package storage

import (
	"context"

	"dana/internal/domain"
)

// PriceList возвращает прайс деревом разделов с позициями.
// Если задан sectionSlug, отдаётся только этот раздел с потомками.
func (s *Storage) PriceList(ctx context.Context, sectionSlug string) ([]*domain.PriceSection, error) {
	rows, err := s.pool.Query(ctx, `
		SELECT id, parent_id, slug, name
		FROM price_sections
		WHERE published
		ORDER BY sort, name`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	byID := map[int64]*domain.PriceSection{}
	var all []*domain.PriceSection
	for rows.Next() {
		sec := &domain.PriceSection{}
		if err := rows.Scan(&sec.ID, &sec.ParentID, &sec.Slug, &sec.Name); err != nil {
			return nil, err
		}
		byID[sec.ID] = sec
		all = append(all, sec)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	itemRows, err := s.pool.Query(ctx, `
		SELECT id, section_id, service_id, name, price, unit, price_from
		FROM price_items
		WHERE published
		ORDER BY sort, name`)
	if err != nil {
		return nil, err
	}
	defer itemRows.Close()

	for itemRows.Next() {
		var it domain.PriceItem
		var sectionID int64
		if err := itemRows.Scan(&it.ID, &sectionID, &it.ServiceID, &it.Name,
			&it.Price, &it.Unit, &it.From); err != nil {
			return nil, err
		}
		if sec, ok := byID[sectionID]; ok {
			sec.Items = append(sec.Items, it)
		}
	}
	if err := itemRows.Err(); err != nil {
		return nil, err
	}

	var roots []*domain.PriceSection
	for _, sec := range all {
		if sec.ParentID == nil {
			roots = append(roots, sec)
			continue
		}
		if parent, ok := byID[*sec.ParentID]; ok {
			parent.Children = append(parent.Children, sec)
		}
	}

	if sectionSlug != "" {
		for _, sec := range all {
			if sec.Slug == sectionSlug {
				return []*domain.PriceSection{sec}, nil
			}
		}
		return nil, ErrNotFound
	}
	return roots, nil
}