package repository

import (
	"database/sql"
	"encoding/json"
	"errors"
	"fmt"
	"strings"

	"github.com/go-sql-driver/mysql"

	"cmautobuy/admin/model"
)

var (
	// ErrCatalogImportRunExists 表示同一来源的批次号已经登记，由 service 判断是否重放。
	ErrCatalogImportRunExists   = errors.New("商品目录批次已经存在")
	ErrCatalogImportRunNotFound = errors.New("商品目录批次不存在")
)

// InsertCatalogImportRun 先登记 processing 批次；表的复合主键是并发幂等的最终防线。
func InsertCatalogImportRun(q Execer, run model.CatalogImportRun) error {
	_, err := q.Exec(`INSERT INTO catalog_import_runs (
		source,batch_id,request_hash,status,request_count,conflict_count,observed_at,
		update_policy,last_request_at,created_at
	) VALUES (?,?,?,?,1,0,NULLIF(?,''),?,?,?)`, run.Source, run.BatchID, run.RequestHash,
		run.Status, run.ObservedAt, run.UpdatePolicy, run.LastRequestAt, run.CreatedAt)
	if err == nil {
		return nil
	}
	var mysqlErr *mysql.MySQLError
	if errors.As(err, &mysqlErr) && mysqlErr.Number == 1062 {
		return ErrCatalogImportRunExists
	}
	if strings.Contains(strings.ToLower(err.Error()), "unique constraint failed") {
		return ErrCatalogImportRunExists
	}
	return fmt.Errorf("登记商品目录批次失败: %w", err)
}

// GetCatalogImportRun 查询一个批次的摘要，不读取原始请求体。
func GetCatalogImportRun(q Execer, source, batchID string) (model.CatalogImportRun, error) {
	var run model.CatalogImportRun
	var observedAt, lastConflictAt, errorSummary, responseBody, finishedAt sql.NullString
	err := q.QueryRow(`SELECT source,batch_id,request_hash,status,request_count,conflict_count,
		observed_at,update_policy,last_request_at,last_conflict_at,shopee_created,shopee_updated,shopee_fields_filled,shopee_fields_same_source_updated,shopee_fields_manual_skipped,shopee_fields_stale_skipped,sku_created,
		sku_updated,sku_filled,sku_same_source_updated,sku_skipped,sku_manual_skipped,sku_stale_skipped,
		pdd_created,pdd_updated,association_created,association_unchanged,failure_count,
		error_summary,response_body,created_at,finished_at
		FROM catalog_import_runs WHERE source=? AND batch_id=?`, source, batchID).Scan(
		&run.Source, &run.BatchID, &run.RequestHash, &run.Status, &run.RequestCount, &run.ConflictCount,
		&observedAt, &run.UpdatePolicy, &run.LastRequestAt, &lastConflictAt, &run.ShopeeCreated, &run.ShopeeUpdated, &run.ShopeeFieldsFilled, &run.ShopeeFieldsSameSourceUpdated, &run.ShopeeFieldsManualSkipped, &run.ShopeeFieldsStaleSkipped,
		&run.SKUCreated, &run.SKUUpdated, &run.SKUFilled, &run.SKUSameSourceUpdated, &run.SKUSkipped,
		&run.SKUManualSkipped, &run.SKUStaleSkipped, &run.PddCreated, &run.PddUpdated, &run.AssociationCreated,
		&run.AssociationUnchanged, &run.FailureCount, &errorSummary, &responseBody, &run.CreatedAt, &finishedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return model.CatalogImportRun{}, ErrCatalogImportRunNotFound
	}
	if err != nil {
		return model.CatalogImportRun{}, fmt.Errorf("查询商品目录批次失败: %w", err)
	}
	run.ObservedAt = observedAt.String
	run.LastConflictAt = lastConflictAt.String
	run.ErrorSummary = errorSummary.String
	run.ResponseBody = responseBody.String
	run.FinishedAt = finishedAt.String
	return run, nil
}

