n8n/packages/nodes-base/nodes/Google/Gmail/utils/replyToEmail.ts

import uniq from 'lodash/uniq';
import { NodeOperationError, type IDataObject, type IExecuteFunctions } from 'n8n-workflow';

import type { IEmail } from '@utils/sendAndWait/interfaces';

import {
	encodeEmail,
	googleApiRequest,
	prepareEmailAttachments,
	prepareEmailBody,
	prepareEmailsInput,
} from '../GenericFunctions';
import type { GmailMessage, GmailMessageMetadata, GmailUserProfile } from '../types';

export async function replyToEmail(
	this: IExecuteFunctions,
	gmailId: string,
	options: IDataObject,
	itemIndex: number,
	nodeVersion: number,
) {
	if (options.replyToSenderOnly && options.replyToRecipientsOnly) {
		throw new NodeOperationError(
			this.getNode(),
			'Both "Reply to Sender Only" and "Reply to Recipient Only" cannot be enabled at the same time. Please select only one option.',
			{ itemIndex },
		);
	}

	let qs: IDataObject = {};

	let cc = '';
	let bcc = '';

	if (options.ccList) {
		cc = prepareEmailsInput.call(this, options.ccList as string, 'CC', itemIndex);
	}

	if (options.bccList) {
		bcc = prepareEmailsInput.call(this, options.bccList as string, 'BCC', itemIndex);
	}
	let attachments: IDataObject[] = [];
	if (options.attachmentsUi) {
		attachments = await prepareEmailAttachments.call(
			this,
			options.attachmentsUi as IDataObject,
			itemIndex,
		);
		if (attachments.length) {
			qs = {
				userId: 'me',
				uploadType: 'media',
			};
		}
	}

	const endpoint = `/gmail/v1/users/me/messages/${gmailId}`;

	qs.format = 'metadata';
	const { payload, threadId } = (await googleApiRequest.call(
		this,
		'GET',
		endpoint,
		{},
		qs,
	)) as GmailMessageMetadata;

	const subject =
		payload.headers.filter(
			(data: { [key: string]: string }) => data.name.toLowerCase() === 'subject',
		)[0]?.value || '';

	const messageIdGlobal =
		payload.headers.filter(
			(data: { [key: string]: string }) => data.name.toLowerCase() === 'message-id',
		)[0]?.value || '';

	const { emailAddress } = (await googleApiRequest.call(
		this,
		'GET',
		'/gmail/v1/users/me/profile',
	)) as GmailUserProfile;

	const to: string[] = [];
	const replyToSenderOnly =
		options.replyToSenderOnly === undefined ? false : (options.replyToSenderOnly as boolean);
	const replyToRecipientsOnly =
		options.replyToRecipientsOnly === undefined
			? false
			: (options.replyToRecipientsOnly as boolean);

	const prepareEmailString = (email: string) => {
		if (email.includes(emailAddress)) return;
		if (email.includes('<') && email.includes('>')) {
			to.push(email);
		} else {
			to.push(`<${email}>`);
		}
	};

	let replyToHeaderName = 'from';
	if (nodeVersion >= 2.2 && payload.headers.some((h) => h.name.toLowerCase() === 'reply-to')) {
		replyToHeaderName = 'reply-to';
	}

	for (const header of payload.headers) {
		const headerName = (header.name || '').toLowerCase();
		if (headerName === replyToHeaderName && !replyToRecipientsOnly) {
			const replyToEmail = header.value;
			if (replyToEmail.includes('<') && replyToEmail.includes('>')) {
				to.push(replyToEmail);
			} else {
				to.push(`<${replyToEmail}>`);
			}
		}

		if (headerName === 'to' && !replyToSenderOnly) {
			const toEmails = header.value;
			toEmails.split(',').forEach(prepareEmailString);
		}
	}

	let from = '';
	if (options.senderName) {
		from = `${options.senderName as string} <${emailAddress}>`;
	}

	const toString = uniq(to).join(', ');

	const email: IEmail = {
		from,
		to: toString,
		cc,
		bcc,
		subject,
		attachments,
		inReplyTo: messageIdGlobal,
		reference: messageIdGlobal,
		...prepareEmailBody.call(this, itemIndex),
	};

	const body = {
		raw: await encodeEmail(email),
		threadId,
	};

	return (await googleApiRequest.call(
		this,
		'POST',
		'/gmail/v1/users/me/messages/send',
		body,
		qs,
	)) as GmailMessage;
}