goods/api/internal/adminstore/stats.go

package adminstore

import "context"

// QualifiedMinScore is the quality_score threshold at or above which a product
// counts as "qualified" (合格) in admin and public stats.
const QualifiedMinScore = 0.6

// AdminStats summarizes the catalog for the admin overview dashboard.
type AdminStats struct {
	Products   int            `json:"products"`
	Qualified  int            `json:"qualified"`
	MinScore   float64        `json:"min_score"`
	ByStatus   map[string]int `json:"by_status"`
	Brands     int            `json:"brands"`
	Categories int            `json:"categories"`
	Pending    int            `json:"pending_submissions"`
	AvgQuality float64        `json:"avg_quality"`
}

// Stats gathers the dashboard counters in a handful of aggregate queries.
func (s *Store) Stats(ctx context.Context) (*AdminStats, error) {
	out := &AdminStats{MinScore: QualifiedMinScore, ByStatus: map[string]int{}}

	if err := s.pool.QueryRow(ctx, `
SELECT count(*),
       count(*) FILTER (WHERE quality_score >= $1 AND status = 'active'),
       COALESCE(avg(quality_score), 0)
FROM product`, QualifiedMinScore).Scan(&out.Products, &out.Qualified, &out.AvgQuality); err != nil {
		return nil, err
	}

	rows, err := s.pool.Query(ctx, "SELECT status, count(*) FROM product GROUP BY status")
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	for rows.Next() {
		var st string
		var n int
		if err := rows.Scan(&st, &n); err != nil {
			return nil, err
		}
		out.ByStatus[st] = n
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	if err := s.pool.QueryRow(ctx, "SELECT count(*) FROM brand").Scan(&out.Brands); err != nil {
		return nil, err
	}
	if err := s.pool.QueryRow(ctx, "SELECT count(*) FROM category").Scan(&out.Categories); err != nil {
		return nil, err
	}
	if err := s.pool.QueryRow(ctx,
		"SELECT count(*) FROM submission WHERE status = 'pending'").Scan(&out.Pending); err != nil {
		return nil, err
	}
	return out, nil
}