feat(server): move updating plaid transactions to background job

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

@@ -0,0 +1,104 @@
+import HasTenancyService from '@/services/Tenancy/TenancyService';
+import { Inject, Service } from 'typedi';
+import { PlaidClientWrapper } from '@/lib/Plaid/Plaid';
+import { PlaidSyncDb } from './PlaidSyncDB';
+import { PlaidFetchedTransactionsUpdates } from '@/interfaces';
+
+@Service()
+export class PlaidUpdateTransactions {
+  @Inject()
+  private tenancy: HasTenancyService;
+
+  @Inject()
+  private plaidSync: PlaidSyncDb;
+
+  /**
+   * Handles the fetching and storing of new, modified, or removed transactions
+   * @param {number} tenantId Tenant ID.
+   * @param {string} plaidItemId the Plaid ID for the item.
+   */
+  public async updateTransactions(tenantId: number, plaidItemId: string) {
+    // Fetch new transactions from plaid api.
+    const { added, modified, removed, cursor, accessToken } =
+      await this.fetchTransactionUpdates(tenantId, plaidItemId);
+
+    const request = { access_token: accessToken };
+    const plaidInstance = new PlaidClientWrapper();
+    const {
+      data: { accounts },
+    } = await plaidInstance.accountsGet(request);
+
+    // Update the DB.
+    await this.plaidSync.syncBankAccounts(tenantId, accounts);
+    await this.plaidSync.syncAccountsTransactions(
+      tenantId,
+      added.concat(modified)
+    );
+    await this.plaidSync.syncTransactionsCursor(tenantId, plaidItemId, cursor);
+
+    return {
+      addedCount: added.length,
+      modifiedCount: modified.length,
+      removedCount: removed.length,
+    };
+  }
+
+  /**
+   * Fetches transactions from the `Plaid API` for a given item.
+   * @param {number} tenantId - Tenant ID.
+   * @param {string} plaidItemId - The Plaid ID for the item.
+   * @returns {Promise<PlaidFetchedTransactionsUpdates>}
+   */
+  private async fetchTransactionUpdates(
+    tenantId: number,
+    plaidItemId: string
+  ): Promise<PlaidFetchedTransactionsUpdates> {
+    // the transactions endpoint is paginated, so we may need to hit it multiple times to
+    // retrieve all available transactions.
+    const { PlaidItem } = this.tenancy.models(tenantId);
+
+    const plaidItem = await PlaidItem.query().findOne(
+      'plaidItemId',
+      plaidItemId
+    );
+    if (!plaidItem) {
+      throw new Error('The given Plaid item id is not found.');
+    }
+    const { plaidAccessToken, lastCursor } = plaidItem;
+    let cursor = lastCursor;
+
+    // New transaction updates since "cursor"
+    let added = [];
+    let modified = [];
+    // Removed transaction ids
+    let removed = [];
+    let hasMore = true;
+
+    const batchSize = 100;
+    try {
+      // Iterate through each page of new transaction updates for item
+      /* eslint-disable no-await-in-loop */
+      while (hasMore) {
+        const request = {
+          access_token: plaidAccessToken,
+          cursor: cursor,
+          count: batchSize,
+        };
+        const plaidInstance = new PlaidClientWrapper();
+        const response = await plaidInstance.transactionsSync(request);
+        const data = response.data;
+        // Add this page of results
+        added = added.concat(data.added);
+        modified = modified.concat(data.modified);
+        removed = removed.concat(data.removed);
+        hasMore = data.has_more;
+        // Update cursor to the next cursor
+        cursor = data.next_cursor;
+      }
+    } catch (err) {
+      console.error(`Error fetching transactions: ${err.message}`);
+      cursor = lastCursor;
+    }
+    return { added, modified, removed, cursor, accessToken: plaidAccessToken };
+  }
+}