<?php
/**
 * Parsers of the currencies' exchange rates some banks of the world.
 *
 * Applying on the project http://currency.servisator.ru
 *
 * @author Voronin Valentin aka direqtor <direqtor@mail.ru>
 *
 * @link http://shaman.asiadata.ru
 * @link http://currency.servisator.ru
 * 
 */

/**
 * Data format returned by functions
 *
 * Array of elements. Each element is an array with the fields
 *
 * country – Country code by ISO
 * bank – Abbreviation name of the bank
 * fromvalue – Source currency value as 10 power (... 0.001, 0.01, 0.1, 1, 10, 100, 1000, 10 000 ...)
 * fromcurrency – Source currency code by ISO
 * tovalue – Currency exchange rate from 20 to 200 (normalized)
 * tocurrency – Target currency code by ISO
 * date - Currency exchange rate date as YYYYMMDD
 *
 */

/**
 * Parser 
 *
 * Australia (AU)
 * Reserve Bank of Australia (RBA)
 * Australian dollar (AUD)
 * http://www.rba.gov.au/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_rba_get_rates() {
    $url = 'http://www.rba.gov.au/rss/rss-cb-exchange-rates.xml';
    $result = array();
    if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->item)) {
      foreach ($xml->item as $cur) {
        $tmp = $cur->children('cb', true);
        $tmp = $tmp->statistics->exchangeRate;
        if (isset($tmp->observation->value, $tmp->baseCurrency, $tmp->targetCurrency, $tmp->observationPeriod->period)) {
          $date = trim((string) $tmp->observationPeriod->period);
          $result[] = curency_prepare_rate(array(
            'country' => 'AU',
            'bank' => 'RBA',
            'fromvalue' => 1,
            'fromcurrency' => (string) $tmp->targetCurrency,
            'tovalue' => (double) 1.0/(double) $tmp->observation->value,
            'tocurrency' => (string) $tmp->baseCurrency,
            'date' => substr($date, 0, 4) . substr($date, 5, 2) . substr($date, 8, 2),
          ));
        }   
      }
    }
    return $result;
}

/**
 * Parser
 *
 * Armenia (AM)
 * Central Bank of Armenia (CBA)
 * Armenian dram (AMD)
 * http://www.cba.am/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_cba_get_rates() {
    $url = 'http://www.cba.am/_layouts/rssreader.aspx?rss=280F57B8-763C-4EE4-90E0-8136C13E47DA';
    $result = array();
    if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->channel) && isset($xml->channel->item)) {
      foreach ($xml->channel->item as $cur) {
        $title = isset($cur->title) ? trim((string) $cur->title) : '';
        $pubDdate = isset($cur->pubDate) ? trim((string) $cur->pubDate) : '';
        $fromvalue = $fromcurrency = $tovalue = $date = NULL;
        if(preg_match('/^([A-Z]{3})[- ]*([0-9]*)[- ]*([\.0-9]*)$/', $title, $regs)){
          $fromcurrency = (string) $regs[1];
          $fromvalue = (int) $regs[2];
          $tovalue = (double) $regs[3];
        }
        if(preg_match('/^([0-9]{1,2})\/([0-9]{1,2})\/([0-9]{4}).*$/', $pubDdate, $regs)){
          $date = $regs[3] . ($regs[1] > 10 ? $regs[1] : '0'. $regs[1]) . ($regs[2] > 10 ? $regs[2] : '0'. $regs[2]);
        }
        if (!(is_null($fromvalue) || is_null($fromcurrency) || is_null($tovalue)) && ($tovalue > 0)) {
          $result[] = curency_prepare_rate(array(
            'country'=>'AM',
            'bank'=>'CBA',
            'fromvalue'=>$fromvalue,
            'fromcurrency'=>$fromcurrency,
            'tovalue'=>$tovalue,
            'tocurrency'=>'AMD',
            'date'=>$date
          ));   
        }
      }
    }
    return $result;
}

