feat: email template model, migration script for marketing templates (#696)

* feat: add email template model, and add migration script for marketing email templates

* style: separate requests with const, add migration failure message

Co-authored-by: Tracy <[email protected]>

Author: chenxuan-zhou

models/emailTemplate.model.js

@@ -0,0 +1,28 @@
+"use strict";
+const mongoose = require("mongoose");
+
+// describes the data type
+const EmailTemplateSchema = new mongoose.Schema({
+    name: {
+        type: String,
+        required: true
+    },
+    content: {
+        type: String,
+        required: true
+    }
+});
+
+EmailTemplateSchema.methods.toJSON = function () {
+    const emailTemplateObj = this.toObject();
+    delete emailTemplateObj.__v;
+    emailTemplateObj.id = emailTemplateObj._id;
+    delete emailTemplateObj._id;
+    return emailTemplateObj;
+};
+
+// export the model
+module.exports = mongoose.model(
+    "EmailTemplate",
+    EmailTemplateSchema
+);

scripts/migrate_email_templates.js

@@ -0,0 +1,68 @@
+"use strict";
+const env = require("../services/env.service");
+const db = require("../services/database.service");
+
+const fs = require("fs").promises;
+const path = require("path");
+const templatesDirPath = path.join(__dirname, "../assets/email/marketingEmail/");
+
+const EmailTemplate = require("../models/emailTemplate.model");
+
+// load env
+const envLoadResult = env.load(path.join(__dirname, "../.env"));
+if (envLoadResult.error) {
+    console.error(envLoadResult.error);
+}
+
+// connect to db
+db.connect(undefined, () => {
+    onConnected()
+        .catch((reason) => {
+            console.error(reason);
+            process.exit(1);
+        })
+        .then(() => {
+            process.exit(0);
+        });
+});
+
+/**
+ * Called when the db is connected.
+ */
+async function onConnected() {
+    await migrateAll();
+    console.log("Finished migrating.");
+}
+
+/**
+ * Inserts all email templates in assets to the db.
+ */
+async function migrateAll() {
+    const filenames = await fs.readdir(templatesDirPath);
+    for (const filename of filenames) {
+        const filepath = path.join(templatesDirPath, filename);
+        const data = await fs.readFile(filepath, 'utf-8');
+        const emailTemplateDoc = new EmailTemplate(
+            {
+                name: filename,
+                content: data
+            }
+        );
+        await insertOne(emailTemplateDoc);
+    }
+}
+
+
+/**
+ * Inserts an EmailTemplate document to the db. Prevents duplicate name.
+ * @param {EmailTemplate} emailTemplateDoc 
+ */
+async function insertOne(emailTemplateDoc) {
+    const dup = await EmailTemplate.collection.findOne({ name: emailTemplateDoc.name });
+    if (!dup) {
+        await EmailTemplate.collection.insertOne(emailTemplateDoc);
+        console.log(`${emailTemplateDoc.name} is migrated.`);
+    } else {
+        console.error(`${emailTemplateDoc.name} already in database.`);
+    }
+}