- Replace log.Fatal() with proper error returns for better control flow
- Add type safety with dedicated structs instead of interface{} maps
- Implement proper HTTP client with timeout configuration
- Fix goroutine closure variable capture issues
- Add input validation for URL format and board extraction
- Ensure destination directory exists before writing files
- Improve error messages with context and proper error wrapping
- Add resource cleanup with defer statements for HTTP responses
- Separate concerns into dedicated functions for better organization
- Use filepath.Join for cross-platform path handling
- Add comprehensive logging throughout the application
This refactoring makes the downloader more robust, maintainable, and production-ready while preserving all original functionality.