<?php

namespace Facebook\WebDriver\Net;

use Exception;
use Facebook\WebDriver\Exception\TimeoutException;

class URLChecker
{
    const POLL_INTERVAL_MS = 500;
    const CONNECT_TIMEOUT_MS = 500;

    public function waitUntilAvailable($timeout_in_ms, $url)
    {
        $end = microtime(true) + $timeout_in_ms / 1000;

        while ($end > microtime(true)) {
            if ($this->getHTTPResponseCode($url) === 200) {
                return $this;
            }
            usleep(self::POLL_INTERVAL_MS);
        }

        throw new TimeoutException(sprintf(
            'Timed out waiting for %s to become available after %d ms.',
            $url,
            $timeout_in_ms
        ));
    }

    public function waitUntilUnavailable($timeout_in_ms, $url)
    {
        $end = microtime(true) + $timeout_in_ms / 1000;

        while ($end > microtime(true)) {
            if ($this->getHTTPResponseCode($url) !== 200) {
                return $this;
            }
            usleep(self::POLL_INTERVAL_MS);
        }

        throw new TimeoutException(sprintf(
            'Timed out waiting for %s to become unavailable after %d ms.',
            $url,
            $timeout_in_ms
        ));
    }

    private function getHTTPResponseCode($url)
    {
        $ch = curl_init();
        curl_setopt($ch, CURLOPT_URL, $url);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        // The PHP doc indicates that CURLOPT_CONNECTTIMEOUT_MS constant is added in cURL 7.16.2
        // available since PHP 5.2.3.
        if (!defined('CURLOPT_CONNECTTIMEOUT_MS')) {
            define('CURLOPT_CONNECTTIMEOUT_MS', 156);  // default value for CURLOPT_CONNECTTIMEOUT_MS
        }
        curl_setopt($ch, CURLOPT_CONNECTTIMEOUT_MS, self::CONNECT_TIMEOUT_MS);

        $code = null;

        try {
            curl_exec($ch);
            $info = curl_getinfo($ch);
            $code = $info['http_code'];
        } catch (Exception $e) {
        }
        curl_close($ch);

        return $code;
    }
}