Initial support for SimpleFin.

src/app-simplefin/app-simplefin.js

@@ -0,0 +1,202 @@
+import express from 'express';
+import path from 'path';
+import { inspect } from 'util';
+import https from 'https';
+import { SecretName, secretsService } from '../services/secrets-service.js';
+
+const app = express();
+export { app as handlers };
+app.use(express.json());
+
+app.post('/status', async (req, res) => {
+
+  let configured = false;
+
+  let token = secretsService.get(SecretName.simplefin_token);
+  if (token === null || token === undefined || token === "Forbidden") {
+
+  } else {
+    configured = true;
+  }
+
+  res.send({
+    status: 'ok',
+    data: {
+      configured: configured,
+    },
+  });
+});
+
+app.post('/accounts', async (req, res) => {
+
+  let accessKey = secretsService.get(SecretName.simplefin_accessKey);
+
+  if (accessKey === null || accessKey === undefined || accessKey === "Forbidden") {
+    let token = secretsService.get(SecretName.simplefin_token);
+    if (token === null || token === undefined || token === "Forbidden") {
+      return;
+    } else {
+      accessKey = await getAccessKey(token);
+      secretsService.set(SecretName.simplefin_accessKey, accessKey);
+    }
+  }
+
+  const now = new Date()
+  let startDate = new Date(now.getFullYear(), now.getMonth(), 1)
+  let endDate = new Date(now.getFullYear(), now.getMonth() + 1, 1)
+
+  let accounts = await getAccounts(accessKey, startDate, endDate)
+
+  res.send({
+    status: 'ok',
+    data: {
+      accounts: accounts,
+    },
+  });
+});
+
+app.post('/transactions', async (req, res) => {
+
+  const { accountId, startDate } = req.body;
+
+  let accessKey = secretsService.get(SecretName.simplefin_accessKey);
+
+  if (accessKey === null || accessKey === undefined || accessKey === "Forbidden") {
+    return;
+  }
+
+  try {
+    let results = await getTransactions(
+      accessKey,
+      new Date(startDate),
+    );
+
+    let account = results.accounts.find(a => a.id === accountId);
+
+    let response = {};
+
+    let balance = parseInt(account.balance.replace('.', ''))
+    let date = new Date(account["balance-date"] * 1000).toISOString().split('T')[0]
+
+    response.balances = [{balanceAmount: {amount: account.balance, currency: account.currency}, balanceType: "expected", referenceDate: date}, {balanceAmount: {amount: account.balance, currency: account.currency}, balanceType: "interimAvailable", referenceDate: date}]
+    response.iban = "thisismadeup"
+    response.institutionId = "thisismadeup"
+    response.startingBalance = balance // should be named differently in this use case.
+
+    let allTransactions = [];
+
+    for (let i = 0; i < account.transactions.length; i++) {
+      let trans = account.transactions[i];
+      let newTrans = {};
+
+      //newTrans.bankTransactionCode = don't have, not sure if issue.
+      newTrans.booked = true;
+      newTrans.bookingDate = new Date(trans.posted * 1000).toISOString().split('T')[0]
+      newTrans.date = new Date(trans.posted * 1000).toISOString().split('T')[0]
+      newTrans.debtorName = trans.payee;
+      //newTrans.debtorAccount = don't have, not sure if issue.
+      newTrans.remittanceInformationUnstructured = trans.description;
+      newTrans.transactionAmount = {amount: trans.amount, currency: "USD"};
+      newTrans.transactionId = trans.id;
+      newTrans.valueDate = new Date(trans.posted * 1000).toISOString().split('T')[0]
+
+      allTransactions.push(newTrans);
+    }
+
+    response.transactions = {all: allTransactions, booked: allTransactions, pending: []}
+
+    res.send({
+      status: 'ok',
