feat(goods): support merged secondary origin goods in create/update/detail

apps/api/src/goods/goods.service.ts

@@ -9,38 +9,50 @@ import { CreateGoodDto } from './dto/create-good.dto';
 import { UpdateGoodDto } from './dto/update-good.dto';
 import { QueryGoodDto } from './dto/query-good.dto';
 import { BatchCreateGoodDto } from './dto/batch-create-good.dto';
-import { BatchPriorityDto } from './dto/batch-priority.dto';
-import { GoodDetailDto, GoodDto, PaginatedGoods } from './dto/good.dto';
-import { SyncService } from '../sync/sync.service';
-import { randomUUID } from 'crypto';
-import {
-  CreateCustomGoodDto,
-  CustomGoodDetailDto,
-  CustomGoodVariantDto,
-  UpdateCustomGoodContentDto,
-} from './dto/custom-good.dto';
+import { BatchPriorityDto } from './dto/batch-priority.dto';
+import { GoodDetailDto, GoodDto, PaginatedGoods } from './dto/good.dto';
+import { SyncService } from '../sync/sync.service';
+import { randomUUID } from 'crypto';
+import {
+  CreateCustomGoodDto,
+  CustomGoodDetailDto,
+  CustomGoodVariantDto,
+  UpdateCustomGoodContentDto,
+} from './dto/custom-good.dto';
 
 const GOOD_INCLUDE = {
   country: true,
   category: true,
   tag: true,
   position: true,
-  originGood: {
-    include: {
-      detail: true,
-      variants: { orderBy: [{ sortOrder: 'asc' }, { id: 'asc' }] },
-      _count: { select: { variants: true } },
-    },
-  },
+  originGood: {
+    include: {
+      detail: true,
+      variants: { orderBy: [{ sortOrder: 'asc' }, { id: 'asc' }] },
+      _count: { select: { variants: true } },
+    },
+  },
   goodTags: { include: { tag: true } },
+  mergedOriginGoods: {
+    orderBy: { createdAt: 'asc' },
+    include: {
+      originGood: {
+        include: {
+          detail: true,
+          variants: { orderBy: [{ sortOrder: 'asc' }, { id: 'asc' }] },
+          _count: { select: { variants: true } },
+        },
+      },
+    },
+  },
 } satisfies Prisma.GoodInclude;
 
 @Injectable()
 export class GoodsService {
-  constructor(
-    private readonly prisma: PrismaService,
-    private readonly syncService: SyncService,
-  ) {}
+  constructor(
+    private readonly prisma: PrismaService,
+    private readonly syncService: SyncService,
+  ) {}
 
   async findAll(query: QueryGoodDto): Promise<PaginatedGoods> {
     const { page, pageSize, countryId, categoryId, tagId, positionId, keyword } = query;
@@ -75,6 +87,7 @@ export class GoodsService {
         position: g.position,
         originGood: g.originGood,
         goodTags: g.goodTags,
+        mergedOriginGoods: g.mergedOriginGoods,
       })),
       total,
       page,
@@ -82,25 +95,31 @@ export class GoodsService {
     };
   }
 
-  async findOne(id: bigint): Promise<GoodDetailDto> {
+  async findOne(id: bigint): Promise<GoodDetailDto> {
     const good = await this.prisma.good.findUnique({
       where: { id },
       include: GOOD_INCLUDE,
     });
     if (!good) throw new NotFoundException(`Good ${id} not found`);
-    return GoodDetailDto.fromGood(good, {
+    return GoodDetailDto.fromGood(good, {
       country: good.country,
       category: good.category,
       tag: good.tag,
       position: good.position,
       originGood: good.originGood,
       goodTags: good.goodTags,
+      mergedOriginGoods: good.mergedOriginGoods,
     });
   }
 
