<?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\Util;

use Symfony\Component\Config\Util\Exception\InvalidXmlException;
use Symfony\Component\Config\Util\Exception\XmlParsingException;

/**
 * XMLUtils is a bunch of utility methods to XML operations.
 *
 * This class contains static methods only and is not meant to be instantiated.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 * @author Martin Hasoň <martin.hason@gmail.com>
 * @author Ole Rößner <ole@roessner.it>
 */
class XmlUtils
{
    /**
     * This class should not be instantiated.
     */
    private function __construct()
    {
    }

    /**
     * Parses an XML string.
     *
     * @param string               $content          An XML string
     * @param string|callable|null $schemaOrCallable An XSD schema file path, a callable, or null to disable validation
     *
     * @return \DOMDocument
     *
     * @throws XmlParsingException When parsing of XML file returns error
     * @throws InvalidXmlException When parsing of XML with schema or callable produces any errors unrelated to the XML parsing itself
     * @throws \RuntimeException   When DOM extension is missing
     */
    public static function parse(string $content, $schemaOrCallable = null)
    {
        if (!\extension_loaded('dom')) {
            throw new \LogicException('Extension DOM is required.');
        }

        $internalErrors = libxml_use_internal_errors(true);
        if (\LIBXML_VERSION < 20900) {
            $disableEntities = libxml_disable_entity_loader(true);
        }
        libxml_clear_errors();

        $dom = new \DOMDocument();
        $dom->validateOnParse = true;
        if (!$dom->loadXML($content, \LIBXML_NONET | (\defined('LIBXML_COMPACT') ? \LIBXML_COMPACT : 0))) {
            if (\LIBXML_VERSION < 20900) {
                libxml_disable_entity_loader($disableEntities);
            }

            throw new XmlParsingException(implode("\n", static::getXmlErrors($internalErrors)));
        }

        $dom->normalizeDocument();

        libxml_use_internal_errors($internalErrors);
        if (\LIBXML_VERSION < 20900) {
            libxml_disable_entity_loader($disableEntities);
        }

        foreach ($dom->childNodes as $child) {
            if (\XML_DOCUMENT_TYPE_NODE === $child->nodeType) {
                throw new XmlParsingException('Document types are not allowed.');
            }
        }

        if (null !== $schemaOrCallable) {
            $internalErrors = libxml_use_internal_errors(true);
            libxml_clear_errors();

            $e = null;
            if (\is_callable($schemaOrCallable)) {
                try {
                    $valid = $schemaOrCallable($dom, $internalErrors);
                } catch (\Exception $e) {
                    $valid = false;
                }
            } elseif (!\is_array($schemaOrCallable) && is_file((string) $schemaOrCallable)) {
                $schemaSource = file_get_contents((string) $schemaOrCallable);
                $valid = @$dom->schemaValidateSource($schemaSource);
            } else {
                libxml_use_internal_errors($internalErrors);

                throw new XmlParsingException('The schemaOrCallable argument has to be a valid path to XSD file or callable.');
            }

            if (!$valid) {
                $messages = static::getXmlErrors($internalErrors);
                if (empty($messages)) {
                    throw new InvalidXmlException('The XML is not valid.', 0, $e);
                }
                throw new XmlParsingException(implode("\n", $messages), 0, $e);
            }
        }

        libxml_clear_errors();
        libxml_use_internal_errors($internalErrors);

        return $dom;
    }

    /**
     * Loads an XML file.
     *
     * @param string               $file             An XML file path
     * @param string|callable|null $schemaOrCallable An XSD schema file path, a callable, or null to disable validation
     *
     * @return \DOMDocument
     *
     * @throws \InvalidArgumentException When loading of XML file returns error
     * @throws XmlParsingException       When XML parsing returns any errors
     * @throws \RuntimeException         When DOM extension is missing
     */
    public static function loadFile(string $file, $schemaOrCallable = null)
    {
        if (!is_file($file)) {
            throw new \InvalidArgumentException(sprintf('Resource "%s" is not a file.', $file));
        }

        if (!is_readable($file)) {
            throw new \InvalidArgumentException(sprintf('File "%s" is not readable.', $file));
        }

