feat(next/api): has one through pointer relation

next/api/src/model/Ticket.ts

@@ -10,8 +10,8 @@ import {
   pointerId,
   pointerIds,
   pointTo,
-  hasManyThroughPointer,
   hasManyThroughPointerArray,
+  hasOneThroughPointer,
   serialize,
 } from '@/orm';
 import { TicketUpdater, UpdateOptions } from '@/ticket/TicketUpdater';
@@ -210,8 +210,8 @@ export class Ticket extends Model {
   @field()
   privateTags?: Tag[];
 
-  @hasManyThroughPointer(() => Notification)
-  notifications?: Notification[];
+  @hasOneThroughPointer(() => Notification)
+  notification?: Notification;
 
   @pointerId(() => Ticket)
   parentId?: string;

next/api/src/orm/helpers.ts

@@ -168,6 +168,25 @@ export function hasManyThroughRelation(getRelatedModel: ModelGetter, relatedKey?
   };
 }
 
+export function hasOneThroughPointer(
+  getRelatedModel: ModelGetter,
+  foreignPointerKey?: string,
+  foreignKeyField?: string
+) {
+  return (target: Model, field: string) => {
+    const model = target.constructor as typeof Model;
+    foreignPointerKey ??= lowercaseFirstChar(model.getClassName());
+    model.setRelation({
+      type: RelationType.HasOneThroughPointer,
+      model,
+      field,
+      getRelatedModel,
+      foreignPointerKey,
+      foreignKeyField: foreignKeyField ?? foreignPointerKey + 'Id',
+    });
+  };
+}
+
 function serializeDecoratorFactory(config?: Partial<Omit<SerializedField, 'key'>>) {
   return (target: Model, key: string) => {
     const model = target.constructor as typeof Model;

next/api/src/orm/preloader.ts

@@ -10,6 +10,7 @@ import {
   HasManyThroughPointer,
   HasManyThroughPointerArray,
   HasManyThroughRelation,
+  HasOneThroughPointer,
   RelationName,
   RelationType,
 } from './relation';
@@ -258,6 +259,44 @@ class HasManyThroughRelationPreloader {
   }
 }
 
+class HasOneThroughPointerPreloader implements Preloader {
+  queryModifier?: (query: QueryBuilder<any>) => void;
+
+  constructor(private relation: HasOneThroughPointer) {}
+
+  async load(items: Item[], options?: AuthOptions) {
+    if (items.length === 0) {
+      return;
+    }
+
+    const { model, field, getRelatedModel, foreignPointerKey, foreignKeyField } = this.relation;
+
+    const itemsChunks = _(items)
+      .uniqBy((item) => item.id)
+      .chunk(50)
+      .value();
+
+    const relatedItemsChunks: Item[][] = [];
+
+    for (const items of itemsChunks) {
+      const query = getRelatedModel().queryBuilder();
+      this.queryModifier?.(query);
+      const pointers = items.map((item) => model.ptr(item.id));
+      query.where(foreignPointerKey, 'in', pointers);
+      const relatedItems = await query.find(options);
+      relatedItemsChunks.push(relatedItems);
+    }
+
+    const relatedItemsGroups = _(relatedItemsChunks).flatten().groupBy(foreignKeyField).value();
+    for (const item of items) {
+      const relatedItems = relatedItemsGroups[item.id];
+      if (relatedItems) {
+        item[field] = relatedItems[0];
+      }
+    }
+  }
+}
+
 export function preloaderFactory<M extends typeof Model, N extends RelationName<M>>(
   model: M,
   name: N
@@ -281,5 +320,7 @@ export function preloaderFactory<M extends typeof Model, N extends RelationName<
       return new HasManyThroughPointerArrayPreloader(relation);
     case RelationType.HasManyThroughRelation:
       return new HasManyThroughRelationPreloader(relation);
+    case RelationType.HasOneThroughPointer:
+      return new HasOneThroughPointerPreloader(relation);
   }
 }

next/api/src/orm/relation.ts

@@ -17,6 +17,7 @@ export enum RelationType {
   HasManyThroughIdArray,
   HasManyThroughPointerArray,
   HasManyThroughRelation,
+  HasOneThroughPointer,
 }
 
 export interface BelongsTo {
@@ -79,11 +80,21 @@ export interface HasManyThroughRelation {
   relatedKey: string;
 }
 
+export interface HasOneThroughPointer {
+  type: RelationType.HasOneThroughPointer;
+  model: typeof Model;
+  field: string;
+  getRelatedModel: ModelGetter;
+  foreignPointerKey: string;
+  foreignKeyField: string;
+}
+
 export type Relation =
   | BelongsTo
   | BelongsToThroughPointer
   | HasMany
   | HasManyThroughPointer
   | HasManyThroughIdArray
   | HasManyThroughPointerArray
-  | HasManyThroughRelation;
+  | HasManyThroughRelation
+  | HasOneThroughPointer;

next/api/src/response/ticket.ts

@@ -50,8 +50,7 @@ export class TicketListItemResponse extends BaseTicketResponse {
   toJSON(options?: TicketResponseOptions) {
     return {
       ...super.toJSON(options),
-      // 因为限定 notification.user 为当前用户，所以 notifications 最多只有一个元素
-      unreadCount: this.ticket.notifications?.[0]?.unreadCount,
+      unreadCount: this.ticket.notification?.unreadCount,
     };
   }
 }

next/api/src/router/ticket.ts

@@ -256,7 +256,7 @@ router.get(
       finalQuery.preload('files');
     }
     if (params.includeUnreadCount) {
-      finalQuery.preload('notifications', {
+      finalQuery.preload('notification', {
         onQuery: (query) => {
           return query.where('user', '==', currentUser.toPointer());
         },