-  async create(dto: CreateGoodDto): Promise<GoodDto> {
-    await this.ensureReferences(dto);
-    const result = await this.prisma.$transaction(async (tx) => {
+  async create(dto: CreateGoodDto): Promise<GoodDto> {
+    await this.ensureReferences(dto);
+    const mergedIds = this.dedupeMergedIds(
+      BigInt(dto.originGoodId),
+      dto.mergedOriginGoodIds,
+    );
+    await this.ensureMergedOriginGoods(mergedIds);
+    const result = await this.prisma.$transaction(async (tx) => {
       const created = await tx.good.create({
         data: {
           goodName: dto.goodName,
@@ -120,132 +139,152 @@ export class GoodsService {
           })),
         });
       }
+      if (mergedIds.length > 0) {
+        await tx.goodOriginGood.createMany({
+          data: mergedIds.map((originGoodId) => ({
+            goodId: created.id,
+            originGoodId,
+          })),
+        });
+      }
       const result = await tx.good.findUniqueOrThrow({
         where: { id: created.id },
         include: GOOD_INCLUDE,
       });
-      return GoodDto.from(result, {
+      return GoodDto.from(result, {
         country: result.country,
         category: result.category,
         tag: result.tag,
         position: result.position,
         originGood: result.originGood,
         goodTags: result.goodTags,
-      });
-    });
-    if (
-      result.originGood?.source === 'SDS' &&
-      result.originGood.sdsGoodId &&
-      !result.originGood.hasDetail
-    ) {
-      this.syncService.queueProductDetailSync(result.originGood.sdsGoodId);
-    }
-    return result;
-  }
-
-  async createCustom(dto: CreateCustomGoodDto): Promise<GoodDetailDto> {
-    await this.ensureCountry(dto.countryId);
-    await this.ensureCategory(dto.categoryId);
-    if (dto.positionId !== undefined) await this.ensurePosition(dto.positionId);
-    for (const tagId of dto.tagIds ?? []) await this.ensureTag(tagId);
-
-    const goodId = await this.prisma.$transaction(async (tx) => {
-      const originGood = await tx.originGood.create({
-        data: {
-          source: 'CUSTOM',
-          sdsGoodId: `custom-${randomUUID()}`,
-          goodName: dto.goodName,
-          goodImage: dto.goodImage ?? null,
-          goodPrice: this.decimal(dto.goodPrice),
-          detail: {
-            create: this.customDetailData(
-              dto.detail ?? {},
-            ) as Prisma.OriginGoodDetailUncheckedCreateWithoutOriginGoodInput,
-          },
-        },
-      });
-      if (dto.variants?.length) {
-        await this.replaceCustomVariants(tx, originGood.id, dto.variants);
-      }
-      const good = await tx.good.create({
-        data: {
-          originGoodId: originGood.id,
-          countryId: BigInt(dto.countryId),
-          categoryId: BigInt(dto.categoryId),
-          positionId:
-            dto.positionId === undefined ? null : BigInt(dto.positionId),
-          goodName: dto.goodName,
-          goodImage: dto.goodImage ?? null,
-          goodPriority: dto.goodPriority ?? 0,
-        },
-      });
-      if (dto.tagIds?.length) {
-        await tx.goodTag.createMany({
-          data: dto.tagIds.map((tagId) => ({
-            goodId: good.id,
-            tagId: BigInt(tagId),
-          })),
-        });
-      }
-      return good.id;
-    });
-    return this.findOne(goodId);
-  }
-
-  async updateCustomContent(
-    id: bigint,
-    dto: UpdateCustomGoodContentDto,
-  ): Promise<GoodDetailDto> {
-    const existing = await this.prisma.good.findUnique({
-      where: { id },
-      include: { originGood: true },
-    });
-    if (!existing) throw new NotFoundException(`Good ${id} not found`);
-    if (existing.originGood.source !== 'CUSTOM') {
-      throw new BadRequestException('SDS 映射商品的上游信息不可修改');
-    }
-
-    await this.prisma.$transaction(async (tx) => {
-      await tx.originGood.update({
-        where: { id: existing.originGoodId },
-        data: {
-          goodName: dto.goodName,
-          goodImage: dto.goodImage,
-          goodPrice:
-            dto.goodPrice === undefined ? undefined : this.decimal(dto.goodPrice),
-        },
-      });
-      if (dto.detail !== undefined) {
-        await tx.originGoodDetail.upsert({
-          where: { originGoodId: existing.originGoodId },
-          create: {
-            originGoodId: existing.originGoodId,
-            ...(this.customDetailData(
-              dto.detail,
-            ) as Prisma.OriginGoodDetailUncheckedCreateWithoutOriginGoodInput),
