//exit;
anchorRedirect($anchor, $tab);
} else {
if ($action == "addtogroup") {
$anchor = rt("anchor");
$tab = rt("tab");
$gid = rt("gid");
$students = $_GET["student"];
$sql = "select count(*) from users where active=1 and teacher_code={$teacher_code} and group_id={$gid}";
$rs = dbExec($sql);
$spaceleft = 4 - $rs->fields(0);
$numprovided = count($students);
$n = $spaceleft;
dbg("spaceleft={$spaceleft}");
if ($spaceleft < 1) {
msgRedirectRed("No students added - TEAM FULL!", $anchor);
}
dbg("numprovided={$numprovided}");
dbg("n={$n}");
// Add students to the group
$added = 0;
foreach ($students as $s) {
$sql = "update users set group_id={$gid} where active=1 and id={$s} and teacher_code={$teacher_code} and group_id=0";
$rs = dbExec($sql);
logit("student {$id} added to group {$gid} by teacher {$teacher_code}");
$added++;
$n--;
if ($n == 0) {
break;
}
}
function make_a_group($teacher_code)
{
global $db;
// make sure this teacher is below their quota of groups
$sql = "select count(*) from groups where teacher_code={$teacher_code}";
$rs = $db->Execute($sql);
if (!$rs) {
p_sqlfail($db, $sql);
}
$maxgrps = $db->GetOne("select val from config where tag='max_groups_per_teacher'");
if ($rs->fields(0) >= $maxgrps) {
msgRedirectRed("group quota for teacher-{$teacher_code} maxed out");
}
$n = 0;
while (true) {
if ($n > 10) {
dbg("ACK!! {$id} {$tc}");
exit;
}
// look for a free group slot
$sql = "select * from groups where teacher_code=0 and grab=0 order by rand() limit 1";
$rs = $db->Execute($sql);
if (!$rs) {
p_sqlfail($db, $sql);
}
if ($rs->RecordCount() == 0) {
msgRedirectRed("no available group slots. Please try again later.");
}
// attempt to increment grab by 1
$id = $rs->fields("id");
$g = $rs->fields("grab");
$sql = "update groups set grab=grab+1 where id={$id}";
$rs = $db->Execute($sql);
if (!$rs) {
p_sqlfail($db, $sql);
}
dbg("grab count incremented");
// check to see if grab has in fact only grown by 1
$sql = "select grab from groups where id={$id}";
$rs = $db->Execute($sql);
if (!$rs) {
p_sqlfail($db, $sql);
}
if ($rs->fields("grab") == $g + 1) {
// we won the grab!
dbg("grab successful!");
break;
}
// someone else tried to grab at the same time as us.
// decrement my grab and try again ...
dbg("grab failed");
$sql = "update groups set grab=grab-1 where id={$id}";
$rs = $db->Execute($sql);
dbg("grab count decremented");
logit("grab failed (id={$id})");
$n++;
}
// Store my info into the group
$name = "DEVGROUP_" . $teacher_code . "_{$id}";
$sql = "update groups set teacher_code={$teacher_code}, name='{$name}' where id={$id}";
$rs = $db->Execute($sql);
if (!$rs) {
p_sqlfail($db, $sql);
}
logit("group {$id} acquired by DEV for teacher {$teacher_code}");
dbg("group created: {$id}");
return $id;
}
