Added question service and linked it with the gateway service

gatewayservice/gateway-service.js

@@ -8,6 +8,7 @@ const port = 8000;
 
 const authServiceUrl = process.env.AUTH_SERVICE_URL || 'http://localhost:8002';
 const userServiceUrl = process.env.USER_SERVICE_URL || 'http://localhost:8001';
+const questionServiceUrl = process.env.QUESTION_SERVICE_URL || 'http://localhost:8010';
 
 app.use(cors());
 app.use(express.json());
@@ -41,6 +42,26 @@ app.post('/adduser', async (req, res) => {
   }
 });
 
+app.get('/flags/question', async (req, res) => {
+  try {
+    // Forward the request to the question service
+    const questionResponse = await axios.get(questionServiceUrl+'/flags/question', req.body);
+    res.json(questionResponse.data);
+  } catch (error) {
+    res.status(error.response.status).json({ error: error.response.data.error });
+  }
+});
+
+app.get('/flags/answer', async (req, res) => {
+  try {
+    // Forward the request to the question service
+    const questionResponse = await axios.get(questionServiceUrl+'/flags/answer', req.body);
+    res.json(questionResponse.data);
+  } catch (error) {
+    res.status(error.response.status).json({ error: error.response.data.error });
+  }
+});
+
 // Start the gateway service
 const server = app.listen(port, () => {
   console.log(`Gateway Service listening at http://localhost:${port}`);

questionservice/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "wikibase-sdk": "^8.1.1"
+  }
+}

questionservice/question-service.js

@@ -0,0 +1,126 @@
+const WBK = require('wikibase-sdk')
+const wbk = WBK({
+  instance: 'https://www.wikidata.org',
+  sparqlEndpoint: 'https://query.wikidata.org/sparql' // Required to use `sparqlQuery` and `getReverseClaims` functions, optional otherwise
+})
+const express = require('express');
+const app = express();
+const port = 8010;
+
+app.use(express.static('public'));
+
+app.use(express.text());
+
+//Correct image
+var correctAnswerFlag
+//Associates flags with their countries
+var flagToCountryMap = new Map()
+
+class WIQ_API{
+  /**
+   * 
+   * @returns JSON with the question and the flags
+   */
+  async getQuestionAndCountryFlags() {
+    //Reset the map for the new question
+    flagToCountryMap = new Map()
+
+    //Num of fetched countries
+    const countriesNum = 100 
+
+    //Required by wikidata to accept the request
+    const headers = new Headers();
+    headers.append('User-Agent', 'Mozilla/5.0 (Windows NT 10.0; Win64; x64)'
+    +' AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36');
+
+    const sparql = `SELECT ?país ?paísLabel ?imagen_de_la_bandera WHERE {
+      SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
+      ?país wdt:P31 wd:Q6256.
+      OPTIONAL { ?país wdt:P41 ?imagen_de_la_bandera. }
+    }
+    LIMIT ${countriesNum}`
+
+    //Constructing the url for the wikidata request
+    var url = wbk.sparqlQuery(sparql);
+
+    const response = await fetch(url, { headers });
+    const data = await response.json()
+
+    var chosenNums = [];
+    const numOfChosen = 4
+    // Generate n random numbers
+    for (let i = 0; i < numOfChosen; i++) {
+      this.#getRandomNumNotInSetAndUpdate(countriesNum, chosenNums)
+    }
+
+    const countries = []
+    const imgs = []
+    for(var i=0;i<numOfChosen;i++){
+        //Making sure there is an image associated
+        while(!'imagen_de_la_bandera' in data.results.bindings[chosenNums[i]]){
+          chosenNums[i] = this.#getRandomNumNotInSetAndUpdate(countriesNum, chosenNums)
+        }
+        imgs.push(data.results.bindings[chosenNums[i]].imagen_de_la_bandera.value)
+        countries.push(data.results.bindings[chosenNums[i]].paísLabel.value)
+        flagToCountryMap.set(imgs[i], countries[i])
+    }
+
+    chosenNums = []
+    //Choose a random country of the chosen to make the question
+    const chosenCountry = countries[this.#getRandomNumNotInSetAndUpdate(numOfChosen,chosenNums)]
+
+    const questionAndFlags = {
+      question: `Which of the following flags belongs to ${chosenCountry}?`,
+      flags: [`${imgs[0]}`,`${imgs[1]}`,`${imgs[2]}`,`${imgs[3]}`]
+    }
+
+    return JSON.stringify(questionAndFlags)
+  }
+
+  #getRandomNumNotInSetAndUpdate(numLimit, set){
+    let randomNumber;
+        do {
+            randomNumber = Math.floor(Math.random() * numLimit);
+        } while (set.includes(randomNumber)); // Ensure the number is unique
+        set.push(randomNumber);
+    return randomNumber
+  }
+}
+
+const wiq = new WIQ_API()
+
+/**
+ * Returns the needed information to construct a question of the form
+ * "Which of the following flags belongs to (insert country)?" with 4 options
+ * @param {} req - Not used
+ * @param {Object} res - Contains the question (question) and the images of the flags (flags)
+*/
+app.get('flags/question', async (req, res) => {
+  const question = await wiq.getQuestionAndCountryFlags()
+  res.json(question);
+});
+
+/**
+ * Gets a response indicating if the chosen flag img was correct or not
+ * @param {string} req - Flag img url selected by the player
+ * @param {Object} res - JSON containing whether the answer was correct "true" 
+ * or not "false". In case it was incorrect, the chosen 
+ * country will be returned as well
+*/
+app.get('flags/answer', (req, res) => {
+  const answeredFlag = req.body
+  if(correctAnswerFlag==answeredFlag){
+    res.json({
+      correct: "true"
+    })
+  } else {
+    res.json({
+      correct: "false",
+      country: `${flagToCountryMap.get(answeredFlag)}`
+    })
+  }
+});
+
+app.listen(port, () => {
+  console.log(`Questions service listening on http://localhost:${port}`);
+});