<?php
class LWNprevBridge extends BridgeAbstract
{
	const MAINTAINER = 'Pierre Mazière';
	const NAME = 'LWN Free Weekly Edition';
	const URI = 'https://lwn.net/';
	const CACHE_TIMEOUT = 604800; // 1 week
  const DESCRIPTION = 'LWN Free Weekly Edition available one week late';

	public function getURI()
	{
		return self::URI.'free/bigpage';
	}

	private function jumpToNextTag(&$node)
	{
		while ($node && $node->nodeType===XML_TEXT_NODE) {
			$nextNode=$node->nextSibling;
			if (!$nextNode) {
				break;
			}
			$node=$nextNode;
		}
	}

	private function jumpToPreviousTag(&$node)
	{
		while ($node && $node->nodeType===XML_TEXT_NODE) {
			$previousNode=$node->previousSibling;
			if (!$previousNode) {
				break;
			}
			$node=$previousNode;
		}
	}

	public function collectData()
	{
		// Because the LWN page is written in loose HTML and not XHTML,
	// Simple HTML Dom is not accurate enough for the job
	$content=getContents($this->getURI())
	  or returnServerError('No results for LWNprev');

		libxml_use_internal_errors(true);
		$html=new DOMDocument();
		$html->loadHTML($content);
		libxml_clear_errors();

		$cat1='';
		$cat2='';

		foreach ($html->getElementsByTagName('a') as $a) {
			if ($a->textContent==='Multi-page format') {
				break;
			}
		}
		$realURI=self::URI.$a->getAttribute('href');
		$URICounter=0;

		$edition=$html->getElementsByTagName('h1')->item(0)->textContent;
		$editionTimeStamp=strtotime(
	  substr($edition, strpos($edition, 'for ')+strlen('for '))
	);

		foreach ($html->getElementsByTagName('h2') as $h2) {
			if ($h2->getAttribute('class')!=='SummaryHL') {
				continue;
			}

			$item = array();

			$h2NextSibling=$h2->nextSibling;
			$this->jumpToNextTag($h2NextSibling);

			switch ($h2NextSibling->getAttribute('class')) {
	  case 'FeatureByline':
		$item['author']=$h2NextSibling->getElementsByTagName('b')->item(0)->textContent;
		break;
	  case 'GAByline':
		$text=$h2NextSibling->textContent;
		$item['author']=substr($text, strpos($text, 'by '));
		break;
	  default:
		$item['author']='LWN';
		break;
	  };

			$h2FirstChild=$h2->firstChild;
			$this->jumpToNextTag($h2FirstChild);
			if ($h2FirstChild->nodeName==='a') {
				$item['uri']=self::URI.$h2FirstChild->getAttribute('href');
			} else {
				$item['uri']=$realURI.'#'.$URICounter;
			}
			$URICounter++;

			$item['timestamp']=$editionTimeStamp+$URICounter;

			$h2PrevSibling=$h2->previousSibling;
			$this->jumpToPreviousTag($h2PrevSibling);
			switch ($h2PrevSibling->getAttribute('class')) {
	  case 'Cat2HL':
		$cat2=$h2PrevSibling->textContent;
		$h2PrevSibling=$h2PrevSibling->previousSibling;
		$this->jumpToPreviousTag($h2PrevSibling);
		if ($h2PrevSibling->getAttribute('class')!=='Cat1HL') {
			break;
		}
		$cat1=$h2PrevSibling->textContent;
		break;
	  case 'Cat1HL':
		$cat1=$h2PrevSibling->textContent;
		$cat2='';
		break;
	  default:
		break;
	  }
			$h2PrevSibling=null;

			$item['title']='';
			if (!empty($cat1)) {
				$item['title'].='['.$cat1.($cat2?'/'.$cat2:'').'] ';
			}
			$item['title'].=$h2->textContent;

			$node=$h2;
			$content='';
			$contentEnd=false;
			while (!$contentEnd) {
				$node=$node->nextSibling;
				if (
		  !$node || (
			$node->nodeType!==XML_TEXT_NODE && (
			  $node->nodeName==='h2' ||
			  (!is_null($node->attributes) && !is_null($class=$node->attributes->getNamedItem('class')) &&
			  in_array($class->nodeValue, array('Cat1HL','Cat2HL')))
			)
		  )
		) {
					$contentEnd=true;
				} else {
					$content.=$node->C14N();
				}
			}
			$item['content']=$content;
			$this->items[]=$item;
		}
	}
}