I need help fixing this code - php

Question

So, I made a PHP page/link checker, which should not allow an user to visit/redirect to a page if isn't passed certain minutes from last visit/redirect.
The problem is, the user is being redirected to the page ALWAYS even if he already did it 1 min ago and the timer is 7 min (example). The timer is setted into MySQL as minutes.
can't figure out what is wrong in the code
this is the first page:
<?php
session_start();
$sql = "SELECT * FROM table_records";
$result = mysql_query($sql);
$records = array();
while ($row = mysql_fetch_assoc($result)) {
$records[] = $row;
}
foreach ($records as $record) {
$now = new DateTime();
if (!array_key_exists($record, $_SESSION['records']) || ($now->getTimestamp()-$_SESSION['records'][$record]) <= 600) {
echo "<td><center>".$record['id']."</center></td>";
echo "<td><center>".$record['name']."</center></td>";
echo "<td><center>".$record['link']."</center></td>";
echo "<td><center>".$record['delay']."</center></td>";`
} else {
// link disabled
}
}
?>
and this is the page the users are redirected to, to check the timer, and in case redirect them to the link.
$waiting_time = $delay * 60; //calculate delay time in seconds
if (!array_key_exists($id, $_SESSION['records'])) {
$_SESSION['records'][$id] = $now->getTimestamp();
header("Location: $link");
exit();
} elseif (array_key_exists($id, $_SESSION['records']) && ($now->getTimestamp()-$_SESSION['records'][$id]) >= $waiting_time) {
echo "Looks like you already visited this page";
} elseif (array_key_exists($id, $_SESSION['records']) && ($now->getTimestamp()-$_SESSION['records'][$id]) < $waiting_time) {
$_SESSION['records'][$id] = $now->getTimestamp();
header("Location: $link");
exit();
}
The problem is, the user is being redirected to the $link ALWAYS, even if he already visited, and the time of delay isn't passed.
What is wrong with the code?

Answer 1

DRY, you can write your if/elseif statements much easier:
if (array_key_exists($id, $_SESSION['records']) && ($now->getTimestamp()-$_SESSION['records'][$id]) < $waiting_time) {
echo "Looks like you already visited this page";
} else {
$_SESSION['records'][$id] = $now->getTimestamp();
header("Location: $link");
exit();
}
Now, if you look at it you'll see there are two things to check at first:
Is $_SESSION['records'] not empty (maybe session wasn't intialized on second page?) - var_dump ($_SESSION['records']) - what's in there?
what's the result of ($now->getTimestamp()-$_SESSION['records'][$id]) and what's in $waiting_time variable - var_dump it
Don't forget to call exit() after dumping the code and before redirection or simply comment location () lines, otherwise you'll see nothing
Third possibility (you'll know this is the case if you don't see var_dump printout) is that your browser remembers 301 redirection and when you go second time to same address it redirects automatically without calling your script - restart your browser or try different one.