/**
* @throws \InvalidArgumentException
*
* @return Collection|PotentialOffer[]
*/
private function collect() : Collection
{
/*
* Create buckets for each offer, keeping duplicate offers.
* Assign each product to the first applicable bucket with spaces left.
* Filter the buckets to those that are full.
*/
return $this->components->sort(function (OfferComponent $a, OfferComponent $b) {
$priceA = $a->product()->price()->asFloat();
$priceB = $b->product()->price()->asFloat();
return $priceA <=> $priceB;
})->reduce(function (Collection $potentials, OfferComponent $component) {
$potentials->first(function (PotentialOffer $potential) use($component) {
return $potential->takeComponent($component);
});
return $potentials;
}, $this->potentials())->filter(function (PotentialOffer $offer) {
return $offer->requirementsAreMet();
})->sort(function (PotentialOffer $offer) {
return $offer->linePrice()->negative()->amount();
});
}
