bamort/backend/transfer/README.md

Transfer Package

The transfer package provides character export and import functionality for the Bamort application.

Features

• Complete Character Export: Exports a character with all related data including:

  • Basic character information (race, type, grade, attributes, etc.)
  • Skills (Fertigkeiten) and Weapon Skills (Waffenfertigkeiten)
  • Spells (Zauber)
  • Equipment (Waffen, Ausrüstung, Behältnisse, Transportmittel)
  • Learning data (all learning_* tables)
  • Audit log entries
  • GSM master data (skills, spells, weapons, equipment definitions)

• Smart Import:

  • Identifies existing GSM data by name (not ID) to avoid duplicates
  • Updates incomplete GSM records with missing information
  • Sets default source_id values (1 for skills/equipment, 2 for spells)
  • Preserves audit log history
  • Creates new character with fresh IDs

• JSON Format: All data is exported/imported as JSON for portability

API Endpoints

All endpoints are under /api/transfer:

GET /api/transfer/export/:id

Exports a character as JSON data (for API consumption)

Response: CharacterExport JSON object

GET /api/transfer/download/:id

Downloads a character as a JSON file

Response: JSON file with Content-Disposition: attachment header

POST /api/transfer/import

Imports a character from JSON data

Request Body: CharacterExport JSON object Response:

{
  "message": "Character imported successfully",
  "character_id": 123
}

Usage Examples

Export a Character

curl http://localhost:8180/api/transfer/export/18 > character_export.json

Download a Character

wget http://localhost:8180/api/transfer/download/18

Import a Character

curl -X POST http://localhost:8180/api/transfer/import \
  -H "Content-Type: application/json" \
  -d @character_export.json

Testing

The package includes comprehensive tests:

• Export Tests (7 tests):

  • Basic export functionality
  • Skills inclusion
  • Spells inclusion
  • Equipment inclusion
  • Learning data inclusion
  • Audit log inclusion
  • Error handling for non-existent characters

• Import Tests (6 tests):

  • Basic import functionality
  • Handling existing GSM data
  • Updating incomplete GSM data
  • Default source_id assignment
  • Audit log import
  • JSON round-trip testing

• Handler/API Tests (5 tests):

  • Export endpoint
  • Download endpoint
  • Import endpoint
  • Error handling

Total: 18 tests, all passing

Run tests with:

cd backend
go test -v ./transfer/

Implementation Notes

TDD Approach

The package was developed using Test-Driven Development (TDD):

1. Tests written first
2. Implementation follows to make tests pass
3. Refactoring as needed

KISS Principle

The implementation follows the "Keep It Simple, Stupid" principle:

• Simple, clear function names
• Each function does one thing well
• No over-engineering
• Straightforward error handling

GSM Data Handling

• Skills, weapons, equipment, and spells are identified by name, not ID
• Prevents duplicate creation of master data
• Updates existing records only if they have missing information
• Default source_id: 1 for general data, 2 for spells

Source ID Rules

When importing, if source_id is 0:

• Spells: Set to 2
• All other data: Set to 1

Files

• exporter.go - Character export functionality
• exporter_test.go - Export tests
• importer.go - Character import functionality
• importer_test.go - Import tests
• handlers.go - HTTP handlers for API endpoints
• handlers_test.go - API handler tests
• routes.go - Route registration
• README.md - This file

Future Enhancements

Possible improvements:

• Batch export/import of multiple characters
• Export filtering (e.g., export without audit log)
• Import validation and conflict resolution options
• Export format versioning
• Compression for large exports