tercul-backend/internal/data/sql/work_repository.go

package sql

import (
	"context"
	"errors"
	"fmt"
	"tercul/internal/domain"
	"tercul/internal/domain/work"

	"gorm.io/gorm"
)

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

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

// FindByTitle finds works by title (partial match)
func (r *workRepository) FindByTitle(ctx context.Context, title string) ([]work.Work, error) {
	var works []work.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) ([]work.Work, error) {
	var works []work.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) ([]work.Work, error) {
	var works []work.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) (*domain.PaginatedResult[work.Work], error) {
	if page < 1 {
		page = 1
	}

	if pageSize < 1 {
		pageSize = 20
	}

	var works []work.Work
	var totalCount int64

	// Get total count
	if err := r.db.WithContext(ctx).Model(&work.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 &domain.PaginatedResult[work.Work]{
		Items:      works,
		TotalCount: totalCount,
		Page:       page,
		PageSize:   pageSize,
		TotalPages: totalPages,
		HasNext:    hasNext,
		HasPrev:    hasPrev,
	}, nil
}

// Delete removes a work and its associations
func (r *workRepository) Delete(ctx context.Context, id uint) error {
	return r.db.WithContext(ctx).Transaction(func(tx *gorm.DB) error {
		// Manually delete associations
		if err := tx.Select("Copyrights", "Monetizations", "Authors", "Tags", "Categories").Delete(&work.Work{TranslatableModel: domain.TranslatableModel{BaseModel: domain.BaseModel{ID: id}}}).Error; err != nil {
			return err
		}
		// Also delete the work itself
		if err := tx.Delete(&work.Work{}, id).Error; err != nil {
			return err
		}
		return nil
	})
}

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

// GetWithAssociations gets a work with all of its direct and many-to-many associations.
func (r *workRepository) GetWithAssociations(ctx context.Context, id uint) (*work.Work, error) {
	associations := []string{
		"Translations",
		"Authors",
		"Tags",
		"Categories",
		"Copyrights",
		"Monetizations",
	}
	return r.FindWithPreload(ctx, associations, id)
}

// GetWithAssociationsInTx gets a work with all associations within a transaction.
func (r *workRepository) GetWithAssociationsInTx(ctx context.Context, tx *gorm.DB, id uint) (*work.Work, error) {
	var entity work.Work
	query := tx.WithContext(ctx)
	associations := []string{
		"Translations",
		"Authors",
		"Tags",
		"Categories",
		"Copyrights",
		"Monetizations",
	}
	for _, preload := range associations {
		query = query.Preload(preload)
	}
	if err := query.First(&entity, id).Error; err != nil {
		if errors.Is(err, gorm.ErrRecordNotFound) {
			return nil, ErrEntityNotFound
		}
		return nil, fmt.Errorf("%w: %v", ErrDatabaseOperation, err)
	}
	return &entity, nil
}

// IsAuthor checks if a user is an author of a work.
// Note: This assumes a direct relationship between user ID and author ID,
// which may need to be revised based on the actual domain model.
func (r *workRepository) IsAuthor(ctx context.Context, workID uint, authorID uint) (bool, error) {
	var count int64
	err := r.db.WithContext(ctx).
		Table("work_authors").
		Where("work_id = ? AND author_id = ?", workID, authorID).
		Count(&count).Error
	if err != nil {
		return false, err
	}
	return count > 0, nil
}

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

	if pageSize < 1 {
		pageSize = 20
	}

	var works []work.Work
	var totalCount int64

	// Get total count
	if err := r.db.WithContext(ctx).Model(&work.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 &domain.PaginatedResult[work.Work]{
		Items:      works,
		TotalCount: totalCount,
		Page:       page,
		PageSize:   pageSize,
		TotalPages: totalPages,
		HasNext:    hasNext,
		HasPrev:    hasPrev,
	}, nil
}