iTunes Podcast URL Extractor

<?php
 
/*
 * Podcast URL Extractor
 * implemented at http://itunes.so-nik.com
 *
 * All code has been re-written by lasavior. 
 * Original code & inspiration from Michael Sitarzewski, zerologic.com
 *
 * Ex: http://ax.phobos.apple.com.edgesuite.net/WebObjects/MZStore.woa/wa/viewPodcast?id=269238657
 * Ex: http://itunes.apple.com/us/podcast/hombre-potato/id319810190?uo=4
 *
 *   Usage: itunes.php?http://itunes.apple.com/us/podcast/the-morning-stream/id414564832?uo=4
 *   Returns: http://myextralife.com/ftp/radio/morningstream.xml
 
CHANGE LOG:::
EDIT 5/10/11: Removed flat-file database storing. Reformatted for SQLite (requires PHP 5 and above). Script will create database & table if they dont exist.
 
EDIT 6/2/11: Added safety catch for iTunes-U URL's. (Currently Apple does not offer a way to subscribe to these outside of iTunes [as far as i've seen]). Also touched up a little bit of code here & there.
 
EDIT 6/21/11: Added another safety catch for iTunes-U pages. Now instead of just checking the URL, it will also check the page content (as there are links that do not include the tag 'itunes-u' that was previously checked for).
 
EDIT 6/28/11: Previous iTunes-U update was flawed and resulted in a lot of false-positives. Fixed in new update.
 
EDIT 8/29/11: Added catch for material not available in the US store.
 */
 
 
//-----------------------------------------
// a couple of settings
$_SETT = array(
  'hashalgo' => 'md5',
  'contactemail' => '-INSERT-EMAIL-HERE-',
  'dbtable' => 'feedurls',
  'dbfilename' => 'itnfedb.sqdb'
  );
 
//-----------------------------------------
// the base URL
$url = ($_POST['terms'] != null) ? $_POST['terms'] : $_SERVER['QUERY_STRING'];
$urlhash = hash($_SETT['hashalgo'], $url);
 
//-----------------------------------------
//Functions
function curlfeed($churl) {
 
  $ch = curl_init();
  curl_setopt_array ($ch, array(
    CURLOPT_RETURNTRANSFER => TRUE,
    CURLOPT_FOLLOWLOCATION => TRUE,
    CURLOPT_MAXREDIRS => 10,
    CURLOPT_CONNECTTIMEOUT => 5,
    CURLOPT_URL => $churl,
    CURLOPT_USERAGENT => 'iTunes/9.1.1'
    ));
  $chresult = curl_exec($ch);
  curl_close($ch);
 
  return $chresult;
  }
 
function subURL($urltosub, $string1 = 'feed-url="', $string2 ='"') {
 
  $str1 = strpos($urltosub, $string1) + strlen($string1);
  $str2 = strpos($urltosub, $string2, $str1);
  $subbedstring = substr($urltosub, $str1, ($str2 - $str1));
 
  return $subbedstring;
  }
 
function checkFEED($thefeed, $mainURL) {
 
  global $feedURL, $invalidURL, $_SETT;
 
  //For your reference, the following is called a HEREDOC
  $badURL = <<<BADURL
    <div style="font-size:15px;white-space:normal;max-width:400px">iTunes failed to return the feed-url. 
    <br>
    <br>This may be due to different reasons: 
    <br>&nbsp;&nbsp;1) the podcast has been deleted,
    <br>&nbsp;&nbsp;2) the podcast has no items,
    <br>and many other reasons im not aware of. Unfortunately iTunes isnt perfect (hence why your here).
    <br>
    <br>Im sorry my script was of no help to you. If you feel this was in error, you can <a href="outfeed.php?$mainURL" style="text-decoration:underline" target="_blank">view the source,</a><br> or you can always <a href="mailto:{$_SETT['contactemail']}?subject=IFE Error&body=URL i tried: $mainURL" style="display:inline;text-decoration:underline">email me</a> the URL and i will see if its fixable.</div>
BADURL;
 
  if (substr($thefeed, 0, 7) != "http://"): 
 
    $feedURL = $badURL;
    $invalidURL = "The cake is a lie.";
    endif;
 
  }
 
//-----------------------------------------
//Here we initiate the sqlite database and setup the cached variables
if ($database = sqlite_open($_SETT['dbfilename'], 0666, $sqlerror)):
 
