<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;

class LicenseCheck
{
    public function handle(Request $request, Closure $next)
    {
        $domain = $this->parseDomain($request->getHost());

        $cacheKey      = 'lic_ok_'   . md5($domain);
        $graceKey      = 'lic_grace_' . md5($domain);
        $cacheHours    = config('license.cache_hours', 24);
        $graceHours    = config('license.grace_hours', 72);

        /* 1. Serve from cache if still fresh */
        if (Cache::has($cacheKey)) {
            return $next($request);
        }

        /* 2. Call license server */
        $valid = $this->callServer($domain);

        if ($valid) {
            Cache::put($cacheKey, true, now()->addHours($cacheHours));
            Cache::put($graceKey, true, now()->addHours($graceHours));
            return $next($request);
        }

        /* 3. License server returned invalid — but allow grace window */
        if (Cache::has($graceKey)) {
            Log::warning("License invalid for [{$domain}] — running on grace period.");
            return $next($request);
        }

        /* 4. No grace — block */
        return response()->view('license.invalid', ['domain' => $domain], 403);
    }

    private function parseDomain(string $host): string
    {
        $domain = strtolower(trim($host));
        $domain = preg_replace('/^www\./i', '', $domain);
        return explode(':', $domain)[0];
    }

    private function callServer(string $domain): bool
    {
        try {
            $response = Http::timeout(8)->get(config('license.server_url'), [
                'secret' => config('license.secret'),
                'domain' => $domain,
            ]);

            if ($response->successful()) {
                return (bool) ($response->json('valid') ?? false);
            }
        } catch (\Exception $e) {
            Log::error("License server unreachable for [{$domain}]: " . $e->getMessage());
        }

        return false;
    }
}