reCAPTCHA v3 support and general tidy up

public/functions.php

@@ -0,0 +1,67 @@
+<?php
+
+/**
+ * Return which method is being used for preventing spam,
+ * based on the site config.
+ *
+ * @return string login/recaptcha_v3/recaptcha/basic
+ */
+function is_get_antispam_method() {
+	if( 1 == yourls_is_valid_user() ) {
+		return 'login';
+	} elseif( isset( ISQ::$recaptcha_v3['sitekey'] ) && ISQ::$recaptcha_v3['sitekey'] && isset( ISQ::$recaptcha_v3['secret'] ) && ISQ::$recaptcha_v3['secret'] ) {
+		return 'recaptcha_v3';
+	} elseif( isset( ISQ::$recaptcha['sitekey'] ) && ISQ::$recaptcha['sitekey'] && isset( ISQ::$recaptcha['secret'] ) && ISQ::$recaptcha['secret'] ) {
+		return 'recaptcha';
+	} else {
+		return 'basic';
+	}
+}
+
+
+/**
+ * Terminate the request without shortening the URL and
+ * display an error.
+ *
+ * @param string $message Error message.
+ * @param string $action Action message, defaults to "Go home".
+ */
+function display_error( $message, $action = null ) {
+	echo '<div class="content error">';
+		echo '<p class="message">' . $message . '</p>';
+
+		echo '<p class="action">';
+			if( !empty( $action ) ) {
+				echo $action;
+			} else {
+				echo '<a href="' . YOURLS_SITE . '" class="button">' . yourls__( '&larr; Go home and try again', 'isq_translation' ) . '</a>';
+			}
+		echo '</p>';
+	echo '</div>';
+
+	include('footer.php');
+	die();
+}
+
+
+/**
+ * Get remote file, either using CURL or file_get_contents
+ * depending on server configuration.
+ *
+ * @param string $url Remote file URL.
+ * @return string Remote file contents.
+ */
+function get_remote_file( $url ) {
+	if( function_exists( 'curl_init' ) ) {
+		$curl = curl_init();
+		curl_setopt( $curl, CURLOPT_URL, $url );
+		curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
+		$output = curl_exec( $curl );
+		curl_close( $curl );
+		return $output;
+	} elseif( ini_get( 'allow_url_fopen' ) ) {
+		return file_get_contents( $url );
+	} else {
+		display_error( yourls__( 'Your server doesn\'t support reCAPTCHA. Ask your host to install cURL or turn on allow_url_fopen.', 'isq_translation' ) );
+	}
+}