import type { IHookFunctions, IWebhookFunctions, IDataObject, ILoadOptionsFunctions, INodePropertyOptions, INodeType, INodeTypeDescription, IWebhookResponseData, JsonObject, } from 'n8n-workflow'; import { NodeApiError } from 'n8n-workflow'; import { v4 as uuid } from 'uuid'; import { snakeCase } from 'change-case'; import { facebookApiRequest, getAllFields, getFields } from './GenericFunctions'; import { createHmac } from 'crypto'; export class FacebookTrigger implements INodeType { description: INodeTypeDescription = { displayName: 'Facebook Trigger', name: 'facebookTrigger', icon: 'file:facebook.svg', group: ['trigger'], version: 1, subtitle: '={{$parameter["appId"] +"/"+ $parameter["object"]}}', description: 'Starts the workflow when Facebook events occur', defaults: { name: 'Facebook Trigger', }, inputs: [], outputs: ['main'], credentials: [ { name: 'facebookGraphAppApi', required: true, }, ], webhooks: [ { name: 'setup', httpMethod: 'GET', responseMode: 'onReceived', path: 'webhook', }, { name: 'default', httpMethod: 'POST', responseMode: 'onReceived', path: 'webhook', }, ], properties: [ { displayName: 'APP ID', name: 'appId', type: 'string', required: true, default: '', description: 'Facebook APP ID', }, { displayName: 'Object', name: 'object', type: 'options', options: [ { name: 'Ad Account', value: 'adAccount', description: 'Get updates about Ad Account', }, { name: 'Application', value: 'application', description: 'Get updates about the app', }, { name: 'Certificate Transparency', value: 'certificateTransparency', description: 'Get updates about Certificate Transparency', }, { name: 'Group', value: 'group', description: 'Get updates about activity in groups and events in groups for Workplace', }, { name: 'Instagram', value: 'instagram', description: 'Get updates about comments on your media', }, { name: 'Link', value: 'link', description: 'Get updates about links for rich previews by an external provider', }, { name: 'Page', value: 'page', description: 'Page updates', }, { name: 'Permissions', value: 'permissions', description: 'Updates regarding granting or revoking permissions', }, { name: 'User', value: 'user', description: 'User profile updates', }, { name: 'Whatsapp Business Account', value: 'whatsappBusinessAccount', description: 'Get updates about Whatsapp business account', }, { name: 'Workplace Security', value: 'workplaceSecurity', description: 'Get updates about Workplace Security', }, ], required: true, default: 'user', description: 'The object to subscribe to', }, //https://developers.facebook.com/docs/graph-api/webhooks/reference/page { displayName: 'Field Names or IDs', name: 'fields', type: 'multiOptions', typeOptions: { loadOptionsMethod: 'getObjectFields', loadOptionsDependsOn: ['object'], }, default: [], description: 'The set of fields in this object that are subscribed to. Choose from the list, or specify IDs using an expression.', }, { displayName: 'Options', name: 'options', type: 'collection', default: {}, placeholder: 'Add option', options: [ { displayName: 'Include Values', name: 'includeValues', type: 'boolean', default: true, description: 'Whether change notifications should include the new values', }, ], }, ], }; methods = { loadOptions: { // Get all the available organizations to display them to user so that they can // select them easily async getObjectFields(this: ILoadOptionsFunctions): Promise { const object = this.getCurrentNodeParameter('object') as string; return getFields(object) as INodePropertyOptions[]; }, }, }; webhookMethods = { default: { async checkExists(this: IHookFunctions): Promise { const webhookUrl = this.getNodeWebhookUrl('default') as string; const object = this.getNodeParameter('object') as string; const appId = this.getNodeParameter('appId') as string; const { data } = await facebookApiRequest.call(this, 'GET', `/${appId}/subscriptions`, {}); for (const webhook of data) { if ( webhook.target === webhookUrl && webhook.object === object && webhook.status === true ) { return true; } } return false; }, async create(this: IHookFunctions): Promise { const webhookData = this.getWorkflowStaticData('node'); const webhookUrl = this.getNodeWebhookUrl('default') as string; const object = this.getNodeParameter('object') as string; const appId = this.getNodeParameter('appId') as string; const fields = this.getNodeParameter('fields') as string[]; const options = this.getNodeParameter('options') as IDataObject; const body = { object: snakeCase(object), callback_url: webhookUrl, verify_token: uuid(), fields: fields.includes('*') ? getAllFields(object) : fields, } as IDataObject; if (options.includeValues !== undefined) { body.include_values = options.includeValues; } const responseData = await facebookApiRequest.call( this, 'POST', `/${appId}/subscriptions`, body, ); webhookData.verifyToken = body.verify_token; if (responseData.success !== true) { // Facebook did not return success, so something went wrong throw new NodeApiError(this.getNode(), responseData as JsonObject, { message: 'Facebook webhook creation response did not contain the expected data.', }); } return true; }, async delete(this: IHookFunctions): Promise { const appId = this.getNodeParameter('appId') as string; const object = this.getNodeParameter('object') as string; try { await facebookApiRequest.call(this, 'DELETE', `/${appId}/subscriptions`, { object: snakeCase(object), }); } catch (error) { return false; } return true; }, }, }; async webhook(this: IWebhookFunctions): Promise { const bodyData = this.getBodyData(); const query = this.getQueryData() as IDataObject; const res = this.getResponseObject(); const req = this.getRequestObject(); const headerData = this.getHeaderData() as IDataObject; const credentials = await this.getCredentials('facebookGraphAppApi'); // Check if we're getting facebook's challenge request (https://developers.facebook.com/docs/graph-api/webhooks/getting-started) if (this.getWebhookName() === 'setup') { if (query['hub.challenge']) { //TODO //compare hub.verify_token with the saved token //const webhookData = this.getWorkflowStaticData('node'); // if (webhookData.verifyToken !== query['hub.verify_token']) { // return {}; // } res.status(200).send(query['hub.challenge']).end(); return { noWebhookResponse: true, }; } } // validate signature if app secret is set if (credentials.appSecret !== '') { const computedSignature = createHmac('sha1', credentials.appSecret as string) .update(req.rawBody) .digest('hex'); if (headerData['x-hub-signature'] !== `sha1=${computedSignature}`) { return {}; } } return { workflowData: [this.helpers.returnJsonArray(bodyData.entry as IDataObject[])], }; } }