+      data: response,
+    });
+  } catch (error) {
+    const sendErrorResponse = (data) =>
+      res.send({ status: 'ok', data: { ...data, details: error.details } });
+      console.log('Something went wrong', inspect(error, { depth: null }));
+  }
+});
+
+function parseAccessKey (accessKey) {
+  let scheme = null
+  let rest = null
+  let auth = null
+  let username = null
+  let password = null
+  let baseUrl = null
+  ;[scheme, rest] = accessKey.split('//')
+  ;[auth, rest] = rest.split('@')
+  ;[username, password] = auth.split(':')
+  baseUrl = `${scheme}//${rest}`
+  return {
+    baseUrl: baseUrl,
+    username: username,
+    password: password
+  }
+}
+
+async function getAccessKey (base64Token) {
+  const token = Buffer.from(base64Token, 'base64').toString()
+  const options = {
+    method: 'POST',
+    port: 443,
+    headers: { 'Content-Length': 0 }
+  }
+  return new Promise((resolve, reject) => {
+    const req = https.request(new URL(token), options, (res) => {
+      res.on('data', (d) => {
+        resolve(d.toString())
+      })
+    })
+    req.on('error', (e) => {
+      reject(e)
+    })
+    req.end()
+  })
+}
+
+async function getTransactions (accessKey, startDate, endDate) {
+  const now = new Date()
+  startDate = startDate || new Date(now.getFullYear(), now.getMonth(), 1)
+  endDate = endDate || new Date(now.getFullYear(), now.getMonth() + 1, 1)
+  console.log(`${startDate.toISOString().split('T')[0]} - ${endDate.toISOString().split('T')[0]}`)
+  return await getAccounts(accessKey, startDate, endDate)
+}
+
+function normalizeDate (date) {
+  return (date.valueOf() - date.getTimezoneOffset() * 60 * 1000) / 1000
+}
+
+async function getAccounts (accessKey, startDate, endDate) {
+  const sfin = parseAccessKey(accessKey)
+  const options = {
+    headers: {
+      Authorization: `Basic ${Buffer.from(`${sfin.username}:${sfin.password}`).toString('base64')}`
+    }
+  }
+  const params = []
+  let queryString = ''
+  if (startDate) {
+    params.push(`start-date=${normalizeDate(startDate)}`)
+  }
+  if (endDate) {
+    params.push(`end-date=${normalizeDate(endDate)}`)
+  }
+  if (params.length > 0) {
+    queryString += '?' + params.join('&')
+  }
+  return new Promise((resolve, reject) => {
+    const req = https.request(new URL(`${sfin.baseUrl}/accounts${queryString}`), options, (res) => {
+      let data = ''
+      res.on('data', (d) => {
+        data += d
+      })
+      res.on('end', () => {
+        resolve(JSON.parse(data))
+      })
+    })
+    req.on('error', (e) => {
+      reject(e)
+    })
+    req.end()
+  })
+}

src/app.js

@@ -9,6 +9,7 @@ import rateLimit from 'express-rate-limit';
 import * as accountApp from './app-account.js';
 import * as syncApp from './app-sync.js';
 import * as goCardlessApp from './app-gocardless/app-gocardless.js';
+import * as simpleFinApp from './app-simplefin/app-simplefin.js';
 import * as secretApp from './app-secrets.js';
 
 const app = express();
@@ -45,6 +46,7 @@ app.use('/sync', syncApp.handlers);
 app.use('/account', accountApp.handlers);
 app.use('/nordigen', goCardlessApp.handlers);
 app.use('/gocardless', goCardlessApp.handlers);
+app.use('/simplefin', simpleFinApp.handlers);
 app.use('/secret', secretApp.handlers);
 
 app.get('/mode', (req, res) => {

src/services/secrets-service.js

@@ -9,6 +9,8 @@ import getAccountDb from '../account-db.js';
 export const SecretName = {
   nordigen_secretId: 'nordigen_secretId',
   nordigen_secretKey: 'nordigen_secretKey',
+  simplefin_token: 'simplefin_token',
+  simplefin_accessKey: 'simplefin_accessKey',
 };
 
 class SecretsDb {