/**
 * Parser
 *
 * Republic of Belarus (BY)
 * National Bank of the Republic of Belarus (NBRB)
 * Belarusian ruble (BYR)
 * http://www.nbrb.by/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_nbrb_get_rates() {
   $url = 'http://www.nbrb.by/statistics/Rates/RatesPrint.asp';
   $result = array();
   if
     (
       ($datafetch = currency_http_request($url)) &&
       ($html = currency_convert_to_utf8($datafetch->data, 'windows-1251')) &&
//       eregi("на[[:space:]]+([0-9][0-9]).([0-9][0-9]).([0-9][0-9][0-9][0-9])", $html, $tmp)
       preg_match('/на[[:space:]]+([0-9][0-9]).([0-9][0-9]).([0-9][0-9][0-9][0-9])/i', $html, $tmp)
     ) {
       $date = $tmp[3].$tmp[2].$tmp[1];
       $tables = preg_split ('/<table[^>]*>/i', $html);
       $table = isSet ($tables[1]) ? $tables[1] : "";
       $trs = preg_split('/<tr[^>]*>/i', $table);
       $lines = array();
       foreach($trs as $i=>$l) {
         $c = preg_split('/<td[^>]*>/i', $l);
         $lines[] = currency_clear_array($c);
     }
     foreach ($lines as $line) {
       if ($line[0] && $line[1] && ($line[2] > 0)) {
         $result[] = curency_prepare_rate(array(
           'country' => 'BY',
           'bank' => 'NBRB',
           'fromvalue' => (int) $line[1],
           'fromcurrency' => $line[0],
           'tovalue' => doubleval(0.0 + $line[2]),
           'tocurrency' => 'BYR',
           'date' => $date,
         ));
       }
     }
     return $result;
   }
}

