Add session file

app/scripts/classes/session.js

@@ -0,0 +1,141 @@
+"use strict";
+
+// Core modules
+const fs = require("fs");
+const promisify = require("util").promisify;
+
+// Public modules from npm
+const md5 = require("md5");
+
+// Promisifed functions
+const areadfile = promisify(fs.readFile);
+const awritefile = promisify(fs.writeFile);
+const aunlinkfile = promisify(fs.unlink);
+
+class Session {
+    constructor(path) {
+        /**
+         * Max number of days the session is valid.
+         */
+        this.SESSION_TIME = 1;
+
+        /**
+         * Path of the session map file on disk.
+         */
+        this._path = path;
+
+        /**
+         * Indicates if the session is mapped on disk.
+         */
+        this._isMapped = fs.existsSync(this._path);
+        
+        /**
+         * Date of creation of the session.
+         */
+        this._created = new Date(Date.now());
+
+        /**
+         * MD5 hash of the username and the password.
+         */
+        this._hash = null;
+    }
+
+    //#region Private Methods
+    /**
+     * @private
+     * Get the difference in days between two dates.
+     * @param {Date} a 
+     * @param {Date} b 
+     */
+    _dateDiffInDays(a, b) {
+        const MS_PER_DAY = 1000 * 60 * 60 * 24;
+
+        // Discard the time and time-zone information.
+        const utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate());
+        const utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate());
+
+        return Math.floor((utc2 - utc1) / MS_PER_DAY);
+    }
+
+    /**
+     * @private
+     * Convert the object to a dictionary serializable in JSON.
+     */
+    _toJSON() {
+        return {
+            created: this._created,
+            hash: this._hash,
+        };
+    }
+    //#endregion Private Methods
+
+    //#region Public Methods
+    create(username, password) {
+        // First, create the hash of the credentials
+        const value = `${username}%%%${password}`;
+        this._hash = md5(value);
+
+        // Update the creation date
+        this._created = new Date(Date.now());
+    }
+
+    /**
+     * @public
+     * Save the session to disk.
+     */
+    async save() {
+        // Update the creation date
+        this._created = new Date(Date.now());
+
+        // Convert data
+        const json = this._toJSON();
+        const data = JSON.stringify(json);
+
+        // Write data
+        await awritefile(this._path, data);
+    }
+
+    /**
+     * @public
+     * Load the session from disk.
+     */
+    async load() {
+        // Read data
+        const data = await areadfile(this._path);
+        const json = JSON.parse(data);
+
+        // Assign values
+        this._created = json.created;
+        this._hash = json.hash;
+    }
+
+    /**
+     * @public
+     * Delete the session from disk.
+     */
+    async delete() {
+        await aunlinkfile(this._path);
+    }
+
+    /**
+     * @public
+     * Check if the session is valid.
+     */
+    isValid(username, password) {
+        // Get the number of days from the file creation
+        const diff = this._dateDiffInDays(new Date(Date.now()), this._created);
+
+        // The session is valid if the number of days is minor than SESSION_TIME
+        let valid = diff < this.SESSION_TIME;
+        
+        if(valid) {
+            // Check the hash
+            const value = `${username}%%%${password}`;
+            valid = md5(value) === this._hash;
+        }
+        return valid;
+    }
+    //#endregion Public Methods
+}
+
+module.exports = Session;

app/scripts/shared.js

@@ -8,6 +8,9 @@ const {join} = require("path");
 // Public modules from npm
 const log4js = require("log4js");
 
+// Modules from file
+const Session = require("./classes/session");
+
 /**
  * Class containing variables shared between modules.
  */
@@ -43,6 +46,10 @@ class Shared {
      * @type log4js.Logger
      */
     static #_logger = log4js.getLogger();
+    /**
+     * Session on the F95Zone platform.
+     */
+    static #_session = new Session(join(tmpdir(), "f95session.json"));
     //#endregion Properties
 
     //#region Getters
@@ -94,6 +101,12 @@ class Shared {
     static get cachePath() {
         return join(tmpdir(), "f95cache.json");
     }
+    /**
+     * Session on the F95Zone platform.
+     */
+    static get session() {
+        return this.#_session;
+    }
     //#endregion Getters
 
     //#region Setters