gochat/backend/internal/repository/category_repo.go

package repository

import (
	"context"

	"github.com/gochat/gochat/internal/model"
	"gorm.io/gorm"
)

// CategoryRepo provides data access for Category.
type CategoryRepo struct {
	db *gorm.DB
}

func NewCategoryRepo(db *gorm.DB) *CategoryRepo {
	return &CategoryRepo{db: db}
}

func (r *CategoryRepo) Create(ctx context.Context, category *model.Category) error {
	return r.db.WithContext(ctx).Create(category).Error
}

func (r *CategoryRepo) GetByID(ctx context.Context, id uint) (*model.Category, error) {
	var category model.Category
	if err := r.db.WithContext(ctx).Preload("Parent").Preload("RelatedCategories.RelatedCategory").Preload("Folders").Preload("Articles").First(&category, id).Error; err != nil {
		return nil, err
	}
	return &category, nil
}

func (r *CategoryRepo) GetByPortalAndID(ctx context.Context, portalID, id uint) (*model.Category, error) {
	var category model.Category
	if err := r.db.WithContext(ctx).
		Preload("Parent").Preload("RelatedCategories.RelatedCategory").Preload("Folders").Preload("Articles").
		Where("portal_id = ?", portalID).
		First(&category, id).Error; err != nil {
		return nil, err
	}
	return &category, nil
}

func (r *CategoryRepo) Update(ctx context.Context, category *model.Category) error {
	return r.db.WithContext(ctx).Save(category).Error
}

func (r *CategoryRepo) Delete(ctx context.Context, id uint) error {
	return r.db.WithContext(ctx).Delete(&model.Category{}, id).Error
}

// FindByPortalID returns categories for a portal with pagination, ordered by position.
func (r *CategoryRepo) FindByPortalID(ctx context.Context, portalID uint, offset, limit int) ([]model.Category, int64, error) {
	var categories []model.Category
	var count int64
	db := r.db.WithContext(ctx).Model(&model.Category{}).Where("portal_id = ?", portalID)
	db.Count(&count)
	query := db.Preload("Parent").Preload("RelatedCategories.RelatedCategory").Preload("Articles").Order("position ASC")
	if limit > 0 {
		query = query.Offset(offset).Limit(limit)
	}
	if err := query.Find(&categories).Error; err != nil {
		return nil, 0, err
	}
	return categories, count, nil
}

// FindByPortalIDAndLocale returns categories for a portal filtered by locale.
func (r *CategoryRepo) FindByPortalIDAndLocale(ctx context.Context, portalID uint, locale string, offset, limit int) ([]model.Category, int64, error) {
	var categories []model.Category
	var count int64
	db := r.db.WithContext(ctx).Model(&model.Category{}).Where("portal_id = ? AND locale = ?", portalID, locale)
	db.Count(&count)
	query := db.Preload("Parent").Preload("RelatedCategories.RelatedCategory").Preload("Articles").Order("position ASC")
	if limit > 0 {
		query = query.Offset(offset).Limit(limit)
	}
	if err := query.Find(&categories).Error; err != nil {
		return nil, 0, err
	}
	return categories, count, nil
}

// FindByPortalIDAndParentID returns sub-categories for a parent.
func (r *CategoryRepo) FindByPortalIDAndParentID(ctx context.Context, portalID uint, parentID uint, offset, limit int) ([]model.Category, int64, error) {
	var categories []model.Category
	var count int64
	db := r.db.WithContext(ctx).Model(&model.Category{}).Where("portal_id = ? AND parent_id = ?", portalID, parentID)
	db.Count(&count)
	if err := db.Offset(offset).Limit(limit).Order("position ASC").Find(&categories).Error; err != nil {
		return nil, 0, err
	}
	return categories, count, nil
}

// UpdatePositions batch-updates category positions for ordering.
// Implements Category.update_positions from M9 spec.
func (r *CategoryRepo) UpdatePositions(ctx context.Context, positions map[uint]int) error {
	for id, pos := range positions {
		if err := r.db.WithContext(ctx).Model(&model.Category{}).Where("id = ?", id).Update("position", pos).Error; err != nil {
			return err
		}
	}
	return nil
}

func (r *CategoryRepo) UpdatePositionsForPortal(ctx context.Context, portalID uint, positions map[uint]int) error {
	for id, pos := range positions {
		if err := r.db.WithContext(ctx).Model(&model.Category{}).Where("id = ? AND portal_id = ?", id, portalID).Update("position", pos).Error; err != nil {
			return err
		}
	}
	return nil
}

// FindBySlugAndPortalIDAndLocale returns a category by slug, portal, and locale.
func (r *CategoryRepo) FindBySlugAndPortalIDAndLocale(ctx context.Context, slug string, portalID uint, locale string) (*model.Category, error) {
	var category model.Category
	if err := r.db.WithContext(ctx).
		Preload("Articles").
		Where("slug = ? AND portal_id = ? AND locale = ?", slug, portalID, locale).
		First(&category).Error; err != nil {
		return nil, err
	}
	return &category, nil
}