/**
 * Parser
 *
 * Georgia (GE)
 * National Bank of Georgia (NBG)
 * Georgian lari (GEL)
 * http://www.nbg.ge/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_nbg_get_rates() {
   $url = 'http://www.nbg.ge/rss.php';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($html = $datafetch->data)) {
     $tables = preg_split('/<table[^>]*>/i', $html);
     $table = isSet ($tables[1]) ? $tables[1] : "";
     $trs = preg_split('/<tr[^>]*>/i', $table);
     $lines = array();
     foreach($trs as $i=>$l) {
       $l = preg_replace('/<\/tr>.*/', '', $l);
       $c = preg_split('/<td[^>]*>/i', $l);
       $lines[] = currency_clear_array($c);
     }
     $dtable = isSet ($tables[0]) ? $tables[0] : "";
     $date = preg_match('/<title>Currency Rates ([0-9][0-9][0-9][0-9])-([0-9][0-9])-([0-9][0-9])<\/title>/i', $dtable, $regs) ? $regs[1] . $regs[2] . $regs[3] : date('Ymd');
     foreach ($lines as $line) {
       if ($line[0] && $line[1] && $line[2]) {
         $result[] = curency_prepare_rate(array(
           'country' => 'GE',
           'bank' => 'NBG',
           'fromvalue' => (int) $line[1],
           'fromcurrency' => $line[0],
           'tovalue' => (double) (0.0 + $line[2]),
           'tocurrency' => 'GEL',
           'date' => $date,
         ));
       }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Europe (EU)
 * European Central Bank (ECB)
 * Euro (EUR)
 * http://www.ecb.europa.eu/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_ecb_get_rates() {
   $url = 'http://www.ecb.europa.eu/stats/eurofxref/eurofxref-daily.xml';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->Cube->Cube)) {
     $cube = $xml->Cube->Cube;
     $date = date('Ymd');
     foreach($cube->attributes() as $n=>$v) if($n=='time') $date = implode('', explode('-', $v));
     foreach ($cube->Cube as $cur) {
       $fromvalue = $fromcurrency = NULL;
       foreach($cur->attributes() as $n=>$v)
         if($n=='currency') {
           $fromcurrency = (string) $v;
         }
         elseif ($n=='rate') {
           $fromvalue = $v;
         }
       if (!(is_null($fromvalue) || is_null($fromcurrency))) {
         $result[] = curency_prepare_rate(array(
           'country'=>'EU',
           'bank'=>'ECB',
           'fromvalue'=>1,
           'fromcurrency'=>$fromcurrency,
           'tovalue'=>(double) 1.0/(double) $fromvalue,
           'tocurrency'=>'EUR',
           'date'=>$date
         ));
       }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Israil (IL)
 * Bank of Israil (BOI)
 * Israeli new sheqel (ILS)
 * http://www.bankisrael.gov.il/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_boi_get_rates() {
   $url = 'http://www.bankisrael.gov.il/currency.xml';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->CURRENCY) && isset($xml->LAST_UPDATE) ) {
     $date = implode('', explode('-', $xml->LAST_UPDATE));
     foreach ($xml->CURRENCY as $cur) {
       $fromvalue = isset($cur->UNIT) ? (int) $cur->UNIT : NULL;
       $fromcurrency = isset($cur->CURRENCYCODE) ? (string) $cur->CURRENCYCODE : NULL;
       $tovalue = isset($cur->RATE) ? (double) $cur->RATE : NULL;
       if (!(is_null($fromvalue) || is_null($fromcurrency) || is_null($tovalue))) {
         $result[] = curency_prepare_rate(array(
           'country'=>'IL',
           'bank'=>'BOI',
           'fromvalue'=>$fromvalue,
           'fromcurrency'=>$fromcurrency,
           'tovalue'=>$tovalue,
           'tocurrency'=>'ILS',
           'date'=>$date
         ));      
       }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Kazakhstan (KZ)
 * National Bank of Kazakhstan (NBK)
 * Kazakhstani tenge (KZT)
 * http://www.nationalbank.kz/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_nbk_get_rates() {
   $url = 'http://www.nationalbank.kz/rss/rates_all.xml';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->channel->item)) {
     foreach ($xml->channel->item as $cur) {
       $fromvalue = isset($cur->quant) ? (int) $cur->quant : NULL;
       $fromcurrency = isset($cur->title) ? (string) $cur->title : NULL;
       $tovalue = isset($cur->description) ? (double) $cur->description : NULL;
       $date = '20'. implode('', array_reverse(explode('.', (string) $cur->pubDate)));
