W5 done

w5/userdb.js

@@ -0,0 +1,90 @@
+"use strict";
+
+import { readFileSync, writeFileSync } from "fs";
+
+export class User {
+    /**
+     * 
+     * @param {String} login 
+     * @param {String} password 
+     * @param {String} status 
+     */
+    constructor(login, password, status) {
+        this.login = login;
+        this.password = password;
+        this.status = status;
+    }
+}
+
+export class UserDB {
+    /** @type {Map.<String, User>} */
+    users = new Map();
+
+    constructor() {
+        this.#loadData();
+    }
+
+    #loadData() {
+        try {
+            const fileData = readFileSync("users.json", "utf-8");
+            const usersData = JSON.parse(fileData);
+            usersData.forEach(user => {
+                this.users.set(
+                    user["login"],
+                    new User(user["login"], user["password"], user["status"])
+                );
+            });
+        } catch (_) { }
+    }
+
+    saveData() {
+        const data = JSON.stringify(Array.from(this.users.keys()).map(k => {
+            const user = this.users.get(k);
+            return {
+                login: user.login,
+                password: user.password,
+                status: user.status
+            };
+        }));
+        writeFileSync("./users.json", data, { encoding: "utf-8", flag: "w+" });
+    }
+
+    /**
+     * 
+     * @param {User} login 
+     * @returns Exists user in DB or not
+     */
+    hasUser(login) {
+        return this.users.has(login);
+    }
+
+    /**
+     * 
+     * @param {User} user 
+     */
+    putUser(user) {
+        if (this.hasUser(user.login)) {
+            throw new Error(`User ${user.login} exists!`);
+        }
+
+        this.users.set(user.login, user);
+        this.saveData();
+    }
+
+    /**
+     * 
+     * @param {String} login 
+     * @returns User object
+     */
+    getUser(login) {
+        return this.users.get(login);
+    }
+
+    /**
+     * 
+     * @returns Users count
+     */
+    getUsersCount() {
+        return this.users.size;
+    }
+}