# SAAS-012: CRUD Base

## Metadata
- **Codigo:** SAAS-012
- **Modulo:** CRUD Base
- **Prioridad:** P0
- **Estado:** Completado
- **Fase:** 1 - Foundation

## Descripcion

Componentes base reutilizables para operaciones CRUD: servicios genericos, controladores, DTOs, validacion, paginacion, filtros, ordenamiento, y soft delete estandarizado.

## Objetivos

1. Servicio CRUD generico
2. Controlador base reutilizable
3. DTOs de paginacion estandar
4. Filtros y ordenamiento
5. Soft delete consistente

## Alcance

### Incluido
- BaseCrudService<T>
- BaseCrudController<T>
- PaginationDto, PaginatedResponse
- FilterDto generico
- SortDto
- Soft delete con deleted_at
- Auditoria basica (created_at, updated_at)

### Excluido
- Generacion automatica de codigo
- Admin panels generados
- GraphQL resolvers

## Componentes Base

### BaseCrudService

```typescript
abstract class BaseCrudService<T> {
  constructor(
    protected readonly repository: Repository<T>,
    protected readonly entityName: string
  ) {}

  async findAll(options: FindAllOptions): Promise<PaginatedResponse<T>> {
    const { page = 1, limit = 20, filters, sort } = options;

    const queryBuilder = this.repository.createQueryBuilder('entity');

    // Aplicar tenant
    queryBuilder.where('entity.tenant_id = :tenantId', { tenantId: this.tenantId });

    // Aplicar filtros
    this.applyFilters(queryBuilder, filters);

    // Aplicar ordenamiento
    this.applySort(queryBuilder, sort);

    // Soft delete
    queryBuilder.andWhere('entity.deleted_at IS NULL');

    // Paginacion
    const [items, total] = await queryBuilder
      .skip((page - 1) * limit)
      .take(limit)
      .getManyAndCount();

    return {
      items,
      meta: {
        total,
        page,
        limit,
        totalPages: Math.ceil(total / limit)
      }
    };
  }

  async findById(id: string): Promise<T> {
    const entity = await this.repository.findOne({
      where: { id, tenant_id: this.tenantId, deleted_at: null }
    });
    if (!entity) {
      throw new NotFoundException(`${this.entityName} not found`);
    }
    return entity;
  }

  async create(dto: CreateDto): Promise<T> {
    const entity = this.repository.create({
      ...dto,
      tenant_id: this.tenantId,
      created_at: new Date()
    });
    return this.repository.save(entity);
  }

  async update(id: string, dto: UpdateDto): Promise<T> {
    const entity = await this.findById(id);
    Object.assign(entity, dto, { updated_at: new Date() });
    return this.repository.save(entity);
  }

  async delete(id: string): Promise<void> {
    const entity = await this.findById(id);
    entity.deleted_at = new Date();
    await this.repository.save(entity);
  }

  async hardDelete(id: string): Promise<void> {
    await this.findById(id);
    await this.repository.delete(id);
  }

  async restore(id: string): Promise<T> {
    const entity = await this.repository.findOne({
      where: { id, tenant_id: this.tenantId }
    });
    if (!entity) {
      throw new NotFoundException(`${this.entityName} not found`);
    }
    entity.deleted_at = null;
    return this.repository.save(entity);
  }
}
```

### BaseCrudController

```typescript
abstract class BaseCrudController<T> {
  constructor(protected readonly service: BaseCrudService<T>) {}

  @Get()
  async findAll(@Query() query: PaginationDto): Promise<PaginatedResponse<T>> {
    return this.service.findAll(query);
  }

  @Get(':id')
  async findById(@Param('id') id: string): Promise<T> {
    return this.service.findById(id);
  }

  @Post()
  async create(@Body() dto: CreateDto): Promise<T> {
    return this.service.create(dto);
  }

  @Put(':id')
  async update(@Param('id') id: string, @Body() dto: UpdateDto): Promise<T> {
    return this.service.update(id, dto);
  }

  @Delete(':id')
  async delete(@Param('id') id: string): Promise<void> {
    return this.service.delete(id);
  }
}
```

## DTOs Estandar

### PaginationDto
```typescript
class PaginationDto {
  @IsOptional()
  @IsInt()
  @Min(1)
  @Transform(({ value }) => parseInt(value))
  page?: number = 1;

  @IsOptional()
  @IsInt()
  @Min(1)
  @Max(100)
  @Transform(({ value }) => parseInt(value))
  limit?: number = 20;

  @IsOptional()
  @IsString()
  sort?: string; // "field:asc" o "field:desc"

  @IsOptional()
  @IsString()
  search?: string;
}
```

