<?php
/**
 * Content handler for wiki text pages.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @since 1.21
 *
 * @file
 * @ingroup Content
 */

use MediaWiki\MediaWikiServices;

/**
 * Content handler for wiki text pages.
 *
 * @ingroup Content
 */
class WikitextContentHandler extends TextContentHandler {

	public function __construct( $modelId = CONTENT_MODEL_WIKITEXT ) {
		parent::__construct( $modelId, [ CONTENT_FORMAT_WIKITEXT ] );
	}

	protected function getContentClass() {
		return WikitextContent::class;
	}

	/**
	 * Returns a WikitextContent object representing a redirect to the given destination page.
	 *
	 * @param Title $destination The page to redirect to.
	 * @param string $text Text to include in the redirect, if possible.
	 *
	 * @return Content
	 *
	 * @see ContentHandler::makeRedirectContent
	 */
	public function makeRedirectContent( Title $destination, $text = '' ) {
		$optionalColon = '';

		if ( $destination->getNamespace() == NS_CATEGORY ) {
			$optionalColon = ':';
		} else {
			$iw = $destination->getInterwiki();
			if ( $iw && Language::fetchLanguageName( $iw, null, 'mw' ) ) {
				$optionalColon = ':';
			}
		}

		$mwRedir = MediaWikiServices::getInstance()->getMagicWordFactory()->get( 'redirect' );
		$redirectText = $mwRedir->getSynonym( 0 ) .
			' [[' . $optionalColon . $destination->getFullText() . ']]';

		if ( $text != '' ) {
			$redirectText .= "\n" . $text;
		}

		$class = $this->getContentClass();
		return new $class( $redirectText );
	}

	/**
	 * Returns true because wikitext supports redirects.
	 *
	 * @return bool Always true.
	 *
	 * @see ContentHandler::supportsRedirects
	 */
	public function supportsRedirects() {
		return true;
	}

	/**
	 * Returns true because wikitext supports sections.
	 *
	 * @return bool Always true.
	 *
	 * @see ContentHandler::supportsSections
	 */
	public function supportsSections() {
		return true;
	}

	/**
	 * Returns true, because wikitext supports caching using the
	 * ParserCache mechanism.
	 *
	 * @since 1.21
	 *
	 * @return bool Always true.
	 *
	 * @see ContentHandler::isParserCacheSupported
	 */
	public function isParserCacheSupported() {
		return true;
	}

	/**
	 * Get file handler
	 * @return FileContentHandler
	 */
	protected function getFileHandler() {
		return new FileContentHandler();
	}

	public function getFieldsForSearchIndex( SearchEngine $engine ) {
		$fields = parent::getFieldsForSearchIndex( $engine );

		$fields['heading'] =
			$engine->makeSearchFieldMapping( 'heading', SearchIndexField::INDEX_TYPE_TEXT );
		$fields['heading']->setFlag( SearchIndexField::FLAG_SCORING );

		$fields['auxiliary_text'] =
			$engine->makeSearchFieldMapping( 'auxiliary_text', SearchIndexField::INDEX_TYPE_TEXT );

		$fields['opening_text'] =
			$engine->makeSearchFieldMapping( 'opening_text', SearchIndexField::INDEX_TYPE_TEXT );
		$fields['opening_text']->setFlag(
			SearchIndexField::FLAG_SCORING | SearchIndexField::FLAG_NO_HIGHLIGHT
		);
		// Until we have full first-class content handler for files, we invoke it explicitly here
		$fields = array_merge( $fields, $this->getFileHandler()->getFieldsForSearchIndex( $engine ) );

		return $fields;
	}

	public function getDataForSearchIndex(
		WikiPage $page,
		ParserOutput $parserOutput,
		SearchEngine $engine
	) {
		$fields = parent::getDataForSearchIndex( $page, $parserOutput, $engine );

		$structure = new WikiTextStructure( $parserOutput );
		$fields['heading'] = $structure->headings();
		// text fields
		$fields['opening_text'] = $structure->getOpeningText();
		$fields['text'] = $structure->getMainText(); // overwrites one from ContentHandler
		$fields['auxiliary_text'] = $structure->getAuxiliaryText();
		$fields['defaultsort'] = $structure->getDefaultSort();

		// Until we have full first-class content handler for files, we invoke it explicitly here
		if ( NS_FILE == $page->getTitle()->getNamespace() ) {
			$fields = array_merge( $fields,
					$this->getFileHandler()->getDataForSearchIndex( $page, $parserOutput, $engine ) );
		}
		return $fields;
	}

	/**
	 * Returns the content's text as-is.
	 *
	 * @param Content $content
	 * @param string|null $format The serialization format to check
	 *
	 * @return mixed
	 */
	public function serializeContent( Content $content, $format = null ) {
		$this->checkFormat( $format );

		// NOTE: MessageContent also uses CONTENT_MODEL_WIKITEXT, but it's not a TextContent!
		// Perhaps MessageContent should use a separate ContentHandler instead.
		if ( $content instanceof MessageContent ) {
			return $content->getMessage()->plain();
		}

		return parent::serializeContent( $content, $format );
	}

}
