/**
* Calculates the next session for a course
* @param Course $course
* @return Offering
*/
public static function getNextSession(Course $course)
{
$offerings = $course->getOfferings();
// Remove all the offerings that are not valid
$offerings->filter(function ($offering) {
return $offering->getStatus() == Offering::COURSE_NA;
});
if ($offerings->isEmpty()) {
return null;
}
// Categorize offerings into finished, ongoing, selfpaced, upcoming
// Initialize the state map
$offeringStateMap = array();
foreach (Offering::$stateMap as $key => $value) {
$offeringStateMap[$key] = array();
}
// Build the state map;
foreach ($offerings as $offering) {
$states = self::getStates($offering);
foreach ($states as $state) {
$offeringStateMap[$state][] = $offering;
}
}
// Now that the state map is build - traverse in the following order until the next session is found
// upcoming, self paced, ongoing, finished
// upcoming
if (!empty($offeringStateMap['upcoming'])) {
if (count($offeringStateMap['upcoming']) == 1) {
return array_pop($offeringStateMap['upcoming']);
}
// Multiple sessions. Pick the next earliest upcoming session
$next = array_shift($offeringStateMap['upcoming']);
foreach ($offeringStateMap['upcoming'] as $uo) {
if ($uo->getStartDate() < $next->getStartDate()) {
$next = $uo;
}
}
return $next;
}
// selfpaced
if (!empty($offeringStateMap['selfpaced'])) {
return array_pop($offeringStateMap['selfpaced']);
}
// Ongoing
if (!empty($offeringStateMap['ongoing'])) {
return array_pop($offeringStateMap['ongoing']);
}
// finished
if (!empty($offeringStateMap['past'])) {
if (count($offeringStateMap['past']) == 1) {
return array_pop($offeringStateMap['past']);
}
// Multiple sessions. Pick the last finished session
$last = array_shift($offeringStateMap['past']);
foreach ($offeringStateMap['past'] as $uo) {
if ($uo->getStartDate() > $last->getStartDate()) {
$last = $uo;
}
}
return $last;
}
// Error: Should not come here
return null;
}
