tercul-backend/internal/repositories/category_repository.go

package repositories

import (
	"context"
	"errors"
	"gorm.io/gorm"
	"tercul/internal/models"
)

// CategoryRepository defines CRUD methods specific to Category.
type CategoryRepository interface {
	BaseRepository[models.Category]
	FindByName(ctx context.Context, name string) (*models.Category, error)
	ListByWorkID(ctx context.Context, workID uint) ([]models.Category, error)
	ListByParentID(ctx context.Context, parentID *uint) ([]models.Category, error)
}

type categoryRepository struct {
	BaseRepository[models.Category]
	db *gorm.DB
}

// NewCategoryRepository creates a new CategoryRepository.
func NewCategoryRepository(db *gorm.DB) CategoryRepository {
	return &categoryRepository{
		BaseRepository: NewBaseRepositoryImpl[models.Category](db),
		db:             db,
	}
}

// FindByName finds a category by name
func (r *categoryRepository) FindByName(ctx context.Context, name string) (*models.Category, error) {
	var category models.Category
	if err := r.db.WithContext(ctx).Where("name = ?", name).First(&category).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrEntityNotFound
		}
		return nil, err
	}
	return &category, nil
}

// ListByWorkID finds categories by work ID
func (r *categoryRepository) ListByWorkID(ctx context.Context, workID uint) ([]models.Category, error) {
	var categories []models.Category
	if err := r.db.WithContext(ctx).Joins("JOIN work_categories ON work_categories.category_id = categories.id").
		Where("work_categories.work_id = ?", workID).
		Find(&categories).Error; err != nil {
		return nil, err
	}
	return categories, nil
}

// ListByParentID finds categories by parent ID
func (r *categoryRepository) ListByParentID(ctx context.Context, parentID *uint) ([]models.Category, error) {
	var categories []models.Category
	if parentID == nil {
		if err := r.db.WithContext(ctx).Where("parent_id IS NULL").Find(&categories).Error; err != nil {
			return nil, err
		}
	} else {
		if err := r.db.WithContext(ctx).Where("parent_id = ?", *parentID).Find(&categories).Error; err != nil {
			return nil, err
		}
	}
	return categories, nil
}