feat: daily cron scrape endpoint with concurrency + alert dispatch

src/app/api/cron/scrape/route.ts

@@ -0,0 +1,123 @@
+import { NextRequest, NextResponse } from 'next/server'
+import { eq, and } from 'drizzle-orm'
+import { db, products, priceSnapshots, alerts } from '@/lib/db'
+import { scrapeUrl } from '@/lib/scrapers'
+import { ensureScrapersRegistered } from '@/lib/scrapers/register'
+import { evaluateAlert, type SnapshotInput } from '@/lib/alerts/evaluate'
+import { sendPush } from '@/lib/pushover'
+
+export const maxDuration = 300
+
+const CONCURRENCY = 2
+const FAIL_WARN_THRESHOLD = 3
+
+export async function POST(req: NextRequest) {
+  const auth = req.headers.get('authorization')
+  if (auth !== `Bearer ${process.env.CRON_SECRET}`) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 })
+  }
+  ensureScrapersRegistered()
+
+  const productsToScrape = await db.select().from(products).where(eq(products.enabled, true))
+  console.log(`[cron] scraping ${productsToScrape.length} products`)
+
+  const queue = [...productsToScrape]
+  const summary = { ok: 0, failed: 0, alertsTriggered: 0 }
+
+  async function worker() {
+    while (queue.length > 0) {
+      const p = queue.shift()
+      if (!p) break
+      try {
+        await processProduct(p, summary)
+      } catch (err) {
+        console.error(`[cron] product ${p.id} crashed`, err)
+      }
+    }
+  }
+  await Promise.all(Array.from({ length: CONCURRENCY }, () => worker()))
+
+  return NextResponse.json(summary)
+}
+
+async function processProduct(p: typeof products.$inferSelect, summary: { ok: number; failed: number; alertsTriggered: number }) {
+  const result = await scrapeUrl(p.url)
+  await db.insert(priceSnapshots).values({
+    productId: p.id,
+    price: result.price !== null ? String(result.price) : null,
+    currency: result.currency,
+    availability: result.availability,
+    error: result.error ?? null,
+  })
+
+  if (result.price === null) {
+    const failures = p.consecutiveFailures + 1
+    await db.update(products).set({
+      lastScrapedAt: new Date(),
+      consecutiveFailures: failures,
+    }).where(eq(products.id, p.id))
+    summary.failed++
+    if (failures === FAIL_WARN_THRESHOLD) {
+      await sendPush({
+        title: `⚠ Scrape-Fehler`,
+        message: `${p.name} ist ${failures}× hintereinander fehlgeschlagen: ${result.error ?? 'unknown'}`,
+        url: p.url,
+      }).catch((e) => console.error('pushover failed', e))
+    }
+    return
+  }
+
+  summary.ok++
+  await db.update(products).set({ lastScrapedAt: new Date(), consecutiveFailures: 0 }).where(eq(products.id, p.id))
+
+  const allSnapshots = await db.select().from(priceSnapshots)
+    .where(and(eq(priceSnapshots.productId, p.id)))
+  const maxId = Math.max(...allSnapshots.map((x) => x.id))
+  const history: SnapshotInput[] = allSnapshots
+    .filter((s) => s.price !== null)
+    .filter((s) => s.id !== maxId)
+    .map((s) => ({ price: Number(s.price), scrapedAt: s.scrapedAt }))
+
+  const productAlerts = await db.select().from(alerts)
+    .where(and(eq(alerts.productId, p.id), eq(alerts.enabled, true)))
+
+  for (const alert of productAlerts) {
+    const r = evaluateAlert({
+      alert: {
+        type: alert.type as 'target_price' | 'all_time_low' | 'percent_drop',
+        config: alert.config as Record<string, unknown>,
+        lastTriggeredAt: alert.lastTriggeredAt,
+      },
+      currentPrice: result.price,
+      history,
+    })
+    if (r.triggered) {
+      summary.alertsTriggered++
+      await sendPush({
+        title: alertTitle(alert.type as string, r.context, p.name),
+        message: alertMessage(alert.type as string, r.context, result.price),
+        url: p.url,
+        urlTitle: 'Zum Shop',
+      }).catch((e) => console.error('pushover failed', e))
+      await db.update(alerts).set({ lastTriggeredAt: new Date() }).where(eq(alerts.id, alert.id))
+    }
+  }
+}
+
+function alertTitle(type: string, ctx: Record<string, number | string>, name: string): string {
+  switch (type) {
+    case 'target_price': return `📉 ${name} unter ${ctx.threshold}€`
+    case 'all_time_low': return `🎯 Allzeit-Tief: ${name}`
+    case 'percent_drop': return `⬇️ ${name} −${ctx.percent}%`
+    default: return name
+  }
+}
+
+function alertMessage(type: string, ctx: Record<string, number | string>, price: number): string {
+  switch (type) {
+    case 'target_price': return `Jetzt ${price}€ (Ziel: ${ctx.threshold}€)`
+    case 'all_time_low': return `Jetzt ${price}€ (vorher min: ${ctx.prevMin}€)`
+    case 'percent_drop': return `Jetzt ${price}€ (vorher Ø ${ctx.avg}€ in ${ctx.percent ?? '?'}% Drop)`
+    default: return `Jetzt ${price}€`
+  }
+}