<?php
/**
 *  OpenLSS - Lighter Smarter Simpler
 *
 *	This file is part of OpenLSS.
 *
 *	OpenLSS is free software: you can redistribute it and/or modify
 *	it under the terms of the GNU Lesser General Public License as
 *	published by the Free Software Foundation, either version 3 of
 *	the License, or (at your option) any later version.
 *
 *	OpenLSS is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU Lesser General Public License for more details.
 *
 *	You should have received a copy of the 
 *	GNU Lesser General Public License along with OpenLSS.
 *	If not, see <http://www.gnu.org/licenses/>.
 */
namespace LSS;
use \DOMDocument;
use \Exception;

/**
 * XML2Array: A class to convert XML to array in PHP
 * It returns the array which can be converted back to XML using the Array2XML script
 * It takes an XML string or a DOMDocument object as an input.
 *
 * See Array2XML: http://www.lalit.org/lab/convert-php-array-to-xml-with-attributes
 *
 * Author : Lalit Patel
 * Website: http://www.lalit.org/lab/convert-xml-to-array-in-php-xml2array
 * License: Apache License 2.0
 *          http://www.apache.org/licenses/LICENSE-2.0
 * Version: 0.1 (07 Dec 2011)
 * Version: 0.2 (04 Mar 2012)
 * 			Fixed typo 'DomDocument' to 'DOMDocument'
 *
 * Usage:
 *       $array = XML2Array::createArray($xml);
 */

class XML2Array {

    protected static $xml = null;
    protected static $encoding = 'UTF-8';
    protected static $prefix_attributes = '@';

    /**
     * Initialize the root XML node [optional]
     * @param $version
     * @param $encoding
     * @param $format_output
     */
    public static function init($version = '1.0', $encoding = 'UTF-8', $format_output = true) {
        self::$xml = new DOMDocument($version, $encoding);
        self::$xml->formatOutput = $format_output;
		self::$encoding = $encoding;
    }

    /**
     * Convert an XML to Array
     * @param string $node_name - name of the root node to be converted
     * @param int - Bitwise OR of the libxml option constants see @link http://php.net/manual/zh/libxml.constants.php
     * @param array $arr - aray to be converterd
     * @return DOMDocument
     */
    public static function &createArray($input_xml, $options = 0) {
        $xml = self::getXMLRoot();
		if(is_string($input_xml)) {
			$parsed = $xml->loadXML($input_xml, $options);
			if(!$parsed) {
				throw new Exception('[XML2Array] Error parsing the XML string.');
			}
		} else {
			if(get_class($input_xml) != 'DOMDocument') {
				throw new Exception('[XML2Array] The input XML object should be of type: DOMDocument.');
			}
			$xml = self::$xml = $input_xml;
		}
		$array[$xml->documentElement->tagName] = self::convert($xml->documentElement);
        self::$xml = null;    // clear the xml node in the class for 2nd time use.
        return $array;
    }

    /**
     * Convert an Array to XML
     * @param mixed $node - XML as a string or as an object of DOMDocument
     * @return mixed
     */
    protected static function &convert($node) {
		$output = array();

		switch ($node->nodeType) {
			case XML_CDATA_SECTION_NODE:
				$output[static::$prefix_attributes.'cdata'] = trim($node->textContent);
				break;

			case XML_TEXT_NODE:
				$output = trim($node->textContent);
				break;

			case XML_ELEMENT_NODE:

				// for each child node, call the covert function recursively
				for ($i=0, $m=$node->childNodes->length; $i<$m; $i++) {
					$child = $node->childNodes->item($i);
					$v = self::convert($child);
					if(isset($child->tagName)) {
						$t = $child->tagName;

                        // avoid fatal error if the content looks like '<html><body>You are being <a href="https://some.url">redirected</a>.</body></html>'
                        if(isset($output) && !is_array($output)) {
                            continue;
                        }
						// assume more nodes of same kind are coming
						if(!isset($output[$t])) {
							$output[$t] = array();
						}
						$output[$t][] = $v;
					} else {
						//check if it is not an empty text node
						if($v !== '') {
							$output = $v;
						}
					}
				}

				if(is_array($output)) {
					// if only one node of its kind, assign it directly instead if array($value);
					foreach ($output as $t => $v) {
						if(is_array($v) && count($v)==1) {
							$output[$t] = $v[0];
						}
					}
					if(empty($output)) {
						//for empty nodes
						$output = '';
					}
				}

				// loop through the attributes and collect them
				if($node->attributes->length) {
					$a = array();
					foreach($node->attributes as $attrName => $attrNode) {
						$a[$attrName] = (string) $attrNode->value;
					}
					// if its an leaf node, store the value in @value instead of directly storing it.
					if(!is_array($output)) {
						$output = array(static::$prefix_attributes.'value' => $output);
					}
					$output[static::$prefix_attributes.'attributes'] = $a;
				}
				break;
		}
		return $output;
    }

    /*
     * Get the root XML node, if there isn't one, create it.
     */
    protected static function getXMLRoot(){
        if(empty(self::$xml)) {
            self::init();
        }
        return self::$xml;
    }
}