-          },
-          update: this.customDetailData(dto.detail, true),
-        });
-      }
-      if (dto.variants !== undefined) {
-        await this.replaceCustomVariants(
-          tx,
-          existing.originGoodId,
-          dto.variants,
-        );
-      }
-      const goodData: Prisma.GoodUpdateInput = {};
-      if (dto.goodName !== undefined) goodData.goodName = dto.goodName;
-      if (dto.goodImage !== undefined) goodData.goodImage = dto.goodImage;
-      if (Object.keys(goodData).length) {
-        await tx.good.update({ where: { id }, data: goodData });
-      }
-    });
-    return this.findOne(id);
-  }
+        mergedOriginGoods: result.mergedOriginGoods,
+      });
+    });
+    if (
+      result.originGood?.source === 'SDS' &&
+      result.originGood.sdsGoodId &&
+      !result.originGood.hasDetail
+    ) {
+      this.syncService.queueProductDetailSync(result.originGood.sdsGoodId);
+    }
+    return result;
+  }
+
+  async createCustom(dto: CreateCustomGoodDto): Promise<GoodDetailDto> {
+    await this.ensureCountry(dto.countryId);
+    await this.ensureCategory(dto.categoryId);
+    if (dto.positionId !== undefined) await this.ensurePosition(dto.positionId);
+    for (const tagId of dto.tagIds ?? []) await this.ensureTag(tagId);
+
+    const goodId = await this.prisma.$transaction(async (tx) => {
+      const originGood = await tx.originGood.create({
+        data: {
+          source: 'CUSTOM',
+          sdsGoodId: `custom-${randomUUID()}`,
+          goodName: dto.goodName,
+          goodImage: dto.goodImage ?? null,
+          goodPrice: this.decimal(dto.goodPrice),
+          detail: {
+            create: this.customDetailData(
+              dto.detail ?? {},
+            ) as Prisma.OriginGoodDetailUncheckedCreateWithoutOriginGoodInput,
+          },
+        },
+      });
+      if (dto.variants?.length) {
+        await this.replaceCustomVariants(tx, originGood.id, dto.variants);
+      }
+      const good = await tx.good.create({
+        data: {
+          originGoodId: originGood.id,
+          countryId: BigInt(dto.countryId),
+          categoryId: BigInt(dto.categoryId),
+          positionId:
+            dto.positionId === undefined ? null : BigInt(dto.positionId),
+          goodName: dto.goodName,
+          goodImage: dto.goodImage ?? null,
+          goodPriority: dto.goodPriority ?? 0,
+        },
+      });
+      if (dto.tagIds?.length) {
+        await tx.goodTag.createMany({
+          data: dto.tagIds.map((tagId) => ({
+            goodId: good.id,
+            tagId: BigInt(tagId),
+          })),
+        });
+      }
+      return good.id;
+    });
+    return this.findOne(goodId);
+  }
+
+  async updateCustomContent(
+    id: bigint,
+    dto: UpdateCustomGoodContentDto,
+  ): Promise<GoodDetailDto> {
+    const existing = await this.prisma.good.findUnique({
+      where: { id },
+      include: { originGood: true },
+    });
+    if (!existing) throw new NotFoundException(`Good ${id} not found`);
+    if (existing.originGood.source !== 'CUSTOM') {
+      throw new BadRequestException('SDS 映射商品的上游信息不可修改');
+    }
+
+    await this.prisma.$transaction(async (tx) => {
+      await tx.originGood.update({
+        where: { id: existing.originGoodId },
+        data: {
+          goodName: dto.goodName,
+          goodImage: dto.goodImage,
+          goodPrice:
+            dto.goodPrice === undefined ? undefined : this.decimal(dto.goodPrice),
+        },
+      });
+      if (dto.detail !== undefined) {
+        await tx.originGoodDetail.upsert({
+          where: { originGoodId: existing.originGoodId },
+          create: {
+            originGoodId: existing.originGoodId,
+            ...(this.customDetailData(
+              dto.detail,
+            ) as Prisma.OriginGoodDetailUncheckedCreateWithoutOriginGoodInput),
+          },
+          update: this.customDetailData(dto.detail, true),
+        });
+      }
+      if (dto.variants !== undefined) {
+        await this.replaceCustomVariants(
+          tx,
+          existing.originGoodId,
+          dto.variants,
+        );
+      }
+      const goodData: Prisma.GoodUpdateInput = {};
+      if (dto.goodName !== undefined) goodData.goodName = dto.goodName;
+      if (dto.goodImage !== undefined) goodData.goodImage = dto.goodImage;
+      if (Object.keys(goodData).length) {
+        await tx.good.update({ where: { id }, data: goodData });
+      }
+    });
+    return this.findOne(id);
+  }
 