// ListCatalogImportRuns 在数据库中按来源、状态筛选并倒序分页。
func ListCatalogImportRuns(q Execer, source string, status model.CatalogImportStatus, limit, offset int) ([]model.CatalogImportRun, int, error) {
	where := " WHERE 1=1"
	args := make([]any, 0, 4)
	if source != "" {
		where += " AND source=?"
		args = append(args, source)
	}
	if status != "" {
		where += " AND status=?"
		args = append(args, status)
	}
	var total int
	if err := q.QueryRow(`SELECT COUNT(*) FROM catalog_import_runs`+where, args...).Scan(&total); err != nil {
		return nil, 0, fmt.Errorf("统计商品目录批次失败: %w", err)
	}
	listArgs := append(append([]any{}, args...), limit, offset)
	rows, err := q.Query(`SELECT source,batch_id FROM catalog_import_runs`+where+` ORDER BY created_at DESC,source,batch_id LIMIT ? OFFSET ?`, listArgs...)
	if err != nil {
		return nil, 0, fmt.Errorf("查询商品目录批次列表失败: %w", err)
	}
	defer rows.Close()
	keys := make([][2]string, 0, limit)
	for rows.Next() {
		var key [2]string
		if err := rows.Scan(&key[0], &key[1]); err != nil {
			return nil, 0, err
		}
		keys = append(keys, key)
	}
	if err := rows.Err(); err != nil {
		return nil, 0, err
	}
	if err := rows.Close(); err != nil {
		return nil, 0, err
	}
	list := make([]model.CatalogImportRun, 0, len(keys))
	for _, key := range keys {
		run, err := GetCatalogImportRun(q, key[0], key[1])
		if err != nil {
			return nil, 0, err
		}
		list = append(list, run)
	}
	return list, total, nil
}

// ListCatalogImportSources 返回筛选下拉框所需的稳定来源名。
func ListCatalogImportSources(q Execer) ([]string, error) {
	rows, err := q.Query(`SELECT DISTINCT source FROM catalog_import_runs ORDER BY source`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	var list []string
	for rows.Next() {
		var source string
		if err := rows.Scan(&source); err != nil {
			return nil, err
		}
		list = append(list, source)
	}
	return list, rows.Err()
}

// RecordCatalogImportReplay 记录相同请求的重复提交，业务数据不会再次写入。
func RecordCatalogImportReplay(q Execer, source, batchID, requestedAt string) error {
	result, err := q.Exec(`UPDATE catalog_import_runs SET request_count=request_count+1,last_request_at=?
		WHERE source=? AND batch_id=?`, requestedAt, source, batchID)
	return catalogRunUpdateResult(result, err, "记录商品目录批次重放")
}

// RecordCatalogImportConflict 记录同一批次号携带不同内容的冲突。
func RecordCatalogImportConflict(q Execer, source, batchID, requestedAt string) error {
	result, err := q.Exec(`UPDATE catalog_import_runs SET request_count=request_count+1,
		conflict_count=conflict_count+1,last_request_at=?,last_conflict_at=?
		WHERE source=? AND batch_id=?`, requestedAt, requestedAt, source, batchID)
	return catalogRunUpdateResult(result, err, "记录商品目录批次冲突")
}

// CompleteCatalogImportRun 把处理结果摘要和安全的响应 JSON 固化，供幂等重放。
func CompleteCatalogImportRun(q Execer, run model.CatalogImportRun) error {
	result, err := q.Exec(`UPDATE catalog_import_runs SET status=?,shopee_created=?,shopee_updated=?,shopee_fields_filled=?,shopee_fields_same_source_updated=?,shopee_fields_manual_skipped=?,shopee_fields_stale_skipped=?,
		sku_created=?,sku_updated=?,sku_filled=?,sku_same_source_updated=?,sku_skipped=?,
		sku_manual_skipped=?,sku_stale_skipped=?,pdd_created=?,pdd_updated=?,association_created=?,
		association_unchanged=?,failure_count=?,error_summary=NULLIF(?,''),response_body=NULLIF(?,''),
		finished_at=? WHERE source=? AND batch_id=?`, run.Status, run.ShopeeCreated, run.ShopeeUpdated,
		run.ShopeeFieldsFilled, run.ShopeeFieldsSameSourceUpdated, run.ShopeeFieldsManualSkipped, run.ShopeeFieldsStaleSkipped, run.SKUCreated, run.SKUUpdated, run.SKUFilled, run.SKUSameSourceUpdated, run.SKUSkipped,
		run.SKUManualSkipped, run.SKUStaleSkipped, run.PddCreated, run.PddUpdated, run.AssociationCreated,
		run.AssociationUnchanged, run.FailureCount, run.ErrorSummary, run.ResponseBody,
		run.FinishedAt, run.Source, run.BatchID)
	return catalogRunUpdateResult(result, err, "完成商品目录批次")
}

