<?
#
# New releases on Spotify
#
# A quick Spotify metadata API hack which displays a list of recently added
# albums in Spotify.
#
# MIT license (basically do what you want as long as this license is reproduced):
# 
# Copyright (c) 2010 Rasmus Andersson
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
error_reporting(E_ALL);
$baseDir = dirname(realpath(__FILE__));
$cachePath = $baseDir.'/cache';
$cacheStat = @stat($cachePath);
$cacheTTL = 3600;
$isDevel = isset($_GET['devel']);
$cacheValid = $cacheStat 
  && !$isDevel
  && $cacheStat['mtime']+$cacheTTL > time();
$headers = array('Content-type: text/html; charset=UTF-8');
$status = '200 OK';

function sendHead() {
  global $headers, $status;
  header('HTTP/1.1 '.$status);
  foreach ($headers as $header) {
    header($header);
  }
}

if ($cacheValid) {
  $etag = md5($cacheStat['dev'].':'.$cacheStat['ino']
    .':'.$cacheStat['size'].':'.$cacheStat['mtime']);
  $headers[] = 'Last-modified: '.gmdate('r', $cacheStat['mtime']);
	$headers[] = 'Etag: "'.$etag.'"';
	if (isset($_SERVER['HTTP_IF_NONE_MATCH'])) {
	  if ($etag === trim($_SERVER['HTTP_IF_NONE_MATCH'],'"')) {
	    $headers[] = 'Content-length: 0';
	    $status = '304 Not Modified';
	    sendHead();
	    exit(0);
    }
  }
  $headers[] = 'Content-length: '.$cacheStat['size'];
  sendHead();
  readfile($cachePath);
  exit(0);
}

$headers[] = 'Cache-control: must-revalidate';

$albums = array();
$vaAlbums = array();
$fetchPageLimit = 5;
$totalResults = $startIndex = $itemsPerPage = 0;

function loadCountryCodesMap($path) {
  $map = array();
  $buf = file_get_contents($path);
  $buf = explode("\n", $buf);
  foreach ($buf as $line) {
    $line = explode("\t", $line);
    if (count($line) > 1 && strlen($line[0]) === 2) {
      $map[$line[0]] = $line[1];
    }
  }
  return $map;
}

$allCountries = loadCountryCodesMap($baseDir.'/ISO-3166-1-alpha-2-country-codes.tsv');
$spotifyCountries = loadCountryCodesMap($baseDir.'/ISO-3166-1-alpha-2-country-codes-spotify.tsv');
$spotifyCountriesList = array_keys($spotifyCountries);

function countryCodeToName($xx) {
  global $allCountries;
  return isset($allCountries[$xx]) ? $allCountries[$xx] : $xx;
}

function spotifyCountriesFilter($v) {
  global $spotifyCountries;
  return isset($spotifyCountries[$v]);
}

function xe($s) {
	static $u = array('&','"','<','>');
	static $e = array('&#38;','&#34;','&#60;','&#62;');
	return str_replace($u, $e, $s);
}

function firstChild($node, $nodeName) {
  $nl = $node->childNodes;
  for ($i=0;$i<min($nl->length,4);$i++) {
    $n = $nl->item($i);
    if ($n->nodeType === XML_ELEMENT_NODE && $n->nodeName === $nodeName) {
      return $n;
    }
  }
}

function parseArtist($n) {
  return (object)array(
    'uri' => $n->getAttribute('href'),
    'name' => firstChild($n, 'name')->nodeValue,
  );
}

function parseId($n) {
  return (object)array(
    'type' => $n->getAttribute('type'),
    'id' => $n->nodeValue,
    'href' => $n->hasAttribute('href') ? $n->getAttribute('href') : null,
  );
}

function parseAvailability($n) {
  global $spotifyCountriesList;
  $terrs = array();
  $unrestricted = false;
  $nl = $n->childNodes;
  for ($i=0;$i<$nl->length;$i++) {
    $n2 = $nl->item($i);
    if ($n2->nodeName === 'territories') {
      if ($n2->nodeValue === 'worldwide')
        $unrestricted = true;
      else
        $terrs = explode(' ', $n2->nodeValue);
      break;
    }
  }
  $terrs = array_filter($terrs, 'spotifyCountriesFilter');
  if (!$unrestricted)
    $unrestricted = count($terrs) === count($spotifyCountriesList);
  return (object)array(
    'unrestricted' => $unrestricted,
    'territories' => $unrestricted ? array() : $terrs,
  );
}

function parseAlbum($n) {
  $artists = array();
  $ids = array();
  $album = array(
    'uri' => $n->getAttribute('href'),
    'name' => null,
    'artists' => array(),
    'ids' => array(),
    'popularity' => 0.0,
    'isVariousArtists' => false,
    'availability' => (object)array(
      'unrestricted' => false,
      'territories' => array()),
  );
  
  $nl = $n->childNodes;
  
  for ($i=0;$i<$nl->length;$i++) {
    $n2 = $nl->item($i);
    if ($n2->nodeType === XML_ELEMENT_NODE) {
      switch ($n2->nodeName) {
      case 'name':
        $album['name'] = $n2->nodeValue;
        break;
        
      case 'artist':
	$artist = parseArtist($n2);
        $artists[] = $artist;
	if ($album['isVariousArtists'] === false)
		$album['isVariousArtists'] = ($artist->name === 'Various Artists' ? true : false);
        break;
      
      case 'id':
        $ids[] = parseId($n2);
        break;
      
      case 'popularity':
        $album['popularity'] = floatval($n2->nodeValue);
        break;
      
      case 'availability':
        $album['availability'] = parseAvailability($n2);
        break;
      }
    }
  }
  
