class ComplexityCollection

final class ComplexityCollection implements Countable, IteratorAggregate {
    
    /**
     * @psalm-var list<Complexity>
     */
    private readonly array $items;
    public static function fromList(Complexity ...$items) : self {
        return new self($items);
    }
    
    /**
     * @psalm-param list<Complexity> $items
     */
    private function __construct(array $items) {
        $this->items = $items;
    }
    
    /**
     * @psalm-return list<Complexity>
     */
    public function asArray() : array {
        return $this->items;
    }
    public function getIterator() : ComplexityCollectionIterator {
        return new ComplexityCollectionIterator($this);
    }
    
    /**
     * @psalm-return non-negative-int
     */
    public function count() : int {
        return count($this->items);
    }
    public function isEmpty() : bool {
        return empty($this->items);
    }
    
    /**
     * @psalm-return non-negative-int
     */
    public function cyclomaticComplexity() : int {
        $cyclomaticComplexity = 0;
        foreach ($this as $item) {
            $cyclomaticComplexity += $item->cyclomaticComplexity();
        }
        return $cyclomaticComplexity;
    }
    public function isFunction() : self {
        return new self(array_values(array_filter($this->items, static fn(Complexity $complexity): bool => $complexity->isFunction())));
    }
    public function isMethod() : self {
        return new self(array_values(array_filter($this->items, static fn(Complexity $complexity): bool => $complexity->isMethod())));
    }
    public function mergeWith(self $other) : self {
        return new self(array_merge($this->asArray(), $other->asArray()));
    }
    public function sortByDescendingCyclomaticComplexity() : self {
        $items = $this->items;
        usort($items, static function (Complexity $a, Complexity $b) : int {
            return $a->cyclomaticComplexity() <=> $b->cyclomaticComplexity();
        });
        return new self(array_reverse($items));
    }

}