   async update(id: bigint, dto: UpdateGoodDto): Promise<GoodDto> {
     await this.findOne(id);
+    let mergedIds: bigint[] | undefined;
+    if (dto.mergedOriginGoodIds !== undefined || dto.originGoodId !== undefined) {
+      const current = await this.prisma.good.findUniqueOrThrow({
+        where: { id },
+        select: { originGoodId: true },
+      });
+      const primaryId =
+        dto.originGoodId !== undefined ? BigInt(dto.originGoodId) : current.originGoodId;
+      mergedIds = this.dedupeMergedIds(primaryId, dto.mergedOriginGoodIds);
+      await this.ensureMergedOriginGoods(mergedIds);
+    }
     const data: Prisma.GoodUpdateInput = {};
     if (dto.goodName !== undefined) data.goodName = dto.goodName;
     if (dto.originGoodId !== undefined) {
@@ -274,7 +313,7 @@ export class GoodsService {
       }
     }
 
-    const result = await this.prisma.$transaction(async (tx) => {
+    const result = await this.prisma.$transaction(async (tx) => {
       if (dto.tagIds !== undefined) {
         await tx.goodTag.deleteMany({ where: { goodId: id } });
         if (dto.tagIds.length > 0) {
@@ -286,47 +325,59 @@ export class GoodsService {
           });
         }
       }
+      if (mergedIds !== undefined) {
+        await tx.goodOriginGood.deleteMany({ where: { goodId: id } });
+        if (mergedIds.length > 0) {
+          await tx.goodOriginGood.createMany({
+            data: mergedIds.map((originGoodId) => ({
+              goodId: id,
+              originGoodId,
+            })),
+          });
+        }
+      }
       const updated = await tx.good.update({
         where: { id },
         data,
         include: GOOD_INCLUDE,
       });
-      return GoodDto.from(updated, {
+      return GoodDto.from(updated, {
         country: updated.country,
         category: updated.category,
         tag: updated.tag,
         position: updated.position,
         originGood: updated.originGood,
         goodTags: updated.goodTags,
-      });
-    });
-    if (
-      result.originGood?.source === 'SDS' &&
-      result.originGood.sdsGoodId &&
-      !result.originGood.hasDetail
-    ) {
-      this.syncService.queueProductDetailSync(result.originGood.sdsGoodId);
-    }
-    return result;
+        mergedOriginGoods: updated.mergedOriginGoods,
+      });
+    });
+    if (
+      result.originGood?.source === 'SDS' &&
+      result.originGood.sdsGoodId &&
+      !result.originGood.hasDetail
+    ) {
+      this.syncService.queueProductDetailSync(result.originGood.sdsGoodId);
+    }
+    return result;
   }
 
-  async remove(id: bigint): Promise<{ id: string }> {
-    const good = await this.prisma.good.findUnique({
-      where: { id },
-      include: { originGood: true },
-    });
-    if (!good) throw new NotFoundException(`Good ${id} not found`);
-    await this.prisma.$transaction(async (tx) => {
-      await tx.good.delete({ where: { id } });
-      if (good.originGood.source === 'CUSTOM') {
-        const remaining = await tx.good.count({
-          where: { originGoodId: good.originGoodId },
-        });
-        if (remaining === 0) {
-          await tx.originGood.delete({ where: { id: good.originGoodId } });
-        }
-      }
-    });
+  async remove(id: bigint): Promise<{ id: string }> {
+    const good = await this.prisma.good.findUnique({
+      where: { id },
+      include: { originGood: true },
+    });
+    if (!good) throw new NotFoundException(`Good ${id} not found`);
+    await this.prisma.$transaction(async (tx) => {
+      await tx.good.delete({ where: { id } });
+      if (good.originGood.source === 'CUSTOM') {
+        const remaining = await tx.good.count({
+          where: { originGoodId: good.originGoodId },
+        });
+        if (remaining === 0) {
+          await tx.originGood.delete({ where: { id: good.originGoodId } });
+        }
+      }
+    });
     return { id: id.toString() };
   }
 
