<?php

declare(strict_types=1);

namespace App\Chatbot\Search;

use App\Repository\ContentDocumentRepository;

/**
 * Full-text search over the mirrored website content.
 *
 * Ranked by relevance, weighted by type in the order people need them: what they book
 * (products, hotels), where they go (destinations, concepts), general pages, then blog
 * posts. The weights are multipliers on the relevance score, so a much better match of a
 * lower type still wins.
 */
class ContentSearch
{
    /**
     * The tool's `type` values. `destination` covers region, country and city.
     */
    public const TYPES = [
        'page' => ['page'],
        'product' => ['product'],
        'hotel' => ['hotel'],
        'destination' => ['region', 'country', 'city'],
        'concept' => ['concept'],
        'news' => ['news'],
    ];

    private const TYPE_WEIGHTS = [
        'product' => 1.4,
        'hotel' => 1.4,
        'region' => 1.2,
        'country' => 1.2,
        'city' => 1.2,
        'concept' => 1.2,
        'page' => 1.0,
        'news' => 0.8,
    ];

    public function __construct(private readonly ContentDocumentRepository $repository)
    {
    }

    /**
     * @param string|null $type a key of TYPES
     *
     * @return list<array{type: string, title: string, url: string, site: ?string, breadcrumb: ?string, excerpt: string}>
     */
    public function search(string $query, ?string $type, ?string $site, int $limit): array
    {
        $booleanQuery = ContentSearchQuery::booleanQuery($query);

        if (null === $booleanQuery) {
            return [];
        }

        $rows = $this->repository->searchFulltext($booleanQuery, null === $type ? [] : self::TYPES[$type], $site, self::TYPE_WEIGHTS, $limit);
        $terms = ContentSearchQuery::terms($query);

        return array_map(static fn (array $row): array => [
            'type' => self::publicType($row['type']),
            'title' => $row['title'],
            'url' => $row['url'],
            'site' => $row['site'],
            'breadcrumb' => $row['breadcrumb'],
            'excerpt' => Excerpt::around($row['body_md'], $terms),
        ], $rows);
    }

    /**
     * The tool's name for a stored type.
     */
    public static function publicType(string $type): string
    {
        foreach (self::TYPES as $public => $types) {
            if (in_array($type, $types, true)) {
                return $public;
            }
        }

        return $type;
    }
}