Send weekly digest

server/package.json

@@ -47,6 +47,7 @@
     "jsonwebtoken": "^9.0.2",
     "mongodb-memory-server": "^10.1.0",
     "mongoose": "^8.3.2",
+    "node-cron": "^4.2.1",
     "nodemailer": "^7.0.5"
   }
 }

server/src/config.js

@@ -55,6 +55,9 @@ const config = {
   EMAIL_PASSWORD: getEnvVariable("EMAIL_PASSWORD", null),
   // Google OAuth configuration
   CLIENT_ID: getEnvVariable("CLIENT_ID", null),
+
+  IS_TEST_MODE: getEnvVariable("IS_TEST_MODE", "false"),
+  TEST_EMAIL: getEnvVariable("TEST_EMAIL", null),
 };
 
 export default config;

server/src/cron/weeklyDigestCron.js

@@ -0,0 +1,58 @@
+import cron from "node-cron";
+import { generateWeeklyDigest } from "../services/weeklyDigest.js";
+import { makeDigestHtml } from "../util/makeDigestHtml.js";
+import { sendWeeklyEmail } from "../util/sendWeeklyEmail.js";
+import config from "../config.js";
+
+const { IS_TEST_MODE, TEST_EMAIL } = config;
+
+// Sleep function
+function sleep(ms) {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+// cron.schedule("0 10 * * 5", async () => {          //every Friday at 10:00 AM (server time).
+cron.schedule("*/2 * * * *", async () => {
+  //will run the task every 2nd minute.
+  try {
+    const digests = await generateWeeklyDigest();
+    const maxEmailsPerRun = 10;
+    let sentCount = 0;
+
+    if (IS_TEST_MODE === "true") {
+      // TEST MODE
+      if (digests.length > 0) {
+        const digest = digests[0];
+        const html = makeDigestHtml(digest.topPosts);
+        const subject = "Your Weekly Digest — TEST";
+
+        await sendWeeklyEmail({
+          to: TEST_EMAIL,
+          subject,
+          text: "Test: check out the top posts of the week on our website.",
+          html,
+        });
+      }
+    } else {
+      // PROD MODE
+      for (const digest of digests) {
+        if (sentCount >= maxEmailsPerRun) {
+          break;
+        }
+        const html = makeDigestHtml(digest.topPosts);
+        const subject = "Your Weekly Digest — Top 5 Posts";
+
+        await sendWeeklyEmail({
+          to: digest.email,
+          subject,
+          text: "Check out the top posts of the week on our website.",
+          html,
+        });
+        sentCount++;
+        await sleep(10000);
+      }
+    }
+  } catch (e) {
+    console.error("Weekly digest cron error:", e);
+  }
+});

server/src/index.js

@@ -1,4 +1,3 @@
-// index.js
 import express from "express";
 import app from "./app.js";
 import { logInfo, logError } from "./util/logging.js";
@@ -7,6 +6,7 @@ import testRouter from "./testRouter.js";
 import config from "./config.js";
 import path from "path";
 import { fileURLToPath } from "url";
+import "./cron/weeklyDigestCron.js";
 
 const { PORT, NODE_ENV } = config;
 

server/src/services/weeklyDigest.js

@@ -0,0 +1,76 @@
+import Post from "../models/Post.js";
+import User from "../models/User.js";
+import { calculatePostScore } from "../util/score.js";
+
+export async function generateWeeklyDigest(limit = 50, skip = 0) {
+  const users = await User.find().skip(skip).limit(limit);
+  const oneWeekAgo = new Date();
+  oneWeekAgo.setDate(oneWeekAgo.getDate() - 7);
+
+  const recentPosts = await Post.aggregate([
+    {
+      $match: {
+        published_at: { $gte: oneWeekAgo },
+        tags: { $exists: true, $ne: [] },
+      },
+    },
+    {
+      $lookup: {
+        from: "likes",
+        localField: "_id",
+        foreignField: "post",
+        as: "likes",
+      },
+    },
+    {
+      $addFields: {
+        likeCount: { $size: "$likes" },
+      },
+    },
+    {
+      $project: {
+        _id: 1,
+        title: 1,
+        content: 1,
+        tags: 1,
+        likeCount: 1,
+        published_at: 1,
+        author: 1,
+      },
+    },
+  ]);
+
+  const digestByUser = [];
+
+  for (const user of users) {
+    const userPosts = recentPosts.filter(
+      (post) => post.author?.toString() === user._id.toString(),
+    );
+    const tagFrequency = {};
+
+    userPosts.forEach((post) => {
+      if (Array.isArray(post.tags)) {
+        post.tags.forEach((tag) => {
+          tagFrequency[tag] = (tagFrequency[tag] || 0) + 1;
+        });
+      }
+    });
+
+    const scoredPosts = recentPosts.map((post) => ({
+      title: post.title,
+      content: post.content,
+      tags: post.tags,
+      score: calculatePostScore(post.likeCount, post.tags, tagFrequency),
+    }));
+
+    scoredPosts.sort((a, b) => b.score - a.score);
+
+    digestByUser.push({
+      userId: user._id,
+      email: user.email,
+      topPosts: scoredPosts.slice(0, 5),
+    });
+  }
+
+  return digestByUser;
+}

server/src/util/makeDigestHtml.js

@@ -0,0 +1,24 @@
+export function makeDigestHtml(posts) {
+  return `
+    <div style="background:#fafafa; border-radius:8px; padding:32px 24px; font-family:sans-serif; color:#222; max-width:520px; margin:auto;">
+      <h2 style="color: #fe4a22; text-align:center; margin-bottom: 16px;">Top 5 posts of the week</h2>
+      <ol style="padding-left:20px;">
+        ${posts
+          .map(
+            (p) => `
+          <li style="margin-bottom: 18px;">
+            <strong style="font-size:1.1em;">${p.title}</strong><br>
+            <span style="color:#444;">${p.content.slice(0, 150)}...</span><br>
+            <em style="color:#fe4a22;">Tags: ${p.tags.join(", ")}</em>
+          </li>`,
+          )
+          .join("")}
+      </ol>
+      <div style="text-align:center; margin:32px 0;">
+        <a href="https://c52a.hyf.dev/" style="background:#fe4a22; color:white; padding:12px 28px; border-radius:5px; text-decoration:none; font-weight:bold; font-size:16px;">See more on our website</a>
+      </div>
+      <hr style="border:none; border-top:1px solid #eee; margin:24px 0;">
+      <p style="color:#aaa; font-size:12px; text-align:center; margin:0;">This is an automated email, please do not reply.</p>
+    </div>
+  `;
+}

server/src/util/sendWeeklyEmail.js

@@ -0,0 +1,32 @@
+import nodemailer from "nodemailer";
+import { logError } from "./logging.js";
+import config from "../config.js";
+
+const { EMAIL, EMAIL_PASSWORD, EMAIL_PROVIDER } = config;
+
+const transporter = nodemailer.createTransport({
+  service: EMAIL_PROVIDER,
+  auth: {
+    user: EMAIL,
+    pass: EMAIL_PASSWORD,
+  },
+});
+
+async function sendWeeklyEmail({ to, subject, text, html }) {
+  const mailOptions = {
+    from: `'MySite' <${EMAIL}>`,
+    to,
+    subject,
+    text,
+    html,
+  };
+
+  try {
+    return await transporter.sendMail(mailOptions);
+  } catch (error) {
+    logError(`Error sending weekly email to ${to}:`, error);
+    throw error;
+  }
+}
+
+export { sendWeeklyEmail };