<?php

namespace Modules\Core\Localization;

use Closure;
use Illuminate\Http\Request;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\App;
use Illuminate\Support\Facades\Cache;
use Lunar\Models\Language;
use Symfony\Component\HttpFoundation\Response;

class LocaleMiddleware
{
    private const CACHE_KEY = 'core.localization.languages';

    public function handle(Request $request, Closure $next): Response
    {
        $languages = $this->availableLanguages();

        if ($languages->isEmpty()) {
            return $next($request);
        }

        $segment = (string) $request->segment(1);
        $language = $languages->firstWhere('code', $segment);

        if (! $language) {
            return $this->redirectToLocalizedUrl($request, $languages);
        }

        App::setLocale($language->code);
        $request->attributes->set('locale', $language->code);
        $request->attributes->set('language', $language);

        return $next($request);
    }

    public static function forgetLanguagesCache(): void
    {
        Cache::forget(self::CACHE_KEY);
    }

    private function redirectToLocalizedUrl(Request $request, Collection $languages): Response
    {
        $locale = $this->negotiateLocale($request, $languages);

        $path = trim($request->getPathInfo(), '/');
        $target = '/'.$locale.($path !== '' ? '/'.$path : '');

        $query = $request->getQueryString();
        if ($query) {
            $target .= '?'.$query;
        }

        return redirect($target);
    }

    private function negotiateLocale(Request $request, Collection $languages): string
    {
        $preferred = $request->getPreferredLanguage($languages->pluck('code')->all());

        if ($preferred) {
            return $preferred;
        }

        return $languages->firstWhere('default', true)?->code
            ?? $languages->first()->code;
    }

    private function availableLanguages(): Collection
    {
        return Cache::rememberForever(
            self::CACHE_KEY,
            fn () => Language::query()->get(['id', 'code', 'name', 'default']),
        );
    }
}