       if (!(is_null($fromvalue) || is_null($fromcurrency) || is_null($tovalue) || empty($date))) {
         $result[] = curency_prepare_rate(array(
           'country'=>'KZ',
           'bank'=>'NBK',
           'fromvalue'=>$fromvalue,
           'fromcurrency'=>$fromcurrency,
           'tovalue'=>$tovalue,
           'tocurrency'=>'KZT',
           'date'=>$date
         ));
       }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Canada (CA)
 * Banque du Canada ()
 * Canadian dollar (CAD)
 * http://www.bankofcanada.ca/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_bdc_get_rates() {
   $url = 'http://www.bankofcanada.ca/stats/assets/rates_rss/noon/en_all.xml';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && isset($xml->item)) {
     foreach ($xml->item as $cur) {
       $tmp = $cur->children('cb', true);
       $tmp = $tmp->statistics->exchangeRate;
       if (isset($tmp->value, $tmp->baseCurrency, $tmp->targetCurrency, $tmp->observationPeriod))  {
         $date = trim((string) $tmp->observationPeriod);
         $result[] = curency_prepare_rate(array(
           'country' => 'CA',
           'bank' => 'BDC',
           'fromvalue' => 1,
           'fromcurrency' => (string) $tmp->targetCurrency,
           'tovalue' => (double) 1.0/(double) $tmp->value,
           'tocurrency' => (string) $tmp->baseCurrency,
           'date' => substr($date, 0, 4) . substr($date, 5, 2) . substr($date, 8, 2),
         ));
       }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * China (CN)
 * Bank of China (BOC)
 * Chinese yuan (CNY)
 * http://www.boc.cn/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_boc_get_rates() {
   $url = 'http://www.boc.cn/sourcedb/whpj/enindex.html';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($html = $datafetch->data)) {
     $tables = preg_split('/<table[^>]*>/i', $html);
     $table = isSet ($tables[8]) ? $tables[8] : "";
     $trs = preg_split('/<tr[^>]*>/i', $table);
     $lines = array();
     foreach($trs as $i=>$l) {
       $l = preg_replace('/<\/tr>.*/i', '', $l);
       $c = preg_split('/<td[^>]*>/i', $l);
       $lines[] = currency_clear_array($c);
     }
     $date = date('Ymd');
     foreach ($lines as $line) {
       if ($line[0] && $line[1] && $line[3] && preg_match('/([0-9][0-9][0-9][0-9])-([0-9][0-9])-([0-9][0-9])/i', $line[6], $regs)) {
         $date = $regs[1] . $regs[2] . $regs[3];
         $result[] = curency_prepare_rate(array(
           'country'=>'CN',
           'bank'=>'BOC',
           'fromvalue'=>100,
           'fromcurrency'=>$line[0],
           'tovalue'=>(doubleval ($line[1]) + doubleval ($line[3]))/2.0,
           'tocurrency'=>'CNY',
           'date'=>$date,
         ));
        }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Mongolia (CN)
 * Bank of Mongolia (BOM)
 * Mongolian tugrik (MNT)
 * http://www.mongolbank.mn/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_bom_get_rates() {
  $url = 'http://www.mongolbank.mn/eng/dblistofficialdailyrate.aspx';
  $result = array();
  if (($datafetch = currency_http_request($url)) && ($html = $datafetch->data)) {
 	$tables = preg_split('/<table[^>]*>/is', $html);
	$trs = array_slice($tables, 12, 37);
	$lines = array();
    foreach($trs as $i=>$l) {
	  $l = preg_replace('/<\/span>.*/is', '', $l);
	  $c = spliti ('<td[^>]*>', $l);
	  $lines[] = currency_clear_array($c);
    }
    $date = date('Ymd');
    $dtable = isSet ($tables[11]) ? $tables[11] : "";
    $months = array('Jan'=>'01','Feb'=>'02','Mar'=>'03','Apr'=>'04','May'=>'05','Jun'=>'06','Jul'=>'07','Aug'=>'08','Sep'=>'09','Oct'=>'10','Nov'=>'11','Dec'=>'12');
	if(preg_match('/(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec) ([0-9]{1,2}), ([0-9][0-9][0-9][0-9])/', $dtable, $regs)) {
	  $date = $regs[3].$months[$regs[1]].$regs[2];
	}
	foreach ($lines as $line) {
      $line[2] = str_replace(array(' ', ','), '', $line[2]);
      if ($line[1] && ($line[2] > 0)) {
         $result[] = curency_prepare_rate(array(
           'country'=>'MN',
           'bank'=>'BOM',
           'fromvalue'=>1,
           'fromcurrency'=>$line[1],
           'tovalue'=>doubleval($line[2]),
           'tocurrency'=>'MNT',
           'date'=>$date,
         ));
        }
     }
   }
   return $result;
}

