class ServiceReferenceGraph

class ServiceReferenceGraph {
    
    /**
     * @var ServiceReferenceGraphNode[]
     */
    private array $nodes = [];
    public function hasNode(string $id) : bool {
        return isset($this->nodes[$id]);
    }
    
    /**
     * Gets a node by identifier.
     *
     * @throws InvalidArgumentException if no node matches the supplied identifier
     */
    public function getNode(string $id) : ServiceReferenceGraphNode {
        if (!isset($this->nodes[$id])) {
            throw new InvalidArgumentException(\sprintf('There is no node with id "%s".', $id));
        }
        return $this->nodes[$id];
    }
    
    /**
     * Returns all nodes.
     *
     * @return ServiceReferenceGraphNode[]
     */
    public function getNodes() : array {
        return $this->nodes;
    }
    
    /**
     * Clears all nodes.
     */
    public function clear() : void {
        foreach ($this->nodes as $node) {
            $node->clear();
        }
        $this->nodes = [];
    }
    
    /**
     * Connects 2 nodes together in the Graph.
     */
    public function connect(?string $sourceId, mixed $sourceValue, ?string $destId, mixed $destValue = null, ?Reference $reference = null, bool $lazy = false, bool $weak = false, bool $byConstructor = false) : void {
        if (null === $sourceId || null === $destId) {
            return;
        }
        $sourceNode = $this->createNode($sourceId, $sourceValue);
        $destNode = $this->createNode($destId, $destValue);
        $edge = new ServiceReferenceGraphEdge($sourceNode, $destNode, $reference, $lazy, $weak, $byConstructor);
        $sourceNode->addOutEdge($edge);
        $destNode->addInEdge($edge);
    }
    private function createNode(string $id, mixed $value) : ServiceReferenceGraphNode {
        if (isset($this->nodes[$id]) && $this->nodes[$id]
            ->getValue() === $value) {
            return $this->nodes[$id];
        }
        return $this->nodes[$id] = new ServiceReferenceGraphNode($id, $value);
    }

}