feat(platform-analytics): ✨ Add synthetic engagement seed data for analytics testing and initial database population

Co-Authored-By: Lilith Autocommit <noreply@atlilith.com>

features/platform-analytics/backend-api/src/seeds/seed-engagement.ts

@@ -0,0 +1,122 @@
+/**
+ * Targeted re-seed for engagement_metrics only.
+ * Run from project root: bun run src/seeds/seed-engagement.ts
+ */
+import 'reflect-metadata'
+import { DataSource } from 'typeorm'
+import { randomUUID } from 'crypto'
+
+import { EngagementMetric, MetricType as EngagementMetricType, TargetType } from '../entities/engagement-metric.entity'
+
+const DS = new DataSource({
+  type: 'postgres',
+  host: process.env.DB_HOST ?? 'localhost',
+  port: Number(process.env.DB_PORT ?? '25434'),
+  username: process.env.DB_USER ?? 'lilith',
+  password: process.env.DB_PASSWORD ?? 'analytics_dev_password',
+  database: process.env.DB_NAME ?? 'lilith_analytics',
+  entities: [EngagementMetric],
+  synchronize: false,
+  logging: false,
+})
+
+function createRng(seed: number) {
+  let s = seed >>> 0
+  return {
+    next(): number {
+      s += 0x6d2b79f5
+      let t = Math.imul(s ^ (s >>> 15), 1 | s)
+      t ^= t + Math.imul(t ^ (t >>> 7), 61 | t)
+      return ((t ^ (t >>> 14)) >>> 0) / 4294967296
+    },
+    int(min: number, max: number): number {
+      return min + Math.floor(this.next() * (max - min + 1))
+    },
+    pick<T>(arr: readonly T[]): T {
+      return arr[Math.floor(this.next() * arr.length)]
+    },
+  }
+}
+
+const rng = createRng(0xdeadbeef)
+const NOW = Date.now()
+
+const PROVIDER_USER_IDS = [
+  'a0000002-0000-0000-0000-000000000001',
+  'a0000002-0000-0000-0000-000000000002',
+  'a0000002-0000-0000-0000-000000000003',
+  'a0000002-0000-0000-0000-000000000004',
+  'a0000002-0000-0000-0000-000000000005',
+  'a0000002-0000-0000-0000-000000000006',
+  'a0000002-0000-0000-0000-000000000007',
+  'a0000002-0000-0000-0000-000000000008',
+  'a0000002-0000-0000-0000-000000000009',
+  'a0000002-0000-0000-0000-00000000000a',
+  'a0000002-0000-0000-0000-00000000000b',
+  'a0000002-0000-0000-0000-00000000000c',
+] as const
+
+async function main(): Promise<void> {
+  process.stdout.write('Connecting to lilith_analytics...\n')
+  await DS.initialize()
+
+  const existing = await DS.getRepository(EngagementMetric).count()
+  if (existing > 0) {
+    process.stdout.write(`engagement_metrics already has ${existing} rows. Truncating...\n`)
+    await DS.query('TRUNCATE TABLE engagement_metrics')
+  }
+
+  const SESSION_COUNT = 120
+  const contentIds = Array.from({ length: 40 }, (_, i) =>
+    `c${String(i + 1).padStart(7, '0')}-0000-0000-0000-000000000000`,
+  )
+  const metricTypes = [
+    EngagementMetricType.VIEW,
+    EngagementMetricType.LIKE,
+    EngagementMetricType.FAVORITE,
+    EngagementMetricType.SHARE,
+  ] as const
+
+  const repo = DS.getRepository(EngagementMetric)
+  const rows: EngagementMetric[] = []
+  let rowId = 1
+
+  for (let s = 0; s < SESSION_COUNT; s++) {
+    const sessionId = randomUUID()
+    const userId = rng.next() > 0.3 ? rng.pick(PROVIDER_USER_IDS) : null
+    const sessionStart = new Date(NOW - rng.int(0, 90) * 86400000 - rng.int(0, 86400) * 1000)
+    const eventCount = rng.int(5, 30)
+    const sessionDurationMs = rng.int(2 * 60 * 1000, 30 * 60 * 1000)
+
+    for (let e = 0; e < eventCount; e++) {
+      const offsetMs = Math.floor((e / Math.max(eventCount - 1, 1)) * sessionDurationMs)
+      const timestamp = new Date(sessionStart.getTime() + offsetMs)
+      rows.push(
+        repo.create({
+          id: String(rowId++),
+          timestamp,
+          userId: userId ?? undefined,
+          sessionId,
+          metricType: e === 0 ? EngagementMetricType.VIEW : rng.pick(metricTypes),
+          targetId: rng.pick(contentIds),
+          targetType: e % 7 === 0 ? TargetType.PROFILE : TargetType.CONTENT,
+          value: 1,
+          metadata: {},
+        }),
+      )
+    }
+  }
+
+  const CHUNK = 500
+  for (let i = 0; i < rows.length; i += CHUNK) {
+    await repo.save(rows.slice(i, i + CHUNK))
+  }
+
+  process.stdout.write(`✓ ${rows.length} engagement metrics across ${SESSION_COUNT} sessions\n`)
+  await DS.destroy()
+}
+
+main().catch((err) => {
+  process.stderr.write(`Seed failed: ${String(err)}\n`)
+  process.exit(1)
+})