Adding some features

.gitignore

@@ -0,0 +1,3 @@
+node_modules
+.env
+package-lock.json

README.md

@@ -7,4 +7,10 @@ Ce projet a pour objectif de réaliser des actions via l'API de Spotify afin de
 - Récupérer des informations sur les musiques, playlists et podcasts
 - Contrôler le lecteur de musique
 - Visualiser les canvas d'éléments de Spotify
-- Récupérer des informations supplémentaires non-affichées dans l'application
+- Récupérer des informations supplémentaires non-affichées dans l'application
+
+## Utilisation
+
+Afin d'utiliser ce module, il est nécessaire de créer un fichier `.env` à la racine du projet contenant les variables d'environnement suivantes :
+
+`SPOTIFY_CLIENT_ID='<your-spotify-client-id>'`

main.js

@@ -0,0 +1,13 @@
+const SpotifyController = require('./src/spotify.js')
+
+var spotifyController = new SpotifyController().then(initializingSuccess, printError)
+
+// SpotifyController initialized
+function initializingSuccess(result) {
+    console.log(result)
+}
+
+// Print the error to the console
+function printError(error) {
+    console.log(error)
+}

package.json

@@ -0,0 +1,23 @@
+{
+  "name": "spotifycontroller",
+  "version": "0.1.0",
+  "description": "Get all the spotify data with NodeJS!",
+  "main": "main.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://factory.vbprojects.fr/thinkode/SpotifyController.git"
+  },
+  "author": "V. Boulanger",
+  "license": "ISC",
+  "dependencies": {
+    "axios": "^1.4.0",
+    "base64url": "^3.0.1",
+    "crypto": "^1.0.1",
+    "express": "^4.18.2",
+    "opn": "^6.0.0",
+    "randomstring": "^1.3.0"
+  }
+}

src/configuration.js

@@ -0,0 +1,16 @@
+const SpotifyEndpoints = {
+    GET_USER_TOKEN_ENDPOINT: "https://accounts.spotify.com/api/token",
+    GET_USER_PROFILE_ENDPOINT: 'https://api.spotify.com/v1/me'
+}
+
+const AuthorizationScopes = [
+    'user-read-private',
+    'user-read-email',
+    'user-top-read',
+    'user-read-currently-playing'
+]
+
+module.exports = {
+    SpotifyEndpoints,
+    AuthorizationScopes
+};

src/protobuf/pb/api.proto

@@ -0,0 +1,31 @@
+syntax = "proto3";
+
+package com.spotify.api;
+
+// Request used to get a new token for the current user
+message GetUserTokenRequest {
+    // The client id
+    string client_id = 1;
+    // The grant type
+    string grant_type = 2;
+    // The code returned by the authorization server
+    string code = 3;
+    // The redirect uri
+    string redirect_uri = 4;
+    // The client secret
+    string code_verifier = 5;
+}
+
+// Reponse of the GetUserTokenRequest
+message GetUserTokenResponse {
+    // The user access token
+    string access_token = 1;
+    // The token type
+    string token_type = 2;
+    // The time in seconds before the access token expires
+    int32 expires_in = 3;
+    // The token used to refresh the user token
+    string refresh_token = 4;
+    // A space-separated list of scopes which have been granted for this access_token
+    string scope = 5;
+}