@@ -335,16 +386,16 @@ export class GoodsService {
    * or none do.
    */
   async batchUpdatePriority(dto: BatchPriorityDto): Promise<{ count: number }> {
-    const result = await this.prisma.$transaction(async (tx) => {
+    const result = await this.prisma.$transaction(async (tx) => {
       for (const item of dto.items) {
         await tx.good.update({
           where: { id: BigInt(item.id) },
           data: { goodPriority: item.priority },
         });
       }
-      return { count: dto.items.length };
-    });
-    return result;
+      return { count: dto.items.length };
+    });
+    return result;
   }
 
   /**
@@ -358,7 +409,7 @@ export class GoodsService {
         await this.ensureTag(tagId);
       }
     }
-    const result = await this.prisma.$transaction(async (tx) => {
+    const result = await this.prisma.$transaction(async (tx) => {
       const created: GoodDto[] = [];
       for (const item of dto.items) {
         const og = await tx.originGood.findUnique({
@@ -388,6 +439,24 @@ export class GoodsService {
             })),
           });
         }
+        const itemMerged = this.dedupeMergedIds(og.id, item.mergedOriginGoodIds);
+        if (itemMerged.length > 0) {
+          const existRows = await tx.originGood.findMany({
+            where: { id: { in: itemMerged } },
+            select: { id: true },
+          });
+          if (existRows.length !== itemMerged.length) {
+            const found = new Set(existRows.map((r) => r.id.toString()));
+            const missing = itemMerged.find((mid) => !found.has(mid.toString()));
+            throw new BadRequestException(`Origin good ${missing} not found`);
+          }
+          await tx.goodOriginGood.createMany({
+            data: itemMerged.map((originGoodId) => ({
+              goodId: row.id,
+              originGoodId,
+            })),
+          });
+        }
         const result = await tx.good.findUniqueOrThrow({
           where: { id: row.id },
           include: GOOD_INCLUDE,
@@ -399,23 +468,24 @@ export class GoodsService {
           position: result.position,
           originGood: result.originGood,
           goodTags: result.goodTags,
+          mergedOriginGoods: result.mergedOriginGoods,
         }));
       }
-      return created;
-    });
-    for (const goodId of new Set(
-      result
-        .filter(
-          (item) =>
-            item.originGood?.source === 'SDS' &&
-            !item.originGood.hasDetail,
-        )
-        .map((item) => item.originGood?.sdsGoodId)
-        .filter((id): id is string => Boolean(id)),
-    )) {
-      this.syncService.queueProductDetailSync(goodId);
-    }
-    return result;
+      return created;
+    });
+    for (const goodId of new Set(
+      result
+        .filter(
+          (item) =>
+            item.originGood?.source === 'SDS' &&
+            !item.originGood.hasDetail,
+        )
+        .map((item) => item.originGood?.sdsGoodId)
+        .filter((id): id is string => Boolean(id)),
+    )) {
+      this.syncService.queueProductDetailSync(goodId);
+    }
+    return result;
   }
 
   /**
@@ -446,6 +516,31 @@ export class GoodsService {
     if (!og) throw new BadRequestException(`Origin good ${id} not found`);
   }
 
+  /** Dedupe merged ids and reject any that equals the primary source. */
+  private dedupeMergedIds(primaryId: bigint, ids?: number[]): bigint[] {
+    if (!ids || ids.length === 0) return [];
+    const unique = [...new Set(ids.map((id) => BigInt(id)))];
+    if (unique.includes(primaryId)) {
+      throw new BadRequestException(
+        'mergedOriginGoodIds 不能包含主源 originGoodId',
+      );
+    }
+    return unique;
+  }
+
+  private async ensureMergedOriginGoods(ids: bigint[]) {
+    if (ids.length === 0) return;
+    const rows = await this.prisma.originGood.findMany({
+      where: { id: { in: ids } },
+      select: { id: true },
+    });
+    if (rows.length !== ids.length) {
+      const found = new Set(rows.map((r) => r.id.toString()));
+      const missing = ids.find((id) => !found.has(id.toString()));
+      throw new BadRequestException(`Origin good ${missing} not found`);
+    }
+  }
+
   private async ensureCountry(id: number) {
     const c = await this.prisma.country.findUnique({ where: { id: BigInt(id) } });
     if (!c) throw new BadRequestException(`Country ${id} not found`);
@@ -456,12 +551,12 @@ export class GoodsService {
     if (!c) throw new BadRequestException(`Category ${id} not found`);
   }
 
