<?php

namespace App\Services\Wikidata;

use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;

class WikidataClient
{
    protected static string $cachePrefix = 'wikidata';

    public function __construct(protected array $config)
    {
    }

    /**
     * Search for an entity ID for text submitted as $expression
     */
    public function searchEntityId(string $expression)
    {
        $data = [
            'action'   => 'wbsearchentities',
            'search'   => $expression,
            'language' => 'en',
            'limit'    => 10,
            'format'   => 'json',
        ];

        $response = $this->getFromApi($data);
        $items    = [];

        if (!empty($response['search'])) {
            foreach ($response['search'] as $item) {
                $items[$item['id']] = sprintf('[%s] %s (%s)', $item['id'], $item['label'], $item['description'] ?? null);
            }
        }

        return $items;
    }

    /**
     * Return complete set of data related to specified entity
     */
    public function getEntityData(string $entityId)
    {
        $data = [
            'action'    => 'wbgetentities',
            'ids'       => $entityId,
            'languages' => 'fr|en',
            'format'    => 'json',
        ];

        return $this->getFromApi($data);
    }

    /**
     * Return an array containing Wikidata Entities Id as keys and corresponding
     * labels as values
     */
    public function getLabelsForEntities(array $entities)
    {
        $result    = [];
        $batchSize = 50;
        $batches   = array_chunk($entities, $batchSize);

        foreach ($batches as $batch) {
            $ids  = implode('|', $batch);
            $data = [
                'action'    => 'wbgetentities',
                'ids'       => $ids,
                'props'     => 'labels|descriptions',
                'languages' => 'fr|en',
                'format'    => 'json',
            ];

            $result += $this->getFromApi($data)['entities'];
        }

        $labels = [];

        foreach ($result as $id => $entity) {
            if (
                !isset($entity['labels']['fr']['value'])
                && !isset($entity['labels']['en']['value'])
            ) {
                continue;
            }

            $label = $entity['labels']['fr']['value']
                ?? $entity['labels']['en']['value'];

            $description = $entity['descriptions']['fr']['value']
                ?? $entity['descriptions']['en']['value']
                ?? null;

            if ($label) {
                $labels[$id] = Str::ucfirst($label);
            }
        }

        return $labels;
    }

    /**
     * Perform a GET request against wikidata API
     */
    private function getFromApi(array $params)
    {
        $baseUrl  = $this->config['base_api_url'];
        $slug     = Str::slug(http_build_query($params));
        $cacheKey = sprintf('%s_%s', static::$cachePrefix, $slug);

        if (Cache::has($cacheKey)) {
            return Cache::get($cacheKey);
        }

        $response = Http::throw()->get($baseUrl, $params)->json();

        Cache::put($cacheKey, $response, now()->addMonth());

        return $response;
    }
}