<?php

namespace Symfony\Component\Serializer\Encoder;

use Symfony\Component\Serializer\SerializerInterface;

use Symfony\Component\Serializer\Exception\UnexpectedValueException;

/*

 * This file is part of the Symfony framework.

 *

 * (c) Fabien Potencier <fabien@symfony.com>

 *

 * This source file is subject to the MIT license that is bundled

 * with this source code in the file LICENSE.

 */

/**

 * Encodes XML data

 *

 * @author Jordi Boggiano <j.boggiano@seld.be>

 * @author John Wards <jwards@whiteoctober.co.uk>

 * @author Fabian Vogler <fabian@equivalence.ch>

 */

class XmlEncoder extends SerializerAwareEncoder implements EncoderInterface, DecoderInterface, NormalizationAwareInterface

{

    private $dom;

    private $format;

    private $rootNodeName = 'response';

    /**

     * {@inheritdoc}

     */

    public function encode($data, $format)

    {

        if ($data instanceof \DOMDocument) {

            return $data->saveXML();

        }

        $this->dom = new \DOMDocument();

        $this->format = $format;

        if (null !== $data && !is_scalar($data)) {

            $root = $this->dom->createElement($this->rootNodeName);

            $this->dom->appendChild($root);

            $this->buildXml($root, $data);

        } else {

            $this->appendNode($this->dom, $data, $this->rootNodeName);

        }

        return $this->dom->saveXML();

    }

    /**

     * {@inheritdoc}

     */

    public function decode($data, $format)

    {

        $xml = simplexml_load_string($data);

        if (!$xml->count()) {

            if (!$xml->attributes()) {

                return (string) $xml;

            }

            $data = array();

            foreach ($xml->attributes() as $attrkey => $attr) {

                $data['@'.$attrkey] = (string) $attr;

            }

            $data['#'] = (string) $xml;

            return $data;

        }

        return $this->parseXml($xml);

    }

    /**

     * Sets the root node name

     * @param string $name root node name

     */

    public function setRootNodeName($name)

    {

        $this->rootNodeName = $name;

    }

    /**

     * Returns the root node name

     * @return string

     */

    public function getRootNodeName()

    {

        return $this->rootNodeName;

    }

    /**

     * @param DOMNode $node

     * @param string $val

     * @return Boolean

     */

    final protected function appendXMLString($node, $val)

    {

        if (strlen($val) > 0) {

            $frag = $this->dom->createDocumentFragment();

            $frag->appendXML($val);

            $node->appendChild($frag);

            return true;

        }

        return false;

    }

    /**

     * @param DOMNode $node

     * @param string $val

     * @return Boolean

     */

    final protected function appendText($node, $val)

    {

        $nodeText = $this->dom->createTextNode($val);

        $node->appendChild($nodeText);

        return true;

    }

    /**

     * @param DOMNode $node

     * @param string $val

     * @return Boolean

     */

    final protected function appendCData($node, $val)

    {

        $nodeText = $this->dom->createCDATASection($val);

        $node->appendChild($nodeText);

        return true;

    }

    /**

     * @param DOMNode $node

     * @param DOMDocumentFragment $fragment

     * @return Boolean

     */

    final protected function appendDocumentFragment($node, $fragment)

    {

        if ($fragment instanceof \DOMDocumentFragment) {

            $node->appendChild($fragment);

            return true;

        }

        return false;

    }

    /**

     * Checks the name is a valid xml element name

     * @param string $name

     * @return Boolean

     */

    final protected function isElementNameValid($name)

    {

        return $name &&

            false === strpos($name, ' ') &&

            preg_match('#^[\pL_][\pL0-9._-]*$#ui', $name);

    }

    /**

     * Parse the input SimpleXmlElement into an array

     *

     * @param SimpleXmlElement $node xml to parse

     * @return array

     */

    private function parseXml($node)

    {

        $data = array();

        if ($node->attributes()) {

            foreach ($node->attributes() as $attrkey => $attr) {

                $data['@'.$attrkey] = (string) $attr;

            }

        }

        foreach ($node->children() as $key => $subnode) {

            if ($subnode->count()) {

                $value = $this->parseXml($subnode);

            } elseif ($subnode->attributes()) {

                $value = array();

                foreach ($subnode->attributes() as $attrkey => $attr) {

                    $value['@'.$attrkey] = (string) $attr;

                }

                $value['#'] = (string) $subnode;

            } else {

                $value = (string) $subnode;