-  private async ensureTag(id: number) {
+  private async ensureTag(id: number) {
     const t = await this.prisma.tag.findUnique({ where: { id: BigInt(id) } });
     if (!t) throw new BadRequestException(`Tag ${id} not found`);
   }
 
-  private async ensureReferences(dto: CreateGoodDto) {
+  private async ensureReferences(dto: CreateGoodDto) {
     await this.ensureOriginGood(dto.originGoodId);
     await this.ensureCountry(dto.countryId);
     await this.ensureCategory(dto.categoryId);
@@ -474,94 +569,94 @@ export class GoodsService {
       const p = await this.prisma.position.findUnique({ where: { id: BigInt(dto.positionId) } });
       if (!p) throw new BadRequestException(`Position ${dto.positionId} not found`);
     }
-  }
-
-  private async ensurePosition(id: number) {
-    const position = await this.prisma.position.findUnique({
-      where: { id: BigInt(id) },
-    });
-    if (!position) throw new BadRequestException(`Position ${id} not found`);
-  }
-
-  private decimal(value: string | null | undefined): Prisma.Decimal | null {
-    return value === undefined || value === null || value === ''
-      ? null
-      : new Prisma.Decimal(value);
-  }
-
-  private customDetailData(
-    detail: CustomGoodDetailDto,
-    preserveMissing = false,
-  ): Prisma.OriginGoodDetailUncheckedUpdateInput {
-    const nullable = <T>(value: T | null | undefined): T | null | undefined =>
-      preserveMissing && value === undefined ? undefined : value ?? null;
-    const decimal = (value: string | null | undefined) =>
-      preserveMissing && value === undefined ? undefined : this.decimal(value);
-    const json = (
-      value: Record<string, unknown> | null | undefined,
-    ): Prisma.InputJsonValue | Prisma.NullTypes.DbNull | undefined =>
-      preserveMissing && value === undefined
-        ? undefined
-        : value === null || value === undefined
-          ? Prisma.DbNull
-          : (value as Prisma.InputJsonValue);
-    return {
-      productCode: nullable(detail.productCode),
-      englishName: nullable(detail.englishName),
-      blankDesignUrl: nullable(detail.blankDesignUrl),
-      detailsPageVideoUrl: nullable(detail.detailsPageVideoUrl),
-      textureName: nullable(detail.textureName),
-      productionCycleHours: nullable(detail.productionCycleHours),
-      minWeightG: decimal(detail.minWeightG),
-      reminder: nullable(detail.reminder),
-      productionProcess: nullable(detail.productionProcess),
-      materialDescription: nullable(detail.materialDescription),
-      productPerformance: nullable(detail.productPerformance),
-      applicableScenarios: nullable(detail.applicableScenarios),
-      washingInstructions: nullable(detail.washingInstructions),
-      specialDescription: nullable(detail.specialDescription),
-      designExplanation: nullable(detail.designExplanation),
-      designArea: nullable(detail.designArea),
-      pictureRequest: nullable(detail.pictureRequest),
-      sizeChart: json(detail.sizeChart),
-      packageSpecs: json(detail.packageSpecs),
-      options: json(detail.options),
-      media: json(detail.media),
-    };
-  }
-
-  private async replaceCustomVariants(
-    tx: Prisma.TransactionClient,
-    originGoodId: bigint,
-    variants: CustomGoodVariantDto[],
-  ): Promise<void> {
-    await tx.originGoodVariant.deleteMany({ where: { originGoodId } });
-    for (const variant of variants) {
-      await tx.originGoodVariant.create({
-        data: {
-          originGoodId,
-          sdsVariantId: `custom-${randomUUID()}`,
-          sku: variant.sku,
-          sizeId: variant.sizeId ?? null,
-          sizeName: variant.sizeName ?? null,
-          colorId: variant.colorId ?? null,
-          colorName: variant.colorName ?? null,
-          colorHex: variant.colorHex ?? null,
-          imageUrl: variant.imageUrl ?? null,
-          price: this.decimal(variant.price),
-          originalPrice: this.decimal(variant.originalPrice),
-          weightG: this.decimal(variant.weightG),
-          boxLengthCm: this.decimal(variant.boxLengthCm),
-          boxWidthCm: this.decimal(variant.boxWidthCm),
