⚡ Download images and files with Telegram Trigger (#919)

* ⚡ Download images and files.

* ⚡ Improvements

* ⚡ Small improvements

packages/nodes-base/nodes/Telegram/GenericFunctions.ts

@@ -2,12 +2,16 @@ import {
 	IExecuteFunctions,
 	IHookFunctions,
 	ILoadOptionsFunctions,
+	IWebhookFunctions,
 } from 'n8n-core';
 
-import { OptionsWithUri } from 'request';
+import {
-import { IDataObject } from 'n8n-workflow';
+	OptionsWithUri,
-
+} from 'request';
 
+import {
+	IDataObject,
+} from 'n8n-workflow';
 
 // Interface in n8n
 export interface IMarkupKeyboard {
@@ -138,7 +142,7 @@ export function addAdditionalFields(this: IExecuteFunctions, body: IDataObject,
  * @param {object} body
  * @returns {Promise<any>}
  */
-export async function apiRequest(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions, method: string, endpoint: string, body: object, query?: IDataObject): Promise<any> { // tslint:disable-line:no-any
+export async function apiRequest(this: IHookFunctions | IExecuteFunctions | ILoadOptionsFunctions | IWebhookFunctions, method: string, endpoint: string, body: object, query?: IDataObject, option: IDataObject = {}): Promise<any> { // tslint:disable-line:no-any
 	const credentials = this.getCredentials('telegramApi');
 
 	if (credentials === undefined) {
@@ -157,9 +161,22 @@ export async function apiRequest(this: IHookFunctions | IExecuteFunctions | ILoa
 		json: true,
 	};
 
+	if (Object.keys(option).length > 0) {
+		Object.assign(options, option);
+	}
+
+	if (Object.keys(body).length === 0) {
+		delete options.body;
+	}
+
+	if (Object.keys(query).length === 0) {
+		delete options.qs;
+	}
+
 	try {
 		return await this.helpers.request!(options);
 	} catch (error) {
+
 		if (error.statusCode === 401) {
 			// Return a clear error
 			throw new Error('The Telegram credentials are not valid!');
@@ -175,3 +192,16 @@ export async function apiRequest(this: IHookFunctions | IExecuteFunctions | ILoa
 		throw error;
 	}
 }
+
+export function getImageBySize(photos: IDataObject[], size: string): IDataObject | undefined {
+
+	const sizes = {
+		'small': 0,
+		'medium': 1,
+		'large': 2,
+	} as IDataObject;
+
+	const index = sizes[size] as number;
+
+	return photos[index];
+}

packages/nodes-base/nodes/Telegram/IEvent.ts

@@ -0,0 +1,12 @@
+export interface IEvent {
+	message?: {
+		photo?: [
+			{
+				file_id: string,
+			},
+		],
+		document?: {
+			file_id: string;
+		},
+	};
+}

packages/nodes-base/nodes/Telegram/TelegramTrigger.node.ts

@@ -4,15 +4,20 @@ import {
 } from 'n8n-core';
 
 import {
-	INodeTypeDescription,
+	IDataObject,
 	INodeType,
+	INodeTypeDescription,
 	IWebhookResponseData,
 } from 'n8n-workflow';
 
 import {
 	apiRequest,
+	getImageBySize,
 } from './GenericFunctions';
 
+import {
+	IEvent,
+} from './IEvent';
 
 export class TelegramTrigger implements INodeType {
 	description: INodeTypeDescription = {
@@ -33,7 +38,7 @@ export class TelegramTrigger implements INodeType {
 			{
 				name: 'telegramApi',
 				required: true,
-			}
+			},
 		],
 		webhooks: [
 			{
@@ -105,6 +110,45 @@ export class TelegramTrigger implements INodeType {
 				default: [],
 				description: 'The update types to listen to.',
 			},
+			{
+				displayName: 'Additional Fields',
+				name: 'additionalFields',
+				type: 'collection',
+				placeholder: 'Add Field',
+				default: {},
+				options: [
+					{
+						displayName: 'Download Images/Files',
+						name: 'donwload',
+						type: 'boolean',
+						default: false,
+						description: `Telegram develiers the image in 3 sizes.<br>
+						By default, just the larger image would be downloaded.<br>
+						if you want to change the size set the field 'Image Size'`,
+					},
+					{
+						displayName: 'Image Size',
+						name: 'imageSize',
+						type: 'options',
+						options: [
+							{
+								name: 'Small',
+								value: 'small',
+							},
+							{
+								name: 'Medium',
+								value: 'medium',
+							},
+							{
+								name: 'Large',
+								value: 'large',
+							},
+						],
+						default: 'large',
+						description: 'The size of the image to be downloaded',
+					},
+				],
+			},
 		],
 	};
 
@@ -157,14 +201,74 @@ export class TelegramTrigger implements INodeType {
 		},
 	};
 
-
-
 	async webhook(this: IWebhookFunctions): Promise<IWebhookResponseData> {
-		const bodyData = this.getBodyData();
+
+		const credentials = this.getCredentials('telegramApi') as IDataObject;
+
+		const bodyData = this.getBodyData() as IEvent;
+
+		const additionalFields = this.getNodeParameter('additionalFields') as IDataObject;
+
+		if (additionalFields.donwload === true) {
+
+			let imageSize = 'large';
+
+			if ((bodyData.message && bodyData.message.photo && Array.isArray(bodyData.message.photo) || bodyData.message?.document)) {
+
+				if (additionalFields.imageSize) {
+
+					imageSize = additionalFields.imageSize as string;
+
+				}
+
+				let fileId;
+
+				if (bodyData.message.photo) {
+
+					let image = getImageBySize(bodyData.message.photo as IDataObject[], imageSize) as IDataObject;
+
+					// When the image is sent from the desktop app telegram does not resize the image
+					// So return the only image avaiable
+					// Basically the Image Size parameter would work just when the images comes from the mobile app
+					if (image === undefined) {
+						image = bodyData.message.photo[0];
+					}
+
+					fileId = image.file_id;
+
+				} else {
+
+					fileId = bodyData.message?.document?.file_id;
+				}
+
+				const { result: { file_path } } = await apiRequest.call(this, 'GET', `getFile?file_id=${fileId}`, {});
+
+				const file = await apiRequest.call(this, 'GET', '', {}, {}, { json: false, encoding: null, uri: `https://api.telegram.org/file/bot${credentials.accessToken}/${file_path}`, resolveWithFullResponse: true });
+
+				const data = Buffer.from(file.body as string);
+
+				const fileName = file_path.split('/').pop();
+
+				const binaryData = await this.helpers.prepareBinaryData(data as unknown as Buffer, fileName);
+
+				return {
+					workflowData: [
+						[
+							{
+								json: bodyData as unknown as IDataObject,
+								binary: {
+									data: binaryData,
+								},
+							}
+						]
+					],
+				};
+			}
+		}
 
 		return {
 			workflowData: [
-				this.helpers.returnJsonArray([bodyData])
+				this.helpers.returnJsonArray([bodyData as unknown as IDataObject])
 			],
 		};
 	}