Add function processing and basic !Replace to cfnpp

app/Dom/Node.php

@@ -77,6 +77,17 @@ class Node implements \ArrayAccess, \Iterator
 		return $this->parent;
 	}
 
+	/**
+	 * Set this node's parent.
+	 *
+	 * @param  Node $parent
+	 * @return void
+	 */
+	public function setParent(Node $parent): void
+	{
+		$this->parent = $parent;
+	}
+
 	/**
 	 * Check whether this node has any child nodes.
 	 *

app/Engine/Cfnpp.php

@@ -6,6 +6,8 @@ namespace App\Engine;
 
 use App\Dom\Document;
 use App\Dom\Node;
+use App\Dom\NodeFunction;
+use App\Dom\NodeFunctionValue;
 use App\Dom\NodeValue;
 
 class Cfnpp implements ICompile
@@ -13,6 +15,28 @@ class Cfnpp implements ICompile
 	/** @var Document */
 	protected $document;
 
+	/** @var array<string, callable> */
+	protected $functions;
+
+	public function __construct()
+	{
+		$this->functions = [];
+
+		$this->registerFunction('Replace', static function(Node $orig_p, Node $tgt_p, Node $t) {
+			if ($t instanceof NodeFunctionValue)
+			{
+				return $t->getValue();
+			}
+
+			return $t->getChildren();
+		});
+	}
+
+	public function registerFunction(string $name, callable $callback): void
+	{
+		$this->functions[$name] = $callback;
+	}
+
 	public function setDocument(Document $document): void
 	{
 		$this->document = $document;
@@ -25,7 +49,6 @@ class Cfnpp implements ICompile
 
 	protected function compileNodes(Node $original, Node $target): void
 	{
-		var_dump(get_class($original), get_class($target));
 		if ($target instanceof NodeValue)
 		{
 			if ($original instanceof NodeValue)
@@ -39,7 +62,10 @@ class Cfnpp implements ICompile
 				$parent->addChild($target);
 			}
 		}
-		// TODO: Add nodefunctions
+		elseif ($target instanceof NodeFunction)
+		{
+			$this->resolveFunction($original->getParent(), $target->getParent(), $target);
+		}
 		elseif ($target instanceof Node)
 		{
 			// if they're both maps, add/overwrite by name
@@ -48,13 +74,24 @@ class Cfnpp implements ICompile
 				foreach ($target as $target_child)
 				{
 					$orig_child = $original->getChildByName($target_child->getName());
-					if (!isset($orig_child))
+					if ($target_child instanceof NodeFunction)
 					{
-						$original->addChild($target_child);
+						if (!isset($orig_child))
+						{
+							$original->addChild($orig_child = new Node($original, $target->getName()));
+						}
+						$this->compileNodes($orig_child, $target_child);
 					}
 					else
 					{
-						$this->compileNodes($orig_child, $target_child);
+						if (!isset($orig_child))
+						{
+							$original->addChild($target_child);
+						}
+						else
+						{
+							$this->compileNodes($orig_child, $target_child);
+						}
 					}
 				}
 			}
@@ -76,6 +113,54 @@ class Cfnpp implements ICompile
 		}
 	}
 
+	protected function resolveFunction(Node $original_parent, Node $target_parent, Node $target): void
+	{
+		// Execute nodefunction
+		$function = $target->getName();
+
+		if (!isset($this->functions[$function]))
+		{
+			throw new \Exception('Unrecognized function: '.$function);
+		}
+
+		$result = $this->functions[$function]($original_parent, $target_parent, $target);
+
+		if (is_scalar($result))
+		{
+			$original_grandparent = $original_parent->getParent();
+			$original_grandparent->removeChild($original_parent);
+			$node = new NodeValue($original_grandparent, $target_parent->getName(), $result);
+			$original_grandparent->addChild($node);
+			// Remove processed function
+			$target_parent->getParent()->removeChild($target_parent);
+		}
+		elseif (is_array($result))
+		{
+			// Update original _and_ target so we can reprocess sensibly
+			$original_grandparent = $original_parent->getParent();
+			$original_grandparent->removeChild($original_parent);
+			$original_parent = new Node($original_grandparent, $original_parent->getName());
+			$original_grandparent->addChild($original_parent);
+			foreach ($result as $node)
+			{
+				$original_parent->addChild($node);
+				$node->setParent($original_parent->getParent());
+			}
+
+			$target_grandparent = $target_parent->getParent();
+			$target_grandparent->removeChild($target_parent);
+			$target_parent = new Node($target_grandparent, $target_parent->getName());
+			$target_grandparent->addChild($target_parent);
+			foreach ($result as $node)
+			{
+				$node = clone $node;
+				$target_parent->addChild($node);
+				$node->setParent($target_parent->getParent());
+			}
+			$this->compileNodes($original_parent, $target_parent);
+		}
+	}
+
 	public function getDocument(): Document
 	{
 		return $this->document;