/* eslint-disable n8n-nodes-base/node-filename-against-convention */
import { ITriggerFunctions } from 'n8n-core';
import {
createDeferredPromise,
IBinaryData,
IBinaryKeyData,
ICredentialsDecrypted,
ICredentialTestFunctions,
IDataObject,
IDeferredPromise,
INodeCredentialTestResult,
INodeExecutionData,
INodeType,
INodeTypeBaseDescription,
INodeTypeDescription,
ITriggerResponse,
LoggerProxy as Logger,
NodeOperationError,
} from 'n8n-workflow';
import {
connect as imapConnect,
getParts,
ImapSimple,
ImapSimpleOptions,
Message,
} from 'imap-simple';
import { simpleParser, Source as ParserSource } from 'mailparser';
import _ from 'lodash';
import { ICredentialsDataImap, isCredentialsDataImap } from '../../../credentials/Imap.credentials';
const versionDescription: INodeTypeDescription = {
displayName: 'Email Trigger (IMAP)',
name: 'emailReadImap',
icon: 'fa:inbox',
group: ['trigger'],
version: 2,
description: 'Triggers the workflow when a new email is received',
eventTriggerDescription: 'Waiting for you to receive an email',
defaults: {
name: 'IMAP Email',
color: '#44AA22',
},
// eslint-disable-next-line n8n-nodes-base/node-class-description-inputs-wrong-regular-node
inputs: [],
outputs: ['main'],
credentials: [
{
name: 'imap',
required: true,
testedBy: 'imapConnectionTest',
},
],
properties: [
{
displayName: 'Mailbox Name',
name: 'mailbox',
type: 'string',
default: 'INBOX',
},
{
displayName: 'Action',
name: 'postProcessAction',
type: 'options',
options: [
{
name: 'Mark as Read',
value: 'read',
},
{
name: 'Nothing',
value: 'nothing',
},
],
default: 'read',
description:
'What to do after the email has been received. If "nothing" gets selected it will be processed multiple times.',
},
{
displayName: 'Download Attachments',
name: 'downloadAttachments',
type: 'boolean',
default: false,
displayOptions: {
show: {
format: ['simple'],
},
},
description:
'Whether attachments of emails should be downloaded. Only set if needed as it increases processing.',
},
{
displayName: 'Format',
name: 'format',
type: 'options',
options: [
{
name: 'RAW',
value: 'raw',
description:
'Returns the full email message data with body content in the raw field as a base64url encoded string; the payload field is not used',
},
{
name: 'Resolved',
value: 'resolved',
description:
'Returns the full email with all data resolved and attachments saved as binary data',
},
{
name: 'Simple',
value: 'simple',
description:
'Returns the full email; do not use if you wish to gather inline attachments',
},
],
default: 'simple',
description: 'The format to return the message in',
},
{
displayName: 'Property Prefix Name',
name: 'dataPropertyAttachmentsPrefixName',
type: 'string',
default: 'attachment_',
displayOptions: {
show: {
format: ['resolved'],
},
},
description:
'Prefix for name of the binary property to which to write the attachments. An index starting with 0 will be added. So if name is "attachment_" the first attachment is saved to "attachment_0"',
},
{
displayName: 'Property Prefix Name',
name: 'dataPropertyAttachmentsPrefixName',
type: 'string',
default: 'attachment_',
displayOptions: {
show: {
format: ['simple'],
downloadAttachments: [true],
},
},
description:
'Prefix for name of the binary property to which to write the attachments. An index starting with 0 will be added. So if name is "attachment_" the first attachment is saved to "attachment_0"',
},
{
displayName: 'Options',
name: 'options',
type: 'collection',
placeholder: 'Add Option',
default: {},
options: [
{
displayName: 'Custom Email Rules',
name: 'customEmailConfig',
type: 'string',
default: '["UNSEEN"]',
description:
'Custom email fetching rules. See node-imap\'s search function for more details.',
},
{
displayName: 'Force Reconnect Every Minutes',
name: 'forceReconnect',
type: 'number',
default: 60,
description: 'Sets an interval (in minutes) to force a reconnection',
},
],
},
],
};
export class EmailReadImapV2 implements INodeType {
description: INodeTypeDescription;
constructor(baseDescription: INodeTypeBaseDescription) {