type CatalogShopeeProductInput struct{ GoodsID, Title, Status, MainSKU, ImageURL, ShopName, Source, ObservedAt, Now, UpdatePolicy string }
type CatalogProductOutcome struct {
	Created, Updated                                                               bool
	FieldsFilled, FieldsSameSourceUpdated, FieldsManualSkipped, FieldsStaleSkipped int
}

// UpsertCatalogShopeeProduct 独立保护主图和店铺字段，绝不覆盖人工 PDD 关联。
func UpsertCatalogShopeeProduct(q Execer, in CatalogShopeeProductInput) (out CatalogProductOutcome, err error) {
	var oldObserved, oldShopID, imageURL, shopName, imageSource, imageObserved, shopSource, shopObserved sql.NullString
	var imageManual, shopManual int
	shopID, err := FindShopIDByName(q, in.ShopName)
	if err != nil {
		return out, err
	}
	err = q.QueryRow(`SELECT source_observed_at,shop_id,image_url,shopee_shop_name,image_source,image_observed_at,image_is_manual,shop_name_source,shop_name_observed_at,shop_name_is_manual FROM shopee_products WHERE goods_id=?`, in.GoodsID).Scan(&oldObserved, &oldShopID, &imageURL, &shopName, &imageSource, &imageObserved, &imageManual, &shopSource, &shopObserved, &shopManual)
	if errors.Is(err, sql.ErrNoRows) {
		_, err = q.Exec(`INSERT INTO shopee_products(goods_id,shop_id,title,shopee_status,main_sku_code,image_url,shopee_shop_name,image_source,image_observed_at,image_is_manual,shop_name_source,shop_name_observed_at,shop_name_is_manual,source,source_observed_at,created_at,updated_at) VALUES(?,NULLIF(?,''),?,NULLIF(?,''),NULLIF(?,''),NULLIF(?,''),NULLIF(?,''),CASE WHEN TRIM(?)='' THEN NULL ELSE ? END,CASE WHEN TRIM(?)='' THEN NULL ELSE ? END,0,CASE WHEN TRIM(?)='' THEN NULL ELSE ? END,CASE WHEN TRIM(?)='' THEN NULL ELSE ? END,0,'api',?,?,?)`, in.GoodsID, shopID, in.Title, in.Status, in.MainSKU, in.ImageURL, in.ShopName, in.ImageURL, in.Source, in.ImageURL, in.ObservedAt, in.ShopName, in.Source, in.ShopName, in.ObservedAt, in.ObservedAt, in.Now, in.Now)
		out.Created = err == nil
		return out, err
	}
	if err != nil {
		return out, err
	}
	baseUpdate := !oldObserved.Valid || oldObserved.String <= in.ObservedAt
	newImage, newShop := imageURL.String, shopName.String
	imageChanged, shopChanged := false, false
	apply := func(incoming string, current *string, source, observed sql.NullString, manual int) (changed bool) {
		if strings.TrimSpace(incoming) == "" || in.UpdatePolicy == "insert_only" {
			return false
		}
		if manual != 0 {
			out.FieldsManualSkipped++
			return false
		}
		// 商品目录是权威来源，可以替换顺运宝为了预览而填入的低优先级值。
		// 这不是任意跨来源覆盖：只有明确标记为 syb 的值享受升级规则。
		if source.Valid && source.String == "syb" {
			if *current != incoming {
				*current = incoming
				out.FieldsFilled++
				return true
			}
			return false
		}
		if in.UpdatePolicy == "fill_missing" {
			if *current == "" {
				*current = incoming
				out.FieldsFilled++
				return true
			}
			return false
		}
		if !source.Valid || source.String != in.Source {
			return false
		}
		if observed.Valid && observed.String > in.ObservedAt {
			out.FieldsStaleSkipped++
			return false
		}
		if *current != incoming {
			*current = incoming
			out.FieldsSameSourceUpdated++
			return true
		}
		return false
	}
	imageChanged = apply(in.ImageURL, &newImage, imageSource, imageObserved, imageManual)
	shopChanged = apply(in.ShopName, &newShop, shopSource, shopObserved, shopManual)
	resolvedShopID := oldShopID.String
	shopAssociationChanged := false
	if shopChanged {
		resolvedShopID, err = FindShopIDByName(q, newShop)
		if err != nil {
			return out, err
		}
		shopAssociationChanged = resolvedShopID != oldShopID.String
	} else if resolvedShopID == "" && shopID != "" && strings.TrimSpace(newShop) == strings.TrimSpace(in.ShopName) {
		resolvedShopID = shopID
		shopAssociationChanged = true
	}
	if !baseUpdate && !imageChanged && !shopChanged && !shopAssociationChanged {
		return out, nil
	}
	_, err = q.Exec(`UPDATE shopee_products SET title=CASE WHEN ? THEN ? ELSE title END,shopee_status=CASE WHEN ? THEN NULLIF(?,'') ELSE shopee_status END,main_sku_code=CASE WHEN ? THEN NULLIF(?,'') ELSE main_sku_code END,source=CASE WHEN ? THEN 'api' ELSE source END,source_observed_at=CASE WHEN ? THEN ? ELSE source_observed_at END,shop_id=CASE WHEN ? THEN NULLIF(?,'') ELSE shop_id END,image_url=NULLIF(?,''),shopee_shop_name=NULLIF(?,''),image_source=CASE WHEN ? THEN ? ELSE image_source END,image_observed_at=CASE WHEN ? THEN ? ELSE image_observed_at END,shop_name_source=CASE WHEN ? THEN ? ELSE shop_name_source END,shop_name_observed_at=CASE WHEN ? THEN ? ELSE shop_name_observed_at END,updated_at=? WHERE goods_id=?`, baseUpdate, in.Title, baseUpdate, in.Status, baseUpdate, in.MainSKU, baseUpdate, baseUpdate, in.ObservedAt, shopAssociationChanged, resolvedShopID, newImage, newShop, imageChanged, in.Source, imageChanged, in.ObservedAt, shopChanged, in.Source, shopChanged, in.ObservedAt, in.Now, in.GoodsID)
	out.Updated = err == nil
	return out, err
}

