<?php
require_once '../auth_helper.php';
require_login();

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

$input = json_decode(file_get_contents('php://input'), true);
$theme = $input['theme'] ?? 'light';

if (!in_array($theme, ['light', 'dark'])) {
    echo json_encode(['success' => false, 'error' => 'Invalid theme']);
    exit;
}

try {
    $stmt = db()->prepare("UPDATE users SET theme = ? WHERE id = ?");
    $stmt->execute([$theme, $_SESSION['user_id']]);
    echo json_encode(['success' => true]);
} catch (Exception $e) {
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}