n8n/packages/@n8n/nodes-langchain/nodes/trigger/ChatTrigger/ChatTrigger.node.ts

import { Node, NodeConnectionType } from 'n8n-workflow';
import type {
	IDataObject,
	IWebhookFunctions,
	IWebhookResponseData,
	INodeTypeDescription,
	MultiPartFormData,
	INodeExecutionData,
	IBinaryData,
	INodeProperties,
} from 'n8n-workflow';

import { pick } from 'lodash';
import type { BaseChatMemory } from '@langchain/community/memory/chat_memory';
import { createPage } from './templates';
import { validateAuth } from './GenericFunctions';
import type { LoadPreviousSessionChatOption } from './types';

const CHAT_TRIGGER_PATH_IDENTIFIER = 'chat';
const allowFileUploadsOption: INodeProperties = {
	displayName: 'Allow File Uploads',
	name: 'allowFileUploads',
	type: 'boolean',
	default: false,
	description: 'Whether to allow file uploads in the chat',
};
const allowedFileMimeTypeOption: INodeProperties = {
	displayName: 'Allowed File Mime Types',
	name: 'allowedFilesMimeTypes',
	type: 'string',
	default: '*',
	placeholder: 'e.g. image/*, text/*, application/pdf',
	description:
		'Allowed file types for upload. Comma-separated list of <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types" target="_blank">MIME types</a>.',
};

export class ChatTrigger extends Node {
	description: INodeTypeDescription = {
		displayName: 'Chat Trigger',
		name: 'chatTrigger',
		icon: 'fa:comments',
		iconColor: 'black',
		group: ['trigger'],
		version: [1, 1.1],
		description: 'Runs the workflow when an n8n generated webchat is submitted',
		defaults: {
			name: 'When chat message received',
		},
		codex: {
			categories: ['Core Nodes'],
			resources: {
				primaryDocumentation: [
					{
						url: 'https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-langchain.chattrigger/',
					},
				],
			},
		},
		supportsCORS: true,
		maxNodes: 1,
		inputs: `={{ (() => {
			if (!['hostedChat', 'webhook'].includes($parameter.mode)) {
				return [];
			}
			if ($parameter.options?.loadPreviousSession !== 'memory') {
				return [];
			}

