feat(server): api endpoint to get Plaid link token

packages/server/package.json

@@ -91,6 +91,7 @@
     "pluralize": "^8.0.0",
     "pug": "^3.0.2",
     "puppeteer": "^10.2.0",
+    "plaid": "^10.3.0",
     "qim": "0.0.52",
     "ramda": "^0.27.1",
     "rate-limiter-flexible": "^2.1.14",

packages/server/src/api/controllers/Banking/BankingController.ts

@@ -0,0 +1,18 @@
+import Container, { Inject, Service } from 'typedi';
+import { Router } from 'express';
+import BaseController from '@/api/controllers/BaseController';
+import { PlaidBankingController } from './PlaidBankingController';
+
+@Service()
+export class BankingController extends BaseController {
+  /**
+   * Router constructor.
+   */
+  router() {
+    const router = Router();
+
+    router.use('/plaid', Container.get(PlaidBankingController).router());
+
+    return router;
+  }
+}

packages/server/src/api/controllers/Banking/PlaidBankingController.ts

@@ -0,0 +1,29 @@
+import { Inject, Service } from 'typedi';
+import { Router, Request, Response } from 'express';
+import BaseController from '@/api/controllers/BaseController';
+import { PlaidApplication } from '@/services/Banking/Plaid/PlaidApplication';
+
+@Service()
+export class PlaidBankingController extends BaseController {
+  @Inject()
+  private plaidApp: PlaidApplication;
+
+  /**
+   * Router constructor.
+   */
+  router() {
+    const router = Router();
+
+    router.post('/link-token', this.linkToken.bind(this));
+
+    return router;
+  }
+
+  private async linkToken(req: Request, res: Response) {
+    const { tenantId } = req;
+
+    const linkToken = await this.plaidApp.getLinkToken(tenantId);
+
+    return res.status(200).send(linkToken);
+  }
+}

packages/server/src/api/index.ts

@@ -56,6 +56,7 @@ import { ProjectsController } from './controllers/Projects/Projects';
 import { ProjectTasksController } from './controllers/Projects/Tasks';
 import { ProjectTimesController } from './controllers/Projects/Times';
 import { TaxRatesController } from './controllers/TaxRates/TaxRates';
+import { BankingController } from './controllers/Banking/BankingController';
 
 export default () => {
   const app = Router();
@@ -118,6 +119,7 @@ export default () => {
     Container.get(InventoryItemsCostController).router()
   );
   dashboard.use('/cashflow', Container.get(CashflowController).router());
+  dashboard.use('/banking', Container.get(BankingController).router());
   dashboard.use('/roles', Container.get(RolesController).router());
   dashboard.use(
     '/transactions-locking',

packages/server/src/config/index.ts

@@ -177,6 +177,18 @@ module.exports = {
     service: 'open-exchange-rate',
     openExchangeRate: {
       appId: process.env.OPEN_EXCHANGE_RATE_APP_ID,
-    }
-  }
+    },
+  },
+
+  /**
+   * Plaid.
+   */
+  plaid: {
+    env: process.env.PLAID_ENV || 'sandbox',
+    clientId: process.env.PLAID_CLIENT_ID,
+    secretDevelopment: process.env.PLAID_SECRET_DEVELOPMENT,
+    secretSandbox: process.env.PLAID_SECRET_SANDBOX,
+    redirectSandBox: process.env.PLAID_SANDBOX_REDIRECT_URI,
+    redirectDevelopment: process.env.PLAID_DEVELOPMENT_REDIRECT_URI,
+  },
 };

