n8n/packages/nodes-base/nodes/Google/Chat/GenericFunctions.ts

import {
	OptionsWithUri,
} from 'request';

import {
	IExecuteFunctions,
	IExecuteSingleFunctions,
	ILoadOptionsFunctions,
} from 'n8n-core';

import {
	// ICredentialDataDecryptedObject,
	ICredentialTestFunctions,
	IDataObject,
	INodeProperties,
	NodeApiError,
	NodeOperationError,
} from 'n8n-workflow';

import moment from 'moment-timezone';

import jwt from 'jsonwebtoken';

interface IGoogleAuthCredentials {
	delegatedEmail?: string;
	email: string;
	inpersonate: boolean;
	privateKey: string;
}

export async function googleApiRequest(this: IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions, method: string, resource: string, body: any = {}, qs: IDataObject = {}, uri?: string, noCredentials = false, encoding?: null | undefined): Promise<any> { // tslint:disable-line:no-any

	const options: OptionsWithUri = {
		headers: {
			'Content-Type': 'application/json',
		},
		method,
		body,
		qs,
		uri: uri || `https://chat.googleapis.com${resource}`,
		json: true,
	};

	if (Object.keys(body).length === 0) {
		delete options.body;
	}

	if (encoding === null) {
		options.encoding = null;
	}

	let responseData: IDataObject | undefined;
	try {
		if (noCredentials) {
			//@ts-ignore
			responseData = await this.helpers.request(options);
		} else{
			const credentials = await this.getCredentials('googleApi');

			const { access_token } = await getAccessToken.call(this, credentials as unknown as IGoogleAuthCredentials);
			options.headers!.Authorization = `Bearer ${access_token}`;
			//@ts-ignore
			responseData = await this.helpers.request(options);
		}
	} catch (error) {
		if (error.code === 'ERR_OSSL_PEM_NO_START_LINE') {
			error.statusCode = '401';
		}

		throw new NodeApiError(this.getNode(), error);
	}
	if(Object.keys(responseData as IDataObject).length !== 0) {
		return responseData;
	}
	else {
		return { 'success': true };
	}
}

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.pageSize = 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;
}

export function getAccessToken(this: IExecuteFunctions | IExecuteSingleFunctions | ILoadOptionsFunctions | ICredentialTestFunctions, credentials: IGoogleAuthCredentials): Promise<IDataObject> {
	//https://developers.google.com/identity/protocols/oauth2/service-account#httprest

	const scopes = [
		'https://www.googleapis.com/auth/chat.bot',
	];

	const now = moment().unix();

	credentials.email = credentials.email.trim();
	const privateKey = (credentials.privateKey as string).replace(/\\n/g, '\n').trim();

	const signature = jwt.sign(
		{
			'iss': credentials.email as string,
			'sub': credentials.delegatedEmail || credentials.email as string,
			'scope': scopes.join(' '),
			'aud': `https://oauth2.googleapis.com/token`,
			'iat': now,
			'exp': now + 3600,
		},
		privateKey,
		{
			algorithm: 'RS256',
			header: {
				'kid': privateKey,
				'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);
}

export function validateJSON(json: string | undefined): any { // tslint:disable-line:no-any
	let result;
	try {
		result = JSON.parse(json!);
	} catch (exception) {
		result = undefined;
	}
	return result;
}

export function getPagingParameters(resource: string, operation = 'getAll') {
	const pagingParameters: INodeProperties [] = [
		{
			displayName: 'Return All',
			name: 'returnAll',
			type: 'boolean',
			displayOptions: {
				show: {
					resource: [
						resource,
					],
					operation: [
						operation,
					],
				},
			},
			default: false,
			description: 'Whether to return all results or only up to a given limit',
		},
		{
			displayName: 'Limit',
			name: 'limit',
			type: 'number',
			typeOptions: {
				maxValue: 1000,
			},
			displayOptions: {
				show: {
					resource: [
						resource,
					],
					operation: [
						operation,
					],
					returnAll: [
						false,
					],
				},
			},
			default: 100,
			description: 'Max number of results to return',
		},
	];
	return pagingParameters;
}