-          boxHeightCm: this.decimal(variant.boxHeightCm),
-          enabled: variant.enabled ?? true,
-          sortOrder: variant.sortOrder ?? 0,
-          designData:
-            variant.designData === null || variant.designData === undefined
-              ? Prisma.DbNull
-              : (variant.designData as Prisma.InputJsonValue),
-        },
-      });
-    }
-  }
-}
+  }
+
+  private async ensurePosition(id: number) {
+    const position = await this.prisma.position.findUnique({
+      where: { id: BigInt(id) },
+    });
+    if (!position) throw new BadRequestException(`Position ${id} not found`);
+  }
+
+  private decimal(value: string | null | undefined): Prisma.Decimal | null {
+    return value === undefined || value === null || value === ''
+      ? null
+      : new Prisma.Decimal(value);
+  }
+
+  private customDetailData(
+    detail: CustomGoodDetailDto,
+    preserveMissing = false,
+  ): Prisma.OriginGoodDetailUncheckedUpdateInput {
+    const nullable = <T>(value: T | null | undefined): T | null | undefined =>
+      preserveMissing && value === undefined ? undefined : value ?? null;
+    const decimal = (value: string | null | undefined) =>
+      preserveMissing && value === undefined ? undefined : this.decimal(value);
+    const json = (
+      value: Record<string, unknown> | null | undefined,
+    ): Prisma.InputJsonValue | Prisma.NullTypes.DbNull | undefined =>
+      preserveMissing && value === undefined
+        ? undefined
+        : value === null || value === undefined
+          ? Prisma.DbNull
+          : (value as Prisma.InputJsonValue);
+    return {
+      productCode: nullable(detail.productCode),
+      englishName: nullable(detail.englishName),
+      blankDesignUrl: nullable(detail.blankDesignUrl),
+      detailsPageVideoUrl: nullable(detail.detailsPageVideoUrl),
+      textureName: nullable(detail.textureName),
+      productionCycleHours: nullable(detail.productionCycleHours),
+      minWeightG: decimal(detail.minWeightG),
+      reminder: nullable(detail.reminder),
+      productionProcess: nullable(detail.productionProcess),
+      materialDescription: nullable(detail.materialDescription),
+      productPerformance: nullable(detail.productPerformance),
+      applicableScenarios: nullable(detail.applicableScenarios),
+      washingInstructions: nullable(detail.washingInstructions),
+      specialDescription: nullable(detail.specialDescription),
+      designExplanation: nullable(detail.designExplanation),
+      designArea: nullable(detail.designArea),
+      pictureRequest: nullable(detail.pictureRequest),
+      sizeChart: json(detail.sizeChart),
+      packageSpecs: json(detail.packageSpecs),
+      options: json(detail.options),
+      media: json(detail.media),
+    };
+  }
+
+  private async replaceCustomVariants(
+    tx: Prisma.TransactionClient,
+    originGoodId: bigint,
+    variants: CustomGoodVariantDto[],
+  ): Promise<void> {
+    await tx.originGoodVariant.deleteMany({ where: { originGoodId } });
+    for (const variant of variants) {
+      await tx.originGoodVariant.create({
+        data: {
+          originGoodId,
+          sdsVariantId: `custom-${randomUUID()}`,
+          sku: variant.sku,
+          sizeId: variant.sizeId ?? null,
+          sizeName: variant.sizeName ?? null,
+          colorId: variant.colorId ?? null,
+          colorName: variant.colorName ?? null,
+          colorHex: variant.colorHex ?? null,
+          imageUrl: variant.imageUrl ?? null,
+          price: this.decimal(variant.price),
+          originalPrice: this.decimal(variant.originalPrice),
+          weightG: this.decimal(variant.weightG),
+          boxLengthCm: this.decimal(variant.boxLengthCm),
+          boxWidthCm: this.decimal(variant.boxWidthCm),
+          boxHeightCm: this.decimal(variant.boxHeightCm),
+          enabled: variant.enabled ?? true,
+          sortOrder: variant.sortOrder ?? 0,
+          designData:
+            variant.designData === null || variant.designData === undefined
+              ? Prisma.DbNull
+              : (variant.designData as Prisma.InputJsonValue),
+        },
+      });
+    }
+  }
+}