packages/server/src/lib/Plaid/Plaid.ts

@@ -0,0 +1,103 @@
+import { forEach } from 'lodash';
+import { Configuration, PlaidApi, PlaidEnvironments } from 'plaid';
+import { createPlaidApiEvent } from './PlaidApiEventsDBSync';
+import config from '@/config';
+
+const OPTIONS = { clientApp: 'Plaid-Pattern' };
+
+// We want to log requests to / responses from the Plaid API (via the Plaid client), as this data
+// can be useful for troubleshooting.
+
+/**
+ * Logging function for Plaid client methods that use an access_token as an argument. Associates
+ * the Plaid API event log entry with the item and user the request is for.
+ *
+ * @param {string} clientMethod the name of the Plaid client method called.
+ * @param {Array} clientMethodArgs the arguments passed to the Plaid client method.
+ * @param {Object} response the response from the Plaid client.
+ */
+const defaultLogger = async (clientMethod, clientMethodArgs, response) => {
+  const accessToken = clientMethodArgs[0].access_token;
+  // const { id: itemId, user_id: userId } = await retrieveItemByPlaidAccessToken(
+  //   accessToken
+  // );
+  // await createPlaidApiEvent(1, 1, clientMethod, clientMethodArgs, response);
+
+  console.log(response);
+};
+
+/**
+ * Logging function for Plaid client methods that do not use access_token as an argument. These
+ * Plaid API event log entries will not be associated with an item or user.
+ *
+ * @param {string} clientMethod the name of the Plaid client method called.
+ * @param {Array} clientMethodArgs the arguments passed to the Plaid client method.
+ * @param {Object} response the response from the Plaid client.
+ */
+const noAccessTokenLogger = async (
+  clientMethod,
+  clientMethodArgs,
+  response
+) => {
+  console.log(response);
+
+  // await createPlaidApiEvent(
+  //   undefined,
+  //   undefined,
+  //   clientMethod,
+  //   clientMethodArgs,
+  //   response
+  // );
+};
+
+// Plaid client methods used in this app, mapped to their appropriate logging functions.
+const clientMethodLoggingFns = {
+  accountsGet: defaultLogger,
+  institutionsGet: noAccessTokenLogger,
+  institutionsGetById: noAccessTokenLogger,
+  itemPublicTokenExchange: noAccessTokenLogger,
+  itemRemove: defaultLogger,
+  linkTokenCreate: noAccessTokenLogger,
+  transactionsSync: defaultLogger,
+  sandboxItemResetLogin: defaultLogger,
+};
+// Wrapper for the Plaid client. This allows us to easily log data for all Plaid client requests.
+export class PlaidClientWrapper {
+  constructor() {
+    // Initialize the Plaid client.
+    const configuration = new Configuration({
+      basePath: PlaidEnvironments[config.plaid.env],
+      baseOptions: {
+        headers: {
+          'PLAID-CLIENT-ID': config.plaid.clientId,
+          'PLAID-SECRET':
+            config.plaid.env === 'development'
+              ? config.plaid.secretDevelopment
+              : config.plaid.secretSandbox,
+          'Plaid-Version': '2020-09-14',
+        },
+      },
+    });
+
+    this.client = new PlaidApi(configuration);
+
+    // Wrap the Plaid client methods to add a logging function.
+    forEach(clientMethodLoggingFns, (logFn, method) => {
+      this[method] = this.createWrappedClientMethod(method, logFn);
+    });
+  }
+
+  // Allows us to log API request data for troubleshooting purposes.
+  createWrappedClientMethod(clientMethod, log) {
+    return async (...args) => {
+      try {
+        const res = await this.client[clientMethod](...args);
+        await log(clientMethod, args, res);
+        return res;
+      } catch (err) {
+        await log(clientMethod, args, err?.response?.data);
+        throw err;
+      }
+    };
+  }
+}

packages/server/src/lib/Plaid/PlaidApiEventsDBSync.ts

@@ -0,0 +1,48 @@
+/**
+ * Creates a single Plaid api event log entry.
+ *
+ * @param {string} itemId the item id in the request.
+ * @param {string} userId the user id in the request.
+ * @param {string} plaidMethod the Plaid client method called.
+ * @param {Array} clientMethodArgs the arguments passed to the Plaid client method.
+ * @param {Object} response the Plaid api response object.
+ */
+export const createPlaidApiEvent = async (
+  itemId,
+  userId,
+  plaidMethod,
+  clientMethodArgs,
+  response
+) => {
+  const {
+    error_code: errorCode,
+    error_type: errorType,
+    request_id: requestId,
+  } = response;
+  const query = {
+    text: `
+      INSERT INTO plaid_api_events_table
+        (
+          item_id,
+          user_id,
+          plaid_method,
+          arguments,
+          request_id,
+          error_type,
+          error_code
+        )
+      VALUES
+        ($1, $2, $3, $4, $5, $6, $7);
+    `,
+    values: [
+      itemId,
+      userId,
+      plaidMethod,
+      JSON.stringify(clientMethodArgs),
+      requestId,
+      errorType,
+      errorCode,
+    ],
+  };
+  // await db.query(query);
+};

packages/server/src/lib/Plaid/index.ts

@@ -0,0 +1 @@
+export * from './Plaid';

packages/server/src/services/Banking/Plaid/PlaidApplication.ts

@@ -0,0 +1,18 @@
+import { Inject, Service } from 'typedi';
+import { PlaidLinkTokenService } from './PlaidLinkToken';
+
+@Service()
+export class PlaidApplication {
+  @Inject()
+  private getLinkTokenService: PlaidLinkTokenService;
+
+  /**
+   * 
+   * @param tenantId 
+   * @param itemId 
+   * @returns 
+   */
+  public getLinkToken(tenantId: number) {
+    return this.getLinkTokenService.getLinkToken(tenantId);
+  }
+}

packages/server/src/services/Banking/Plaid/PlaidLinkToken.ts

@@ -0,0 +1,37 @@
+import { PlaidClientWrapper } from '@/lib/Plaid';
+import { Service } from 'typedi';
+
+@Service()
+export class PlaidLinkTokenService {
+  /**
+   * Retrieves the plaid link token.
+   * @param {number} tenantId
+   * @returns
+   */
+  async getLinkToken(tenantId: number) {
+    const accessToken = null;
+
+    // must include transactions in order to receive transactions webhooks
+    const products = ['transactions'];
+    const linkTokenParams = {
+      user: {
+        // This should correspond to a unique id for the current user.
+        client_user_id: 'uniqueId' + tenantId,
+      },
+      client_name: 'Pattern',
+      products,
+      country_codes: ['US'],
+      language: 'en',
+      // webhook: httpTunnel.public_url + '/services/webhook',
+      access_token: accessToken,
+    };
+    // If user has entered a redirect uri in the .env file
+    // if (redirect_uri.indexOf('http') === 0) {
+    //   linkTokenParams.redirect_uri = redirect_uri;
+    // }
+    const plaidInstance = new PlaidClientWrapper();
+    const createResponse = await plaidInstance.linkTokenCreate(linkTokenParams);
+
+    return createResponse.data;
+  }
+}