feat: creates backend for the project

backend/src/services/auth.ts

@@ -0,0 +1,30 @@
+import { v4 as uuidv4 } from 'uuid';
+import { pool } from '../db/pool';
+import { config } from '../config';
+import type { LoginRequest, MeResponse } from '@family-budget/shared';
+
+export async function login(
+  body: LoginRequest,
+): Promise<{ sessionId: string } | null> {
+  if (body.login !== config.appUserLogin || body.password !== config.appUserPassword) {
+    return null;
+  }
+
+  const sid = uuidv4();
+  await pool.query(
+    'INSERT INTO sessions (id) VALUES ($1)',
+    [sid],
+  );
+  return { sessionId: sid };
+}
+
+export async function logout(sessionId: string): Promise<void> {
+  await pool.query(
+    'UPDATE sessions SET is_active = FALSE WHERE id = $1',
+    [sessionId],
+  );
+}
+
+export async function me(sessionId: string): Promise<MeResponse> {
+  return { login: config.appUserLogin };
+}