✨ Added OAuth2 support

packages/nodes-base/nodes/Google/Sheet/GenericFunctions.ts

@@ -0,0 +1,129 @@
+import {
+	OptionsWithUri,
+ } from 'request';
+
+import {
+	IExecuteFunctions,
+	IExecuteSingleFunctions,
+	ILoadOptionsFunctions,
+} from 'n8n-core';
+
+import {
+	IDataObject,
+} from 'n8n-workflow';
+
+import * as moment from 'moment-timezone';
+
+import * as jwt from 'jsonwebtoken';
+
+export async function googleApiRequest(this: IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions, method: string, resource: string, body: any = {}, qs: IDataObject = {}, uri?: string, headers: IDataObject = {}): Promise<any> { // tslint:disable-line:no-any
+	const authenticationMethod = this.getNodeParameter('authentication', 0, 'serviceAccount') as string;
+	const options: OptionsWithUri = {
+		headers: {
+			'Content-Type': 'application/json',
+		},
+		method,
+		body,
+		qs,
+		uri: uri || `https://sheets.googleapis.com${resource}`,
+		json: true
+	};
+	try {
+		if (Object.keys(headers).length !== 0) {
+			options.headers = Object.assign({}, options.headers, headers);
+		}
+		if (Object.keys(body).length === 0) {
+			delete options.body;
+		}
+
+		if (authenticationMethod === 'serviceAccount') {
+			const credentials = this.getCredentials('googleApi');
+
+			if (credentials === undefined) {
+				throw new Error('No credentials got returned!');
+			}
+
+			const { access_token } = await getAccessToken.call(this, credentials as IDataObject);
+
+			options.headers!.Authorization = `Bearer ${access_token}`;
+			//@ts-ignore
+			return await this.helpers.request(options);
+		} else {
+			//@ts-ignore
+			return await this.helpers.requestOAuth.call(this, 'googleSheetsOAuth2Api', options);
+		}
+	} catch (error) {
+		if (error.response && error.response.body && error.response.body.message) {
+			// Try to return the error prettier
+			throw new Error(`Google Sheet error response [${error.statusCode}]: ${error.response.body.message}`);
+		}
+		throw error;
+	}
+}
+
+export async function googleApiRequestAllItems(this: IExecuteFunctions | ILoadOptionsFunctions, propertyName: string ,method: string, endpoint: string, body: any = {}, query: IDataObject = {}): Promise<any> { // tslint:disable-line:no-any
+
+	const returnData: IDataObject[] = [];
+
+	let responseData;
+	query.maxResults = 100;
+
+	do {
+		responseData = await googleApiRequest.call(this, method, endpoint, body, query);
+		query.pageToken = responseData['nextPageToken'];
+		returnData.push.apply(returnData, responseData[propertyName]);
+	} while (
+		responseData['nextPageToken'] !== undefined &&
+		responseData['nextPageToken'] !== ''
+	);
+
+	return returnData;
+}
+
+function getAccessToken(this: IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions, credentials: IDataObject) : Promise<IDataObject> {
+	//https://developers.google.com/identity/protocols/oauth2/service-account#httprest
+
+	const scopes = [
+		'https://www.googleapis.com/auth/drive',
+		'https://www.googleapis.com/auth/drive.file',
+		'https://www.googleapis.com/auth/spreadsheets',
+	];
+
+	const now = moment().unix();
+
+	const signature = jwt.sign(
+		{
+		  'iss': credentials.email as string,
+		  'sub': credentials.email as string,
+		  'scope': scopes.join(' '),
+		  'aud': `https://oauth2.googleapis.com/token`,
+		  'iat': now,
+		  'exp': now + 3600,
+		},
+		credentials.privateKey as string,
+		{
+		  algorithm: 'RS256',
+		  header: {
+			'kid': credentials.privateKey as string,
+			'typ': 'JWT',
+			'alg': 'RS256',
+		  },
+		}
+	  );
+
+	  const options: OptionsWithUri = {
+		headers: {
+			'Content-Type': 'application/x-www-form-urlencoded',
+		},
+		method: 'POST',
+		form: {
+			grant_type: 'urn:ietf:params:oauth:grant-type:jwt-bearer',
+			assertion: signature,
+		},
+		uri: 'https://oauth2.googleapis.com/token',
+		json: true
+	};
+
+	//@ts-ignore
+	return this.helpers.request(options);
+}