this.description = {
...baseDescription,
...versionDescription,
};
}
methods = {
credentialTest: {
async imapConnectionTest(
this: ICredentialTestFunctions,
credential: ICredentialsDecrypted,
): Promise {
if (isCredentialsDataImap(credential.data)) {
const credentials = credential.data as ICredentialsDataImap;
try {
const config: ImapSimpleOptions = {
imap: {
user: credentials.user,
password: credentials.password,
host: credentials.host,
port: credentials.port,
tls: credentials.secure,
authTimeout: 20000,
},
};
const tlsOptions: IDataObject = {};
if (credentials.allowUnauthorizedCerts === true) {
tlsOptions.rejectUnauthorized = false;
}
if (credentials.secure) {
tlsOptions.servername = credentials.host;
}
if (!_.isEmpty(tlsOptions)) {
config.imap.tlsOptions = tlsOptions;
}
const connection = await imapConnect(config);
await connection.getBoxes();
connection.end();
} catch (error) {
return {
status: 'Error',
message: error.message,
};
}
return {
status: 'OK',
message: 'Connection successful!',
};
} else {
return {
status: 'Error',
message: 'Credentials are no IMAP credentials.',
};
}
},
},
};
async trigger(this: ITriggerFunctions): Promise {
const credentialsObject = await this.getCredentials('imap');
const credentials = isCredentialsDataImap(credentialsObject) ? credentialsObject : undefined;
if (!credentials) {
throw new NodeOperationError(this.getNode(), `Credentials are not valid for imap node.`);
}
const mailbox = this.getNodeParameter('mailbox') as string;
const postProcessAction = this.getNodeParameter('postProcessAction') as string;
const options = this.getNodeParameter('options', {}) as IDataObject;
const staticData = this.getWorkflowStaticData('node');
Logger.debug('Loaded static data for node "EmailReadImap"', { staticData });
let connection: ImapSimple;
let closeFunctionWasCalled = false;
let isCurrentlyReconnecting = false;
// Returns the email text
// tslint:disable-next-line:no-any
const getText = async (parts: any[], message: Message, subtype: string) => {
if (!message.attributes.struct) {
return '';
}
const textParts = parts.filter((part) => {
return (
part.type.toUpperCase() === 'TEXT' && part.subtype.toUpperCase() === subtype.toUpperCase()
);
});
if (textParts.length === 0) {
return '';
}
try {
return await connection.getPartData(message, textParts[0]);
} catch {
return '';
}
};
// Returns the email attachments
const getAttachment = async (
connection: ImapSimple,
// tslint:disable-next-line:no-any
parts: any[],
message: Message,
): Promise => {
if (!message.attributes.struct) {
return [];
}
// Check if the message has attachments and if so get them
const attachmentParts = parts.filter((part) => {
return part.disposition && part.disposition.type.toUpperCase() === 'ATTACHMENT';
});
const attachmentPromises = [];
let attachmentPromise;
for (const attachmentPart of attachmentParts) {
attachmentPromise = connection.getPartData(message, attachmentPart).then((partData) => {
// Return it in the format n8n expects
return this.helpers.prepareBinaryData(
partData,
attachmentPart.disposition.params.filename,
);
});
attachmentPromises.push(attachmentPromise);
}
return Promise.all(attachmentPromises);
};
// Returns all the new unseen messages
const getNewEmails = async (
connection: ImapSimple,
searchCriteria: Array,
): Promise => {
const format = this.getNodeParameter('format', 0) as string;
let fetchOptions = {};
if (format === 'simple' || format === 'raw') {
fetchOptions = {
bodies: ['TEXT', 'HEADER'],
markSeen: false,
struct: true,
};
} else if (format === 'resolved') {
fetchOptions = {
bodies: [''],
markSeen: false,
struct: true,
};
}
const results = await connection.search(searchCriteria, fetchOptions);
const newEmails: INodeExecutionData[] = [];
let newEmail: INodeExecutionData, messageHeader, messageBody;
let attachments: IBinaryData[];
let propertyName: string;
// All properties get by default moved to metadata except the ones
// which are defined here which get set on the top level.