            }

            if ($key === 'item') {

                if (isset($value['@key'])) {

                    $data[(string)$value['@key']] = $value['#'];

                } elseif (isset($data['item'])) {

                    $tmp = $data['item'];

                    unset($data['item']);

                    $data[] = $tmp;

                    $data[] = $value;

                }

            } elseif (key_exists($key, $data)) {

                if ((false === is_array($data[$key]))  || (false === isset($data[$key][0]))) {

                    $data[$key] = array($data[$key]);

                }

                $data[$key][] = $value;

            } else {

                $data[$key] = $value;

            }

        }

        return $data;

    }

    /**

     * Parse the data and convert it to DOMElements

     *

     * @param DOMNode $parentNode

     * @param array|object $data data

     * @return Boolean

     */

    private function buildXml($parentNode, $data)

    {

        $append = true;

        if (is_array($data) || $data instanceof \Traversable) {

            foreach ($data as $key => $data) {

                //Ah this is the magic @ attribute types.

                if (0 === strpos($key, "@") && is_scalar($data) && $this->isElementNameValid($attributeName = substr($key,1))) {

                    $parentNode->setAttribute($attributeName, $data);

                } elseif ($key === '#') {

                    $append = $this->selectNodeType($parentNode, $data);

                } elseif (is_array($data) && false === is_numeric($key)) {

                    /**

                     * Is this array fully numeric keys?

                     */

                    if (ctype_digit(implode('', array_keys($data)))) {

                        /**

                         * Create nodes to append to $parentNode based on the $key of this array

                         * Produces <xml><item>0</item><item>1</item></xml>

                         * From array("item" => array(0,1));

                         */

                        foreach ($data as $subData) {

                            $append = $this->appendNode($parentNode, $subData, $key);

                        }

                    } else {

                        $append = $this->appendNode($parentNode, $data, $key);

                    }

                } elseif (is_numeric($key) || !$this->isElementNameValid($key)) {

                    $append = $this->appendNode($parentNode, $data, "item", $key);

                } else {

                    $append = $this->appendNode($parentNode, $data, $key);

                }

            }

            return $append;

        }

        if (is_object($data)) {

            $data = $this->serializer->normalize($data, $this->format);

            if (null !== $data && !is_scalar($data)) {

                return $this->buildXml($parentNode, $data);

            }

            // top level data object was normalized into a scalar

            if (!$parentNode->parentNode->parentNode) {

                $root = $parentNode->parentNode;

                $root->removeChild($parentNode);

                return $this->appendNode($root, $data, $this->rootNodeName);

            }

            return $this->appendNode($parentNode, $data, 'data');

        }

        throw new UnexpectedValueException('An unexpected value could not be serialized: '.var_export($data, true));

    }

    /**

     * Selects the type of node to create and appends it to the parent.

     *

     * @param DOMNode      $parentNode

     * @param array|object $data

     * @param string       $nodename

     * @param string       $key

     * @return Boolean

     */

    private function appendNode($parentNode, $data, $nodeName, $key = null)

    {

        $node = $this->dom->createElement($nodeName);

        if (null !== $key) {

            $node->setAttribute('key', $key);

        }

        $appendNode = $this->selectNodeType($node, $data);

        // we may have decided not to append this node, either in error or if its $nodeName is not valid

        if ($appendNode) {

            $parentNode->appendChild($node);

        }

        return $appendNode;

    }

    /**

     * Tests the value being passed and decide what sort of element to create

     *

     * @param DOMNode $node

     * @param mixed $val

     * @return Boolean

     */

    private function selectNodeType($node, $val)

    {

        if (is_array($val)) {

            return $this->buildXml($node, $val);

        } elseif ($val instanceof \SimpleXMLElement) {

            $child = $this->dom->importNode(dom_import_simplexml($val), true);

            $node->appendChild($child);

        } elseif ($val instanceof \Traversable) {

            $this->buildXml($node, $val);

        } elseif (is_object($val)) {

            return $this->buildXml($node, $this->serializer->normalize($val, $this->format));

        } elseif (is_numeric($val)) {

            return $this->appendText($node, (string) $val);

        } elseif (is_string($val)) {

            return $this->appendCData($node, $val);

        } elseif (is_bool($val)) {

            return $this->appendText($node, (int) $val);

        } elseif ($val instanceof \DOMNode) {

            $child = $this->dom->importNode($val, true);

            $node->appendChild($child);

        }

        return true;

    }

}