WordPress

<?php

/**
 * Autolink
 *
 * @since 2.19
 */

namespace CustomFacebookFeed;

if (!defined('ABSPATH')) {
    exit; // Exit if accessed directly
}

class CFF_Autolink
{
    public static function cff_autolink($text = '', $link_color = '', $span_tag = false, $limit = 100, $tagfill = 'class="cff-break-word"', $auto_title = true)
    {
        $text = self::cff_autolink_do($text, $link_color, '![a-z][a-z-]+://!i', $limit, $tagfill, $auto_title, $span_tag);
        $text = self::cff_autolink_do($text, $link_color, '!(mailto|skype):!i', $limit, $tagfill, $auto_title, $span_tag);
        $text = self::cff_autolink_do($text, $link_color, '!www\\.!i', $limit, $tagfill, $auto_title, 'http://', $span_tag);
        return $text;
    }

    public static function cff_autolink_do($text, $link_color, $sub, $limit, $tagfill, $auto_title, $span_tag, $force_prefix = null)
    {
        $text_l = StrToLower($text);
        $cursor = 0;
        $loop = 1;
        $buffer = '';

        $autolink_options = [
            // Should http:// be visibly stripped from the front
            // of URLs?
            'strip_protocols' => true,
        ];

        while (($cursor < strlen($text)) && $loop) {
            $ok = 1;
            $matched = preg_match($sub, $text_l, $m, PREG_OFFSET_CAPTURE, $cursor);

            if (!$matched) {
                $loop = 0;
                $ok = 0;
            } else {
                $pos = $m[0][1];
                $sub_len = strlen($m[0][0]);

                $pre_hit = substr($text, $cursor, $pos - $cursor);
                $hit = substr($text, $pos, $sub_len);
                $pre = substr($text, 0, $pos);
                $post = substr($text, $pos + $sub_len);

                $fail_text = $pre_hit . $hit;
                $fail_len = strlen($fail_text);

                //
                // substring found - first check to see if we're inside a link tag already...
                //

                $bits = preg_split("!</a>!i", $pre);
                $last_bit = array_pop($bits);
                if (preg_match("!<a\s!i", $last_bit)) {
                    // echo "fail 1 at $cursor<br />\n";

                    $ok = 0;
                    $cursor += $fail_len;
                    $buffer .= $fail_text;
                }
            }

            //
            // looks like a nice spot to autolink from - check the pre
            // to see if there was whitespace before this match
            //

            if ($ok) {
                if ($pre) {
                    if (!preg_match('![\s\(\[\{>]$!s', $pre)) {
                        // echo "fail 2 at $cursor ($pre)<br />\n";

                        $ok = 0;
                        $cursor += $fail_len;
                        $buffer .= $fail_text;
                    }
                }
            }

            //
            // we want to autolink here - find the extent of the url
            //

            if ($ok) {
                if (preg_match('/^([a-z0-9\-\.\/\-_%~!?=,:;&+*#@\(\)\$]+)/i', $post, $matches)) {
                    $url = $hit . $matches[1];

                    $cursor += strlen($url) + strlen($pre_hit);
                    $buffer .= $pre_hit;

                    $url = html_entity_decode($url);


                    //
                    // remove trailing punctuation from url
                    //

                    while (preg_match('|[.,!;:?]$|', $url)) {
                        $url = substr($url, 0, strlen($url) - 1);
                        $cursor--;
                    }
                    foreach (array('()', '[]', '{}') as $pair) {
                        $o = substr($pair, 0, 1);
                        $c = substr($pair, 1, 1);
                        if (preg_match("!^(\\$c|^)[^\\$o]+\\$c$!", $url)) {
                            $url = substr($url, 0, strlen($url) - 1);
                            $cursor--;
                        }
                    }


                    //
                    // nice-i-fy url here
                    //

                    $link_url = $url;
                    $display_url = $url;

                    if ($force_prefix) {
                        $link_url = $force_prefix . $link_url;
                    }

                    if ($autolink_options['strip_protocols']) {
                        if (preg_match('!^(http|https)://!i', $display_url, $m)) {
                            $display_url = substr($display_url, strlen($m[1]) + 3);
                        }
                    }