const topLevelProperties = ['cc', 'date', 'from', 'subject', 'to'];
if (format === 'resolved') {
const dataPropertyAttachmentsPrefixName = this.getNodeParameter(
'dataPropertyAttachmentsPrefixName',
) as string;
for (const message of results) {
if (
staticData.lastMessageUid !== undefined &&
message.attributes.uid <= (staticData.lastMessageUid as number)
) {
continue;
}
if (
staticData.lastMessageUid === undefined ||
(staticData.lastMessageUid as number) < message.attributes.uid
) {
staticData.lastMessageUid = message.attributes.uid;
}
const part = _.find(message.parts, { which: '' });
if (part === undefined) {
throw new NodeOperationError(this.getNode(), 'Email part could not be parsed.');
}
const parsedEmail = await parseRawEmail.call(
this,
part.body,
dataPropertyAttachmentsPrefixName,
);
newEmails.push(parsedEmail);
}
} else if (format === 'simple') {
const downloadAttachments = this.getNodeParameter('downloadAttachments') as boolean;
let dataPropertyAttachmentsPrefixName = '';
if (downloadAttachments === true) {
dataPropertyAttachmentsPrefixName = this.getNodeParameter(
'dataPropertyAttachmentsPrefixName',
) as string;
}
for (const message of results) {
if (
staticData.lastMessageUid !== undefined &&
message.attributes.uid <= (staticData.lastMessageUid as number)
) {
continue;
}
if (
staticData.lastMessageUid === undefined ||
(staticData.lastMessageUid as number) < message.attributes.uid
) {
staticData.lastMessageUid = message.attributes.uid;
}
const parts = getParts(message.attributes.struct!);
newEmail = {
json: {
textHtml: await getText(parts, message, 'html'),
textPlain: await getText(parts, message, 'plain'),
metadata: {} as IDataObject,
},
};
messageHeader = message.parts.filter((part) => {
return part.which === 'HEADER';
});
messageBody = messageHeader[0].body;
for (propertyName of Object.keys(messageBody)) {
if (messageBody[propertyName].length) {
if (topLevelProperties.includes(propertyName)) {
newEmail.json[propertyName] = messageBody[propertyName][0];
} else {
(newEmail.json.metadata as IDataObject)[propertyName] =
messageBody[propertyName][0];
}
}
}
if (downloadAttachments === true) {
// Get attachments and add them if any get found
attachments = await getAttachment(connection, parts, message);
if (attachments.length) {
newEmail.binary = {};
for (let i = 0; i < attachments.length; i++) {
newEmail.binary[`${dataPropertyAttachmentsPrefixName}${i}`] = attachments[i];
}
}
}
newEmails.push(newEmail);
}
} else if (format === 'raw') {
for (const message of results) {
if (
staticData.lastMessageUid !== undefined &&
message.attributes.uid <= (staticData.lastMessageUid as number)
) {
continue;
}
if (
staticData.lastMessageUid === undefined ||
(staticData.lastMessageUid as number) < message.attributes.uid
) {
staticData.lastMessageUid = message.attributes.uid;
}
const part = _.find(message.parts, { which: 'TEXT' });
if (part === undefined) {
throw new NodeOperationError(this.getNode(), 'Email part could not be parsed.');
}
// Return base64 string
newEmail = {
json: {
raw: part.body,
},
};
newEmails.push(newEmail);
}
}
// only mark messages as seen once processing has finished
if (postProcessAction === 'read') {
const uidList = results.map((e) => e.attributes.uid);
if (uidList.length > 0) {
connection.addFlags(uidList, '\\SEEN');
}
}
return newEmails;
};
const returnedPromise: IDeferredPromise | undefined = await createDeferredPromise();
const establishConnection = (): Promise => {
let searchCriteria = ['UNSEEN'] as Array;
if (options.customEmailConfig !== undefined) {
try {
searchCriteria = JSON.parse(options.customEmailConfig as string);
} catch (error) {
throw new NodeOperationError(this.getNode(), `Custom email config is not valid JSON.`);
}
}
const config: ImapSimpleOptions = {
imap: {
user: credentials.user,
password: credentials.password,
host: credentials.host,
port: credentials.port,
tls: credentials.secure,
authTimeout: 20000,
},
onmail: async () => {
if (connection) {
if (staticData.lastMessageUid !== undefined) {
searchCriteria.push(['UID', `${staticData.lastMessageUid as number}:*`]);
/**
* A short explanation about UIDs and how they work
* can be found here: https://dev.to/kehers/imap-new-messages-since-last-check-44gm
* TL;DR:
* - You cannot filter using ['UID', 'CURRENT ID + 1:*'] because IMAP
* won't return correct results if current id + 1 does not yet exist.
