if timestamp range is within timestamp range

Question

I have an array of timestamps and duration and an array of occupied timestamps. I now need to check if these timestamps collide.

Basically $start[] cannot be within any of the $occupied[] timestamps

$start[0] = 1486987200; // 12:00
$duration[0] = 3600;

$start[1] = 1487008800; // 18:00
$duration[1] = 7200;

$occupied[0] = 1486989000; // 12:30
$ocDuration[0] = 3600;

$occupied[1] = 1487019600; // 21:00
$ocDuration[1] = 7200;

From the above $start[0] is not possible because $occupied[0] is within its range of 1 hour (3600 seconds), but $start[1] IS possible because it starts at 18:00, and ends 2 hours later.

Another situation could be when $occupied[0] overlaps both $start[]:

So the question is, how can i do such a check ?

Answer 1

If you will use $start and $duration as non-array variables, you can use this one below. Otherwise, just write a double for-loop.

$start[0] = 1486987200; // 12:00
$duration[0] = 3600;

$start[1] = 1487008800; // 18:00
$duration[1] = 7200;

$occupied[0] = 1486989000; // 12:30
$ocDuration[0] = 3600;

$occupied[1] = 1487019600; // 21:00
$ocDuration[1] = 7200;

$occupied[2] = 1486989000; // 12:30
$ocDuration[2] = 23400;

function checkOccupancy($start, $duration, $occupied, $ocDuration){
    $ocLength = count($occupied);
    for($i = 0; $i <= $ocLength; $i++){
        $ocEnd = $occupied[$i] + $ocDuration[$i];
        $end = $start + $duration;
        if(($start > $occupied[$i] && $start < $ocEnd) || ($end > $occupied[$i] && $end < $ocEnd) ){
            return "Not Possible";
        }
    }
    return "Possible";
}

echo checkOccupancy($start[0], $duration[0], $occupied, $ocDuration);
echo checkOccupancy($start[1], $duration[1], $occupied, $ocDuration);