1function change_admin_email_verify_nonce() {
  2    if (!wp_verify_nonce($_POST['change-admin-email-test-email-nonce'], 'change-admin-email')) {
  3        wp_die('Something is very wrong here.');
  4    }
  5}
  6 
  7function change_admin_email_remove_pending() {
  8    delete_option("adminhash");
  9    delete_option("new_admin_email");
 10}
 11 
 12function change_admin_email_run() {
 13    add_action('init', 'change_admin_email_remove_pending');
 14    add_action('admin_notices', 'change_admin_email_display_admin_notice');
 15 
 16    remove_action('add_option_new_admin_email', 'update_option_new_admin_email');
 17    remove_action('update_option_new_admin_email', 'update_option_new_admin_email');
 18 
 19    add_filter('send_site_admin_email_change_email', '__return_false', 10, 3);
 20 
 21    if(isset($_POST['change-admin-email-test-email-nonce'])){
 22        add_action('init', 'change_admin_email_verify_nonce');
 23        add_action('init', 'change_admin_email_test_email');
 24    }
 25    add_action('add_option_new_admin_email', 'change_admin_email_update_option', 10, 2);
 26    add_action('update_option_new_admin_email', 'change_admin_email_update_option', 10, 2);
 27 
 28    add_action('wp_after_admin_bar_render', 'change_admin_email_modify_options_form');
 29}
 30 
 31function change_admin_email_test_email() {
 32    $email = $_POST['new_admin_email'];
 33    $domain = site_url();
 34    $url = "https://generalchicken.guru/wp-json/change-admin-email-plugin/v1/test-email";
 35    $response = wp_remote_post($url, array(
 36            'method'      => 'POST',
 37            'body'        => array(
 38                'email' => $email,
 39                'domain' => $domain
 40            ),
 41        )
 42    );
 43    change_admin_email_display_success(__('Check your email inbox. A test message has been sent to you.'));
 44}
 45 
 46function change_admin_email_update_option($old_value, $value) {
 47    update_option('admin_email', $value);
 48}
 49 
 50function change_admin_email_modify_options_form() {
 51    if (function_exists('get_current_screen')) {
 52        $screen = get_current_screen();
 53        if($screen->base == "options-general"){
 54            add_filter('gettext', 'change_admin_email_filter_text', 10, 3);
 55            echo change_admin_email_return_jquery();
 56        }
 57    }
 58}
 59 
 60function change_admin_email_return_jquery() {
 61    $nonce = wp_create_nonce('change-admin-email');
 62    $output = <<<OUTPUT
 63<script>
 64jQuery(document).ready(function(){
 65    var insertInputButton = "<input type = 'submit' class = 'button button-primary' name = 'changeAdminEmailSubmit' id = 'changeAdminEmailSubmitButton' value = 'Test Email' />";
 66    jQuery(insertInputButton).insertAfter("#new-admin-email-description");
 67 
 68    jQuery("#changeAdminEmailSubmitButton").click(function(event) {
 69        event.preventDefault();
 70        var insertThisNonce = "<input type = 'hidden' name = 'changeAdminEmailAction' value = 'changeEmail' /><input type = 'hidden' name = 'change-admin-email-test-email-nonce' value = '$nonce' />";
 71        jQuery(insertThisNonce).insertAfter("#new-admin-email-description");
 72        jQuery("#submit").click();
 73    });
 74});
 75</script>
 76OUTPUT;
 77    return $output;
 78}
 79 
 80function change_admin_email_filter_text($translated, $original, $domain) {
 81    if ($translated == "This address is used for admin purposes. If you change this, an email will be sent to your new address to confirm it. <strong>The new address will not become active until confirmed.</strong>"){
 82        $translated = __("This address is used for admin purposes.");
 83    }
 84    return $translated;
 85}
 86 
 87function change_admin_email_display_admin_notice() {
 88    $option = get_option('my_admin_notice_message');
 89    $message = isset($option['message']) ? $option['message'] : false;
 90    $noticeLevel = !empty($option['notice-level']) ? $option['notice-level'] : 'notice-error';
 91    if ($message) {
 92        echo "<div class='notice {$noticeLevel} is-dismissible'><p>{$message}</p></div>";
 93        delete_option('my_admin_notice_message');
 94    }
 95}
 96 
 97function change_admin_email_display_error($message) {
 98    change_admin_email_update_option_message($message, 'notice-error');
 99}
100 
101function change_admin_email_display_warning($message) {
102    change_admin_email_update_option_message($message, 'notice-warning');
103}
104 
105function change_admin_email_display_info($message) {
106    change_admin_email_update_option_message($message, 'notice-info');
107}
108 
109function change_admin_email_display_success($message) {
110    change_admin_email_update_option_message($message, 'notice-success');
111}
112 
113function change_admin_email_update_option_message($message, $noticeLevel) {
114    update_option('my_admin_notice_message', [
115        'message' => $message,
116        'notice-level' => $noticeLevel
117    ]);
118}
119 
120change_admin_email_run();