<?php
declare(strict_types=1);

require_once __DIR__ . '/db.php';

header('Content-Type: application/json');

$config = require __DIR__ . '/config.php';
$pdo = ai_backend_db($config);

$body = json_decode(file_get_contents('php://input'), true);
$username = trim((string) ($body['username'] ?? ''));
$password = (string) ($body['password'] ?? '');

if ($username === '' || $password === '') {
    ai_backend_fail(400, 'Benutzername und Passwort erforderlich.');
}

$stmt = $pdo->prepare('SELECT * FROM users WHERE username = ? AND is_active = 1 LIMIT 1');
$stmt->execute([$username]);
$user = $stmt->fetch();

if (!$user || !password_verify($password, $user['password_hash'])) {
    ai_backend_fail(401, 'Benutzername oder Passwort ist falsch.');
}

$token = bin2hex(random_bytes(32));
$tokenHash = hash('sha256', $token);
$expiresAt = (new DateTimeImmutable('+30 days'))->format('Y-m-d H:i:s');

$stmt = $pdo->prepare('INSERT INTO tokens (user_id, token_hash, expires_at) VALUES (?, ?, ?)');
$stmt->execute([$user['id'], $tokenHash, $expiresAt]);

echo json_encode(['token' => $token]);