  $check_cache_query = "SELECT url FROM {$_SETT['dbtable']} WHERE uniqueid='$urlhash'";
  $cache_file = @sqlite_single_query($database, $check_cache_query, true);
  if(sqlite_last_error($database)):
 
    $create_table_query = "CREATE TABLE {$_SETT['dbtable']}(uniqueid TEXT, url TEXT, date TEXT)";
    @sqlite_exec($database, $create_table_query);
    $cache_file = NULL;
    endif;
else:
 
  $failed_to_initialize_sqlite = $sqlerror;
  endif;
 
//-----------------------------------------
//For caching files, this determines if the cached file already exists
if ($cache_file == NULL || isset($failed_to_initialize_sqlite)):
 
  //-----------------------------------------
  //Here we identify the podcast url scheme
  $idstyles = array(
    '?id=',
    '&id=',
    '/id'
    );
 
  for ($counter = 0; $counter < count($idstyles); $counter++):
 
    if (strpos($url, $idstyles[$counter])):
 
      $idstyle = $idstyles[$counter];
      $validID = "So, how are you holding up? Because I'm a potato!";
      break;
      endif;
    endfor;
 
  //-----------------------------------------
  //Since iTunes-U uses the same identifier symbols,
  //this is where we rule them out until it is supported
  //Note: more checking for itunes-u content is done further below
  if (strpos($url, '/itunes-u/')):
 
    unset($validID);
    $invalidID = "itunes-u";
    endif;
 
  //-----------------------------------------
  // extract feed-id, get page from itunes & find feed-url
  if (isset($validID)):
 
    preg_match("/[0-9]+/", $url, $podid, 0, strpos($url, $idstyle)); // here we extract the feed ID
    $curled1 = curlfeed("http://itunes.apple.com/podcast/id".$podid[0]);
    if (strpos($curled1, "<key>kind</key><string>Goto</string>") > 1):
 
      $newURL = subURL($curled1, "<key>url</key><string>", "</string>");
      $curled1 = curlfeed($newURL);
      endif;
    if (strpos($curled1, 'iTunes U')):
 
      $itunesU_title = subURL($curled1, '<title>', '</title>');
      $itunesU_title_char = urlencode($itunesU_title);
      $itunesU_crumbs = subURL($curled1, 'start breadcrumbs', 'end breadcrumbs');
      $itunesU_li = subURL($itunesU_crumbs, '<li>', '</li>');
      if (strpos($itunesU_li, 'iTunes U')):
 
        $feedURL = <<<ITUNESU
        <div style="font-size:15px;white-space:normal;max-width:400px">iTunes-U links not supported.
        <br>
        <br>Currently Apple does not offer a way to subscribe to iTunes-U material outside of iTunes (that i can find). A temporary solution is to search for a similar title as a podcast in hopes that the content providers also posted it to the iTunes Podcast Directory (do no expect this for password protected content). Try searching for: 
        <br>"$itunesU_title"
        <br>
        <br>You can <a href='http://itunes.so-nik.com/index.php?terms=$itunesU_title_char' style="display:inline;text-decoration:underline;color:blue">click here</a> to try that now.</div>
ITUNESU;
        $invalidID_check = 1;
        $invalidID = 'itunes-u';
        endif;
    elseif (strpos($curled1, 'not currently available in the US store')):
 
      $feedURL = <<<ITUNESFOREIGNSTORE
        <div style="font-size:15px;white-space:normal;max-width:400px">This item is not available in the US store.
        <br>
        <br>Apple currently restricts access to some content based on geographic locations. As I reside in the United States, I unfortunately cannot help you with your podcast link.
        <br>
        <br>If you have any PHP knowledge you can use the public source code to retrieve the URL yourself: 
        <br>http://snipplr.com/view/52465</div>
ITUNESFOREIGNSTORE;
      $invalidID_check = 1;
      $invalidID = 'itunes_foreign';
      endif;
    if ($invalidID_check != 1):
 
      $feedURL = subURL($curled1);
      checkFEED($feedURL, $url);
      endif;
    if (!isset($failed_to_initialize_sqlite)):
 