### PaginatedResponse
```typescript
interface PaginatedResponse<T> {
  items: T[];
  meta: {
    total: number;
    page: number;
    limit: number;
    totalPages: number;
    hasNext: boolean;
    hasPrev: boolean;
  };
}
```

### FilterDto
```typescript
class FilterDto {
  @IsOptional()
  @IsDateString()
  createdFrom?: string;

  @IsOptional()
  @IsDateString()
  createdTo?: string;

  @IsOptional()
  @IsString()
  status?: string;

  @IsOptional()
  @IsBoolean()
  includeDeleted?: boolean;
}
```

## Campos Estandar de Entidad

```typescript
// Toda entidad debe tener
interface BaseEntity {
  id: string;           // UUID
  tenant_id: string;    // UUID, FK a tenants
  created_at: Date;     // Timestamp creacion
  updated_at?: Date;    // Timestamp modificacion
  deleted_at?: Date;    // Soft delete
}
```

## SQL Base para Tablas

```sql
-- Template para nuevas tablas
CREATE TABLE schema_name.table_name (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  tenant_id UUID NOT NULL REFERENCES tenants.tenants(id),

  -- Campos especificos aqui --

  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ,
  deleted_at TIMESTAMPTZ
);

-- Indices estandar
CREATE INDEX idx_table_tenant ON schema_name.table_name(tenant_id);
CREATE INDEX idx_table_deleted ON schema_name.table_name(deleted_at) WHERE deleted_at IS NULL;

-- RLS
ALTER TABLE schema_name.table_name ENABLE ROW LEVEL SECURITY;
CREATE POLICY tenant_isolation ON schema_name.table_name
  USING (tenant_id = current_tenant_id());

-- Trigger updated_at
CREATE TRIGGER set_updated_at
  BEFORE UPDATE ON schema_name.table_name
  FOR EACH ROW EXECUTE FUNCTION update_updated_at();
```

## Decoradores Utiles

```typescript
// Excluir de respuesta
@Exclude()
deleted_at: Date;

// Transformar fecha
@Transform(({ value }) => value?.toISOString())
created_at: Date;

// Validacion condicional
@ValidateIf(o => o.type === 'special')
@IsNotEmpty()
specialField: string;
```

## Interceptores

```typescript
// Transformar respuesta
@UseInterceptors(ClassSerializerInterceptor)

// Excluir deleted
@UseInterceptors(ExcludeDeletedInterceptor)

// Log de tiempo
@UseInterceptors(LoggingInterceptor)
```

## Entregables

| Entregable | Estado | Archivo |
|------------|--------|---------|
| base-crud.service.ts | Completado | `common/services/` |
| base-crud.controller.ts | Completado | `common/controllers/` |
| pagination.dto.ts | Completado | `common/dto/` |
| base.entity.ts | Completado | `common/entities/` |
| DDL functions | Completado | `ddl/functions/` |

## Uso en Modulos

```typescript
// Extender servicio
@Injectable()
export class ProductsService extends BaseCrudService<Product> {
  constructor(
    @InjectRepository(Product)
    repository: Repository<Product>
  ) {
    super(repository, 'Product');
  }

  // Metodos adicionales especificos
  async findByCategory(categoryId: string): Promise<Product[]> {
    return this.repository.find({
      where: { category_id: categoryId, tenant_id: this.tenantId, deleted_at: null }
    });
  }
}

// Extender controlador
@Controller('products')
export class ProductsController extends BaseCrudController<Product> {
  constructor(private readonly productsService: ProductsService) {
    super(productsService);
  }

  @Get('category/:categoryId')
  async findByCategory(@Param('categoryId') categoryId: string) {
    return this.productsService.findByCategory(categoryId);
  }
}
```

## Dependencias

### Depende de
- SAAS-002 (Tenants - tenant_id)
- TypeORM / Prisma

### Bloquea a
- Todos los modulos CRUD

## Criterios de Aceptacion

- [x] BaseCrudService funciona
- [x] BaseCrudController funciona
- [x] Paginacion correcta
- [x] Filtros funcionan
- [x] Soft delete funciona
- [x] RLS aplicado

---

**Ultima actualizacion:** 2026-01-07