# Backend — Familienarchiv

## Overview

Spring Boot 4.0 monolith serving the Familienarchiv REST API. Handles document management, person/entity tracking, transcription workflows, OCR orchestration, user management, and full-text search.

## Tech Stack

- **Framework**: Spring Boot 4.0 (Java 21)
- **Build**: Maven (`./mvnw` wrapper)
- **Server**: Jetty (not Tomcat — excluded in pom.xml)
- **Data**: PostgreSQL 16, JPA/Hibernate, Spring Data JPA
- **Migrations**: Flyway (SQL files in `src/main/resources/db/migration/`)
- **Security**: Spring Security, Spring Session JDBC, JWT tokens
- **File Storage**: MinIO via AWS SDK v2 (S3-compatible)
- **Spreadsheet Import**: Apache POI 5.5.0 (Excel/ODS)
- **API Docs**: SpringDoc OpenAPI 3.x (`/v3/api-docs` — dev profile only)
- **Monitoring**: Spring Boot Actuator (`/actuator/health`)

## Package Structure

Package-by-domain: each domain owns its controller, service, repository, entities, and DTOs.

```
src/main/java/org/raddatz/familienarchiv/
├── audit/               # Audit logging (AuditService, AuditLogQueryService)
├── config/              # Infrastructure config (MinioConfig, AsyncConfig, WebConfig)
├── dashboard/           # Dashboard analytics + StatsController/StatsService
├── document/            # Document domain — entities, controller, service, repository, DTOs
│   ├── annotation/      # DocumentAnnotation, AnnotationService, AnnotationController
│   ├── comment/         # DocumentComment, CommentService, CommentController
│   └── transcription/   # TranscriptionBlock, TranscriptionService, TranscriptionBlockQueryService
├── exception/           # DomainException, ErrorCode, GlobalExceptionHandler
├── filestorage/         # FileService (S3/MinIO)
├── geschichte/          # Geschichte (story) domain
├── importing/           # MassImportService
├── notification/        # Notification domain + SseEmitterRegistry
├── ocr/                 # OCR domain — OcrService, OcrBatchService, training
├── person/              # Person domain — Person, PersonService, PersonController
│   └── relationship/    # PersonRelationship sub-domain
├── security/            # SecurityConfig, Permission, @RequirePermission, PermissionAspect
├── tag/                 # Tag domain — Tag, TagService, TagController
└── user/                # User domain — AppUser, UserGroup, UserService, auth controllers
```

## Layering Rules (Strict)

```
Controller → Service → Repository → DB
```

- **Controllers never call repositories directly.**
- **Services never reach into another domain's repository.** Call the other domain's service instead.
  - ✅ `DocumentService` → `PersonService.getById()` → `PersonRepository`
  - ❌ `DocumentService` → `PersonRepository` directly

## Key Entities

| Entity | Table | Key Relationships |
|---|---|---|
| `Document` | `documents` | ManyToOne sender (Person), ManyToMany receivers (Person), ManyToMany tags (Tag) |
| `Person` | `persons` | Referenced by documents as sender/receiver; name aliases table |
| `Tag` | `tag` | ManyToMany with documents via `document_tags`; self-referencing parent for tree |
| `AppUser` | `app_users` | ManyToMany groups (UserGroup) |
| `UserGroup` | `user_groups` | Has a `Set<String> permissions` |
| `TranscriptionBlock` | `transcription_blocks` | Per-document, per-page text blocks with polygons |
| `DocumentAnnotation` | `document_annotations` | Free-form annotations on document pages |
| `Comment` | `document_comments` | Threaded comments with mentions |
| `Notification` | `notifications` | User notification feed |
| `OcrJob` / `OcrJobDocument` | `ocr_jobs`, `ocr_job_documents` | Batch OCR job tracking |

**`DocumentStatus` lifecycle:** `PLACEHOLDER → UPLOADED → TRANSCRIBED → REVIEWED → ARCHIVED`

## Entity Code Style

All entities use these Lombok annotations:

```java
@Entity
@Table(name = "table_name")
@Data
@NoArgsConstructor
@AllArgsConstructor
@Builder
public class MyEntity {
    @Id
    @GeneratedValue(strategy = GenerationType.UUID)
    @Schema(requiredMode = Schema.RequiredMode.REQUIRED)
    private UUID id;
    // ...
}
```

- `@Schema(requiredMode = REQUIRED)` on every field the backend always populates — drives TypeScript generation.
- Collections use `@Builder.Default` with `new HashSet<>()` as default.
- Timestamps use `@CreationTimestamp` / `@UpdateTimestamp`.

## Services

- Annotated with `@Service`, `@RequiredArgsConstructor`, optionally `@Slf4j`.
- Write methods: `@Transactional`.
- Read methods: no annotation (default non-transactional).
- Cross-domain access goes through the other domain's service, never its repository.

## Error Handling

Use `DomainException` for all domain errors:

```java
DomainException.notFound(ErrorCode.DOCUMENT_NOT_FOUND, "...")
DomainException.forbidden("...")
DomainException.conflict(ErrorCode.IMPORT_ALREADY_RUNNING, "...")
DomainException.internal(ErrorCode.FILE_UPLOAD_FAILED, "...")
```

When adding a new `ErrorCode`:
1. Add to `ErrorCode.java`
2. Mirror in frontend `src/lib/errors.ts`
3. Add Paraglide translation key in `messages/{de,en,es}.json`

## Security / Permissions

Use `@RequirePermission` on controller methods or classes:

```java
@RequirePermission(Permission.WRITE_ALL)
public Document updateDocument(...) { ... }
```

Available permissions: `READ_ALL`, `WRITE_ALL`, `ADMIN`, `ADMIN_USER`, `ADMIN_TAG`, `ADMIN_PERMISSION`

`PermissionAspect` checks the current user's `UserGroup.permissions` at runtime.

## OCR Integration

The backend orchestrates OCR by calling the Python `ocr-service` microservice via `RestClient`:

- `OcrClient` interface — mockable for tests
- `RestClientOcrClient` — implementation using Spring `RestClient`
- `OcrService` — orchestrates presigned URL generation, OCR call, block mapping
- `OcrBatchService` — handles batch/job workflows
- `OcrAsyncRunner` — async execution of OCR jobs

## API Testing

HTTP test files in `backend/api_tests/` for the VS Code REST Client extension.

## How to Run

### Local Development

```bash
cd backend

# Run with dev profile (requires PostgreSQL + MinIO running via docker-compose)
./mvnw spring-boot:run

# Build JAR (with tests)
./mvnw clean package

# Build JAR skipping tests
./mvnw clean package -DskipTests

# Run all tests
./mvnw test

# Run a single test class
./mvnw test -Dtest=ClassName

# Run with coverage (JaCoCo)
./mvnw clean verify
```

### OpenAPI TypeScript Generation

1. Build and start backend with `--spring.profiles.active=dev`
2. In `frontend/`, run: `npm run generate:api`

### Profiles

- **dev** (default): Enables OpenAPI, dev configs, e2e seeds
- **prod**: Production profile — no dev endpoints

## Testing

- Unit tests: Mockito + JUnit, pure in-memory
- Slice tests: `@WebMvcTest`, `@DataJpaTest` with Testcontainers PostgreSQL
- Integration tests: Full Spring context with Testcontainers
- Coverage gate: 88% branch coverage overall (JaCoCo)