                    $display_url = self::cff_autolink_label($display_url, $limit);


                    //
                    // add the url
                    //

                    if ($display_url != $link_url && !preg_match('@title=@msi', $tagfill) && $auto_title) {
                        $display_quoted = preg_quote($display_url, '!');

                        if (!preg_match("!^(http|https)://{$display_quoted}$!i", $link_url)) {
                            $tagfill .= ' title="' . $link_url . '"';
                        }
                    }

                    $link_url_enc = HtmlSpecialChars($link_url);
                    $display_url_enc = HtmlSpecialChars($display_url);


                    if (substr($link_url_enc, 0, 4) !== "http") {
                        $link_url_enc = 'https://' . $link_url_enc;
                    }
                    $buffer .= "<a href=\"{$link_url_enc}\" rel='nofollow noopener noreferrer'>{$display_url_enc}</a>";
                } else {
                    // echo "fail 3 at $cursor<br />\n";

                    $ok = 0;
                    $cursor += $fail_len;
                    $buffer .= $fail_text;
                }
            }
        }

        //
        // add everything from the cursor to the end onto the buffer.
        //

        $buffer .= substr($text, $cursor);

        return $buffer;
    }


    public static function cff_autolink_label($text, $limit)
    {
        if (!$limit) {
            return $text;
        }

        if (strlen($text) > $limit) {
            return substr($text, 0, $limit - 3) . '...';
        }

        return $text;
    }


    public static function cff_autolink_email($text = '', $tagfill = '')
    {
        $atom = '[^()<>@,;:\\\\".\\[\\]\\x00-\\x20\\x7f]+'; // from RFC822

        // die($atom);

        $text_l = StrToLower($text);
        $cursor = 0;
        $loop = 1;
        $buffer = '';

        while (($cursor < strlen($text)) && $loop) {
            //
            // find an '@' symbol
            //

            $ok = 1;
            $pos = strpos($text_l, '@', $cursor);

            if ($pos === false) {
                $loop = 0;
                $ok = 0;
            } else {
                $pre = substr($text, $cursor, $pos - $cursor);
                $hit = substr($text, $pos, 1);
                $post = substr($text, $pos + 1);

                $fail_text = $pre . $hit;
                $fail_len = strlen($fail_text);

                // die("$pre::$hit::$post::$fail_text");

                //
                // substring found - first check to see if we're inside a link tag already...
                //

                $bits = preg_split("!</a>!i", $pre);
                $last_bit = array_pop($bits);
                if (preg_match("!<a\s!i", $last_bit)) {
                    // echo "fail 1 at $cursor<br />\n";

                    $ok = 0;
                    $cursor += $fail_len;
                    $buffer .= $fail_text;
                }
            }

            //
            // check backwards
            //

            if ($ok) {
                if (preg_match("!($atom(\.$atom)*)\$!", $pre, $matches)) {
                    // move matched part of address into $hit

                    $len = strlen($matches[1]);
                    $plen = strlen($pre);

                    $hit = substr($pre, $plen - $len) . $hit;
                    $pre = substr($pre, 0, $plen - $len);
                } else {
                    // echo "fail 2 at $cursor ($pre)<br />\n";

                    $ok = 0;
                    $cursor += $fail_len;
                    $buffer .= $fail_text;
                }
            }

            //
            // check forwards
            //

            if ($ok) {
                if (preg_match("!^($atom(\.$atom)*)!", $post, $matches)) {
                    // move matched part of address into $hit

                    $len = strlen($matches[1]);

                    $hit .= substr($post, 0, $len);
                    $post = substr($post, $len);
                } else {
                    // echo "fail 3 at $cursor ($post)<br />\n";

                    $ok = 0;
                    $cursor += $fail_len;
                    $buffer .= $fail_text;
                }
            }

            //
            // commit
            //

            if ($ok) {
                $cursor += strlen($pre) + strlen($hit);
                $buffer .= $pre;
                $buffer .= "<a href=\"mailto:$hit\"$tagfill>$hit</a>";
            }
        }

        //
        // add everything from the cursor to the end onto the buffer.
        //

        $buffer .= substr($text, $cursor);

        return $buffer;
    }
}