NITJSR-OSS · abhishekjnvk · Oct 4, 2020 · Oct 5, 2020
diff --git a/app.js b/app.js
@@ -1,15 +1,34 @@
 'use strict';
 
 const fs = require('fs');
+const fsPromises = fs.promises;
+
 const http = require('http');
 const PORT = 3330 || process.env.PORT;
-const src = "" //source of the pdf file for which thumbnail is to be created
+const src = "http://www.nitjsr.ac.in/uploads/NIRF-2020%20INDIA%20RANK%20(ENGINEERING).pdf" //source of the pdf file for which thumbnail is to be created it may be local file or link of pdf
+
 const hummus = require('hummus');
 const streams = require('memory-streams');
+const { input } = require('node-pdftocairo');
+const imageToBase64 = require('image-to-base64');
+const download = require('download');
+const { compress } = require('compress-images/promise');
+
+
 const PDFRStreamForBuffer = require('./pdfr-stream-for-buffer.js');
 var Blob = require('blob');
 // https://stackoverflow.com/questions/42512982/node-js-get-the-first-page-of-pdf-buffer  => getting buffer array for the first page 
-const getFirstPage = function (buffer) {
+const getFirstPage = async function (src) {
+
+    if (src.includes("http://") || src.includes("https://")) {                  // reading file if it contains http(s):// then read from url or read from local file
+        var buffer = await download(src);                                   //downloading remote file as a buffer
+        console.log("reading from url")
+    }
+    else {
+        buffer = await fsPromises.readFile(src);                               //reading local file 
+        console.log("reading from local storage")
+    }
+
     //Creating a stream, so hummus pushes the result to it
     let outStream = new streams.WritableStream();
     //Using PDFStreamForResponse to be able to pass a writable stream
@@ -32,33 +51,57 @@ const getFirstPage = function (buffer) {
     //we can just grab stream's content and return it
     return outStream.toBuffer();
 };
-function pdf2thumb(buf) {
-    let ResImg=buf;
+async function pdf2thumb(src) {
+
+    try {
+        let firstPageBuffer = await getFirstPage(src); //buffer array for the first page of the given document
+        var file_name = Math.random()
+        // png jpeg tiff ps eps pdf svg
+        const INPUT_path_to_your_images = './' + file_name + '.jpg';
+
+        await input(firstPageBuffer, { format: 'jpeg', singlefile: true }).output(file_name);      //saving a temporary file
+
+        await compress({                                                                       //compressing image file
+            source: INPUT_path_to_your_images,
+            destination: './compressed_',
+            params: { compress_force: true, statistic: false, autoupdate: false },
+            enginesSetup: {
+                jpg: { engine: 'mozjpeg', command: ['-quality', '5'] },
+            }
+        });
 
-    return ResImg;
-
-  }
-
+        fs.unlink(file_name + ".jpg", (err => {                                 //removing uncompressed file
+            if (err) console.log(err);
+        }));
 
-http.createServer(function (req, res) {
-   fs.readFile(src,(err,data)=>{
-       try{
-            let firstPageBuffer = getFirstPage(data); //buffer array for the first page of the given document
+        let response = await imageToBase64("compressed_" + file_name + ".jpg")  //converting compressed file into base64 
 
+        fs.unlink("compressed_" + file_name + ".jpg", (err => {                 //removing compressed file as our work is done
+            if (err) console.log(err);
+        }));
 
+        var html_response = `<!DOCTYPE html><html><body><center><a href="${src}"><img style='display:block; width:300px;height:400px;' id='base64image' src='data:image/jpeg;base64, ${response}' /></a><a href="data:image/jpeg;base64, ${response}" download><button>Download</button></a></center></body></html>`
+        return html_response;
+    }
+    catch (err) {
+        console.log(err);
+    }
+}
 
-            var htmlElement = pdf2thumb(firstPageBuffer); //converting the buffer array of first page of pdf to html element to be returned
-            res.write( htmlElement,()=>{
-                console.log('first page displayed')
-            })
-
 
-
+http.createServer(async function (req, res) {
+    try {
 
-            res.end()
-        }
-        catch(err){
-            console.log(err);
-        }
-   }) 
-  }).listen(PORT,()=>console.log(`Server Started @ ${PORT}`)); 
+
+        var htmlElement = await pdf2thumb(src); //converting the buffer array of first page of pdf to html element to be returned
+        res.write(htmlElement, () => {
+            console.log('first page displayed')
+        })
+        res.end()
+    }
+    catch (err) {
+        console.log(err);
+        res.write("Something Went Wrong:"+err.message)
+        res.end()
+    }
+}).listen(PORT, () => console.log(`Server Started @ ${PORT}`)); 
diff --git a/package.json b/package.json
@@ -19,7 +19,13 @@
   "homepage": "https://github.com/NITJSR-OSS/PDF-Thumbnail-Creator#readme",
   "dependencies": {
     "blob": "^0.1.0",
-    "hummus": "^1.0.108",
-    "memory-streams": "^0.1.3"
+    "compress-images": "^1.9.5",
+    "download": "^8.0.0",
+    "hummus": "^1.0.110",
+    "image-to-base64": "^2.1.1",
+    "memory-streams": "^0.1.3",
+    "node-pdftocairo": "^1.1.0",
+    "pngquant-bin": "^6.0.0",
+    "tslib": "^2.0.1"
   }
 }
diff --git a/sample.pdf b/sample.pdf