/**
 * Parser
 *
 * Russia (RU)
 * Central Bank of Russia (CBR)
 * Russian rouble (RUB)
 * http://www.cbr.ru/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_cbr_get_rates() {
   $url = 'http://www.cbr.ru/scripts/XML_daily.asp';
   $result = array();
   if (($datafetch = currency_http_request($url)) && ($xml = simplexml_load_string($datafetch->data)) && ($xml->getName()=='ValCurs')) {
     $date = date('Ymd');
     foreach($xml->attributes() as $n=>$v) if($n=='Date') $date = implode('', array_reverse(explode('.', $v)));
     foreach ($xml->Valute as $cur)
       if ($cur->getName()=='Valute' && isset($cur->CharCode, $cur->Nominal, $cur->Value))
         $result[] = curency_prepare_rate(array(
           'country' => 'RU',
           'bank' => 'CBR',
           'fromvalue' => str_replace (',', '.', (string) $cur->Nominal),
           'fromcurrency' => (string) $cur->CharCode,
           'tovalue' => str_replace(',', '.', (string) $cur->Value),
           'tocurrency' => 'RUB',
           'date' => $date
         ));
   }
   return $result;
}

/**
 * Parser
 *
 * Ukraine (UA)
 * National Bank of Ukraine (NBU)
 * Ukrainian hryvnia (UAH)
 * http://www.bank.gov.ua/
 *
 * @return
 *   Array of the currencies' exchange rates.
 */
function currency_nbu_get_rates() {
  function currency_nbu_html_parse($html) {
    $result = array();
    $tables = preg_split('/<table[^>]*>/i', $html);
    $table = isSet ($tables[6]) ? $tables[6] : "";
    $trs = preg_split('/<tr[^>]*>/i', $table);
    unset($trs[0], $trs[1]);
    $lines = array();
    foreach($trs as $i=>$l) {
      $l = preg_replace('/<\/tr>.*/i', '', $l);
      $c = preg_split('/<td[^>]*>/i', $l);
      $lines[] = currency_clear_array($c);
    }
    $dtable = isSet ($tables[5]) ? $tables[5] : "";
    $date = preg_match('/([0-9][0-9]).([0-9][0-9]).([0-9][0-9][0-9][0-9])/i', $dtable, $regs) ? $regs[3] . $regs[2] . $regs[1] : date('Ymd');
    foreach ($lines as $line) {
      if ($line[1] && $line[2] && $line[4]) {
        $result[] = curency_prepare_rate(array(
           'country'=>'UA',
           'bank'=>'NBU',
           'fromvalue'=>$line[2],
           'fromcurrency'=>$line[1],
           'tovalue'=>doubleval($line[4]),
           'tocurrency'=>'UAH',
           'date'=>$date,
         ));
       }
    }
    return $result;
  }
  $d_url = 'http://bank.gov.ua/control/en/curmetal/detail/currency?period=daily';
  $m_url = 'http://bank.gov.ua/control/en/curmetal/detail/currency?period=monthly';
  $result = array();
  if (($datafetch = currency_http_request($d_url)) && ($html = $datafetch->data)) {
    $result = currency_nbu_html_parse($html);
  }
  if (($datafetch = currency_http_request($m_url)) && ($html = $datafetch->data)) {
    $result = array_merge($result, currency_nbu_html_parse($html));
  }
  return $result;
}

/**
 * Common functions for the project.
 *
 */

/**
 * Prepare rates to readable view
 *
 * Prepare currencies' exchange rates to readable view.
 *
 * @param $rate
 *   Array with a currency's rate.
 * @param $low_limit
 *   The lower limit of the normalization.
 * @param $precision
 *   Rounding precision of the rate.
 * @return
 *   Normalizing and rounding rate.
 */
function curency_prepare_rate($rate, $low_limit = 20, $precision = 2) {
  $low_limit = (int) $low_limit;
  $high_limit = $low_limit*10;
  $precision = (int) $precision;
  $tovalue = $rate['tovalue'];
  $fromvalue = $rate['fromvalue'];
  if($tovalue < $low_limit) {
    while ($tovalue < $low_limit) {
      $fromvalue = $fromvalue*10;
      $tovalue = $tovalue*10.;
    }
  } 
  else if ($tovalue>=$high_limit) {
    while ($tovalue>=$high_limit) {
      $fromvalue = $fromvalue/10;
      $tovalue = $tovalue/10.;
    }
  }
  $rate['tovalue'] = round($tovalue, $precision);
  $rate['fromvalue'] = $fromvalue;
  return $rate; 
}

