index.js

import { config } from "dotenv";
import express from "express";
import axios from "axios";
import cors from "cors";
import { MongoClient } from "mongodb";

config();
const app = express();

app.use(
	cors({
		origin: [
			"http://localhost:5173",
			"http://127.0.0.1:5173",
			"http://studentaffairs.cu.edu.ng",
			"https://studentaffairs.cu.edu.ng",
		],
	})
);

app.use(express.json());

let mongoClient = await new MongoClient(process.env.MONGO_URI, {
	useUnifiedTopology: true,
	useNewUrlParser: true,
}).connect();

let transactions = mongoClient.db("Waffles").collection("Transactions");

const apiUrl = "https://api.flutterwave.com/v3/transactions";
const apiKey = process.env.FLUTIL_API_KEY;

app.get("/api/transactions", async (req, res) => {
	let cachedTransactions = await readTransactions();
	res.send(cachedTransactions);
});

app.get("/api/update", async (req, res) => {
	let pageNumber = 1;
	let total_pages = 0;
	const allTransactions = [];
	while (pageNumber) {
		await fetch(
			`${apiUrl}?from=2023-04-11&status=successful&page=${pageNumber.toString()}`,
			{
				headers: {
					Authorization: `Bearer ${apiKey}`,
				},
			}
		)
			.then((response) => response.json())
			.then(async (data) => {
				let flutterwaveTransactionCount = data.meta.page_info.total;

				let cacheIsCurrent = await checkCache(flutterwaveTransactionCount);
				if (!cacheIsCurrent) {
					total_pages = Math.ceil(data.meta.page_info.total / 10);

					if (data.data.length < 11 && total_pages !== 0) {
						allTransactions.push(...data.data);
						if (pageNumber === total_pages) {
							pageNumber = false;
							await insertTransactions(allTransactions);
							return res.json({ message: "Updated" });
						}
						pageNumber++;
					} else if (
						allTransactions.length < data.meta.page_info.total &&
						data.meta.page_info.total_pages == total_pages
					) {
						allTransactions.push(...data.data);
						pageNumber = false;
						await insertTransactions(allTransactions);
						return res.json({ message: "Updated" });
					}
				} else {
					pageNumber = false;
					res.json({ message: "Up to date" });
				}
			})
			.catch(async (error) => {
				console.log(error);
				let cachedTransactions = await readTransactions();
				pageNumber = false;
				res.json({ message: "An error occured" });
			});
	}
});

app.listen(4000, () => {
	console.log("server is running");
});

async function insertTransactions(data) {
	// make sure is unique

	await transactions.updateOne(
		{ _id: process.env.DOC_ID },
		{ $set: { data } },
		{ upsert: true }
	);
}

// need to add date field
async function readTransactions() {
	let doc = await transactions.findOne({ _id: process.env.DOC_ID });
	return doc.data;
}

async function checkCache(count) {
	let doc = (await transactions.findOne({ _id: process.env.DOC_ID })) ?? {
		data: [],
	};
	let cacheCount = doc.data.length;
	if (cacheCount === count) {
		return true;
	} else {
		return false;
	}
}