<?php

namespace MediaWiki\Extension\DiscussionTools;

use DOMElement;
use HtmlFormatter\HtmlFormatter;

class CommentFormatter extends HtmlFormatter {

	public function addReplyLinks() {
		// The output of this method can end up in the HTTP cache (Varnish). Avoid changing it;
		// and when doing so, ensure that frontend code can handle both the old and new outputs.
		// See controller#init in JS.

		$doc = $this->getDoc();
		$container = $doc->documentElement->firstChild;
		if ( !( $container instanceof DOMElement ) ) {
			return;
		}

		$parser = CommentParser::newFromGlobalState( $container );
		$threadItems = $parser->getThreadItems();

		foreach ( $threadItems as $threadItem ) {
			// TODO: Consider not attaching JSON data to the DOM.
			// Create a dummy node to attach data to.
			if ( $threadItem instanceof HeadingItem && $threadItem->isPlaceholderHeading() ) {
				$node = $doc->createElement( 'span' );
				$container->firstChild->insertBefore( $node, $container->firstChild->firstChild );
				$threadItem->setRange( new ImmutableRange( $node, 0, $node, 0 ) );
			}

			$id = $threadItem->getId();
			if ( $id ) {
				$range = $threadItem->getRange();
				$startMarker = $doc->createElement( 'span' );
				$startMarker->setAttribute( 'data-mw-comment-start', $id );
				$endMarker = $doc->createElement( 'span' );
				$endMarker->setAttribute( 'data-mw-comment-end', $id );
				$range->setStart( $range->endContainer, $range->endOffset )->insertNode( $endMarker );
				$range->insertNode( $startMarker );
			}

			$itemData = $threadItem->jsonSerialize();
			$itemJSON = json_encode( $itemData );

			if ( $threadItem instanceof HeadingItem ) {
				$threadItem->getRange()->endContainer->setAttribute( 'data-mw-comment', $itemJSON );
			} elseif ( $threadItem instanceof CommentItem ) {
				$replyLinkButtons = $doc->createElement( 'span' );
				$replyLinkButtons->setAttribute( 'class', 'dt-init-replylink-buttons' );

				// Reply
				$replyLink = $doc->createElement( 'a' );
				$replyLink->setAttribute( 'class', 'dt-init-replylink-reply' );
				$replyLink->setAttribute( 'role', 'button' );
				$replyLink->setAttribute( 'tabindex', '0' );
				$replyLink->setAttribute( 'data-mw-comment', $itemJSON );
				$replyLink->nodeValue = wfMessage( 'discussiontools-replylink' );

				$bracket = $doc->createElement( 'span' );
				$bracket->setAttribute( 'class', 'dt-init-replylink-bracket' );
				$bracketLeft = $bracket->cloneNode( false );
				$bracketLeft->nodeValue = '[';
				$bracketRight = $bracket->cloneNode( false );
				$bracketRight->nodeValue = ']';

				$replyLinkButtons->appendChild( $bracketLeft );
				$replyLinkButtons->appendChild( $replyLink );
				$replyLinkButtons->appendChild( $bracketRight );

				CommentModifier::addReplyLink( $threadItem, $replyLinkButtons );
			}
		}
	}

}