/**
 * Clear array of the strings from HTML-code
 *
 * @param $arr
 *   The array of the strings to be cleared.
 * @return
 *   Cleared array of the strings.
 */
function currency_clear_array($arr) {
   $res = array();
   $s = array('</table>', '<br>', '</body>', '</html>', ' ', '&nbsp;', "\xC2"."\xA0");
   $r = array( '', ' ', '', '', '', '', '');
   array_shift($arr);
   foreach ($arr as $el) {
     $el = trim (strip_tags (str_replace( $s, $r, $el)));
     /*if (!empty ($el)) */$res[] = $el;
   }
   return $res;
}

/**
 * Convert data to UTF-8
 *
 * Requires the iconv, GNU recode or mbstring PHP extension.
 *
 * @param $data
 *   The data to be converted.
 * @param $encoding
 *   The encoding that the data is in
 * @return
 *   Converted data or FALSE.
 */
function currency_convert_to_utf8($data, $encoding) {
   if (function_exists('iconv')) {
     $out = @iconv($encoding, 'utf-8', $data);
   }
   else if (function_exists('mb_convert_encoding')) {
     $out = @mb_convert_encoding($encoding, $data, 'utf-8');
   }
   else {
     return FALSE;
   }
   return $out;
}

/**
 * Perform an HTTP request.
 *
 * This is a flexible and powerful HTTP client implementation. Correctly handles
 * GET, POST, PUT or any other HTTP requests. Handles redirects.
 *
 * @param $url
 *   A string containing a fully qualified URI.
 * @param $headers
 *   An array containing an HTTP header => value pair.
 * @param $method
 *   A string defining the HTTP request to use.
 * @param $data
 *   A string containing data to include in the request.
 * @param $retry
 *   An integer representing how many times to retry the request in case of a
 *   redirect.
 * @return
 *   An object containing the HTTP request headers, response code, protocol,
 *   status message, headers, data and redirect status.
 */
function currency_http_request($url, $headers = array(), $method = 'GET', $data = NULL, $retry = 3) {

   $result = new stdClass();

   // Parse the URL and make sure we can handle the schema.
   $uri = parse_url($url);

   if ($uri == FALSE) {
     $result->error = 'unable to parse URL';
     $result->code = -1001;
     return $result;
   }

   if (!isset($uri['scheme'])) {
     $result->error = 'missing schema';
     $result->code = -1002;
     return $result;
   }

   switch ($uri['scheme']) {
     case 'http':
     case 'feed':
       $port = isset($uri['port']) ? $uri['port'] : 80;
       $host = $uri['host'] . ($port != 80 ? ':'. $port : '');
       $fp = @fsockopen($uri['host'], $port, $errno, $errstr, 15);
       break;
     case 'https':
       // Note: Only works for PHP 4.3 compiled with OpenSSL.
       $port = isset($uri['port']) ? $uri['port'] : 443;
       $host = $uri['host'] . ($port != 443 ? ':'. $port : '');
       $fp = @fsockopen('ssl://'. $uri['host'], $port, $errno, $errstr, 20);
       break;
     default:
       $result->error = 'invalid schema '. $uri['scheme'];
       $result->code = -1003;
       return $result;
   }

   // Make sure the socket opened properly.
   if (!$fp) {
     // When a network error occurs, we use a negative number so it does not
     // clash with the HTTP status codes.
     $result->code = -$errno;
     $result->error = trim($errstr);

     return $result;
   }

   // Construct the path to act on.
   $path = isset($uri['path']) ? $uri['path'] : '/';
   if (isset($uri['query'])) {
     $path .= '?'. $uri['query'];
   }

   // Create HTTP request.
   $defaults = array(
     // RFC 2616: "non-standard ports MUST, default ports MAY be included".
     // We don't add the port to prevent from breaking rewrite rules checking the
     // host that do not take into account the port number.
     'Host' => "Host: $host",
     'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)',
   );