type CatalogSKUOutcome string

const (
	CatalogSKUCreated           CatalogSKUOutcome = "created"
	CatalogSKUFilled            CatalogSKUOutcome = "filled"
	CatalogSKUSameSourceUpdated CatalogSKUOutcome = "same_source_updated"
	CatalogSKUSkipped           CatalogSKUOutcome = "skipped"
	CatalogSKUManualSkipped     CatalogSKUOutcome = "manual_skipped"
	CatalogSKUStaleSkipped      CatalogSKUOutcome = "stale_skipped"
)

type CatalogShopeeSKUInput struct {
	RecordID, ShopeeSKUID, GoodsID, SpecRaw, SpecKey string
	Color, Size, Advice, SKUCode                     string
	ParseOK                                          bool
	Source, ObservedAt, Now, UpdatePolicy            string
}

type catalogSKUStored struct {
	RecordID, GoodsID, SpecRaw, SpecKey       string
	ShopeeSKUID, Color, Size, Advice, SKUCode sql.NullString
	ParseOK, IsManual                         int
	Source, ObservedAt                        sql.NullString
	FieldSources, FieldObservedAt             sql.NullString
}

func scanCatalogSKU(dbRow *sql.Row) (*catalogSKUStored, error) {
	var row catalogSKUStored
	err := dbRow.Scan(&row.RecordID, &row.ShopeeSKUID, &row.GoodsID, &row.SpecRaw, &row.SpecKey, &row.Color, &row.Size, &row.Advice, &row.ParseOK, &row.SKUCode, &row.IsManual, &row.Source, &row.ObservedAt, &row.FieldSources, &row.FieldObservedAt)
	if errors.Is(err, sql.ErrNoRows) {
		return nil, nil
	}
	if err != nil {
		return nil, err
	}
	return &row, nil
}

