# Draft: Implement Check-in Logic

## Requirements (User)
- **Input**: 6-digit number from scanner.
- **Action**: Call `/event/checkin/submit` (`postEventCheckinSubmit`).
- **Feedback**: Toaster (success/failure) using `sonner`.

## Research Questions
1. [Resolved] API Client: `postEventCheckinSubmit` exists.
2. [Pending] API Parameters: Need to verify `PostEventCheckinSubmitData`.
3. [Resolved] Toaster Library: `sonner` (`toast.success`, `toast.error`).

## Technical Decisions
- **Logic Placement**: `CheckinScannerNavContainer`.
- **State Management**: `useMutation` from `@tanstack/react-query`.
- **Validation**: Regex `^\d{6}$` for 6-digit number.
- **Error Handling**: `onError` in mutation -> `toast.error`.
- **Success Handling**: `onSuccess` in mutation -> `toast.success`.

## Code Snippets
```typescript
import { useMutation } from '@tanstack/react-query';
import { postEventCheckinSubmit } from '@/client/sdk.gen';
import { toast } from 'sonner';

// In container
const { mutate } = useMutation({
  mutationFn: (code: string) => postEventCheckinSubmit({ body: { code } }),
  onSuccess: () => toast.success('签到成功'),
  onError: () => toast.error('签到失败'),
});
```