feat: split cron into import and mailing jobs

app/api/mailing/route.ts

@@ -0,0 +1,76 @@
+import { NextResponse } from 'next/server';
+import { z } from 'zod';
+import NewsletterTemplate from '../../../components/emails/newsletter';
+import prisma from '../../../prisma/prisma';
+import { NewsSchema } from '../../../utils/schemas';
+import { sender } from '../../../utils/sender';
+
+export async function GET(request: Request) {
+  if (
+    request.headers.get('Authorization') !== `Bearer ${process.env.CRON_SECRET}`
+  ) {
+    return new Response('Unauthorized', { status: 401 });
+  }
+
+  // send newsletter to users who didn't get it in the last 23h 50m, assuming a cron job every 10 minutes
+  // this is to avoid sending the newsletter to the same users multiple times
+  // this is not a perfect solution, but it's good enough for now
+  const users = await prisma.user.findMany({
+    where: {
+      confirmed: true,
+      deleted: false,
+      lastMail: {
+        lt: new Date(Date.now() - 1000 * 60 * 60 * 24 + 1000 * 10 * 60) // 24h - 10m
+      }
+    },
+    select: {
+      id: true,
+      email: true
+    }
+  });
+
+  if (!users) {
+    return new NextResponse('No users.', {
+      status: 200
+    });
+  }
+
+  const news = await prisma.news.findMany({
+    where: {
+      createdAt: {
+        gt: new Date(Date.now() - 1000 * 60 * 60)
+      }
+    }
+  });
+
+  const validRankedNews = news
+    .filter((item): item is z.infer<typeof NewsSchema> => item !== undefined)
+    .sort((a, b) => b.score - a.score);
+
+  const sent = await sender(
+    users.map(user => user.email),
+    NewsletterTemplate(validRankedNews)
+  );
+
+  if (!sent) {
+    return new NextResponse('Internal server error', {
+      status: 500
+    });
+  }
+
+  // update users so they don't get the newsletter again
+  await prisma.user.updateMany({
+    where: {
+      id: {
+        in: users.map(user => user.id)
+      }
+    },
+    data: {
+      lastMail: new Date()
+    }
+  });
+
+  return new NextResponse(`Newsletter sent to ${users.length} addresses.`, {
+    status: 200
+  });
+}