func findCatalogSKUBySpec(q Execer, goodsID, specKey string) (*catalogSKUStored, error) {
	return scanCatalogSKU(q.QueryRow(`SELECT sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,source_observed_at,field_sources,field_observed_at FROM shopee_skus WHERE goods_id=? AND spec_key=?`, goodsID, specKey))
}

func findCatalogSKUByExternalID(q Execer, skuID string) (*catalogSKUStored, error) {
	return scanCatalogSKU(q.QueryRow(`SELECT sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,source_observed_at,field_sources,field_observed_at FROM shopee_skus WHERE shopee_sku_id=?`, skuID))
}

// UpsertCatalogShopeeSKU 用真实 ID 或商品规格身份定位同一内部记录，人工行永不覆盖。
func UpsertCatalogShopeeSKU(q Execer, in CatalogShopeeSKUInput) (CatalogSKUOutcome, error) {
	bySpec, err := findCatalogSKUBySpec(q, in.GoodsID, in.SpecKey)
	if err != nil {
		return "", err
	}
	var byID *catalogSKUStored
	if in.ShopeeSKUID != "" {
		byID, err = findCatalogSKUByExternalID(q, in.ShopeeSKUID)
		if err != nil {
			return "", err
		}
	}
	if byID != nil && (byID.GoodsID != in.GoodsID || byID.SpecKey != in.SpecKey) {
		return "", fmt.Errorf("真实蝦皮 SKU %s 已属于其他商品或规格", in.ShopeeSKUID)
	}
	if byID != nil && bySpec != nil && byID.RecordID != bySpec.RecordID {
		return "", fmt.Errorf("商品 %s 的规格 %s 已对应另一个真实蝦皮 SKU", in.GoodsID, in.SpecRaw)
	}
	current := byID
	if current == nil {
		current = bySpec
	}
	parse := 0
	if in.ParseOK {
		parse = 1
	}
	if current == nil {
		fieldSources, fieldTimes := newCatalogFieldProvenance(in)
		sourcesJSON, _ := json.Marshal(fieldSources)
		timesJSON, _ := json.Marshal(fieldTimes)
		_, err = q.Exec(`INSERT INTO shopee_skus(sku_id,shopee_sku_id,goods_id,spec_raw,spec_key,color,size,advice,parse_ok,sku_code,is_manual,source,field_sources,field_observed_at,source_observed_at,created_at,updated_at) VALUES(?,NULLIF(?,''),?,?,?,NULLIF(?,''),NULLIF(?,''),NULLIF(?,''),?,NULLIF(?,''),0,?,?,?,?,?,?)`, in.RecordID, in.ShopeeSKUID, in.GoodsID, in.SpecRaw, in.SpecKey, in.Color, in.Size, in.Advice, parse, in.SKUCode, in.Source, string(sourcesJSON), string(timesJSON), in.ObservedAt, in.Now, in.Now)
		if err != nil {
			return "", err
		}
		return CatalogSKUCreated, nil
	}
	if current.ShopeeSKUID.Valid && in.ShopeeSKUID != "" && current.ShopeeSKUID.String != in.ShopeeSKUID {
		return "", fmt.Errorf("商品 %s 的规格 %s 已对应真实蝦皮 SKU %s", in.GoodsID, in.SpecRaw, current.ShopeeSKUID.String)
	}
	if in.UpdatePolicy == "insert_only" {
		return CatalogSKUSkipped, nil
	}
	if current.IsManual != 0 {
		return CatalogSKUManualSkipped, nil
	}
	external := current.ShopeeSKUID.String
	externalAdded := external == "" && in.ShopeeSKUID != ""
	if external == "" {
		external = in.ShopeeSKUID
	}
	if in.UpdatePolicy == "fill_missing" {
		color, size, advice, skuCode := current.Color.String, current.Size.String, current.Advice.String, current.SKUCode.String
		sources, times := catalogFieldProvenance(current)
		changed := external != current.ShopeeSKUID.String
		canFill := func(field, current, incoming string) bool {
			return strings.TrimSpace(incoming) != "" && (current == "" || (sources[field] == "syb" && in.Source != "syb"))
		}
		if canFill("color", color, in.Color) {
			color = in.Color
			sources["color"], times["color"] = in.Source, in.ObservedAt
			changed = true
		}
		if canFill("size", size, in.Size) {
			size = in.Size
			sources["size"], times["size"] = in.Source, in.ObservedAt
