<?php
/* loadcards.php - Loads $username's cards $cardlist into the array $cards.
* Also updates information about card weights. */
require_once 'eatcsv.php';
if (!(isset($username) && isset($cardlist))) {
die("Tried to open cardlist <tt>{$cardlist}</tt> of user <tt>{$username}</tt>, and failed.");
}
$cardlist_filename = 'cardlists/' . $username . '/' . $cardlist;
$cards = eatcsv($cardlist_filename) or die("Couldn't open file {$cardlist_filename}.");
/* Weight the cards, and choose a random card. Cards are given more weight if
* the user has got them wrong very often, and if the card hasn't come up
* in a while. */
$weights = array_map(function ($card) {
/* Work out the proportion of times we have got the card right. If it
* has never been tested before, then arbitrarily say that the
* proportion is 0.5. */
$propright = $card['correct'] + $card['incorrect'] > 0 ? $card['correct'] / ($card['correct'] + $card['incorrect']) : 0.5;
$weight = (time() - $card['lasttested']) / 3600 + 1 / ($propright + 1) - 1 / 2;
return $weight;
}, $cards);
//array_map
<?php
/* isloggedin.php - Checks if the user is logged in. If so, prepares the
* variables $username, $cardlist and $cardlist_filename. */
set_include_path('include/');
require_once 'eatcsv.php';
$passwordfile = eatcsv('users.csv');
$passwords = array();
foreach ($passwordfile as $user) {
$passwords[$user['username']] = $user['password'];
}
session_start();
/* If the username and password are given, and they match, then the user is
* logged in. Otherwise, they are not. */
$isloggedin = false;
if (isset($_SESSION['flashcards_username']) && isset($_SESSION['flashcards_password'])) {
if (array_key_exists($_SESSION['flashcards_username'], $passwords) && $passwords[$_SESSION['flashcards_username']] == $_SESSION['flashcards_password']) {
$isloggedin = true;
$username = $_SESSION['flashcards_username'];
/* Check whether the user has a directory in /cardlists/ or not.
* If not, create a directory for them, copying across the files from
* /cardlists/default/. */
if (!file_exists('cardlists/' . $username)) {
system('cp -r cardlists/default cardlists/' . $username);
}
system('touch cardlists/' . $username . '/' . $username);
if (isset($_SESSION['flashcards_cardlist'])) {
$cardlist = $_SESSION['flashcards_cardlist'];
} else {
$cardlist = $username;
}
session_start();
require_once 'isloggedin.php';
if (!$isloggedin) {
die('You are not logged in. Please go to <a href="login.php">login.php</a>.');
}
require_once 'loadcards.php';
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
$file = fopen($cardlist_filename, 'w') or $msg .= "Couldn't open file {$cardlist_filename}.";
fputs($file, $_REQUEST['cardlist']) or $msg .= "Couldn't write to file {$cardlist_filename}. ";
fclose($file);
if (!isset($msg)) {
$msg = "Written to file {$cardlist_filename}. ";
}
/* Sanitise the newly-written cardlist. Fill in missing numerical values as
* zero, and use htmlspecialchars() on the strings. */
$cards = eatcsv($cardlist_filename);
foreach ($cards as &$card) {
$card['side0'] = htmlspecialchars($card['side0']);
$card['side1'] = htmlspecialchars($card['side1']);
if (empty($card['correct'])) {
$card['correct'] = 0;
}
if (empty($card['incorrect'])) {
$card['incorrect'] = 0;
}
if (empty($card['lasttested'])) {
$card['lasttested'] = 0;
}
}
/* Rewrite the cardlist using the sanitised table. */
$file = fopen($cardlist_filename, 'w');
