tercul-backend/repositories/work_repository.go

package repositories

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

// WorkRepository defines methods specific to Work.
type WorkRepository interface {
	BaseRepository[models.Work]
	FindByTitle(ctx context.Context, title string) ([]models.Work, error)
	FindByAuthor(ctx context.Context, authorID uint) ([]models.Work, error)
	FindByCategory(ctx context.Context, categoryID uint) ([]models.Work, error)
	FindByLanguage(ctx context.Context, language string, page, pageSize int) (*PaginatedResult[models.Work], error)
	GetWithTranslations(ctx context.Context, id uint) (*models.Work, error)
	ListWithTranslations(ctx context.Context, page, pageSize int) (*PaginatedResult[models.Work], error)
}

type workRepository struct {
	BaseRepository[models.Work]
	db *gorm.DB
}

// NewWorkRepository creates a new WorkRepository.
func NewWorkRepository(db *gorm.DB) WorkRepository {
	return &workRepository{
		BaseRepository: NewBaseRepositoryImpl[models.Work](db),
		db:             db,
	}
}

// FindByTitle finds works by title (partial match)
func (r *workRepository) FindByTitle(ctx context.Context, title string) ([]models.Work, error) {
	var works []models.Work
	if err := r.db.WithContext(ctx).Where("title LIKE ?", "%"+title+"%").Find(&works).Error; err != nil {
		return nil, err
	}
	return works, nil
}

// FindByAuthor finds works by author ID
func (r *workRepository) FindByAuthor(ctx context.Context, authorID uint) ([]models.Work, error) {
	var works []models.Work
	if err := r.db.WithContext(ctx).Joins("JOIN work_authors ON work_authors.work_id = works.id").
		Where("work_authors.author_id = ?", authorID).
		Find(&works).Error; err != nil {
		return nil, err
	}
	return works, nil
}

// FindByCategory finds works by category ID
func (r *workRepository) FindByCategory(ctx context.Context, categoryID uint) ([]models.Work, error) {
	var works []models.Work
	if err := r.db.WithContext(ctx).Joins("JOIN work_categories ON work_categories.work_id = works.id").
		Where("work_categories.category_id = ?", categoryID).
		Find(&works).Error; err != nil {
		return nil, err
	}
	return works, nil
}

// FindByLanguage finds works by language with pagination
func (r *workRepository) FindByLanguage(ctx context.Context, language string, page, pageSize int) (*PaginatedResult[models.Work], error) {
	if page < 1 {
		page = 1
	}

	if pageSize < 1 {
		pageSize = 20
	}

	var works []models.Work
	var totalCount int64

	// Get total count
	if err := r.db.WithContext(ctx).Model(&models.Work{}).Where("language = ?", language).Count(&totalCount).Error; err != nil {
		return nil, err
	}

	// Calculate offset
	offset := (page - 1) * pageSize

	// Get paginated data
	if err := r.db.WithContext(ctx).Where("language = ?", language).
		Offset(offset).Limit(pageSize).
		Find(&works).Error; err != nil {
		return nil, err
	}

	// Calculate total pages
	totalPages := int(totalCount) / pageSize
	if int(totalCount)%pageSize > 0 {
		totalPages++
	}

	hasNext := page < totalPages
	hasPrev := page > 1

	return &PaginatedResult[models.Work]{
		Items:      works,
		TotalCount: totalCount,
		Page:       page,
		PageSize:   pageSize,
		TotalPages: totalPages,
		HasNext:    hasNext,
		HasPrev:    hasPrev,
	}, nil
}

// GetWithTranslations gets a work with its translations
func (r *workRepository) GetWithTranslations(ctx context.Context, id uint) (*models.Work, error) {
	return r.FindWithPreload(ctx, []string{"Translations"}, id)
}

// ListWithTranslations lists works with their translations
func (r *workRepository) ListWithTranslations(ctx context.Context, page, pageSize int) (*PaginatedResult[models.Work], error) {
	if page < 1 {
		page = 1
	}

	if pageSize < 1 {
		pageSize = 20
	}

	var works []models.Work
	var totalCount int64

	// Get total count
	if err := r.db.WithContext(ctx).Model(&models.Work{}).Count(&totalCount).Error; err != nil {
		return nil, err
	}

	// Calculate offset
	offset := (page - 1) * pageSize

	// Get paginated data with preloaded translations
	if err := r.db.WithContext(ctx).Preload("Translations").
		Offset(offset).Limit(pageSize).
		Find(&works).Error; err != nil {
		return nil, err
	}

	// Calculate total pages
	totalPages := int(totalCount) / pageSize
	if int(totalCount)%pageSize > 0 {
		totalPages++
	}

	hasNext := page < totalPages
	hasPrev := page > 1

	return &PaginatedResult[models.Work]{
		Items:      works,
		TotalCount: totalCount,
		Page:       page,
		PageSize:   pageSize,
		TotalPages: totalPages,
		HasNext:    hasNext,
		HasPrev:    hasPrev,
	}, nil
}