			changed = true
		}
		if canFill("advice", advice, in.Advice) {
			advice = in.Advice
			sources["advice"], times["advice"] = in.Source, in.ObservedAt
			changed = true
		}
		if canFill("sku_code", skuCode, in.SKUCode) {
			skuCode = in.SKUCode
			sources["sku_code"], times["sku_code"] = in.Source, in.ObservedAt
			changed = true
		}
		if !changed {
			return CatalogSKUSkipped, nil
		}
		sourcesJSON, _ := json.Marshal(sources)
		timesJSON, _ := json.Marshal(times)
		_, err = q.Exec(`UPDATE shopee_skus SET shopee_sku_id=NULLIF(?,''),color=NULLIF(?,''),size=NULLIF(?,''),advice=NULLIF(?,''),sku_code=NULLIF(?,''),parse_ok=CASE WHEN parse_ok=1 THEN 1 ELSE ? END,field_sources=?,field_observed_at=?,source_observed_at=CASE WHEN source='syb' AND ?<>'syb' THEN ? ELSE source_observed_at END,source=CASE WHEN source='syb' AND ?<>'syb' THEN ? ELSE source END,updated_at=? WHERE sku_id=?`, external, color, size, advice, skuCode, parse, string(sourcesJSON), string(timesJSON), in.Source, in.ObservedAt, in.Source, in.Source, in.Now, current.RecordID)
		if err != nil {
			return "", err
		}
		return CatalogSKUFilled, nil
	}
	sources, times := catalogFieldProvenance(current)
	color, size, advice, skuCode := current.Color.String, current.Size.String, current.Advice.String, current.SKUCode.String
	changed, stale := false, false
	for _, field := range []struct {
		name     string
		incoming string
		current  *string
	}{{"color", in.Color, &color}, {"size", in.Size, &size}, {"advice", in.Advice, &advice}, {"sku_code", in.SKUCode, &skuCode}} {
		if sources[field.name] != in.Source {
			continue
		}
		if times[field.name] > in.ObservedAt {
			stale = true
			continue
		}
		*field.current = field.incoming
		times[field.name] = in.ObservedAt
		changed = true
	}
	if !changed {
		if externalAdded {
			_, err = q.Exec(`UPDATE shopee_skus SET shopee_sku_id=?,updated_at=? WHERE sku_id=?`, external, in.Now, current.RecordID)
			if err != nil {
				return "", err
			}
			return CatalogSKUFilled, nil
		}
		if stale {
			return CatalogSKUStaleSkipped, nil
		}
		return CatalogSKUSkipped, nil
	}
	sourcesJSON, _ := json.Marshal(sources)
	timesJSON, _ := json.Marshal(times)
	_, err = q.Exec(`UPDATE shopee_skus SET shopee_sku_id=NULLIF(?,''),color=NULLIF(?,''),size=NULLIF(?,''),advice=NULLIF(?,''),parse_ok=?,sku_code=NULLIF(?,''),field_sources=?,field_observed_at=?,source_observed_at=?,updated_at=? WHERE sku_id=?`, external, color, size, advice, parse, skuCode, string(sourcesJSON), string(timesJSON), in.ObservedAt, in.Now, current.RecordID)
	if err != nil {
		return "", err
	}
	return CatalogSKUSameSourceUpdated, nil
}

func newCatalogFieldProvenance(in CatalogShopeeSKUInput) (map[string]string, map[string]string) {
	sources, times := map[string]string{}, map[string]string{}
	for name, value := range map[string]string{"color": in.Color, "size": in.Size, "advice": in.Advice, "sku_code": in.SKUCode} {
		if strings.TrimSpace(value) != "" {
			sources[name], times[name] = in.Source, in.ObservedAt
		}
	}
	return sources, times
}

func catalogFieldProvenance(row *catalogSKUStored) (map[string]string, map[string]string) {
	sources, times := map[string]string{}, map[string]string{}
	_ = json.Unmarshal([]byte(row.FieldSources.String), &sources)
	_ = json.Unmarshal([]byte(row.FieldObservedAt.String), &times)
	return sources, times
}

