Requirements: 5.1, 6.1, 6.4_

- [ ] 9.1 Write property test for filter validation
  - **Property 6: Filter Validation**
  - **Validates: Requirements 2.5, 6.1, 6.4**

- [ ] 10. Implement performance optimizations
  - Apply filters during data collection phase to minimize API calls
  - Leverage AWS API filtering capabilities where available
  - Add caching for tag information to avoid redundant calls
  - Implement progress tracking for long-running filter operations
  - _Requirements: 7.1, 7.2, 7.3, 7.4_

- [ ] 10.1 Write property test for performance optimization
  - **Property 8: Performance Optimization**
  - **Validates: Requirements 7.1, 7.2, 7.3**

- [ ] 11. Add comprehensive error handling and user feedback
  - Implement validation for conflicting filter options
  - Add warnings for empty filter results with applied filter details
  - Add informational messages for services that don't support tags
  - Add warnings for broken relationships in filtered diagrams
  - _Requirements: 6.1, 6.2, 6.3, 6.4, 6.5_

- [ ] 11.1 Write property test for empty result handling
  - **Property 11: Empty Result Handling**
  - **Validates: Requirements 1.4, 6.2**

- [ ] 12. Create comprehensive documentation and help
  - Add CLI help text with examples for all tag filtering options
  - Create documentation covering common use cases and scenarios
  - Add troubleshooting guide for common filtering issues
  - Include examples for single service, multi-service, and account-wide filtering
  - _Requirements: 9.1, 9.2, 9.3, 9.4, 9.5_

- [ ] 13. Checkpoint - Ensure all tests pass
  - Ensure all tests pass, ask the user if questions arise.

- [ ] 14. Integration testing and final validation
  - Test end-to-end filtering scenarios with multiple services
  - Validate performance with large resource sets
  - Test preset management functionality
  - Verify backward compatibility with existing functionality
  - _Requirements: All requirements validation_

- [ ] 14.1 Write integration tests for multi-service filtering
  - Test filtering across Organizations, EC2, and Identity Center plugins
  - Verify consistent behavior and relationship preservation

- [ ] 15. Final checkpoint - Ensure all tests pass
  - Ensure all tests pass, ask the user if questions arise.

## Notes

- All tasks are required for comprehensive implementation from the start
- Each task references specific requirements for traceability
- Checkpoints ensure incremental validation
- Property tests validate universal correctness properties with minimum 100 iterations
- Unit tests validate specific examples and edge cases
- Integration tests ensure end-to-end functionality
- The implementation builds incrementally from core models to full integration

## CLI Usage Examples

After implementation, users will be able to use tag filtering like this:

```bash
# Filter EC2 resources by environment tag
reverse_diagrams --plugin ec2 --tag Environment=Production -r us-east-1

# Filter all services by multiple tags with AND logic
reverse_diagrams -o -i --tag Environment=Production --tag Team=DevOps -r us-east-1

# Filter with OR logic
reverse_diagrams --plugin ec2 --tag Environment=Production --tag Environment=Staging --tag-logic OR -r us-east-1

# Service-specific filtering
reverse_diagrams -o -i --service-tag ec2 Environment=Production -r us-east-1

# Exclude specific tags
reverse_diagrams --plugin ec2 --tag Environment=Production --exclude-tag Status=Deprecated -r us-east-1

# Use saved presets
reverse_diagrams --preset production-env -r us-east-1

# Key-only filtering
reverse_diagrams --plugin ec2 --tag-key CostCenter -r us-east-1
```