The task is to calculate the overlap of events (stored in DB) and show the overlapping times as events. So if I have 3 Users and they have events spread through the day and there are times all 3 Users overlap I want to create an event representing that time and show it on the frontend.
Monday: User1 has Event 12:00-13:00 User2 has Event12:45-13:45 User3 has Event 12:30-14:00
Would give the overlapEvent 12:45-13:00
I have a database with the tables calendar and calendar_events. the calendar represents a user-calendar and calendar_events has all events. Events have the pid field to refer the calendar it belongs to. I have a method that returns all events for each day in the week. I have tried running over all events each day x times (x is the number of users, whose overlap I need to calculate) in for loops, but this seems very inefficient since the processing time increase exponentially with each user. I have tried creating a new array with the pid field as keys, but I don't really know where to go from here. I need to check each event against all events of that day from the other users.
$overlapEvents=array();
foreach ($AllEvents as $key => $days)
{
$eventsSorted=array();
foreach ($days as $day => $events)
{
foreach ($events as $event)
{
array_push($eventSorted[$event['pid'],$event);
}
}
}
This is how $AllEvents looks like
Array
(
[20190516] => Array //date of day 2019 05 16
(
[1558002600] => Array//event start time
(
[0] => Array
(
[id] => 645
[pid] => 16
[tstamp] => 1557905849
[title] => testEvent
[alias] => testEvent
[author] => 1
[addTime] => 1
[startTime] => 1558002600
[endTime] => 1558003500
[startDate] => 1557957600
[endDate] => 1557957600
)
)
)