<?php

namespace App\Filters;

use App\Libraries\RateLimiterService;
use CodeIgniter\Filters\FilterInterface;
use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;

/**
 * JwtApiFilter
 *
 * Applied to API routes that require a valid JWT token.
 * Identity (email or mobile) is extracted from the JWT payload using
 * your existing helper functions: getEmailFromJWT() / getMobileFromJWT().
 *
 * Performs:
 *  - IP-level throttle + progressive block check (via fingerprint)
 *  - User-level throttle + progressive block check (by JWT identity)
 *
 * Usage in Routes.php:
 *   $routes->get('api/profile', 'ProfileController::index', ['filter' => 'jwtApiRateLimit']);
 *
 * Register in app/Config/Filters.php:
 *   'JwtApiRateLimitFilter' => \App\Filters\JwtApiRateLimitFilter::class
 */
class JwtApiRateLimitFilter implements FilterInterface
{
    protected RateLimiterService $limiter;

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

    // -------------------------------------------------------------------------
    // BEFORE — runs before the controller
    // -------------------------------------------------------------------------

    public function before(RequestInterface $request, $arguments = null)
    {
        $fingerprint = generateFingerprint(exclude_ua: true);
        // echo $fingerprint;die;
        // 1. IP-level throttle + block check
        $ipResult = $this->limiter->checkIp($fingerprint, 'jwtApi');
        if ($ipResult) {
            return $this->jsonResponse($ipResult);
        }

        // 2. Resolve user identity from JWT
        //    Uses your existing JWT helper functions.
        //    If neither returns a value, fall back to IP-only limiting.
        // $identity = $this->resolveIdentityFromJwt();
        $identity = '';

        if ($identity) {
            // User-level throttle (request count based for JWT routes)
            $userResult = $this->limiter->checkUserThrottle($identity, 'jwtApi');
            if ($userResult) {
                return $this->jsonResponse($userResult);
            }
        }

        // Stash for after() use
        $request->setGlobal('rateLimitFingerprint', $fingerprint);
        if ($identity) {
            $request->setGlobal('rateLimitIdentity', $identity);
        }

        return null; // pass through
    }

    // -------------------------------------------------------------------------
    // AFTER — records IP failure on controller-level bad responses
    // -------------------------------------------------------------------------

    public function after(RequestInterface $request, ResponseInterface $response, $arguments = null)
    {
        $statusCode = $response->getStatusCode();

        // Only act on auth-related failures from the controller (401, 422, etc.)
        // 429/403/451 are already handled by before(); skip 2xx/3xx.
        if ($statusCode < 400 || in_array($statusCode, [429, 403, 451])) {
            return;
        }

        $fingerprint = $request->getGlobal('rateLimitFingerprint') ?? generateFingerprint(exclude_ua: true);
        
        // $identity    = $request->getGlobal('rateLimitIdentity') ?? $this->resolveIdentityFromJwt();
        $identity    = $request->getGlobal('rateLimitIdentity') ?? '';

        $this->limiter->recordIpFailure($fingerprint);

        if ($identity) {
            $this->limiter->recordUserFailure($identity, 'jwtApi');
        }
    }

    // -------------------------------------------------------------------------
    // HELPERS
    // -------------------------------------------------------------------------

    /**
     * Resolve user identity from JWT using your existing helper functions.
     * Tries email first, then mobile. Returns null if JWT is absent/invalid.
     *
     * IMPORTANT: Replace getEmailFromJWT() / getMobileFromJWT() with your
     * actual function names if they differ.
     */
    protected function resolveIdentityFromJwt(): ?string
    {
        try {
            // Try email from JWT
            if (function_exists('getEmailFromJWT')) {
                $email = getEmailFromJWT();
                if ($email) {
                    return strtolower(trim($email));
                }
            }

            // Try mobile from JWT
            if (function_exists('getMobileFromJWT')) {
                $mobile = getMobileFromJWT();
                if ($mobile) {
                    return trim($mobile);
                }
            }
        } catch (\Throwable $e) {
            // JWT invalid or expired — fall through to IP-only limiting
            log_message('debug', '[RateLimiter] JWT identity resolution failed: ' . $e->getMessage());
        }

        return null;
    }

    /**
     * Build and return a JSON response for blocked/throttled requests.
     */
    protected function jsonResponse(array $result): ResponseInterface
    {
        $response = service('response');
        $response->setStatusCode($result['status']);
        $response->setContentType('application/json');
        $response->setBody(json_encode([
            'success' => false,
            'error'   => [
                'code'    => strtoupper('RATE_LIMIT_' . $result['level']),
                'message' => $result['message'],
                'type'    => $result['type'] ?? 'request',
            ],
        ]));
        return $response;
    }
}