      $newfeedURL = sqlite_escape_string($feedURL);
      $cache_query_put_content = "INSERT INTO {$_SETT['dbtable']} (uniqueid,url,date) VALUES ('$urlhash', '$newfeedURL', '".date("r")."')";
      @sqlite_exec($database, $cache_query_put_content);
      endif;
  else: 
 
    if ($invalidID == "itunes-u"):
 
      //Example URL: http://itunes.apple.com/itunes-u/the-civil-war-reconstruction/id341650730
      $itu_label = subURL($url, '/itunes-u/', '/');
      $itu_label_white = trim(ucwords(str_replace('-', ' ', $itu_label)));
      $itu_label_char = str_replace('-', '%20', $itu_label);
      $feedURL = <<<FEEDURL
        <div style="font-size:15px;white-space:normal;max-width:400px">iTunes-U links not supported.
        <br>
        <br>Currently Apple does not offer a way to subscribe to iTunes-U material outside of iTunes (that i can find). A temporary solution is to search for a similar title as a podcast in hopes that the content providers also posted it to the iTunes Podcast Directory (do no expect this for password protected content). Try searching for: 
        <br>"$itu_label_white"
        <br>
        <br>You can <a href='http://itunes.so-nik.com/index.php?terms=$itu_label_char' style="display:inline;text-decoration:underline;color:blue">click here</a> to try that now.</div>
FEEDURL;
    else:
 
      $feedURL = "URL not supported. <br><br>Please contact <a href='mailto:{$_SETT['contactemail']}?subject=Feed-Error&body=Error on URL:$url' style=\"display:inline;text-decoration:underline\">{$_SETT['contactemail']}</a> <br>and notify me of the URL you are trying.";
      $invalidID = "I was doing fine. Noone was trying to murder me, or put me in a potato, or feed me to birds.";
      endif;
    endif;
else:
 
  $feedURL = $cache_file;
  if (!stripos($feedURL, 'itunes-u')):
 
    checkFEED($feedURL, $url);
  else:
 
    $invalidID = 'itunes-u';
    endif;
  endif;
 
//-----------------------------------------
// html output to browser
$podcastURL = (isset($invalidURL) || isset($invalidID)) ? $feedURL : "<a href=\"$feedURL\">$feedURL</a>";
 
echo <<<OUTTEXT
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
         "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
 
<html xmlns="http://www.w3.org/1999/xhtml" style="height: 100%;"> 
  <head> 
    <title>Podcast URL</title> 
    <meta name="viewport" content="width=320; initial-scale=1.0; maximum-scale=1.0; user-scalable=0;"/> 
    <meta name="robots" content="NOINDEX, NOFOLLOW, NOARCHIVE, NOSNIPPET"> 
    <style type="text/css" media="screen">@import "iphonenav.css";</style>
    <link rel="apple-touch-icon" href="./icon.png" />
    <link rel="shortcut icon" href="./favicon.ico">
  </head> 
  
  <!-- GUI, iTunes Store searching & feed extraction credited to lasavior, so-nik.com --> 
  <!-- Original idea & inspiration credited to Michael Sitarzewski, zerologic.com --> 
  <!-- For the PHP code to extract the podcast feed yourself, visit http://snipplr.com/view/52465 --> 
   
  <body style="height: 100%;"> 
     
    <h1>Podcast URL:</h1> 
    <ul> 
        <li style="height: 100%; padding:10px 10px 10px 10px; font-size:20px; word-wrap:break-word">$podcastURL</li> 
        <li style="height: 100%; padding:10px 10px 10px 10px; font-size:10px; border-bottom: 0px solid;"><div style="color:LightGray;font-size:12px;"><a href="mailto:ife@so-nik.com" style="color:LightGray; font-size:12px; text-decoration:none;">ife@so-nik.com</a>&nbsp;&nbsp;&nbsp;/&nbsp;&nbsp;&nbsp;<a href="http://podcasturlextractor.blogspot.com/" style="color:LightGray; font-size:12px; text-decoration:none;" target="_blank">News</a>&nbsp;&nbsp;&nbsp;/&nbsp;&nbsp;&nbsp;<a href="http://podcasturlextractor.blogspot.com/p/what-it-is-and-why-its-here.html" style="color:LightGray; font-size:12px; text-decoration:none;" target="_blank">About</a></div></li>
    </ul> 
  </body> 
</html>
OUTTEXT;
 
?>