backend-php/controllers/UserChangeEmailController.php

<?php

namespace Controllers;

use Libs\ResponseLib;
use Models\UserModel;
use Psr\Http\Message\ServerRequestInterface;

class UserChangeEmailController
{
    public function __invoke(ServerRequestInterface $request)
    {
        $userId = (int)($request->getAttribute('api_user_id') ?? 0);
        if ($userId <= 0) {
            return ResponseLib::sendFail('Unauthorized', [], 'E_VALIDATE')->withStatus(401);
        }

        $body = json_decode((string)$request->getBody(), true) ?? [];
        $email = $body['email'] ?? '';

        if (empty($email) || !filter_var($email, FILTER_VALIDATE_EMAIL)) {
            return ResponseLib::sendFail('Validation failed: invalid email', [], 'E_VALIDATE')->withStatus(400);
        }

        $model = new UserModel();
        $ok = $model->updateEmail($userId, $email);
        if (!$ok) {
            return ResponseLib::sendFail('Email already in use or update failed', [], 'E_VALIDATE')->withStatus(400);
        }

        return ResponseLib::sendOk(['user_id' => $userId, 'user_email' => $email], 'S_UPDATED');
    }
}