			return [
				{
					displayName: 'Memory',
					maxConnections: 1,
					type: '${NodeConnectionType.AiMemory}',
					required: true,
				}
			];
		 })() }}`,
		outputs: [NodeConnectionType.Main],
		credentials: [
			{
				// eslint-disable-next-line n8n-nodes-base/node-class-description-credentials-name-unsuffixed
				name: 'httpBasicAuth',
				required: true,
				displayOptions: {
					show: {
						authentication: ['basicAuth'],
					},
				},
			},
		],
		webhooks: [
			{
				name: 'setup',
				httpMethod: 'GET',
				responseMode: 'onReceived',
				path: CHAT_TRIGGER_PATH_IDENTIFIER,
				ndvHideUrl: true,
			},
			{
				name: 'default',
				httpMethod: 'POST',
				responseMode: '={{$parameter.options?.["responseMode"] || "lastNode" }}',
				path: CHAT_TRIGGER_PATH_IDENTIFIER,
				ndvHideMethod: true,
				ndvHideUrl: '={{ !$parameter.public }}',
			},
		],
		eventTriggerDescription: 'Waiting for you to submit the chat',
		activationMessage: 'You can now make calls to your production chat URL.',
		triggerPanel: false,
		properties: [
			/**
			 * @note If we change this property, also update it in ChatEmbedModal.vue
			 */
			{
				displayName: 'Make Chat Publicly Available',
				name: 'public',
				type: 'boolean',
				default: false,
				description:
					'Whether the chat should be publicly available or only accessible through the manual chat interface',
			},
			{
				displayName: 'Mode',
				name: 'mode',
				type: 'options',
				options: [
					{
						name: 'Hosted Chat',
						value: 'hostedChat',
						description: 'Chat on a page served by n8n',
					},
					{
						name: 'Embedded Chat',
						value: 'webhook',
						description: 'Chat through a widget embedded in another page, or by calling a webhook',
					},
				],
				default: 'hostedChat',
				displayOptions: {
					show: {
						public: [true],
					},
				},
			},
			{
				displayName:
					'Chat will be live at the URL above once you activate this workflow. Live executions will show up in the ‘executions’ tab',
				name: 'hostedChatNotice',
				type: 'notice',
				displayOptions: {
					show: {
						mode: ['hostedChat'],
						public: [true],
					},
				},
				default: '',
			},
			{
				displayName:
					'Follow the instructions <a href="https://www.npmjs.com/package/@n8n/chat" target="_blank">here</a> to embed chat in a webpage (or just call the webhook URL at the top of this section). Chat will be live once you activate this workflow',
				name: 'embeddedChatNotice',
				type: 'notice',
				displayOptions: {
					show: {
						mode: ['webhook'],
						public: [true],
					},
				},
				default: '',
			},
			{
				displayName: 'Authentication',
				name: 'authentication',
				type: 'options',
				displayOptions: {
					show: {
						public: [true],
					},
				},
				options: [
					{
						name: 'Basic Auth',
						value: 'basicAuth',
						description: 'Simple username and password (the same one for all users)',
					},
					{
						// eslint-disable-next-line n8n-nodes-base/node-param-display-name-miscased
						name: 'n8n User Auth',
						value: 'n8nUserAuth',
						description: 'Require user to be logged in with their n8n account',
					},
					{
						name: 'None',
						value: 'none',
					},
				],
				default: 'none',
				description: 'The way to authenticate',
			},
			{
				displayName: 'Initial Message(s)',
				name: 'initialMessages',
				type: 'string',
				displayOptions: {
					show: {
						mode: ['hostedChat'],
						public: [true],
					},
				},
				typeOptions: {
					rows: 3,
				},
				default: 'Hi there! 👋\nMy name is Nathan. How can I assist you today?',
				description: 'Default messages shown at the start of the chat, one per line',
			},
			{
				displayName: 'Options',
				name: 'options',
				type: 'collection',
				displayOptions: {
					show: {
						public: [false],
						'@version': [{ _cnd: { gte: 1.1 } }],
					},
				},
				placeholder: 'Add Field',
				default: {},
				options: [allowFileUploadsOption, allowedFileMimeTypeOption],
			},
			{
				displayName: 'Options',
				name: 'options',
				type: 'collection',
				displayOptions: {
					show: {
						mode: ['hostedChat', 'webhook'],
						public: [true],
					},
				},
				placeholder: 'Add Field',
				default: {},
				options: [
					{
						...allowFileUploadsOption,
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
					},
					{
						...allowedFileMimeTypeOption,
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
					},
					{
						displayName: 'Input Placeholder',
						name: 'inputPlaceholder',
						type: 'string',
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
						default: 'Type your question..',
						placeholder: 'e.g. Type your message here',
						description: 'Shown as placeholder text in the chat input field',
					},
					{
						displayName: 'Load Previous Session',
						name: 'loadPreviousSession',
						type: 'options',
						options: [
							{
								name: 'Off',
								value: 'notSupported',
								description: 'Loading messages of previous session is turned off',
							},
							{
								name: 'From Memory',
								value: 'memory',
								description: 'Load session messages from memory',
							},
							{
								name: 'Manually',
								value: 'manually',
								description: 'Manually return messages of session',
							},
						],
						default: 'notSupported',
						description: 'If loading messages of a previous session should be enabled',
					},
					{
						displayName: 'Response Mode',
						name: 'responseMode',
						type: 'options',
						options: [
							{
								name: 'When Last Node Finishes',
								value: 'lastNode',
								description: 'Returns data of the last-executed node',
							},
							{
								name: "Using 'Respond to Webhook' Node",
								value: 'responseNode',
								description: 'Response defined in that node',
							},
						],
						default: 'lastNode',
						description: 'When and how to respond to the webhook',
					},
					{
						displayName: 'Require Button Click to Start Chat',
						name: 'showWelcomeScreen',
						type: 'boolean',
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
						default: false,
						description: 'Whether to show the welcome screen at the start of the chat',
					},
					{
						displayName: 'Start Conversation Button Text',
						name: 'getStarted',
						type: 'string',
						displayOptions: {
							show: {
								showWelcomeScreen: [true],
								'/mode': ['hostedChat'],
							},
						},
						default: 'New Conversation',
						placeholder: 'e.g. New Conversation',
						description: 'Shown as part of the welcome screen, in the middle of the chat window',
					},
					{
						displayName: 'Subtitle',
						name: 'subtitle',
						type: 'string',
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
						default: "Start a chat. We're here to help you 24/7.",
						placeholder: "e.g. We're here for you",
						description: 'Shown at the top of the chat, under the title',
					},
					{
						displayName: 'Title',
						name: 'title',
						type: 'string',
						displayOptions: {
							show: {
								'/mode': ['hostedChat'],
							},
						},
						default: 'Hi there! 👋',
						placeholder: 'e.g. Welcome',
						description: 'Shown at the top of the chat',
					},
				],
			},
		],
	};

	private async handleFormData(context: IWebhookFunctions) {
		const req = context.getRequestObject() as MultiPartFormData.Request;
		const options = context.getNodeParameter('options', {}) as IDataObject;
		const { data, files } = req.body;

		const returnItem: INodeExecutionData = {
			json: data,
		};

		if (files && Object.keys(files).length) {
			returnItem.json.files = [] as Array<Omit<IBinaryData, 'data'>>;
			returnItem.binary = {};

			const count = 0;
			for (const fileKey of Object.keys(files)) {
				const processedFiles: MultiPartFormData.File[] = [];
				if (Array.isArray(files[fileKey])) {
					processedFiles.push(...files[fileKey]);
				} else {
					processedFiles.push(files[fileKey]);
				}

				let fileIndex = 0;
				for (const file of processedFiles) {
					let binaryPropertyName = 'data';