* - UIDs can change but this is not being treated here.
* If the mailbox is recreated (lets say you remove all emails, remove
* the mail box and create another with same name, UIDs will change)
* - You can check if UIDs changed in the above example
* by checking UIDValidity.
*/
Logger.debug('Querying for new messages on node "EmailReadImap"', { searchCriteria });
}
try {
const returnData = await getNewEmails(connection, searchCriteria);
if (returnData.length) {
this.emit([returnData]);
}
} catch (error) {
Logger.error('Email Read Imap node encountered an error fetching new emails', {
error,
});
// Wait with resolving till the returnedPromise got resolved, else n8n will be unhappy
// if it receives an error before the workflow got activated
returnedPromise.promise().then(() => {
this.emitError(error as Error);
});
}
}
},
onupdate: async (seqno: number, info) => {
Logger.verbose(`Email Read Imap:update ${seqno}`, info);
},
};
const tlsOptions: IDataObject = {};
if (credentials.allowUnauthorizedCerts === true) {
tlsOptions.rejectUnauthorized = false;
}
if (credentials.secure) {
tlsOptions.servername = credentials.host as string;
}
if (!_.isEmpty(tlsOptions)) {
config.imap.tlsOptions = tlsOptions;
}
// Connect to the IMAP server and open the mailbox
// that we get informed whenever a new email arrives
return imapConnect(config).then(async (conn) => {
conn.on('close', async (hadError: boolean) => {
if (isCurrentlyReconnecting === true) {
Logger.debug(`Email Read Imap: Connected closed for forced reconnecting`);
} else if (closeFunctionWasCalled === true) {
Logger.debug(`Email Read Imap: Shutting down workflow - connected closed`);
} else {
Logger.error(`Email Read Imap: Connected closed unexpectedly`);
this.emitError(new Error('Imap connection closed unexpectedly'));
}
});
conn.on('error', async (error) => {
const errorCode = error.code.toUpperCase();
Logger.verbose(`IMAP connection experienced an error: (${errorCode})`, { error });
await closeFunction();
this.emitError(error);
});
return conn;
});
};
connection = await establishConnection();
await connection.openBox(mailbox);
let reconnectionInterval: NodeJS.Timeout | undefined;
if (options.forceReconnect !== undefined) {
reconnectionInterval = setInterval(async () => {
Logger.verbose(`Forcing reconnect to IMAP server`);
try {
isCurrentlyReconnecting = true;
if (connection.closeBox) connection.closeBox(false);
connection.end();
connection = await establishConnection();
await connection.openBox(mailbox);
} catch (error) {
Logger.error(error);
} finally {
isCurrentlyReconnecting = false;
}
}, (options.forceReconnect as number) * 1000 * 60);
}
// When workflow and so node gets set to inactive close the connectoin
async function closeFunction() {
closeFunctionWasCalled = true;
if (reconnectionInterval) {
clearInterval(reconnectionInterval);
}
if (connection.closeBox) connection.closeBox(false);
connection.end();
}
// Resolve returned-promise so that waiting errors can be emitted
returnedPromise.resolve();
return {
closeFunction,
};
}
}
export async function parseRawEmail(
this: ITriggerFunctions,
messageEncoded: ParserSource,
dataPropertyNameDownload: string,
): Promise {
const responseData = await simpleParser(messageEncoded);
const headers: IDataObject = {};
for (const header of responseData.headerLines) {
headers[header.key] = header.line;
}
// @ts-ignore
responseData.headers = headers;
// @ts-ignore
responseData.headerLines = undefined;
const binaryData: IBinaryKeyData = {};
if (responseData.attachments) {
for (let i = 0; i < responseData.attachments.length; i++) {
const attachment = responseData.attachments[i];
binaryData[`${dataPropertyNameDownload}${i}`] = await this.helpers.prepareBinaryData(
attachment.content,
attachment.filename,
attachment.contentType,
);
}
// @ts-ignore
responseData.attachments = undefined;
}
return {
json: responseData as unknown as IDataObject,
binary: Object.keys(binaryData).length ? binaryData : undefined,
} as INodeExecutionData;
}