feat: 规范 CSV 预检与安全入库 (#281)

admin/service/catalog_import.go

@@ -73,6 +73,8 @@ type CatalogBatchRequest struct {
 	ShopeeSKUs     []CatalogShopeeSKU     `json:"shopee_skus"`
 	PddProducts    []CatalogPddProduct    `json:"pdd_products"`
 	Associations   []CatalogAssociation   `json:"associations"`
+	// DryRun 只执行数据库预检；不得登记导入批次或写入任何业务数据。
+	DryRun         bool                   `json:"dry_run"`
 }
 type CatalogCounts struct {
 	ShopeeCreated                 int `json:"shopee_created"`
@@ -99,6 +101,14 @@ type CatalogBatchResponse struct {
 	Replayed   bool          `json:"replayed"`
 	Counts     CatalogCounts `json:"counts"`
 	FinishedAt string        `json:"finished_at"`
+	Conflicts  []CatalogAssociationConflict `json:"conflicts,omitempty"`
+}
+
+// CatalogAssociationConflict 是预检发现的既有人工关联冲突，不包含请求体或凭据。
+type CatalogAssociationConflict struct {
+	ShopeeGoodsID string `json:"shopee_goods_id"`
+	ExistingPddID string `json:"existing_pdd_goods_id"`
+	IncomingPddID string `json:"incoming_pdd_goods_id"`
 }
 
 type CatalogError struct {
@@ -177,10 +187,52 @@ func ValidateCatalogBatch(req CatalogBatchRequest) error {
 	return nil
 }
 
+// PreviewCatalogBatch 按当前数据库做只读预检。它不登记 catalog_import_runs，
+// 也不写业务表；正式执行仍会重新检查，避免预检后人工修改造成覆盖。
+func PreviewCatalogBatch(db *sql.DB, req CatalogBatchRequest) (CatalogBatchResponse, error) {
+	if err := ValidateCatalogBatch(req); err != nil {
+		return CatalogBatchResponse{}, err
+	}
+	tx, err := db.BeginTx(context.Background(), &sql.TxOptions{ReadOnly: true, Isolation: sql.LevelReadCommitted})
+	if err != nil {
+		return CatalogBatchResponse{}, err
+	}
+	defer tx.Rollback()
+	counts := CatalogCounts{}
+	for _, p := range req.ShopeeProducts {
+		exists, err := repository.CatalogEntityExists(tx, "shopee_products", p.GoodsID)
+		if err != nil { return CatalogBatchResponse{}, err }
+		if exists { counts.ShopeeUpdated++ } else { counts.ShopeeCreated++ }
+	}
+	for _, p := range req.PddProducts {
+		exists, err := repository.CatalogEntityExists(tx, "pdd_products", p.GoodsID)
+		if err != nil { return CatalogBatchResponse{}, err }
+		if exists { counts.PddUpdated++ } else { counts.PddCreated++ }
+	}
+	for _, s := range req.ShopeeSKUs {
+		key, _ := spec.SpecKey(s.SpecRaw)
+		exists, err := repository.CatalogSKUExists(tx, s.GoodsID, key)
+		if err != nil { return CatalogBatchResponse{}, err }
+		if exists { counts.SKUSkipped++ } else { counts.SKUCreated++ }
+	}
+	conflicts := make([]CatalogAssociationConflict, 0)
+	for _, a := range req.Associations {
+		current, exists, err := repository.CatalogAssociationCurrentPDD(tx, a.ShopeeGoodsID)
+		if err != nil { return CatalogBatchResponse{}, err }
+		if !exists || current == "" { counts.AssociationCreated++; continue }
+		if current == a.PddGoodsID { counts.AssociationUnchanged++; continue }
+		conflicts = append(conflicts, CatalogAssociationConflict{ShopeeGoodsID: a.ShopeeGoodsID, ExistingPddID: current, IncomingPddID: a.PddGoodsID})
+	}
+	return CatalogBatchResponse{BatchID: req.BatchID, Status: "previewed", Counts: counts, FinishedAt: model.NowISO(), Conflicts: conflicts}, nil
+}
+
 func ImportCatalogBatch(db *sql.DB, source string, req CatalogBatchRequest, raw []byte) (CatalogBatchResponse, error) {
 	if err := ValidateCatalogBatch(req); err != nil {
 		return CatalogBatchResponse{}, err
 	}
+	if req.DryRun {
+		return PreviewCatalogBatch(db, req)
+	}
 	observed, _ := time.Parse(time.RFC3339Nano, req.ObservedAt)
 	req.ObservedAt = observed.UTC().Format(model.TimeLayout)
 	policy, _ := normalizeCatalogUpdatePolicy(req.UpdatePolicy)
@@ -239,7 +291,7 @@ func ImportCatalogBatch(db *sql.DB, source string, req CatalogBatchRequest, raw
 			b, _ := json.Marshal(map[string]any{"schema_version": 1, "goods_id": p.GoodsID, "title": p.Title, "shop_name": p.ShopName, "dimensions": p.Dimensions, "skus": p.SKUs})
 			skus = string(b)
 		}
-		c, u, e := repository.UpsertCatalogPddProduct(tx, p.GoodsID, p.URL, p.Title, p.ShopName, skus, req.ObservedAt, now)
+		c, u, e := repository.UpsertCatalogPddProduct(tx, p.GoodsID, p.URL, p.Title, p.ShopName, skus, req.ObservedAt, now, policy)
 		if e != nil {
 			return fail(e)
 		}