index.js

'use strict';
const axios = require("axios");
const fs = require('fs');
const Path = require('path')

/**
 * @param {object} mediaData graphql JSON object
 * @returns {string} image or video
 */
function getMediaType(mediaData) {
  if (mediaData.shortcode_media.is_video === true) {
    return "video";
  }
  return "image";
}

/**
 * @param {string} oriUrl
 * @returns {string}
 */
function createNewUrl(oriUrl) {
  if (oriUrl.slice(-1) != "/") {
    oriUrl += "/";
  }
  return oriUrl + "?__a=1";
}

/**
 * Download graphql data
 * @param {string} url media url (https://www.instagram.com/p/[mediaCode]/)
 * @returns {object} graphql JSON object
 */
async function downloadMetaData(url) {
  try {
    const metaData = await axios({
      method: "get",
      url: url,
    });
    return metaData.data.graphql;
  } catch (error) {
    throw error;
  }
}

/**
 * Download media with axios
 * @param {string} url media url
 * @param {string} filename name of media
 * @param {string} savePath path to save media downloaded
 */
async function download(url, filename, savePath) {
    const path = Path.resolve(savePath, filename)
    const writer = fs.createWriteStream(path)
    const response = await axios({
        url,
        method: 'GET',
        responseType: 'stream'
      })
    
      response.data.pipe(writer)
    
      return new Promise((resolve, reject) => {
        writer.on('finish', resolve)
        writer.on('error', reject)
      })
}

/**
 * @typedef {Object} DownlodResult
 * @property {string} file - Main file path
 * @property {string} type - The type of media, video or image
 * @property {string} thumbnail - Thumbnail path if video
 */


/**
 * Download media with axios
 * @param {string} url media url
 * @param {string} savePath path to save media downloaded
 * @returns {DownlodResult} 
 */
async function downloadMedia(url, savePath) {
  const newUrl = createNewUrl(url);
  const getMetaData = await downloadMetaData(newUrl);
  const getType = getMediaType(getMetaData);

  const result = {
    file: '',
    type: '',
    thumbnail: ''
  }

  if (getType == "image") {
    await download(getMetaData.shortcode_media.display_url, `${getMetaData.shortcode_media.shortcode}.jpg`,savePath);
    result.file = Path.resolve(savePath, `${getMetaData.shortcode_media.shortcode}.jpg`)
    result.type = 'Image'
  } else {
    await download(getMetaData.shortcode_media.video_url,`${getMetaData.shortcode_media.shortcode}.mp4`,savePath);
    await download(getMetaData.shortcode_media.thumbnail_src,`${getMetaData.shortcode_media.shortcode}-thumb.jpg`,savePath);

    result.file = Path.resolve(savePath, `${getMetaData.shortcode_media.shortcode}.mp4`)
    result.thumbnail = Path.resolve(savePath, `${getMetaData.shortcode_media.shortcode}-thumb.jpg`)
    result.type = 'Video'
  }

  return result
}

module.exports = {
  createNewUrl,
  getMediaType,
  downloadMetaData,
  downloadMedia
};