modify printer endpoint to edit user pages printed

api/main_endpoints/routes/Printer.js

@@ -6,7 +6,13 @@ const logger = require('../../util/logger');
 const fs = require('fs');
 const path = require('path');
 const { MetricsHandler, register } = require('../../util/metrics.js');
-const { cleanUpChunks, cleanUpExpiredChunks, recordPrintingFolderSize } = require('../util/Printer.js');
+const {
+  cleanUpChunks,
+  cleanUpExpiredChunks,
+  recordPrintingFolderSize,
+  modifyPagesPrinted,
+  getPageCount
+} = require('../util/Printer.js');
 
 const {
   decodeToken,
@@ -84,6 +90,9 @@ router.post('/sendPrintRequest', upload.single('chunk'), async (req, res) => {
     logger.warn('/sendPrintRequest was requested with an invalid token');
     return res.sendStatus(UNAUTHORIZED);
   }
+
+  const userId = decodedToken._id;
+
   if (!PRINTING.ENABLED) {
     logger.warn('Printing is disabled, returning 200 and dummy print id to mock the printing server');
     return res.status(OK).send({ printId: null });
@@ -99,6 +108,7 @@ router.post('/sendPrintRequest', upload.single('chunk'), async (req, res) => {
 
   const { copies, sides, id } = req.body;
 
+  // read and reassemble the pdf
   const chunks = await fs.promises.readdir(dir);
   const assembledPdfFromChunks = path.join(dir, id + '.pdf');
 
@@ -122,6 +132,12 @@ router.post('/sendPrintRequest', upload.single('chunk'), async (req, res) => {
   data.append('copies', copies);
   data.append('sides', sides);
 
+  // update user's printed pages count
+  const pagesPrinted = getPageCount(assembledPdfFromChunks);
+  if (!modifyPagesPrinted(userId, pagesPrinted)) {
+    return res.sendStatus(SERVER_ERROR);
+  }
+
   try {
     // full pdf can be sent to quasar no problem
     const printRes = await axios.post(PRINTER_URL + '/print', data, {

api/main_endpoints/util/Printer.js

@@ -2,6 +2,8 @@ const fs = require('fs');
 const path = require('path');
 const logger = require('../../util/logger');
 const { MetricsHandler } = require('../../util/metrics.js');
+const User = require('../models/User.js');
+const { PDFDocument } = require('pdf-lib');
 
 /**
  * Deletes all chunks with the specified id from a directory
@@ -74,4 +76,45 @@ async function recordPrintingFolderSize(dir) {
   MetricsHandler.currentSizeOfPrintingFolderBytes.set(sizeOfDir);
 }
 
-module.exports = { cleanUpChunks, cleanUpExpiredChunks, recordPrintingFolderSize };
+
+/**
+ * Modify the user's pagesPrinted field based on the length of their print request
+ * @param {string} userId           id of the current user
+ * @param {Number} numPages         the number of pages of the current print request
+ * @returns {boolean}               Returns if the database operation was successful
+ */
+
+function modifyPagesPrinted(userId, numPages) {
+  return new Promise((resolve) => {
+    try {
+      User.findByIdAndUpdate(
+        userId,
+        {
+          $inc: { pagesPrinted: numPages },
+        }, {
+          new: true,
+        }
+        , (error, result) => {
+          if (error) {
+            logger.error('modifyPagesPrinted got an error querying mongodb: ', error);
+            return resolve(false);
+          }
+          if (!result) {
+            logger.info(`User ${userId} not found in the database`);
+          }
+          return resolve(!!result);
+        });
+    } catch (err) {
+      logger.error('modifyPagesPrinted encountered an error querying mongodb: ', err);
+      return resolve(false);
+    }
+  });
+}
+
+async function getPageCount(file) {
+  const buffer = await fs.promises.readFile(file);
+  const pdf = await PDFDocument.load(buffer);
+  return pdf.getPageCount();
+}
+
+module.exports = { cleanUpChunks, cleanUpExpiredChunks, recordPrintingFolderSize, modifyPagesPrinted, getPageCount };

api/package.json

@@ -41,6 +41,7 @@
     "nodemon": "^2.0.4",
     "passport": "^0.4.1",
     "passport-jwt": "^4.0.0",
+    "pdf-lib": "^1.17.1",
     "prom-client": "^15.1.3"
   },
   "devDependencies": {

src/Pages/2DPrinting/2DPrinting.js

@@ -1,11 +1,10 @@
-import React, { useState, useEffect, useRef } from 'react';
+import { useState, useEffect, useRef } from 'react';
 import PageSelectDropdown from './PageSelectDropdown';
 import {
   parseRange,
   printPage,
   getPagesPrinted,
 } from '../../APIFunctions/2DPrinting';
-import { editUser } from '../../APIFunctions/User';
 
 import { PDFDocument } from 'pdf-lib';
 import { healthCheck } from '../../APIFunctions/2DPrinting';
@@ -203,10 +202,6 @@ export default function Printing() {
     let status = await printPage(data, user.token);
 
     if (!status.error) {
-      editUser(
-        { ...user, pagesPrinted: pagesPrinted + pagesToBeUsedInPrintRequest },
-        user.token,
-      );
       setPrintStatus('Printing succeeded!');
       setPrintStatusColor('success');
     } else {

test/api/Printer.js

@@ -25,6 +25,8 @@ const tools = require('../util/tools/tools.js');
 const crypto = require('crypto');
 const token = '';
 const printerUtil = require('../../api/main_endpoints/util/Printer.js');
+const User = require('../../api/main_endpoints/models/User.js');
+const { findByIdAndDelete } = require('../../api/main_endpoints/models/OfficeAccessCard.js');
 
 let app = null;
 let test = null;
@@ -155,4 +157,26 @@ describe('Printer', () => {
       expect(chunksProcessed).to.equal(TOTAL_CHUNKS);
     });
   });
+
+  describe('modifyPagesPrinted', () => {
+    it('Should return true if pages were modified correctly', async () => {
+      const user = await new User({
+        firstName: 'nothing',
+        lastName: 'really',
+        email: 'alerts@one.sce',
+        password: 'vibecoding',
+        pagesPrinted: 1,
+      }).save();
+
+      const userId = user._id;
+
+      const tryModifyPagesPrinted = await printerUtil.modifyPagesPrinted(userId, 3);
+      expect(tryModifyPagesPrinted).to.equal(true);
+
+      const updatedUser = await User.findById(userId);
+      expect(updatedUser.pagesPrinted).to.equal(4);
+
+      await User.findByIdAndDelete(userId);
+    });
+  });
 });