refactor(*): 代码质量治理 - 收敛接口客户端、模型职责与异步计费巡检

backend/internal/repository/billing_review.go

@@ -0,0 +1,68 @@
+package repository
+
+import (
+	"time"
+
+	"infinite-canvas/backend/internal/model"
+)
+
+// BillingReviewStats 记录需要人工关注的长期未闭合订单数量。
+// 巡检只读数据库，不改变订单状态或积分余额。
+type BillingReviewStats struct {
+	Reserved  int64      `json:"reserved"`
+	Running   int64      `json:"running"`
+	Uncertain int64      `json:"uncertain"`
+	Oldest    *time.Time `json:"oldest,omitempty"`
+}
+
+func (s BillingReviewStats) Total() int64 {
+	return s.Reserved + s.Running + s.Uncertain
+}
+
+// StaleBillingReviewStats 查询超过 age 未更新、仍处于未闭合状态的订单。
+func (r *Repository) StaleBillingReviewStats(now time.Time, age time.Duration) (BillingReviewStats, error) {
+	cutoff := now.Add(-age)
+	stats := BillingReviewStats{}
+	var rows []struct {
+		Status model.BillingStatus
+		Count  int64
+	}
+	if err := r.db.Model(&model.BillingOrder{}).
+		Select("status, count(*) AS count").
+		Where("status IN ? AND updated_at < ?", []model.BillingStatus{
+			model.BillingStatusReserved,
+			model.BillingStatusRunning,
+			model.BillingStatusUncertain,
+		}, cutoff).
+		Group("status").Scan(&rows).Error; err != nil {
+		return stats, err
+	}
+	for _, row := range rows {
+		switch row.Status {
+		case model.BillingStatusReserved:
+			stats.Reserved = row.Count
+		case model.BillingStatusRunning:
+			stats.Running = row.Count
+		case model.BillingStatusUncertain:
+			stats.Uncertain = row.Count
+		}
+	}
+	if stats.Total() == 0 {
+		return stats, nil
+	}
+	var oldest struct {
+		CreatedAt time.Time
+	}
+	if err := r.db.Model(&model.BillingOrder{}).
+		Select("created_at").
+		Where("status IN ? AND updated_at < ?", []model.BillingStatus{
+			model.BillingStatusReserved,
+			model.BillingStatusRunning,
+			model.BillingStatusUncertain,
+		}, cutoff).
+		Order("created_at asc").Limit(1).Scan(&oldest).Error; err != nil {
+		return stats, err
+	}
+	stats.Oldest = &oldest.CreatedAt
+	return stats, nil
+}