<?php

namespace App\Controllers\View;

use CodeIgniter\API\ResponseTrait;
use CodeIgniter\Controller;
use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;
use Config\SessionTimeout;
use Psr\Log\LoggerInterface;
use Throwable;

/**
 * Lightweight session heartbeat endpoints.
 * Intentionally does not extend BaseController to avoid school-year / API priming.
 */
class SessionTimeoutController extends Controller
{
    use ResponseTrait;

    public function initController(RequestInterface $request, ResponseInterface $response, LoggerInterface $logger)
    {
        parent::initController($request, $response, $logger);
        session();
    }

    public function getTimeoutConfig()
    {
        return $this->response->setJSON([
            'success' => true,
            'timeout' => SessionTimeout::TIMEOUT_DURATION,
            'warning_time' => SessionTimeout::TIMEOUT_DURATION - SessionTimeout::WARNING_THRESHOLD,
            'check_interval' => SessionTimeout::CLIENT_CHECK_INTERVAL,
            'ping_interval' => SessionTimeout::CLIENT_PING_INTERVAL,
            'logout_url' => site_url('logout'),
            'keep_alive_url' => site_url('session/ping-activity'),
            'check_url' => site_url('session/check-timeout'),
        ]);
    }

    public function checkTimeout()
    {
        try {
            $session = session();

            if (! $session->has('last_activity')) {
                return $this->expireSession();
            }

            $lastActivity = (int) $session->get('last_activity');
            $elapsed = time() - $lastActivity;

            if ($elapsed >= SessionTimeout::TIMEOUT_DURATION) {
                return $this->expireSession();
            }

            if ($elapsed >= SessionTimeout::WARNING_THRESHOLD) {
                return $this->response->setJSON([
                    'status' => 'warning',
                    'time_remaining' => SessionTimeout::TIMEOUT_DURATION - $elapsed,
                ]);
            }

            return $this->response->setJSON([
                'status' => 'active',
                'time_remaining' => SessionTimeout::TIMEOUT_DURATION - $elapsed,
            ]);
        } catch (Throwable $e) {
            $this->logDbFailureOnce('session/check-timeout', $e);

            return $this->response
                ->setStatusCode(503)
                ->setJSON([
                    'status' => 'error',
                    'message' => 'Session check temporarily unavailable.',
                ]);
        }
    }

    public function pingActivity()
    {
        try {
            $session = session();

            if (! $session->has('last_activity')
                || (time() - (int) $session->get('last_activity') >= SessionTimeout::TIMEOUT_DURATION)
            ) {
                return $this->expireSession();
            }

            $session->set('last_activity', time());

            return $this->response->setJSON([
                'status' => 'active',
                'time_remaining' => SessionTimeout::TIMEOUT_DURATION,
            ]);
        } catch (Throwable $e) {
            $this->logDbFailureOnce('session/ping-activity', $e);

            return $this->response
                ->setStatusCode(503)
                ->setJSON([
                    'status' => 'error',
                    'message' => 'Activity ping temporarily unavailable.',
                ]);
        }
    }

    private function expireSession()
    {
        $this->destroySession();

        return $this->response->setJSON([
            'status'   => 'expired',
            'redirect' => site_url('login'),
            'message'  => 'Your session has expired due to inactivity.',
        ]);
    }

    private function destroySession(): void
    {
        try {
            $session = session();
            $session->setFlashdata('error', 'Your session has expired due to inactivity.');
            $session->remove('last_activity');
            $session->destroy();

            if (session_status() === PHP_SESSION_ACTIVE) {
                session_regenerate_id(true);
            }
        } catch (Throwable $e) {
            $this->logDbFailureOnce('session/destroy', $e);
        }
    }

    private function logDbFailureOnce(string $endpoint, Throwable $e): void
    {
        static $logged = [];

        $key = $endpoint . '|' . get_class($e);
        if (isset($logged[$key])) {
            return;
        }

        $logged[$key] = true;
        log_message('error', 'Session endpoint failure on {endpoint}: {message}', [
            'endpoint' => $endpoint,
            'message' => $e->getMessage(),
        ]);
    }
}