<?
   /*  common.php -- Common routines  used by the Opticampus web site.

       PHP scripts accessing this file can do like:

          include('/home/opticamp/common/common.php');

       To have access to these commonly used functions.

   */

  function ConnectToDB() {
    // Connect to the DB and return true on success, false otherwise.
    return mysql_connect('', 'opticamp', 's0laSux') && mysql_select_db('opticamp_quiz');
  }

  function StartSession() {
    // This starts a stateful session.  When students log on, a PHP session is started
    //   and all info regarding the student is stored with the session.  Since this uses
    //   cookies, StartSession() needs called prior to sending non-header info.
    ini_set('session.use_only_cookies', '1');  // Force cookies for sessions
    session_name('OPTICAMP');  // instead of the default PHPSESSID
    session_start();           // start the session
  }

  function AuthUser() {
    // Find the admin user in the database.  This assumes that we're connected to the DB
    //   prior to calling this
    $user = $_SERVER['PHP_AUTH_USER'];
    $pass = $_SERVER['PHP_AUTH_PW'];

    $sql = "SELECT * FROM users WHERE username='$user' AND password=Password('$pass')";

    $result = @mysql_query($sql);

    if (!$result || mysql_numrows($result) == 0) {
      Header("WWW-authenticate: basic realm=\"Opticampus\"");
      Header("HTTP/1.0 401 Unauthorized");
      print "Unauthorized\n";
      return false;
    }

    // Get and return the user's array -- we need things like first name
    $row = mysql_fetch_array($result);

    return $row;
  }

  function CartContents()  {
    // 12 Oct 2002 -- Returns the cart contents as a comma separated string
    return $_SESSION['cart'];
  }

  function CartHasItem($itemid) {
    // 12 Oct 2002 -- Return true if the passed item id is in the 
    //    cart list or false otherwise
    return in_array($itemid, split(',', CartContents()));
  }

  function CartCount() {
    // 13 Oct 2002 -- Return the count of the number of items in the cart
    //   Splitting an empty array results in an array of one element
    $cart = CartContents();
    return (empty($cart) ? 0 : count(split(',', $cart)));
  }

  function CartAdd($itemid) {
    // 12 Oct 2002 - Add this item number to the shopping cart queue in the user's session
    //   The cart is implemented as a comma separated list of ID numbers in the 
    //   $_SESSION array element called 'cart'.
    // Doing a split on an empty string results in an array with one element, an empty string
    if (!CartHasItem($itemid)) {
      // If we don't have items yet, then make the item the only item in the cart 
      if (empty($_SESSION['cart'])) { 
        $_SESSION['cart'] = $itemid;
      } else {
        $_SESSION['cart'] .= ",$itemid";
      }
    }
  }

  function CartClear() {
    // 12 Oct 2002 -- Clear the cart
    $_SESSION['cart'] = '';
  }

  function CartRemove($itemid) {
    // 12 Oct 2002 -- Remove the item from the cart by rebuilding the cart
    //   without the item to be removed
    if (CartHasItem($itemid)) {
      // Rebuild $_SESSION['cart'] without the item id in the list
      $cart = split(',', $_SESSION['cart']);
      CartClear();
      foreach ($cart as $item) {
        if ($item != $itemid) { CartAdd($item); }
      }
    }
  }

  function NotifyMail($subject, $body, $recip) {
    // Sends an e-mail to a specified list of recipients or to
    //    the admins of the site.

    // If $recip is not set to a particular e-mail, then default to
    //   Steve, Darryl and Dave.
    if (empty($recip)) {
//    $recip = 'smachol@optiboard.com,DarrylMeister@aol.com,dave@optivisioninc.com';
$recip = 'dave@optivisioninc.com';
    }

    // Split the e-mail list into an array
    $recplist = split(',', $recip);

    // Create a "To:" list of e-mails
    $header = '';
    for($counter = 0; $counter < count($reciplist); $counter++) {
      $header .= 'To: ' . $reciplist[$counter] . "\n";
    }

    // Tack on a nice "From:" header (the $header ends in a new line from the
    //    above loop).
    $header .= "From: \"Opticampus\" <opticamp@opticampus.com>";

    // Finally, send the e-mail
    return mail($recip, $subject, $body, $header);
  }

  function ExhibitFileName($quesid) {
    // This returns the name of the exhibit file for the passed question ID.  Each question in the
    //   quiz_questions table has a unique ID.  The image file is stored as 'ques' plus the ID number
    //   of the question (e.g. ques114.gif is question 114's GIF file exhibit).
    //   This returns the name of the file used as the exhibit file or an empty string if one does
    //   not exist.  The exhibit file can be .gif, .jpg, or .png.
    if (file_exists('/home/opticamp/exhibits/ques' . $quesid . '.gif')) { 
      return "ques$quesid.gif";
    } else if (file_exists('/home/opticamp/exhibits/ques' . $quesid . '.jpg')) {
      return "ques$quesid.jpg";
    } else if (file_exists('/home/opticamp/exhibits/ques' . $quesid . '.png')) {
      return "ques$quesid.png";
    }

    return '';   // Else, return an empty string
  }

  function WriteToLog($logtype, $logdetails) {
    // Write to the log table with the info passed.  Events such as logins, 
    //   changes, signing up for tests,
    //   etc can be written to this log.  Just a general use log to report site activity.
    $logdetails = addslashes($logdetails);
    mysql_query('INSERT INTO log (logtime, logtype, logdetails) ' . 
                "VALUES (now(), '$logtype', '$logdetails')");

    // 13 Oct 2002 -- return the auto-increment ID number from the insert into the log table.
    //   This can be used to refer to this particular log entry and 
    //   is used when there is a credit card transaction error.
    return mysql_insert_id();
  }

  function WriteExhibit($quesid) {
     // This writes the image link for the exhibit image associated with the current question.
     //   There may not be an image -- in this case, write nothing.
     // 20 Aug 2002 -- This function is moved here as it is called in two or more scripts.
     $fname = ExhibitFileName($quesid);
     if (empty($fname)) { return; }
  
     // Write the link to the image
     print "<img src=\"./exhibit.php?quesid=$quesid\"><br>";
  }


  function PrintComment($txt) {
    // 09 Nov 2003 -- Write an HTML comment with the passed text as the comment
    print "\n<!-- $txt -->\n";
  }

?>