first commit

apps/api/src/discovery/discovery.controller.ts

@@ -0,0 +1,63 @@
+import { Controller, Get, Query } from '@nestjs/common';
+import { InjectRepository } from '@nestjs/typeorm';
+import { In, Repository } from 'typeorm';
+import { CatalogService } from '../catalog/catalog.service';
+import { ClassificationTagEntity } from '../entities/classification-tag.entity';
+
+@Controller('discover')
+export class DiscoveryController {
+  constructor(
+    private readonly catalog: CatalogService,
+    @InjectRepository(ClassificationTagEntity)
+    private readonly tags: Repository<ClassificationTagEntity>,
+  ) {}
+
+  @Get('changes')
+  async changes(@Query('days') days?: string, @Query('limit') limit?: string) {
+    const daysCount = this.clampDays(days ? Number(days) : 7);
+    const take = limit ? Math.min(Number(limit) || 20, 200) : 20;
+    const since = this.startOfDayOffset(daysCount - 1);
+
+    let changes = await this.catalog.listChangesSince(since);
+    changes = changes.sort((a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime());
+    changes = changes.slice(0, take);
+
+    const itemIds = Array.from(new Set(changes.map((c) => c.itemId).filter(Boolean)));
+    const tags = itemIds.length
+      ? await this.tags.find({ where: { itemId: In(itemIds) } })
+      : [];
+
+    const tagsByItem = new Map<string, ClassificationTagEntity[]>();
+    for (const tag of tags) {
+      const list = tagsByItem.get(tag.itemId) || [];
+      list.push(tag);
+      tagsByItem.set(tag.itemId, list);
+    }
+
+    return changes.map((change) => ({
+      ...change,
+      tags: this.groupTags(tagsByItem.get(change.itemId) || []),
+    }));
+  }
+
+  private groupTags(tags: ClassificationTagEntity[]) {
+    return {
+      topics: tags.filter((t) => t.type === 'topic').map((t) => t.value),
+      territories: tags.filter((t) => t.type === 'territory').map((t) => t.value),
+      formats: tags.filter((t) => t.type === 'format').map((t) => t.value),
+      publishers: tags.filter((t) => t.type === 'publisher').map((t) => t.value),
+    };
+  }
+
+  private clampDays(value: number) {
+    if (!value || Number.isNaN(value)) return 7;
+    return Math.min(Math.max(value, 1), 90);
+  }
+
+  private startOfDayOffset(offsetDays: number) {
+    const date = new Date();
+    date.setHours(0, 0, 0, 0);
+    date.setDate(date.getDate() - offsetDays);
+    return date;
+  }
+}