/**
* @param LocalDateTime|null $dt
* @return null|ZoneOffsetTransition|ZoneOffset
* @throws IllegalArgumentException
*/
private function getOffsetInfo($dt)
{
if (empty($this->savingsInstantTransitions)) {
return $this->standardOffsets[0];
}
// check if using last rules
if (!empty($this->lastRules) && $dt->isAfter($this->savingsLocalTransitions[count($this->savingsLocalTransitions) - 1])) {
/** @var ZoneOffsetTransition[] $transArray */
$transArray = $this->findTransitionArray($dt->getYear());
$info = null;
foreach ($transArray as $trans) {
$info = $this->findOffsetInfo($dt, $trans);
if ($info instanceof ZoneOffsetTransition || $info->equals($trans->getOffsetBefore())) {
return $info;
}
}
return $info;
}
// using historic rules
$index = Math::binarySearch($this->savingsLocalTransitions, $dt);
if ($index === -1) {
// before first transition
return $this->wallOffsets[0];
}
if ($index < 0) {
// switch negative insert position to start of matched range
$index = -$index - 2;
} else {
if ($index < count($this->savingsLocalTransitions) - 1 && $this->savingsLocalTransitions[$index]->equals($this->savingsLocalTransitions[$index + 1])) {
// handle overlap immediately following gap
$index++;
}
}
if (($index & 1) === 0) {
// gap or overlap
$dtBefore = $this->savingsLocalTransitions[$index];
$dtAfter = $this->savingsLocalTransitions[$index + 1];
$offsetBefore = $this->wallOffsets[(int) ($index / 2)];
$offsetAfter = $this->wallOffsets[(int) ($index / 2) + 1];
if ($offsetAfter->getTotalSeconds() > $offsetBefore->getTotalSeconds()) {
// gap
return ZoneOffsetTransition::of($dtBefore, $offsetBefore, $offsetAfter);
} else {
// overlap
return ZoneOffsetTransition::of($dtAfter, $offsetBefore, $offsetAfter);
}
} else {
// normal (neither gap or overlap)
return $this->wallOffsets[(int) ($index / 2) + 1];
}
}
