# Document Numbering Refactoring - 2025-12-18

## Overview
Refactored the `DocumentNumberingService` in the backend to split responsibilities into dedicated services (`CounterService`, `ReservationService`) and updated the `DocumentNumberCounter` entity to match the v1.7.0 schema.

## Changes

### 1. Module Restructuring
- **Services**: Created `CounterService` and `ReservationService`.
- **DTOs**: Created `CounterKeyDto`, `ReserveNumberDto`, `ConfirmReservationDto`.
- **Controllers**: Updated `DocumentNumberingController` and `DocumentNumberingAdminController`.

### 2. Entity Updates
- **`DocumentNumberCounter`**:
    - Made `correspondenceTypeId`, `recipientOrganizationId`, etc., non-nullable primary keys (defaulting to 0).
    - Added `resetScope` with length 20.
- **`DocumentNumberReservation`**: Created for two-phase commit reservation logic.

### 3. Service Logic
- **`CounterService`**:
    - Handles atomic counter increment.
    - Implements optimistic locking with retry logic using `OptimisticLockVersionMismatchError`.
- **`ReservationService`**:
    - Manages `DocumentNumberReservation` entity (Reserve -> Confirm/Cancel).
    - Removes unused `userId` from confirmation/cancellation logic.
- **`DocumentNumberingService`**:
    - Delegates counter logic to `CounterService`.
    - Delegates reservation logic to `ReservationService`.
    - Corrected property mapping (e.g., `originatorOrganizationId`).
    - Fixed `resolveDisciplineCode` to use `disciplineCode` column.

## Verification Results

### Automated Tests
Ran unit tests for `DocumentNumberingService`:
```bash
npm test modules/document-numbering/document-numbering.service.spec.ts
```

**Result:**
```
PASS src/modules/document-numbering/document-numbering.service.spec.ts
  DocumentNumberingService
    √ should be defined (13 ms)
    generateNextNumber
      √ should generate a new number successfully (6 ms)
      √ should throw error when increment fails (12 ms)

Test Suites: 1 passed, 1 total
Tests:       3 passed, 3 total
```

### Manual Verification Steps
1.  **Generate Number**: Call `POST /document-numbering/preview` (mapped to `previewNumber`).
2.  **Admin Ops**: Verified `DocumentNumberingAdminController` structure updates.