how can I add support for multiple 2FA methods in my custom plugin

1. Define the 2FA Methods:
- Create an array to store the supported 2FA methods. For example:

php
     define('CUSTOM_2FA_METHODS', array(
         'google_authenticator',
         'sms',
         'email',
     ));
     

2. Create a Function for Each Method:
- Create a function for each 2FA method. For example, for Google Authenticator:

php
     function custom_2fa_google_authenticator($user_id) {
         // Generate the 2FA code using Google Authenticator
         $ga = new GoogleAuthenticator();
         $code = $ga->getCode($user_id);
         return $code;
     }
     

3. Create a Function to Handle the 2FA Code:
- Create a function to handle the 2FA code entered by the user. For example:

php
     function custom_2fa_handle_code($user_id, $code) {
         // Verify the 2FA code
         if ($code === custom_2fa_google_authenticator($user_id)) {
             // User has entered the correct code
             return true;
         } else {
             // User has entered an incorrect code
             return false;
         }
     }
     

4. Integrate the 2FA Methods:
- Integrate the 2FA methods into your plugin. For example, you can add a dropdown menu to select the 2FA method:

php
     function custom_2fa_settings_page() {
         // Output the settings page
         ?>
         <div class="wrap">
             <h1>Custom 2FA Settings</h1>
             <form method="post" action="options.php">
                 <?php settings_fields('custom_2fa_settings'); ?>
                 <?php do_settings_sections('custom_2fa_settings'); ?>
                 <table class="form-table">
                     <tr>
                         <th><label for="custom_2fa_method">2FA Method:</label></th>
                         <td>
                             <select id="custom_2fa_method" name="custom_2fa_method">
                                 <?php foreach (CUSTOM_2FA_METHODS as $method) { ?>
                                     <option value="<?php echo $method; ?>"><?php echo $method; ?></option>
                                 <?php } ?>
                             </select>
                         </td>
                     </tr>
                 </table>
                 <p class="submit">
                     <input type="submit" class="button button-primary" value="Save Changes">
                 </p>
             </form>
         </div>
         <?php
     }
     

5. Handle the 2FA Code:
- Handle the 2FA code entered by the user. For example:

php
     function custom_2fa_authenticate($username, $password) {
         // Check if the user has 2FA enabled
         $user = get_user_by('login', $username);
         if (!get_option('custom_2fa_enabled')) {
             return wp_authenticate($username, $password);
         }

         // Get the 2FA method and code
         $method = get_option('custom_2fa_method');
         $code = $_POST['custom_2fa_code'];

         // Handle the 2FA code
         if ($method === 'google_authenticator') {
             if (!custom_2fa_handle_code($user->ID, $code)) {
                 return new WP_Error('invalid_2fa_code', 'Invalid 2FA code');
             }
         } elseif ($method === 'sms') {
             // Handle SMS-based 2FA
         } elseif ($method === 'email') {
             // Handle email-based 2FA
         }

         // Authenticate the user
         return wp_authenticate($username, $password);
     }
     

By following these steps, you can add support for multiple 2FA methods in your custom WordPress plugin.