   // Only add Content-Length if we actually have any content or if it is a POST
   // or PUT request. Some non-standard servers get confused by Content-Length in
   // at least HEAD/GET requests, and Squid always requires Content-Length in
   // POST/PUT requests.
   $content_length = strlen($data);
   if ($content_length > 0 || $method == 'POST' || $method == 'PUT') {
     $defaults['Content-Length'] = 'Content-Length: '. $content_length;
   }

   // If the server url has a user then attempt to use basic authentication
   if (isset($uri['user'])) {
     $defaults['Authorization'] = 'Authorization: Basic '. base64_encode($uri['user'] . (!empty($uri['pass']) ? ":". $uri['pass'] : ''));
   }

   foreach ($headers as $header => $value) {
     $defaults[$header] = $header .': '. $value;
   }

   $request = $method .' '. $path ." HTTP/1.0\r\n";
   $request .= implode("\r\n", $defaults);
   $request .= "\r\n\r\n";
   $request .= $data;

   $result->request = $request;

   fwrite($fp, $request);

   // Fetch response.
   $response = '';
   while (!feof($fp) && $chunk = fread($fp, 1024)) {
     $response .= $chunk;
   }
   fclose($fp);

   // Parse response.
   list($split, $result->data) = explode("\r\n\r\n", $response, 2);
   $split = preg_split("/\r\n|\n|\r/", $split);

   list($protocol, $code, $status_message) = explode(' ', trim(array_shift($split)), 3);
   $result->protocol = $protocol;
   $result->status_message = $status_message;

   $result->headers = array();

   // Parse headers.
   while ($line = trim(array_shift($split))) {
     list($header, $value) = explode(':', $line, 2);
     if (isset($result->headers[$header]) && $header == 'Set-Cookie') {
       // RFC 2109: the Set-Cookie response header comprises the token Set-
       // Cookie:, followed by a comma-separated list of one or more cookies.
       $result->headers[$header] .= ','. trim($value);
     }
     else {
       $result->headers[$header] = trim($value);
     }
   }

   $responses = array(
     100 => 'Continue', 101 => 'Switching Protocols',
     200 => 'OK', 201 => 'Created', 202 => 'Accepted', 203 => 'Non-Authoritative Information', 204 => 'No Content', 205 => 'Reset Content', 206 => 'Partial Content',
     300 => 'Multiple Choices', 301 => 'Moved Permanently', 302 => 'Found', 303 => 'See Other', 304 => 'Not Modified', 305 => 'Use Proxy', 307 => 'Temporary Redirect',
     400 => 'Bad Request', 401 => 'Unauthorized', 402 => 'Payment Required', 403 => 'Forbidden', 404 => 'Not Found', 405 => 'Method Not Allowed', 406 => 'Not Acceptable', 407 => 'Proxy Authentication Required', 408 => 'Request Time-out', 409 => 'Conflict', 410 => 'Gone', 411 => 'Length Required', 412 => 'Precondition Failed', 413 => 'Request Entity Too Large', 414 => 'Request-URI Too Large', 415 => 'Unsupported Media Type', 416 => 'Requested range not satisfiable', 417 => 'Expectation Failed',
     500 => 'Internal Server Error', 501 => 'Not Implemented', 502 => 'Bad Gateway', 503 => 'Service Unavailable', 504 => 'Gateway Time-out', 505 => 'HTTP Version not supported'
   );
   // RFC 2616 states that all unknown HTTP codes must be treated the same as the
   // base code in their class.
   if (!isset($responses[$code])) {
     $code = floor($code / 100) * 100;
   }

   switch ($code) {
     case 200: // OK
     case 304: // Not modified
       break;
     case 301: // Moved permanently
     case 302: // Moved temporarily
     case 307: // Moved temporarily
       $location = $result->headers['Location'];

       if ($retry) {
         $result = currency_http_request($result->headers['Location'], $headers, $method, $data, --$retry);
         $result->redirect_code = $result->code;
       }
       $result->redirect_url = $location;

       break;
     default:
       $result->error = $status_message;
   }

   $result->code = $code;
   return $result;
}