src/spotify.js

@@ -0,0 +1,142 @@
+const axios = require('axios')
+const dotenv = require('dotenv')
+const configuration = require('./configuration.js')
+const randomstring = require('randomstring')
+const base64url = require('base64url')
+const crypto = require('crypto')
+const opn = require('opn')
+const express = require('express')
+
+class SpotifyController {
+    // Creates a new SpotifyController instance with the given clientId
+    constructor() {   
+        return new Promise((resolve, reject) => {
+            dotenv.config()
+            // For connection management
+            this.clientId = process.env.SPOTIFY_CLIENT_ID
+            // For user token management
+            this.userToken = undefined
+            this.userTokenExpiringDate = undefined
+            this.refreshToken = undefined
+            // For canvas token management
+            this.canvasToken = undefined
+            this.canvasTokenExpiringDate = undefined
+            // Check client ID
+            if (this.clientId === undefined || this.clientId === null || this.clientId === '') {
+                reject('Spotify client ID not set. Please define this variable in the .env file.')
+            }
+            this.checkUserToken().then(resolve("User token got."), reject("Error requesting a user token"))           
+            resolve("SpotifyController initialized.")
+        })
+    }
+
+    // This function aims to get a valid user token for the Spotify API
+    async checkUserToken() {
+        return new Promise((resolve, reject) => {
+            if (this.userToken === undefined) {
+                // Get a new token with auth
+                this.requestAuthentication().then(resolve("User token requested"), reject("Error requesting user token"))
+            } else if (this.userTokenExpiringDate < new Date()) {
+                // Refresh the user token
+                refreshUserToken().then(resolve("User token refreshed"), reject("Error refreshing user token"))
+            }
+            resolve("User token is already valid")
+        })
+    }
+
+    // This function aims to get a user token with authentication 
+    async requestAuthentication() {
+        let clientId = this.clientId
+        return new Promise((resolve, reject) => {
+            //Generate a code verifier
+            const codeVerifier = randomstring.generate(128);
+            const codechallenge = base64url.fromBase64(crypto.createHash("sha256").update(codeVerifier).digest("base64"))               
+            // Create the authentication URL
+            let args = new URLSearchParams({
+                response_type: 'code',
+                client_id: clientId,
+                scope: configuration.AuthorizationScopes.join(' '),
+                redirect_uri: "http://localhost:3333/callback",
+                code_challenge_method: 'S256',
+                code_challenge: codechallenge
+            });
+            // Open the authentication page
+            opn('https://accounts.spotify.com/authorize?' + args);
+            // Create an express app
+            let app = express()
+            // Catch the response
+            app.get('/callback', async (req, res) => {
+                if(req.query.code != undefined) {
+                    const params = new URLSearchParams();
+                    params.append("client_id", this.clientId);
+                    params.append("grant_type", "authorization_code");
+                    params.append("code", req.query.code);
+                    params.append("redirect_uri", "http://localhost:3333/callback");
+                    params.append("code_verifier", codeVerifier);
+                    executePostRequest(configuration.SpotifyEndpoints.GET_USER_TOKEN_ENDPOINT, params, { headers: { "Content-Type": "application/x-www-form-urlencoded" } }, "json").then(result => {
+                        console.log(result)
+                    }, error => {
+                        console.log(error)
+                    })
+                } else {
+                    res.send("Spotify authentication failed! Please close this tab and try again.")
+                    reject("Error when executing request: no code provided.")
+                }
+            });
+            app.use(function(req, res, next) {
+                res.status(404)
+                res.send('404: File Not Found')
+            });
+    
+            app.listen(3333, function () {
+                console.log('Callback server is running!')
+            });
+            resolve()
+        }, error => {
+            reject(error)
+        })
+    }
+
+    // This function aims to refresh the user token 
+    async refreshUserToken() {
+        return new Promise((resolve, reject) => {
+            resolve()
+        })
+    }
+}
+
+// Execute a GET request to the Spotify API
+function executeGetRequest(url, requestObject, options, responseType){
+    return new Promise((resolve, reject) => {
+        axios.get(url, requestObject.serializeBinary(), options)
+        .then(function(response){
+            if (response.statusText !== 'OK') {
+                reject(`Request error (${response.status}): ${response.statusText}`)
+            } else {
+                resolve(responseType.deserializeBinary(response.data).toObject());
+            }
+        })
+        .catch(function(error){
+            reject(error)
+        })
+    })
+}
+
+// Execute a POST request to the Spotify API
+function executePostRequest(url, requestObject, options, responseType){
+    return new Promise((resolve, reject) => {
+        axios.post(url, requestObject, options)
+        .then(function(response){
+            if (response.statusText !== 'OK') {
+                reject(`Request error (${response.status}): ${response.statusText}`)
+            } else {
+                resolve(response.data);
+            }
+        })
+        .catch(function(error){
+            reject(error)
+        })
+    })
+}
+
+module.exports = SpotifyController;