<?php
/**
 * Search engine result
 *
 * 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
 *
 * @file
 * @ingroup Search
 */

use MediaWiki\MediaWikiServices;

/**
 * @todo FIXME: This class is horribly factored. It would probably be better to
 * have a useful base class to which you pass some standard information, then
 * let the fancy self-highlighters extend that.
 * @ingroup Search
 */
class SearchResult {

	/**
	 * @var Revision
	 */
	protected $mRevision = null;

	/**
	 * @var File
	 */
	protected $mImage = null;

	/**
	 * @var Title
	 */
	protected $mTitle;

	/**
	 * @var string
	 */
	protected $mText;

	/**
	 * @var SearchEngine
	 */
	protected $searchEngine;

	/**
	 * A function returning a set of extension data.
	 * @var Closure|null
	 */
	protected $extensionData;

	/**
	 * Return a new SearchResult and initializes it with a title.
	 *
	 * @param Title $title
	 * @param SearchResultSet $parentSet
	 * @return SearchResult
	 */
	public static function newFromTitle( $title, SearchResultSet $parentSet = null ) {
		$result = new static();
		$result->initFromTitle( $title );
		if ( $parentSet ) {
			$parentSet->augmentResult( $result );
		}
		return $result;
	}

	/**
	 * Initialize from a Title and if possible initializes a corresponding
	 * Revision and File.
	 *
	 * @param Title $title
	 */
	protected function initFromTitle( $title ) {
		$this->mTitle = $title;
		if ( !is_null( $this->mTitle ) ) {
			$id = false;
			Hooks::run( 'SearchResultInitFromTitle', [ $title, &$id ] );
			$this->mRevision = Revision::newFromTitle(
				$this->mTitle, $id, Revision::READ_NORMAL );
			if ( $this->mTitle->getNamespace() === NS_FILE ) {
				$this->mImage = wfFindFile( $this->mTitle );
			}
		}
		$this->searchEngine = MediaWikiServices::getInstance()->newSearchEngine();
	}

	/**
	 * Check if this is result points to an invalid title
	 *
	 * @return bool
	 */
	function isBrokenTitle() {
		return is_null( $this->mTitle );
	}

	/**
	 * Check if target page is missing, happens when index is out of date
	 *
	 * @return bool
	 */
	function isMissingRevision() {
		return !$this->mRevision && !$this->mImage;
	}

	/**
	 * @return Title
	 */
	function getTitle() {
		return $this->mTitle;
	}

	/**
	 * Get the file for this page, if one exists
	 * @return File|null
	 */
	function getFile() {
		return $this->mImage;
	}

	/**
	 * Lazy initialization of article text from DB
	 */
	protected function initText() {
		if ( !isset( $this->mText ) ) {
			if ( $this->mRevision != null ) {
				$this->mText = $this->searchEngine->getTextFromContent(
						$this->mTitle, $this->mRevision->getContent() );
			} else { // TODO: can we fetch raw wikitext for commons images?
				$this->mText = '';
			}
		}
	}

	/**
	 * @param array $terms Terms to highlight
	 * @return string Highlighted text snippet, null (and not '') if not supported
	 */
	function getTextSnippet( $terms ) {
		global $wgAdvancedSearchHighlighting;
		$this->initText();

		// TODO: make highliter take a content object. Make ContentHandler a factory for SearchHighliter.
		list( $contextlines, $contextchars ) = $this->searchEngine->userHighlightPrefs();

		$h = new SearchHighlighter();
		if ( count( $terms ) > 0 ) {
			if ( $wgAdvancedSearchHighlighting ) {
				return $h->highlightText( $this->mText, $terms, $contextlines, $contextchars );
			} else {
				return $h->highlightSimple( $this->mText, $terms, $contextlines, $contextchars );
			}
		} else {
			return $h->highlightNone( $this->mText, $contextlines, $contextchars );
		}
	}

	/**
	 * @return string Highlighted title, '' if not supported
	 */
	function getTitleSnippet() {
		return '';
	}

	/**
	 * @return string Highlighted redirect name (redirect to this page), '' if none or not supported
	 */
	function getRedirectSnippet() {
		return '';
	}

	/**
	 * @return Title|null Title object for the redirect to this page, null if none or not supported
	 */
	function getRedirectTitle() {
		return null;
	}

	/**
	 * @return string Highlighted relevant section name, null if none or not supported
	 */
	function getSectionSnippet() {
		return '';
	}

	/**
	 * @return Title|null Title object (pagename+fragment) for the section,
	 *  null if none or not supported
	 */
	function getSectionTitle() {
		return null;
	}

	/**
	 * @return string Highlighted relevant category name or '' if none or not supported
	 */
	public function getCategorySnippet() {
		return '';
	}

	/**
	 * @return string Timestamp
	 */
	function getTimestamp() {
		if ( $this->mRevision ) {
			return $this->mRevision->getTimestamp();
		} elseif ( $this->mImage ) {
			return $this->mImage->getTimestamp();
		}
		return '';
	}

	/**
	 * @return int Number of words
	 */
	function getWordCount() {
		$this->initText();
		return str_word_count( $this->mText );
	}

	/**
	 * @return int Size in bytes
	 */
	function getByteSize() {
		$this->initText();
		return strlen( $this->mText );
	}

	/**
	 * @return string Interwiki prefix of the title (return iw even if title is broken)
	 */
	function getInterwikiPrefix() {
		return '';
	}

	/**
	 * @return string Interwiki namespace of the title (since we likely can't resolve it locally)
	 */
	function getInterwikiNamespaceText() {
		return '';
	}

	/**
	 * Did this match file contents (eg: PDF/DJVU)?
	 * @return bool
	 */
	function isFileMatch() {
		return false;
	}

	/**
	 * Get the extension data as:
	 * augmentor name => data
	 * @return array[]
	 */
	public function getExtensionData() {
		if ( $this->extensionData ) {
			return call_user_func( $this->extensionData );
		} else {
			return [];
		}
	}

	/**
	 * Set extension data for this result.
	 * The data is:
	 * augmentor name => data
	 * @param Closure|array $extensionData Takes no arguments, returns
	 *  either array of extension data or null.
	 */
	public function setExtensionData( $extensionData ) {
		if ( $extensionData instanceof Closure ) {
			$this->extensionData = $extensionData;
		} elseif ( is_array( $extensionData ) ) {
			wfDeprecated( __METHOD__ . ' with array argument', 1.32 );
			$this->extensionData = function () use ( $extensionData ) {
				return $extensionData;
			};
		} else {
			$type = is_object( $extensionData )
				? get_class( $extensionData )
				: gettype( $extensionData );
			throw new \InvalidArgumentException(
				__METHOD__ . " must be called with Closure|array, but received $type" );
		}
	}
}