<?php                                                                                                           

$data_file="private/2019-11-11_GGA1-ModA_turni-n3.csv";

function my_header() {
   //non posso indicare il Content-Type due volte
   //header("Content-Type: text/plain");

   // Allow from any origin - https://stackoverflow.com/questions/8719276/cors-with-php-headers
   if (isset($_SERVER['HTTP_ORIGIN'])) {
        // Decide if the origin in $_SERVER['HTTP_ORIGIN'] is one
        // you want to allow, and if so:
        header("Access-Control-Allow-Origin: {$_SERVER['HTTP_ORIGIN']}");
        header('Access-Control-Allow-Credentials: true');
        header('Access-Control-Max-Age: 86400');    // cache for 1 day
   }

   // Access-Control headers are received during OPTIONS requests
   if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {

        if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_METHOD']))
            // may also be using PUT, PATCH, HEAD etc
            header("Access-Control-Allow-Methods: GET, POST, OPTIONS");         

        if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']))
            header("Access-Control-Allow-Headers: {$_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']}");

        exit(0);
   }
}


/*
function read_data_from_file($macchina, $data_file){
      //echo "Opening $data_file...\n";	 

      $handle = @fopen("$data_file", "r");
      if ($handle) {
         $record_trovato=false;
         while ( ($buffer = fgets($handle))!== false ) {
	    $buffer=rtrim($buffer);
	    $riga_come_array=explode( ":" , $buffer);
	    $postazione_da_file=strtolower( $riga_come_array[0] );
	    $matricola=$riga_come_array[1];

	    if ( strlen($macchina) < 3 ) {
	       $macchina=sprintf("%03d", $macchina);
	    }
	    $postazione_da_ip="dip$macchina";	    

	    //if ( preg_match( '/^${postazione_da_ip}$/i' , "$postazione_da_file" ) ) {
	    if ( "$postazione_da_ip" == "$postazione_da_file" ) {
	       echo $matricola . ":";
	       echo $buffer . "\n";
	       $record_trovato=true;
	       break;
	    }
	    else {
	       // echo "NO $macchina: $buffer\n";
	    }
         }
         if (!feof($handle)) {
            echo "Error: unexpected fgets() fail\n";
         }
	 if ( !$record_trovato ) {
	    echo implode( ":", array(
	       "NESSUNA MATRICOLA - cercare meglio o chiedere al docente",
	       $postazione_da_ip, 
	       "NESSUNA MATRICOLA",
	       $data_file,                                                      //nome
	       "- Postazione non menzionata nel file relativo a questo turno",  //cognome
	       "support@math.unipd.it"                                          //email
	       )
	    ) ;
	 }
      	 fclose($handle);
      }
      return 0;
}
*/


if ( array_key_exists( "REMOTE_ADDR",$_SERVER ) ) {

   my_header();

   $full_ip=$_SERVER["REMOTE_ADDR"];          //e.g.      147.162.84.198
   $debug_msg="<!-- full_ip: $full_ip -->";   //$full_ip="147.162.84.198" ;

   if ( !empty( $_GET["override_ip"] ) ) {
      $candidate_ip=trim( $_GET["override_ip"] );
      
         $debug_msg="<!-- full_ip: $full_ip\t  candidate_ip: $candidate_ip -->";
 
      if ( preg_match( '/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/' , $candidate_ip ) ) {
      	 $full_ip=$candidate_ip;	
      }
   }

   if ( preg_match( '/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/' , $full_ip ) ) {
      $ip       = explode( "." , $full_ip);
      $aula     = $ip[2] ; 
      $macchina = $ip[3] ; 

      /*
      //echo "$full_ip\n";	
      //echo "$macchina\n";	
      if ( $ip[0]=='147' && $ip[1]=='162' && $ip[2]=='84' ) {
      	 read_data_from_file( $macchina, $data_file);
      }
      else {
            echo implode( ":", array(
	       "$full_ip - apparentemente il docente non ha prenotato questa aula",
	       $postazione_da_ip, 
	       "$full_ip",
	       $data_file,                                                      //nome
	       "- Postazione non menzionata nel file relativo a questo turno",  //cognome
	       "support@math.unipd.it"                                          //email
	       )
	    ) ;
      }
      */

      //in alternativa a file locali: https://gestionedidattica.unipd.it/Aule/eventi_giornalieri.php?Giorno=2022-01-06
      $file = 'easyroom.json';

      if (file_exists($file)) {
      	 header('Content-Description: File Transfer');
   	 header('Content-Type: application/json');
    	 header('Content-Disposition: attachment; filename="'.basename($file).'"');
    	 header('Expires: 0');
    	 header('Cache-Control: must-revalidate');
   	 header('Pragma: public');
    	 header('Content-Length: ' . filesize($file));
    	 echo  readfile($file);
    	 exit;
     }

   }
   else {
      echo "MALFORMED ENVIRNMENT DATA\n";
   }
}

else {
   echo "UNEXPECTED ENVIRNMENT\n";

   /*
   read_data_from_file(198, $data_file);
   */
}


/*
total 28
-rw-r--r-- 1 root root 8360 Nov 11 08:25 2019-11-11_GGA1-ModA_turni-n1.csv
-rw-r--r-- 1 root root 7416 Nov 11 08:25 2019-11-11_GGA1-ModA_turni-n2.csv
-rw-r--r-- 1 root root 7793 Nov 11 08:25 2019-11-11_GGA1-ModA_turni-n3.csv
*/

?>