param(
  [string]$longurl = $null,
  [string]$provider = "tinyurl"
);

$script:DIGG_APPKEY = "http://devcentral.f5.com/PoshShrink";
$script:BITLY_LOGIN = "joepruitt";
$script:BITLY_KEY = "R_a49fa1ba91c12356a1ab223f08b2ba30";

#----------------------------------------------------------------------------
# function Set-BitlyServiceInfo
#----------------------------------------------------------------------------
function Set-BitlyServiceInfo()
{
  param(
    [string]$login = $null,
    [string]$key = $null
  );
  if ( $login -and $key )
  {
    $script:BITLY_LOGIN = $login;
    $script:BITLY_KEY = $key;
  }
  else
  {
    Write-Error "Usage: Set-BitlyServiceInfo -login login -key key";
  }
}

#----------------------------------------------------------------------------
# function Shrink-Url
#----------------------------------------------------------------------------
function Shrink-Url()
{
  param(
    [string]$longurl = $null,
    [string]$provider = "tinyurl"
  );
  
  $shorturl = $null;
  if ( $longurl )
  {
    switch ($provider.ToLower())
    {
      "is.gd" {
        $shorturl = Execute-HTTPGetCommand "http://is.gd/api.php?longurl=$longurl";
      }
      "tinyurl" {
        $shorturl = Execute-HTTPGetCommand "http://tinyurl.com/api-create.php?url=$longurl";
      }
      "snurl" {
        $shorturl = Execute-HTTPGetCommand "http://snipr.com/site/snip?r=simple&link=$longurl";
      }
      "digg" {
        [xml]$results = Execute-HTTPGetCommand `
          "http://services.digg.com/url/short/create?url=${longurl}&appkey=${script:DIGG_APPKEY}";
        $shorturl = $results.shorturls.shorturl.short_url;
      }
      "tr.im" {
        [xml]$results = Execute-HTTPGetCommand "http://api.tr.im/api/trim_url.xml?url=$longurl";
        $shorturl = $results.trim.url;
      }
      "bit.ly" {
        if ( !$BITLY_LOGIN -or !$BITLY_KEY )
        {
          Write-Error "ERROR: You must configure your bit.ly LOGIN and APIKEY!"
          exit;
        }
        else
        {
          $results = Execute-HTTPGetCommand `
            "http://api.bit.ly/shorten?version=2.0.1&longUrl=$longurl&login=$script:BITLY_LOGIN&apiKey=$script:BITLY_KEY";
          $shorturl = $results.Split("`n")[7].Split("""")[3];
        }
      }
      default {
        $shorturl = Execute-HTTPGetCommand "http://tinyurl.com/api-create.php?url=$longurl";
      }
    }
  }
  else
  {
    Write-Host "ERROR: Usage: Shrink-Url -longurl http://www.foo.com";
  }
  $shorturl;
}

#----------------------------------------------------------------------------
# function Execute-HTTPGetCommand
#----------------------------------------------------------------------------
function Execute-HTTPGetCommand()
{
  param([string] $url = $null);
  
  $user_agent = "PoshShrink";
  
  if ( $url )
  {
    $request = [System.Net.HttpWebRequest]::Create($url);
    $request.UserAgent = $user_agent;
    $request.Credentials = [System.Net.CredentialCache]::DefaultCredentials;
    if ( $request.Proxy )
    {
      $request.Proxy.Credentials = [System.Net.CredentialCache]::DefaultNetworkCredentials;
    }
    $response = $request.GetResponse();
    $rs = $response.GetResponseStream();
    [System.IO.StreamReader]$sr = New-Object System.IO.StreamReader -argumentList $rs;
    $sr.ReadToEnd();
  }
}

Shrink-Url -longurl $longurl -provider $provider;