<?php

class Curl
{
  const GET = 'GET',
        POST = 'POST',
        PUT = 'PUT',
        DEFAULT_CACHE = 60000;

  public static function get($url, $params = [], $options = [])
  {
    list ($status, $headers, $body) = static::doCurl(static::GET, $url, $params, $options);
    return $body;
  }

  public static function post($url, $params = [], $options = [])
  {
    list ($status, $headers, $body) = static::doCurl(static::POST, $url, $params, $options);
    return $body;
  }

  public static function put($url, $params = [], $options = [])
  {
    list ($status, $headers, $body) = static::doCurl(static::PUT, $url, $params, $options);
    return $body;
  }

  public static function doCurl($method, $url, $params = [], $options = [])
  {
    $defaults = [
      'cache'            => false,
      'headers'          => [],
      'verify'           => true,
      'timeout'          => 10, //5 was timing out on /roadmap for Asana API
      'follow_redirects' => true,
      'user_agent'       => null,
      'proxy'            => null,
      'password'         => null,
      'cookie'           => null,
      'json_data'        => false,
      'json_response'    => false
    ];

    $invalid = array_diff_key($options, $defaults);
    if ($invalid)
    {
      throw new DomainException('Invalid curl options: ' . join(', ', array_keys($invalid)));
    }

    if (!in_array($method, [static::GET, static::POST, static::PUT]))
    {
      throw new DomainException('Invalid method: ' . $method);
    }

    $options = array_merge($defaults, $options);

    if (!Apc::isEnabled())
    {
      $options['cache'] = false;
    }

    if ($options['cache'])
    {
      $cacheKey = md5('z' . $url . $method . serialize($options) . serialize($params));
      $cachedData = apc_fetch($cacheKey);
      if ($cachedData)
      {
        return $cachedData;
      }
    }

    if ($options['headers'] && $options['headers'] !== array_values($options['headers'])) // associative array
    {
      throw new DomainException('Headers must not be an associative array. Its a simple array with values of the form "Header: value"');
    }

    $ch = curl_init();

    if ($ch === false || $ch === null)
    {
      throw new LogicException('Unable to initialize cURL');
    }

    if ($method == static::GET && $params)
    {
      $url .= (strpos($url, '?') === false ? '?' : '&') . http_build_query($params);
    }

    curl_setopt_array($ch, [
      CURLOPT_URL            => $url,
      CURLOPT_HTTPHEADER     => $options['headers'],
      CURLOPT_RETURNTRANSFER => true,
      //      CURLOPT_FAILONERROR    => true,
      CURLOPT_FOLLOWLOCATION => $options['follow_redirects'],
      CURLOPT_MAXREDIRS      => 10,
      CURLOPT_TIMEOUT        => $options['timeout'],
      CURLOPT_SSL_VERIFYPEER => $options['verify'],
      //      CURLOPT_SSL_VERIFYHOST => $options['verify'] ? 2 : 0, // php doc says to always keep this at 2 in production environments
      CURLOPT_USERAGENT      => $options['user_agent'],
    ]);

    if ($method == static::POST)
    {
      curl_setopt($ch, CURLOPT_POST, true);
    }

    if ($method == static::PUT)
    {
      curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
      curl_setopt($ch, CURLOPT_PUT, 1);
      curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");
    }

    if (in_array($method, [static::PUT, static::POST]))
    {
      curl_setopt($ch, CURLOPT_POSTFIELDS, $options['json_data'] ? json_encode($params) : http_build_query($params));
    }

    if ($options['proxy'])
    {
      curl_setopt($ch, CURLOPT_PROXY, $options['proxy']);
      curl_setopt($ch, CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
    }

    if ($options['password'])
    {
      curl_setopt($ch, CURLOPT_USERPWD, $options['password']);
    }

    if ($options['cookie'])
    {
      curl_setopt($ch, CURLOPT_COOKIE, $options['cookie']);
    }

    $startingResponse = false;
    $headers          = [];
    curl_setopt($ch, CURLOPT_HEADERFUNCTION, function ($ch, $h) use (&$headers, &$startingResponse)
    {
      $value = trim($h);
      if ($value === '')
      {
        $startingResponse = true;
      }
      elseif ($startingResponse)
      {
        $startingResponse = false;
        $headers          = [$value];
      }
      else
      {
        $headers[] = $value;
      }
      return strlen($h);
    });

    $rawResponse = curl_exec($ch);

    if ($options['json_response'])
    {
      $responseContent = $rawResponse ? json_decode($rawResponse, true) : [];
    }
    else
    {
      $responseContent = $rawResponse;
    }

    $statusCode = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);

    if (curl_errno($ch))
    {
      throw new CurlException($ch);
    }

    curl_close($ch);

    $response = [$statusCode, $headers, $responseContent];

    if ($options['cache'])
    {
      apc_store($cacheKey, $response, is_numeric($options['cache']) ? $options['cache'] : static::DEFAULT_CACHE);
    }

    return $response;
  }
}

class CurlException extends Exception
{
  protected $errno, $error, $info, $handle;

  public function __construct($curlHandle, Exception $previous = null)
  {
    $this->handle = $curlHandle;
    $this->errno  = curl_errno($curlHandle);
    $this->error  = curl_error($curlHandle);
    $this->info   = curl_getinfo($curlHandle);

    parent::__construct($this->error, $this->errno, $previous);
  }
}