<?php

final class GeocodeService
{
    /**
     * Géocodage via Nominatim (OpenStreetMap)
     * Retour: ['lat'=>float, 'lng'=>float, 'display_name'=>string] ou null
     *
     * IMPORTANT:
     * - Respecte le fair use : pas de spam (cache côté DB chez toi, et TTL)
     * - User-Agent explicite
     */
    public static function geocode(string $query): ?array
    {
        $query = trim($query);
        if ($query === '') {
            return null;
        }

        // Nominatim conseille d'envoyer un UA + un contact
        $email = getenv('GEOCODER_EMAIL') ?: 'contact@localhost';
        $ua = 'TwixRefuge/1.0 (geocoding; contact: ' . $email . ')';

        $url =
            'https://nominatim.openstreetmap.org/search?format=jsonv2&limit=1&addressdetails=0&q=' .
            rawurlencode($query);

        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT => 12,
            CURLOPT_CONNECTTIMEOUT => 6,
            CURLOPT_HTTPHEADER => ['User-Agent: ' . $ua, 'Accept: application/json'],
            CURLOPT_ENCODING => '', // gzip/br si dispo
        ]);

        $body = curl_exec($ch);
        if ($body === false) {
            curl_close($ch);
            return null;
        }

        $status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($status < 200 || $status >= 300) {
            return null;
        }

        $json = json_decode($body, true);
        if (!is_array($json) || empty($json[0])) {
            return null;
        }

        $item = $json[0];

        $lat = isset($item['lat']) ? (float) $item['lat'] : null;
        $lng = isset($item['lon']) ? (float) $item['lon'] : null;
        if ($lat === null || $lng === null) {
            return null;
        }

        return [
            'lat' => $lat,
            'lng' => $lng,
            'display_name' => (string) ($item['display_name'] ?? ''),
        ];
    }
}