<?php
/**
* @package s9e\TextFormatter
* @copyright Copyright (c) 2010-2021 The s9e authors
* @license http://www.opensource.org/licenses/mit-license.php The MIT License
*/
namespace s9e\TextFormatter\Plugins\MediaEmbed;
use s9e\TextFormatter\Parser as TagStack;
use s9e\TextFormatter\Parser\Tag;
use s9e\TextFormatter\Plugins\ParserBase;
use s9e\TextFormatter\Utils\Http;
class Parser extends ParserBase
{
/**
* @var \s9e\TextFormatter\Utils\Http\Client Client used to perform HTTP request
*/
protected static $client;
/**
* @var string|null Cache dir used by cached client
*/
protected static $clientCacheDir;
/**
* {@inheritdoc}
*/
public function parse($text, array $matches)
{
foreach ($matches as $m)
{
$tagName = $this->config['tagName'];
$url = $m[0][0];
$pos = $m[0][1];
$len = strlen($url);
// Give that tag priority over other tags such as Autolink's
$this->parser->addSelfClosingTag($tagName, $pos, $len, -10)->setAttribute('url', $url);
}
}
/**
* Filter a MEDIA tag
*
* This will always invalidate the original tag, and possibly replace it with the tag that
* corresponds to the media site
*
* @param Tag $tag The original tag
* @param TagStack $tagStack Parser instance, so that we can add the new tag to the stack
* @param array $hosts Map of [hostname => siteId]
* @param array $sites Map of [siteId => siteConfig]
* @param string|null $cacheDir Path to the cache directory
* @return void
*/
public static function filterTag(Tag $tag, TagStack $tagStack, array $hosts, array $sites, $cacheDir)
{
// Always invalidate this tag
$tag->invalidate();
if ($tag->hasAttribute('url'))
{
$url = $tag->getAttribute('url');
$siteId = self::getSiteIdFromUrl($url, $hosts);
if (isset($sites[$siteId]))
{
$attributes = self::getAttributes($url, $sites[$siteId], $cacheDir);
if (!empty($attributes))
{
self::createTag(strtoupper($siteId), $tagStack, $tag)->setAttributes($attributes);
}
}
}
}
/**
* Add named captures from a set of regular expressions to a set of attributes
*
* @param array &$attributes Associative array of strings
* @param string $string Text to match
* @param array[] $regexps List of [regexp, map] pairs
* @return bool Whether any regexp matched
*/
protected static function addNamedCaptures(array &$attributes, $string, array $regexps)
{
$matched = 0;
foreach ($regexps as list($regexp, $map))
{
$matched += preg_match($regexp, $string, $m);
foreach ($map as $i => $name)
{
if (isset($m[$i]) && $m[$i] !== '' && $name !== '')
{
$attributes[$name] = $m[$i];
}
}
}
return (bool) $matched;
}
/**
* Create a tag for a media embed
*
* @param string $tagName Tag's name
* @param TagStack $tagStack
* @param Tag $tag Reference tag
* @return Tag New tag
*/
protected static function createTag($tagName, TagStack $tagStack, Tag $tag)
{
$startPos = $tag->getPos();
$endTag = $tag->getEndTag();
if ($endTag)
{
$startLen = $tag->getLen();
$endPos = $endTag->getPos();
$endLen = $endTag->getLen();
}
else
{
$startLen = 0;
$endPos = $tag->getPos() + $tag->getLen();
$endLen = 0;
}
return $tagStack->addTagPair($tagName, $startPos, $startLen, $endPos, $endLen, $tag->getSortPriority());
}
/**
* Return a set of attributes for given URL based on a site's config
*
* @param string $url Original URL
* @param array $config Site config
* @param string|null $cacheDir Path to the cache directory
* @return array Associative array of attributes
*/
protected static function getAttributes($url, array $config, $cacheDir)
{
$attributes = [];
self::addNamedCaptures($attributes, $url, $config[0]);
foreach ($config[1] as $scrapeConfig)
{
self::scrape($attributes, $url, $scrapeConfig, $cacheDir);
}
return $attributes;
}
/**
* Return a cached instance of the HTTP client
*
* @param string|null $cacheDir
* @return \s9e\TextFormatter\Utils\Http\Client
*/
protected static function getHttpClient($cacheDir)
{
if (!isset(self::$client) || self::$clientCacheDir !== $cacheDir)
{
self::$client = (isset($cacheDir)) ? Http::getCachingClient($cacheDir) : Http::getClient();
self::$clientCacheDir = $cacheDir;
}
return self::$client;
}
/**
* Return the siteId that corresponds to given URL
*
* @param string $url Original URL
* @param array $hosts Map of [hostname => siteId]
* @return string URL's siteId, or an empty string
*/
protected static function getSiteIdFromUrl($url, array $hosts)
{
$host = (preg_match('(^https?://([^/]+))', strtolower($url), $m)) ? $m[1] : '';
while ($host > '')
{
if (isset($hosts[$host]))
{
return $hosts[$host];
}
$host = preg_replace('(^[^.]*.)', '', $host);
}
return '';
}
/**
* Interpolate {@vars} in given string
*
* @param string $str Original string
* @param array $vars Associative array
* @return string Interpolated string
*/
protected static function interpolateVars($str, array $vars)
{
return preg_replace_callback(
'(\\{@(\\w+)\\})',
function ($m) use ($vars)
{
return $vars[$m[1]] ?? '';
},
$str
);
}
/**
* Scrape values and add them to current attributes
*
* @param array &$attributes Attributes
* @param string $url Original URL
* @param array $config Scraping config
* @param string|null $cacheDir Path to the cache directory
* @return void
*/
protected static function scrape(array &$attributes, $url, array $config, $cacheDir)
{
$vars = [];
if (self::addNamedCaptures($vars, $url, $config['match']))
{
if (isset($config['url']))
{
$url = self::interpolateVars($config['url'], $vars + $attributes);
}
if (preg_match('(^https?://[^#]+)i', $url, $m))
{
$response = self::wget($m[0], $cacheDir, $config);
self::addNamedCaptures($attributes, $response, $config['extract']);
}
}
}
/**
* Retrieve external content
*
* @param string $url URL
* @param string|null $cacheDir Path to the cache directory
* @param array $config Scraping config
* @return string Response body
*/
protected static function wget($url, $cacheDir, $config)
{
$options = [
'headers' => (isset($config['header'])) ? (array) $config['header'] : [],
'returnHeaders' => true
];
return @self::getHttpClient($cacheDir)->get($url, $options);
}
}