  $album['artists'] = $artists;
  $album['ids'] = $ids;
  return (object)$album;
}

$totalPages = 1;

for ($pageNo = 1; $pageNo <= $totalPages; $pageNo++) {
  $startIndex = $itemsPerPage = 0; # reset
  $dom = new DOMDocument();
  $xml->preserveWhiteSpace = false;
  if ($isDevel)
    $dom->load(sprintf('page%d.xml', $pageNo));
  else
    $dom->load('http://ws.spotify.com/search/1/album?q=tag:new&page='.$pageNo);
  $doc = $dom->documentElement;
  
  $nl = $doc->childNodes;
  for ($i=0;$i<$nl->length;$i++) {
    $n = $nl->item($i);
    if ($n->nodeType === XML_ELEMENT_NODE) {
      switch ($n->nodeName) {
      case 'opensearch:totalResults':
        $totalResults = max(intval($n->nodeValue), $totalResults);
	if ($itemsPerPage !== 0)
		$totalPages = ceil($totalResults/$itemsPerPage);
        break;
      
      case 'opensearch:startIndex':
        $startIndex = intval($n->nodeValue);
        break;
      
      case 'opensearch:itemsPerPage':
        $itemsPerPage = intval($n->nodeValue);
	if ($totalResults !== 0)
		$totalPages = ceil($totalResults/$itemsPerPage);
        break;
      
      case 'album':
        $album = parseAlbum($n);
        if ($album->availability->unrestricted || count($album->availability->territories)) {
	  # separate VA so we can put the at bottom later
	  if ($album->isVariousArtists)
	    $vaAlbums[] = $album;
	  else
            $albums[] = $album;
	}
        break;
      }
    }
  }
  
  if ($isDevel)
    break;
}

# mux vaAlbums
foreach ($vaAlbums as $album) $albums[] = $album;

ob_start();
?>
<!DOCTYPE HTML>
<html lang="en">
	<head>
		<meta charset="utf-8">
		<title>New releases on Spotify</title>
		<style type="text/css" media="screen">
		  html { font-size:12px; }
      body { margin:0; padding:1em 0 0 4em; font-family:helvetica,arial,sans-serif; }
      ol { list-style-type:decimal; padding:0; }
      a { text-decoration:none; color:#111; }
      a:link:hover, a:visited:hover, a:active:hover { color:#17f !important; }
      header {}
        header h1 { margin:0; }
        header p { 
          border-bottom:1px solid #eee;
          margin:0.618em 0 0 -4em; padding:0 0 1em 4em;
          color:#aaa;
        }
      footer { 
	display:block;
	color:#140; background-color:#6fc008; margin:0.618em 0 0 -4em; padding:1em 1em 2em 4em;
      }
        footer a:link, footer a:visited, footer a:active { color:#140; background:#9f4; padding:0 0.2em; }
        footer a:link:hover, footer a:visited:hover, footer a:active:hover { background:#140; color:#9f4 !important; }
        footer h2 { margin:0.5em 0 0 0; }
      li.album {
        display:inline-block;
        margin:0 3em 1.618em 0; width:40em;
      }
        li.album p.no {
          margin:0 0 0 -3.5em; float:left; color:#ccc; font-size:1.3em;
          text-align:right; width:3em;
        }
        li.album h3 {
          font-size:1.3em; margin:0; color:#aaa; font-weight:normal;
          white-space:nowrap;
          overflow:hidden;
          text-overflow:ellipsis;
        }
          li.album h3 a { font-weight:bold; }
            li.album h3 a.artist { color:#888; }
        li.album p { margin:0.3em 0 0 0; }
          li.album p.avail { color:#777; }
          li.album.ANY p.avail { color:#ccc; }
		</style>
	</head>
	<body>
		<header>
			<h1>New releases on <a href="http://www.spotify.com/">Spotify</a></h1>
			<p>
			  Showing the latest <?= count($albums) ?> albums
			  released during the last 7 days, sorted on artist popularity.
			  
			  Updated <?= gmdate('Y-m-d H:i:s') ?> UTC.
			</p>
		</header>
		<section>
		  <ol>
			<? foreach ($albums as $no => $album): ?>
			  <li class="album <?= $album->availability->unrestricted
			    ? 'ANY' : xe(implode(' ', $album->availability->territories)) ?>">
			    <p class="no"><?= ($no+1) ?></p>
			    <h3>
			      <a class="name" href="<?=xe($album->uri)?>"><?=xe($album->name)?></a>
			      by
			      <?
			      $buf=array();
			      foreach ($album->artists as $artist) {
		          $buf[] = '<a class="artist"'
		            .($artist->uri ? ' href="'.xe($artist->uri).'"':'').'>'
		            .xe($artist->name).'</a>';
			      }
			      echo implode(', ',$buf);
			      ?>
			    </h3>
			    <p class="avail">
			      <? if ($album->availability->unrestricted): ?>
			        Available to all Spotify users.
			      <? else: ?>
			        Only available in <?= xe(implode(', ', array_map('countryCodeToName', 
			          $album->availability->territories))) ?>
			      <? endif; ?>
			    </p>
			  </li>
			<? endforeach; ?>
			</ol>
		</section>
		<footer>
		  <h2>Built on the open Spotify metadata API</h2>
		  <p>
			  This is a simple hack built on top of the open
			  <a href="http://developer.spotify.com/metadata-api/">Spotify metadata API</a>.
			  Grab the <a href="index.php.txt">PHP source code here</a> if you like.
			</p>
		</footer>
	</body>
</html>
<?

$output = ob_get_clean();
$cachedOutput = @file_get_contents($cachePath);
if (!$isDevel && !$cachedOutput || $cachedOutput !== $output) {
  file_put_contents($cachePath, $output, LOCK_EX);
}

$headers[] = 'Content-length: '.strlen($output);
sendHead();
echo $output;

?>