					// Remove the '[]' suffix from the binaryPropertyName if it exists
					if (binaryPropertyName.endsWith('[]')) {
						binaryPropertyName = binaryPropertyName.slice(0, -2);
					}
					if (options.binaryPropertyName) {
						binaryPropertyName = `${options.binaryPropertyName.toString()}${count}`;
					}

					const binaryFile = await context.nodeHelpers.copyBinaryFile(
						file.filepath,
						file.originalFilename ?? file.newFilename,
						file.mimetype,
					);

					const binaryKey = `${binaryPropertyName}${fileIndex}`;

					const binaryInfo = {
						...pick(binaryFile, ['fileName', 'fileSize', 'fileType', 'mimeType', 'fileExtension']),
						binaryKey,
					};

					returnItem.binary = Object.assign(returnItem.binary ?? {}, {
						[`${binaryKey}`]: binaryFile,
					});
					returnItem.json.files = [
						...(returnItem.json.files as Array<Omit<IBinaryData, 'data'>>),
						binaryInfo,
					];
					fileIndex += 1;
				}
			}
		}

		return returnItem;
	}

	async webhook(ctx: IWebhookFunctions): Promise<IWebhookResponseData> {
		const res = ctx.getResponseObject();

		const isPublic = ctx.getNodeParameter('public', false) as boolean;
		const nodeMode = ctx.getNodeParameter('mode', 'hostedChat') as string;
		if (!isPublic) {
			res.status(404).end();
			return {
				noWebhookResponse: true,
			};
		}

		const options = ctx.getNodeParameter('options', {}) as {
			getStarted?: string;
			inputPlaceholder?: string;
			loadPreviousSession?: LoadPreviousSessionChatOption;
			showWelcomeScreen?: boolean;
			subtitle?: string;
			title?: string;
			allowFileUploads?: boolean;
			allowedFilesMimeTypes?: string;
		};

		const req = ctx.getRequestObject();
		const webhookName = ctx.getWebhookName();
		const mode = ctx.getMode() === 'manual' ? 'test' : 'production';
		const bodyData = ctx.getBodyData() ?? {};

		try {
			await validateAuth(ctx);
		} catch (error) {
			if (error) {
				res.writeHead((error as IDataObject).responseCode as number, {
					'www-authenticate': 'Basic realm="Webhook"',
				});
				res.end((error as IDataObject).message as string);
				return { noWebhookResponse: true };
			}
			throw error;
		}
		if (nodeMode === 'hostedChat') {
			// Show the chat on GET request
			if (webhookName === 'setup') {
				const webhookUrlRaw = ctx.getNodeWebhookUrl('default') as string;
				const webhookUrl =
					mode === 'test' ? webhookUrlRaw.replace('/webhook', '/webhook-test') : webhookUrlRaw;
				const authentication = ctx.getNodeParameter('authentication') as
					| 'none'
					| 'basicAuth'
					| 'n8nUserAuth';
				const initialMessagesRaw = ctx.getNodeParameter('initialMessages', '') as string;
				const initialMessages = initialMessagesRaw
					.split('\n')
					.filter((line) => line)
					.map((line) => line.trim());
				const instanceId = ctx.getInstanceId();

				const i18nConfig = pick(options, ['getStarted', 'inputPlaceholder', 'subtitle', 'title']);

				const page = createPage({
					i18n: {
						en: i18nConfig,
					},
					showWelcomeScreen: options.showWelcomeScreen,
					loadPreviousSession: options.loadPreviousSession,
					initialMessages,
					webhookUrl,
					mode,
					instanceId,
					authentication,
					allowFileUploads: options.allowFileUploads,
					allowedFilesMimeTypes: options.allowedFilesMimeTypes,
				});

				res.status(200).send(page).end();
				return {
					noWebhookResponse: true,
				};
			}
		}

		if (bodyData.action === 'loadPreviousSession') {
			if (options?.loadPreviousSession === 'memory') {
				const memory = (await ctx.getInputConnectionData(NodeConnectionType.AiMemory, 0)) as
					| BaseChatMemory
					| undefined;
				const messages = ((await memory?.chatHistory.getMessages()) ?? [])
					.filter((message) => !message?.additional_kwargs?.hideFromUI)
					.map((message) => message?.toJSON());
				return {
					webhookResponse: { data: messages },
				};
			} else if (options?.loadPreviousSession === 'notSupported') {
				// If messages of a previous session should not be loaded, simply return an empty array
				return {
					webhookResponse: { data: [] },
				};
			}
		}

		let returnData: INodeExecutionData[];
		const webhookResponse: IDataObject = { status: 200 };
		if (req.contentType === 'multipart/form-data') {
			returnData = [await this.handleFormData(ctx)];
			return {
				webhookResponse,
				workflowData: [returnData],
			};
		} else {
			returnData = [{ json: bodyData }];
		}

		return {
			webhookResponse,
			workflowData: [ctx.helpers.returnJsonArray(returnData)],
		};
	}
}