<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Cache\RateLimiter;
use Illuminate\Http\Exceptions\ThrottleRequestsException;
use Symfony\Component\HttpFoundation\Response;

class ApiThrottle
{
    protected $limiter;

    public function __construct(RateLimiter $limiter)
    {
        $this->limiter = $limiter;
    }

    public function handle($request, Closure $next, $maxAttempts = 80, $decayMinutes = 1)
    {
        // Get the real client IP, considering proxy headers
        $clientIp = $request->ip();
        
        $key = $this->resolveRequestSignature($request, $clientIp);
        
        $currentAttempts = $this->limiter->attempts($key);
        $tooMany = $this->limiter->tooManyAttempts($key, $maxAttempts);
        
        // \Log::info('API Throttle Check', [
        //     'client_ip' => $clientIp,
        //     'x_forwarded_for' => $request->header('X-Forwarded-For'),
        //     'path' => $request->path(),
        //     'key' => $key,
        //     'current_attempts' => $currentAttempts,
        //     'max_attempts' => $maxAttempts,
        //     'too_many' => $tooMany ? 'YES' : 'NO',
        //     'decay_minutes' => $decayMinutes
        // ]);

        if ($tooMany) {
            \Log::warning('API Throttle Limit Exceeded', [
                'client_ip' => $clientIp,
                'key' => $key,
                'current_attempts' => $currentAttempts,
                'max_attempts' => $maxAttempts
            ]);
            
            return $this->buildException($key, $maxAttempts);
        }

        $this->limiter->hit($key, $decayMinutes * 60);

        $response = $next($request);

        return $this->addHeaders(
            $response,
            $maxAttempts,
            $this->calculateRemainingAttempts($key, $maxAttempts)
        );
    }

    protected function resolveRequestSignature($request, $clientIp)
    {
        return sha1($clientIp . '|' . $request->path());
    }

    protected function calculateRemainingAttempts($key, $maxAttempts)
    {
        return $this->limiter->retriesLeft($key, $maxAttempts);
    }

    protected function buildException($key, $maxAttempts)
    {
        $retryAfter = $this->limiter->availableIn($key);

        return response()->json([
            'message' => 'Too Many Attempts.',
            'retry_after' => $retryAfter
        ], Response::HTTP_TOO_MANY_REQUESTS, [
            'Retry-After' => $retryAfter,
            'X-RateLimit-Limit' => $maxAttempts,
            'X-RateLimit-Remaining' => 0,
        ]);
    }

    protected function addHeaders(Response $response, $maxAttempts, $remainingAttempts)
    {
        $response->headers->add([
            'X-RateLimit-Limit' => $maxAttempts,
            'X-RateLimit-Remaining' => $remainingAttempts,
        ]);

        return $response;
    }
}