        $content = @file_get_contents($file);

        if ('' === trim($content)) {
            throw new \InvalidArgumentException(sprintf('File "%s" does not contain valid XML, it is empty.', $file));
        }

        try {
            return static::parse($content, $schemaOrCallable);
        } catch (InvalidXmlException $e) {
            throw new XmlParsingException(sprintf('The XML file "%s" is not valid.', $file), 0, $e->getPrevious());
        }
    }

    /**
     * Converts a \DOMElement object to a PHP array.
     *
     * The following rules applies during the conversion:
     *
     *  * Each tag is converted to a key value or an array
     *    if there is more than one "value"
     *
     *  * The content of a tag is set under a "value" key (<foo>bar</foo>)
     *    if the tag also has some nested tags
     *
     *  * The attributes are converted to keys (<foo foo="bar"/>)
     *
     *  * The nested-tags are converted to keys (<foo><foo>bar</foo></foo>)
     *
     * @param \DOMElement $element     A \DOMElement instance
     * @param bool        $checkPrefix Check prefix in an element or an attribute name
     *
     * @return mixed
     */
    public static function convertDomElementToArray(\DOMElement $element, bool $checkPrefix = true)
    {
        $prefix = (string) $element->prefix;
        $empty = true;
        $config = [];
        foreach ($element->attributes as $name => $node) {
            if ($checkPrefix && !\in_array((string) $node->prefix, ['', $prefix], true)) {
                continue;
            }
            $config[$name] = static::phpize($node->value);
            $empty = false;
        }

        $nodeValue = false;
        foreach ($element->childNodes as $node) {
            if ($node instanceof \DOMText) {
                if ('' !== trim($node->nodeValue)) {
                    $nodeValue = trim($node->nodeValue);
                    $empty = false;
                }
            } elseif ($checkPrefix && $prefix != (string) $node->prefix) {
                continue;
            } elseif (!$node instanceof \DOMComment) {
                $value = static::convertDomElementToArray($node, $checkPrefix);

                $key = $node->localName;
                if (isset($config[$key])) {
                    if (!\is_array($config[$key]) || !\is_int(key($config[$key]))) {
                        $config[$key] = [$config[$key]];
                    }
                    $config[$key][] = $value;
                } else {
                    $config[$key] = $value;
                }

                $empty = false;
            }
        }

        if (false !== $nodeValue) {
            $value = static::phpize($nodeValue);
            if (\count($config)) {
                $config['value'] = $value;
            } else {
                $config = $value;
            }
        }

        return !$empty ? $config : null;
    }

    /**
     * Converts an xml value to a PHP type.
     *
     * @param mixed $value
     *
     * @return mixed
     */
    public static function phpize($value)
    {
        $value = (string) $value;
        $lowercaseValue = strtolower($value);

        switch (true) {
            case 'null' === $lowercaseValue:
                return null;
            case ctype_digit($value):
            case isset($value[1]) && '-' === $value[0] && ctype_digit(substr($value, 1)):
                $raw = $value;
                $cast = (int) $value;

                return self::isOctal($value) ? \intval($value, 8) : (($raw === (string) $cast) ? $cast : $raw);
            case 'true' === $lowercaseValue:
                return true;
            case 'false' === $lowercaseValue:
                return false;
            case isset($value[1]) && '0b' == $value[0].$value[1] && preg_match('/^0b[01]*$/', $value):
                return bindec($value);
            case is_numeric($value):
                return '0x' === $value[0].$value[1] ? hexdec($value) : (float) $value;
            case preg_match('/^0x[0-9a-f]++$/i', $value):
                return hexdec($value);
            case preg_match('/^[+-]?[0-9]+(\.[0-9]+)?$/', $value):
                return (float) $value;
            default:
                return $value;
        }
    }

    protected static function getXmlErrors(bool $internalErrors)
    {
        $errors = [];
        foreach (libxml_get_errors() as $error) {
            $errors[] = sprintf('[%s %s] %s (in %s - line %d, column %d)',
                \LIBXML_ERR_WARNING == $error->level ? 'WARNING' : 'ERROR',
                $error->code,
                trim($error->message),
                $error->file ?: 'n/a',
                $error->line,
                $error->column
            );
        }

        libxml_clear_errors();
        libxml_use_internal_errors($internalErrors);

        return $errors;
    }

    private static function isOctal(string $str): bool
    {
        if ('-' === $str[0]) {
            $str = substr($str, 1);
        }

        return $str === '0'.decoct(\intval($str, 8));
    }
}
