/
handler.js
195 lines (167 loc) · 7.22 KB
/
handler.js
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'use strict';
module.exports.getAutomobiles = (event, context, callback) => {
let requestBody = JSON.parse(event.body);
require('./domstubs.js').setStubs(global);
const AWS = require('aws-sdk');
const pdfjsLib = require('pdfjs-dist');
const https = require('https');
const uuid = require('uuid/v1');
let imageUrls = [];
let extractedImages = [];
let automobiles = [];
//initialize amazon with required credentials
let s3 = new AWS.S3({
accessKeyId: '', //replace with your access key
secretAccessKey: '' // replace with your secret key
});
//fetch pdf data from supplied URL
return https.get(requestBody.pdfUrl, (response) => {
let data = [];
response.on('data', (chunk) => {
data.push(chunk);
});
response.on('end', () => {
const automobileLabels = ['Machine', 'Engine', 'Motor', 'Vehicle', 'Transportation', 'Automobile'];
let rawImageFile = new Uint8Array(Buffer.concat(data));
function processImage() {
let lastPromise = Promise.resolve();
for (let i = 0; i < extractedImages.length; i++) {
let base64Image = extractedImages[i];
let imageBytes = getImageBytes(base64Image);
lastPromise = lastPromise.then(checkImageLabel.bind(null, imageBytes, i));
}
lastPromise.then(() => {
//upload images to s3.
let lastPromise = Promise.resolve();
automobiles.forEach((automobileImage) => {
lastPromise = lastPromise.then(uploadToS3.bind(null, getImageBytes(automobileImage)));
});
lastPromise.then(() => {
sendResponse();
})
});
}
function uploadToS3(imageBytes) {
let u = uuid();
return new Promise((resolve, reject) => {
let buffer = Buffer.from(imageBytes, 'base64');
const bucketName = 'autopics';
let params = {
Bucket: bucketName, //this must have been created on amazon s3
Key: u,
Body: buffer,
ContentEncoding: 'base64',
ContentType: 'image/jpeg'
};
s3.putObject(params, (error, data) => {
if (error) {
console.log(`error uploading to s3 ${error}`);
reject(error);
} else {
let imageUrl = `https://s3.amazonaws.com/${bucketName}/${u}`;
imageUrls.push({url: imageUrl});
console.log('image successfully uploaded' + JSON.stringify(data));
resolve('image upload success');
}
});
});
}
function getImageBytes(base64Image) {
let image = null;
let jpg = true;
try {
image = atob(base64Image);
} catch (e) {
jpg = false;
}
if (jpg === false) {
try {
image = atob(base64Image);
} catch (e) {
console.log(`Not an image file Rekognition can process ${e}`);
return;
}
}
let length = image.length;
let imageBytes = new ArrayBuffer(length);
let ua = new Uint8Array(imageBytes);
for (let i = 0; i < length; i++) {
ua[i] = image.charCodeAt(i);
}
return imageBytes;
}
//check whether image is an automobile
function checkImageLabel(imageBytes, imageIndex) {
let rekognition = new AWS.Rekognition();
let params = {
Image: {
Bytes: imageBytes
}
};
return new Promise((resolve, reject) => {
rekognition.detectLabels(params, (err, data) => {
if (err) {
console.log(`error detecting labels for an image: ${err}`);
reject(err);
} else {
console.log(JSON.stringify(data));
let isValidAutoLabel = false;
let imageLabels = data.Labels;
for (let imageLabel of imageLabels) {
if (automobileLabels.includes(imageLabel.Name)) {
isValidAutoLabel = true;
break;
}
}
if (isValidAutoLabel) {
automobiles.push(extractedImages[imageIndex]);
}
resolve(data);
}
});
});
}
let loadingTask = pdfjsLib.getDocument({
data: rawImageFile,
nativeImageDecoderSupport: pdfjsLib.NativeImageDecoding.DISPLAY,
});
loadingTask.promise.then(function (doc) {
let numPages = doc.numPages;
console.log('# Document Loaded');
console.log(`Number of Pages: ${numPages}`);
let lastPromise = Promise.resolve();
let loadPage = function (pageNum) {
return doc.getPage(pageNum).then(page => {
console.log(`# Page ${pageNum}`);
return page.getOperatorList().then(opList => {
let svgGfx = new pdfjsLib.SVGGraphics(page.commonObjs, page.objs);
svgGfx.embedFonts = true;
for (let i = 0; i < opList.fnArray.length; i++) {
if (opList.fnArray[i] === pdfjsLib.OPS.paintJpegXObject) {
let imageInfo = page.objs.get(opList.argsArray[i][0]);
extractedImages.push(imageInfo._src.split('data:image/jpeg;base64,')[1]);
}
}
});
});
};
for (let i = 1; i <= numPages; i++) {
lastPromise = lastPromise.then(loadPage.bind(null, i));
}
return lastPromise;
}).then(() => {
console.log('# End of Document')
return processImage();
}
, (err) => console.error(`Error: ${err}`));
});
});
function sendResponse() {
callback(null, {
statusCode: 200,
body: JSON.stringify({
pdfUrls: imageUrls
}),
});
}
};