invite_

<?php
function base64url_encode($data)
{
    return rtrim(strtr(base64_encode($data) , '+/', '_-') , '=');
}
function base64url_decode($data)
{
    return base64_decode(str_pad(strtr($data, '_-', '+/') , strlen($data) % 4, '=', STR_PAD_RIGHT));
}
function decode_invite_link($link)
{
    $data = bin2hex(base64url_decode($link));
    $link_data[0] = substr($data, 0, 16);
    $link_data[1] = substr($data, 16, strlen($data));
    $invite_hash = base64url_encode(hex2bin($link_data[1])) . "==";
    $invite_chat_id = $link_data[0];
    $b1 = $invite_chat_id[6] . $invite_chat_id[7];
    $b2 = $invite_chat_id[4] . $invite_chat_id[5];
    $b3 = $invite_chat_id[2] . $invite_chat_id[3];
    $b4 = $invite_chat_id[0] . $invite_chat_id[1];
    $b5 = $invite_chat_id[14] . $invite_chat_id[15];
    $b6 = $invite_chat_id[12] . $invite_chat_id[13];
    $b7 = $invite_chat_id[10] . $invite_chat_id[11];
    $b8 = $invite_chat_id[8] . $invite_chat_id[9];
    $invite_chat_id = unpack("J", hex2bin($b1 . $b2 . $b3 . $b4 . $b5 . $b6 . $b7 . $b8)) [1];
    return ["link" => $link, "invite_chat_id" => $invite_chat_id, "invite_hash" => $invite_hash, "hash" => $link_data[1]];
}
// example
var_dump(decode_invite_link("AJQ1d583WQ6yAItekJGsIcCC"));
//result:
/* array(4) {
  ["link"]=>
  string(24) "AJQ1d583WQ6yAItekJGsIcCC"
  ["invite_chat_id"]=>
  int(8589934592240727967)
  ["invite_hash"]=>
  string(16) "sgCLXpCRrCHAgg=="
  ["hash"]=>
  string(20) "b2008b5e9091ac21c082"
} */