// UpsertCatalogPddProduct 写入结构化 PDD 数据转换后的规范 JSON；空规格不清除既有采集结果。
func UpsertCatalogPddProduct(q Execer, goodsID, url, title, shopName, skusJSON, observedAt, now string) (created, updated bool, err error) {
	var oldObserved, deletedAt sql.NullString
	err = q.QueryRow(`SELECT source_observed_at,deleted_at FROM pdd_products WHERE goods_id=?`, goodsID).Scan(&oldObserved, &deletedAt)
	status := "pending"
	if skusJSON != "" {
		status = "collected"
	}
	if errors.Is(err, sql.ErrNoRows) {
		_, err = q.Exec(`INSERT INTO pdd_products(goods_id,url,title,shop_name,skus_json,collect_status,collected_at,
			source,source_observed_at,created_at,updated_at) VALUES(?,?,NULLIF(?,''),NULLIF(?,''),NULLIF(?,''),?,
			CASE WHEN ?='collected' THEN ? ELSE NULL END,'api',?,?,?)`, goodsID, url, title, shopName, skusJSON, status, status, now, observedAt, now, now)
		return err == nil, false, err
	}
	if err != nil {
		return false, false, err
	}
	if oldObserved.Valid && oldObserved.String > observedAt {
		return false, false, nil
	}
	if skusJSON == "" {
		_, err = q.Exec(`UPDATE pdd_products SET url=?,title=CASE WHEN TRIM(?)='' THEN title ELSE ? END,
			shop_name=CASE WHEN TRIM(?)='' THEN shop_name ELSE ? END,deleted_at=NULL,source='api',source_observed_at=?,updated_at=? WHERE goods_id=?`,
			url, title, title, shopName, shopName, observedAt, now, goodsID)
	} else {
		_, err = q.Exec(`UPDATE pdd_products SET url=?,title=NULLIF(?,''),shop_name=NULLIF(?,''),skus_json=?,
			collect_status='collected',collect_msg=NULL,artifact_ref=NULL,collected_at=?,deleted_at=NULL,
			source='api',source_observed_at=?,updated_at=? WHERE goods_id=?`, url, title, shopName, skusJSON, now, observedAt, now, goodsID)
	}
	return false, err == nil, err
}

// ApplyCatalogAssociation 只允许空关联建立或相同关联重放。
func ApplyCatalogAssociation(q Execer, shopeeGoodsID, pddGoodsID, now string) (created, unchanged bool, err error) {
	var current sql.NullString
	if err = q.QueryRow(`SELECT pdd_goods_id FROM shopee_products WHERE goods_id=? AND deleted_at IS NULL`, shopeeGoodsID).Scan(&current); err != nil {
		return
	}
	var url string
	if err = q.QueryRow(`SELECT url FROM pdd_products WHERE goods_id=? AND deleted_at IS NULL`, pddGoodsID).Scan(&url); err != nil {
		return
	}
	if current.Valid && current.String != "" {
		if current.String == pddGoodsID {
			return false, true, nil
		}
		return false, false, fmt.Errorf("蝦皮商品 %s 已关联 PDD 商品 %s", shopeeGoodsID, current.String)
	}
	_, err = q.Exec(`UPDATE shopee_products SET pdd_goods_id=?,pdd_goods_url=?,updated_at=? WHERE goods_id=? AND deleted_at IS NULL`, pddGoodsID, url, now, shopeeGoodsID)
	return err == nil, false, err
}

func catalogRunUpdateResult(result sql.Result, err error, action string) error {
	if err != nil {
		return fmt.Errorf("%s失败: %w", action, err)
	}
	affected, err := result.RowsAffected()
	if err != nil {
		return fmt.Errorf("读取%s结果失败: %w", action, err)
	}
	if affected == 0 {
		return ErrCatalogImportRunNotFound
	}
	return nil
}