<?php // encoding="UTF-8"
/**
Web, libraries for http request or response

© 2010, École nationale des chartes,
licence CeCILL-C
(LGPL compatible droit français)



  
2009–2010 [FG] Frédéric Glorieux



*/
class Web {
  static $mime=array(
    "css"=>'Content-Type: text/css; charset=UTF-8',
    "html"=>'Content-Type: text/html; charset=UTF-8',
    "jpg"=>'Content-Type: image/jpeg',
    "png"=>'Content-Type: image/png',
  );
  
/**
 Return a static file from somwhere with best headers for caching
   */
  public static function get($file) {
    if (!is_file($file) || !is_readable($file)) {
      header('HTTP/1.x 404 Not Found');
      exit;
    }
    header('Content-Length: ' . filesize($file));
    $ext=explode('.',$file);
    $ext=array_pop($ext);
    if ($ext=="html") header('Content-Type: text/html; charset=UTF-8');
    else if ($ext=="png") header('Content-Type: image/png');
    else if ($ext=="jpg") header('Content-Type: image/jpeg');
    else if ($ext=="css") header('Content-Type: text/css');
    else if ($ext=="js") header('Content-Type: text/javascript');
    self::notModified($file);
    // ob_clean(); // a l'air de déconner
    flush();
    readfile($file);
    exit;
  }

  const NO_COOKIE=0;
  const NO_DEFAULT=null;
  
/**
 GET a parameter with possible cookie persistance. This is useful for params
 like "hits per page", "page style", and other value you want to set one time
 for some time.

 $name    : mandatory, the name of the parameter
 $default : a default value
 $expire  : durée de persistance (= cookie) en secondes
 $pattern : regexp to validate value

 return  : the value with quotes escaped (to be inserted in an attribute value)
   */
  public static function param($name, $default=FALSE, $expire=0, $pattern=FALSE, $query=FALSE) {
    $value=FALSE;
    // if key as a dot, hack php
    if (strpos($name, '.') !== FALSE) $name=strtr($name, '.', '_');
    // prendre le paramètre de requête
    if(isset($_GET[$name])) $value=$_GET[$name];
    if(isset($_POST[$name])) $value=$_POST[$name];
    if ($value) {
      if (get_magic_quotes_gpc()) $value = stripslashes($value);
      // is ISO ? find a best test
      // if (preg_match('/[\xC0-\xFD]/', $value)) $value=utf8_encode ($value);
    }
    // validate value against pattern
    if ($pattern && $value && !preg_match($pattern, $value)) $value=FALSE;
    // if no expire, no cookie, neither read or write
    if (!$expire) {
      // if(!$value && isset($_COOKIE[$name])) $value=$_COOKIE[$name];
    }
    // if a value, set cookie, do not $_COOKIE[$name]=$value
    else if ($value) {
      // if a number
      if ($expire > 60) setcookie($name, $value, time()+ $expire);
      // session time
      else setcookie($name, $value);
    }
    // if empty, delete cookie
    else if ($value==="") {
      setcookie ($name);
    }
    // if cookie stored, load it
    else {
      if(isset($_COOKIE[$name])) $value=$_COOKIE[$name];
    }
    if(!$value && $default) $value=$default;
    
    return $value;
  }

  
/**
 Handle repeated parameters values, especially in multiple select.
 $_REQUEST propose a strange PHP centric interpretation of http protocol, with the bracket keys
 &lt;select name="var[]">

 $query : optional, a "query string" ?cl%C3%A9=%C3%A9%C3%A9&param=valeur1&param=&param=valeur2
 return : Array (
   "clé" => array("éé"),
   "param" => array("valeur1", "", "valeur2")
 )


   */
  public static function params( $name=FALSE, $query=FALSE, $expire=0) {
    if (!$query) $query=Web::query();
    // remplir un tableau
    $params=array();
    $a = explode('&', $query);
    // if empty, do not return now, wait for possible cookie store value
    if(!$a || count($a)==0 || !$a[0]);
    else foreach ($a as $p) {
      list($k, $v) = preg_split('/=/', $p);
      $k=urldecode($k);
      $v=urldecode($v);
      // semble une chaîne ISO, traduire les accents
      if (preg_match('/[\xC0-\xFD]/', $k+$v)) {
        $k=utf8_encode ($k);
        $v=utf8_encode ($v);
      }
      $params[$k][]=$v;
    }
    // no key requested, return all params, do not store cookies
    if (!$name) return $params;
    // a param is requested, values found
    else if (isset($params[$name])) $params=$params[$name];
    // no param for this name
    else $params=array();


    // no cookie store requested
    if(!$expire);
    // if empty ?, delete cookie
    else if (count($params)==1 && !$params[0]) {
      setcookie($name);
    }
    // if a value, set cookie, do not $_COOKIE[$name]=$value
    else if (count($params)) {
      // if a number
      if ($expire > 60) setcookie($name, serialize($params), time()+ $expire);
      // session time
      else setcookie($name, serialize($params));
    }
    // if cookie stored, load it
    else if(isset($_COOKIE[$name])) $params=unserialize($_COOKIE[$name]);
    return $params;
  }

