wikimedia/mediawiki-extensions-CirrusSearch

<?php

namespace CirrusSearch\Fallbacks;

use CirrusSearch\Search\CirrusSearchResultSet;
use Closure;
use HtmlArmor;

/**
 * Representation of the result of running a FallbackMethod.
 *
 * Describes the change that the method has decided to apply to the search
 * result set. This primarily allows wrapping the changes into atomic units
 * of execution so the execution trace can be logged.
 */
class FallbackStatus {
    public const NO_ACTION = 'noSuggestion';
    public const ACTION_SUGGEST_QUERY = 'suggestQuery';
    public const ACTION_REPLACE_LOCAL_RESULTS = 'replaceLocalResults';
    public const ACTION_ADD_INTERWIKI_RESULTS = 'addInterwikiResults';

    /** @var string */
    private $actionName;

    /** @var Closure */
    private $fn;

    /**
     * @param string $actionName An ACTION_* class constant, or NO_ACTION. Describes the action
     *  to perform.
     * @param Closure $fn Function accepting a CirrusSearchResultSet and returning a CirrusSearchResultSet.
     *  Called to apply the chosen action to an existing result set. Implementations may return
     *  the provided result set, or a completely different one if desired.
     */
    private function __construct( string $actionName, Closure $fn ) {
        $this->actionName = $actionName;
        $this->fn = $fn;
    }

    public function apply( CirrusSearchResultSet $currentSet ): CirrusSearchResultSet {
        $fn = $this->fn;
        return $fn( $currentSet );
    }

    /**
     * @return string The fallback action to perform
     */
    public function getAction(): string {
        return $this->actionName;
    }

    /**
     * @param string $query
     * @param HtmlArmor|string|null $snippet
     * @return FallbackStatus
     */
    public static function suggestQuery( string $query, $snippet = null ): FallbackStatus {
        return new self( self::ACTION_SUGGEST_QUERY, static function ( CirrusSearchResultSet $currentSet ) use ( $query, $snippet ) {
            $currentSet->setSuggestionQuery( $query, $snippet );
            return $currentSet;
        } );
    }

    /**
     * @param CirrusSearchResultSet $rewrittenResults New result set to replace existing results with
     * @param string $query The search query performed in the new result set.
     * @param HtmlArmor|string|null $snippet A highlighted snippet showing the changes in $query.
     * @return FallbackStatus
     */
    public static function replaceLocalResults( CirrusSearchResultSet $rewrittenResults, string $query, $snippet = null ): FallbackStatus {
        return new self(
            self::ACTION_REPLACE_LOCAL_RESULTS,
            static function ( CirrusSearchResultSet $currentSet ) use ( $rewrittenResults, $query, $snippet ) {
                $rewrittenResults->setRewrittenQuery( $query, $snippet );
                return $rewrittenResults;
            } );
    }

    /**
     * @param CirrusSearchResultSet $results Interwiki results to add to current result set
     * @param string $wikiId The wiki these results come from
     * @return FallbackStatus
     */
    public static function addInterwikiResults( CirrusSearchResultSet $results, string $wikiId ): FallbackStatus {
        return new self( self::ACTION_ADD_INTERWIKI_RESULTS, static function (
            CirrusSearchResultSet $currentSet
        ) use ( $results, $wikiId ) {
            $currentSet->addInterwikiResults( $results, \SearchResultSet::INLINE_RESULTS, $wikiId );
            return $currentSet;
        } );
    }

    public static function noSuggestion(): FallbackStatus {
        return new self( self::NO_ACTION, static function ( CirrusSearchResultSet $currentSet ) {
            return $currentSet;
        } );
    }
}