<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Config\Definition\Builder;

/**
 * This class provides a fluent interface for building a node.
 *
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 */
class NodeBuilder implements NodeParentInterface
{
    protected $parent;
    protected $nodeMapping;

    /**
     * Constructor
     *
     */
    public function __construct()
    {
        $this->nodeMapping = array(
            'variable'    => __NAMESPACE__.'\\VariableNodeDefinition',
            'scalar'      => __NAMESPACE__.'\\ScalarNodeDefinition',
            'boolean'     => __NAMESPACE__.'\\BooleanNodeDefinition',
            'array'       => __NAMESPACE__.'\\ArrayNodeDefinition',
        );
    }

    /**
     * Set the parent node
     *
     * @param ParentNodeDefinitionInterface $parent The parent node
     *
     * @return NodeBuilder This node builder
     */
    public function setParent(ParentNodeDefinitionInterface $parent = null)
    {
        $this->parent = $parent;

        return $this;
    }

    /**
     * Creates a child array node
     *
     * @param string $name The name of the node
     *
     * @return ArrayNodeDefinition The child node
     */
    public function arrayNode($name)
    {
        return $this->node($name, 'array');
    }

    /**
     * Creates a child scalar node.
     *
     * @param string $name the name of the node
     *
     * @return ScalarNodeDefinition The child node
     */
    public function scalarNode($name)
    {
        return $this->node($name, 'scalar');
    }

    /**
     * Creates a child Boolean node.
     *
     * @param string $name The name of the node
     *
     * @return BooleanNodeDefinition The child node
     */
    public function booleanNode($name)
    {
        return $this->node($name, 'boolean');
    }

    /**
     * Creates a child variable node.
     *
     * @param string $name The name of the node
     *
     * @return VariableNodeDefinition The builder of the child node
     */
    public function variableNode($name)
    {
        return $this->node($name, 'variable');
    }

    /**
     * Returns the parent node.
     *
     * @return ParentNodeDefinitionInterface The parent node
     */
    public function end()
    {
        return $this->parent;
    }

    /**
     * Creates a child node.
     *
     * @param string $name The name of the node
     * @param string $type The type of the node
     *
     * @return NodeDefinition The child node
     *
     * @throws \RuntimeException When the node type is not registered
     * @throws \RuntimeException When the node class is not found
     */
    public function node($name, $type)
    {
        $class = $this->getNodeClass($type);

        $node = new $class($name);

        if ($node instanceof ParentNodeDefinitionInterface) {
            $builder = clone $this;
            $builder->setParent(null);
            $node->setBuilder($builder);
        }

        if (null !== $this->parent) {
            $this->parent->append($node);
            // Make this builder the node parent to allow for a fluid interface
            $node->setParent($this);
        }

        return $node;
    }

    /**
     * Add or override a node Type
     *
     * @param string $type The name of the type
     * @param string $class The fully qualified name the node definition class
     */
    public function setNodeClass($type, $class)
    {
        $this->nodeMapping[strtolower($type)] = $class;

        return $this;
    }

    /**
     * Returns the class name of the node definition
     *
     * @param string $type The node type
     *
     * @return string The node definition class name
     *
     * @throws \RuntimeException When the node type is not registered
     * @throws \RuntimeException When the node class is not found
     */
    protected function getNodeClass($type)
    {
        $type = strtolower($type);

        if (!isset($this->nodeMapping[$type])) {
            throw new \RuntimeException(sprintf('The node type "%s" is not registered.', $type));
        }

        $class = $this->nodeMapping[$type];

        if (!class_exists($class)) {
            throw new \RuntimeException(sprintf('The node class "%s" does not exist.', $class));
        }

        return $class;
    }

}