  
/**
 Send the best headers for cache, according to the request and a timestamp
   */
  public static function notModified($file, $force=false) {
    if (!$file) return false;
    $filemtime=false;
    // seems already a filemtime
    if (is_int($file)) $filemtime=$file;
    // if array of file, get the newest
    else if (is_array($file)) foreach($file as $f) {
      // if not file exists, no error
      if (!file_exists($f)) continue;
      $i=filemtime($f);
      if ($i && $i > $filemtime) $filemtime=$i;
    }
    else $filemtime=filemtime($file);
    if(!$filemtime) return $filemtime;
    // take script file date
    header("X-File: ". basename($_SERVER['SCRIPT_FILENAME']));
    // Default expires
    if (filemtime($_SERVER['SCRIPT_FILENAME']) > $filemtime) {
      $filemtime=filemtime($_SERVER['SCRIPT_FILENAME']);
    }
    // $modification=substr(date('r', $filemtime), 0, -5).'GMT';
    $modification=gmdate('D, d M Y H:i:s', $filemtime).' GMT';
    // header("X-Date: ". substr(gmdate('r'), 0, -5).'GMT');
    // date de modification
    header("Last-Modified: $modification");
    // page key
    $etag = '"'.md5($modification).'"';
    header("ETag: $etag");
    // tests for 304
    if($force) return;
    if (self::noCache()) return;
    $if_modified_since = isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) ? stripslashes($_SERVER['HTTP_IF_MODIFIED_SINCE']) :false;
    $if_none_match = isset($_SERVER['HTTP_IF_NONE_MATCH']) ? stripslashes($_SERVER['HTTP_IF_NONE_MATCH']) : false;
    // send 304
    if ( ($if_none_match && $if_none_match == $etag) || $if_modified_since == $modification) {
      header('HTTP/1.x 304 Not Modified');
      exit;
    }
  }

  
/**
 If client ask a forced relaod.
   */
  public static function noCache() {
    // pas de cache en POST
    if ($_SERVER['REQUEST_METHOD'] == 'POST') return 'POST';
    if (isset ($_SERVER['HTTP_PRAGMA']) && stripos($_SERVER['HTTP_PRAGMA'], "no-cache") !== false) return "Pragma: no-cache";
    if (isset ($_SERVER['HTTP_CACHE_CONTROL']) && stripos($_SERVER['HTTP_CACHE_CONTROL'], "no-cache") !== false) return "Cache-Control: no-cache";
    if (isset($_REQUEST['no-cache'])) return '?no-cache=';
    if (isset($_REQUEST['force'])) return '?force=';
    return false;
  }


  
/**
 trouver query string nettoyée de différents paramètres


 query() : retourne la chaîne de requête complète ?A=1&A=&B=2
 query(true) : supprime les paramètres vides ?A=1&B=2
 query("B|C|D") : filtre certains paramètres ?A=1
 query("?X=1&Y=&Z=2", "Y|Z") : filtre certains paramètres ?X=1

   */
  public static function query($p1=false, $p2=false) {
    // query passée en variable
    if ($p2) {
      $exclude=$p2;
      $query=preg_replace( '/&amp;/', '&', $p1);
    }
    // query en POST
    else if ($_SERVER['REQUEST_METHOD'] == "POST") {
      $exclude=$p1;
      if (isset($HTTP_RAW_POST_DATA)) $query=$HTTP_RAW_POST_DATA;
      else $query = file_get_contents("php://input");
    }
    // query en GET
    else {
      $exclude=$p1;
      $query=$_SERVER['QUERY_STRING'];
    }
    // suppression de paramètres en regex
    if (strlen($exclude)) $query=preg_replace( '/&('.$exclude.')=[^&]*/', '', '&'.$query);
    // supprimer les paramètres vides, ne pas chercher à matcher entre deux &, sinon le parser redémarre après pour le suisvant
    if ($exclude)  $query=preg_replace( array('/[^&=]+=&/', '/&$/'), array('', ''), $query.'&');
    return $query;
  }
  
/**
 "Query String Append" (Rewrite rules)
 append non empty parameters as a query string for links
   */
  public static function qsa($exclude=false) {
    $qsa=self::query($exclude);
    $qsa=preg_replace( '/&[^=&]*=&/', '&', '&'.$qsa.'&');
    return preg_replace('/&/', '&amp;', $qsa);
  }

  
/**
 Give pathinfo with priority order of different values.
 The possible variables are not equally robust

 http://localhost/~user/elec/diple/doc/install&sons?a=1&a=2#ancre

 — $_SERVER['REQUEST_URI'] OK /~fred/elec/diple/doc/install&sons?a=1&a=2
 — $_SERVER['SCRIPT_NAME'] OK /~fred/elec/diple/index.php
 — $_SERVER['PHP_SELF'] /~user/elec/diple/index.php/doc/install&sons (le pathinfo n'est parfois pas transmis mod_rewrite)
 — $_SERVER['PATH_INFO'] sometimes unavailable, ex: through mod_rewrite /doc/install&sons
 — $_SERVER['SCRIPT_URI'] sometimes, ex : http://diple.x10.mx/install&bon
 — $_SERVER['PATH_ORIG_INFO'] found on the web

   */
  public static function pathinfo() {
    $pathinfo="";
    if (!isset($_SERVER['REQUEST_URI'])) return $pathinfo; // ligne de commande
    list($request)=explode('?', $_SERVER['REQUEST_URI']);
    if(strpos($request, '%') !== false) $request=urldecode($request);
    if (strpos($request, $_SERVER['SCRIPT_NAME']) === 0)
      $pathinfo=substr($request, strlen($_SERVER['SCRIPT_NAME']));
    else if (strpos($request, dirname($_SERVER['SCRIPT_NAME'])) === 0)
      $pathinfo=substr($request, strlen(dirname($_SERVER['SCRIPT_NAME'])));
    // if nothing found, try other variables
    if ($pathinfo); // something found, keep it
    else if (isset($_SERVER['PATH_ORIG_INFO'])) $pathinfo=$_SERVER['PATH_ORIG_INFO'];
    else if (isset($_SERVER['PATH_INFO'])) $pathinfo=$_SERVER['PATH_INFO'];
    else if (isset($_REQUEST['id'])) $pathinfo=$_REQUEST['id'];
    // why trim last / ?
    return ltrim($pathinfo, '/');
  }
}



?>