<?php
// Copyright 2004-present Facebook. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

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($timeout_in_ms, $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($timeout_in_ms, $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($timeout_in_ms, $url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT_MS, self::CONNECT_TIMEOUT_MS);
    // There is a PHP bug in some versions which didn't define the constant.
    curl_setopt(
      $ch,
      156, // 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;
  }
}