<?php
/**
 * This file was developed by Nathan <nathan@webr3.org>
 *
 * Created:     Nath - 25 Jan 2010 22:26:33
 * Modified:    SVN: $Id$
 * PHP Version: 5.1.6+
 *
 * @package   @project.name@
 * @author    Nathan <nathan@webr3.org>
 * @version   SVN: $Revision$
 */

class RestInterface
{
	const DEFAULT_TIMEOUT = 20;

	const HTTP_METHOD_GET = 'GET';
	const HTTP_METHOD_POST = 'POST';
	
	public static $SUPPORTED_HTTP_METHODS = array(
		self::HTTP_METHOD_GET,
		self::HTTP_METHOD_POST,
	);

	private $endpoint;
	private $headers = array();
	private $method;
	private $params = array();
	private $timeout;
	
	public function __construct()
	{
		$this->reset();
	}

	public function setEndpoint( $endpoint )
	{
		$this->endpoint = $endpoint;
	}

	public function getEndpoint()
	{
		if( is_null( $this->endpoint ) ) {
			throw new InvalidArgumentException( 'no endpoint specified' );
		}
		return $this->endpoint;
	}
	
	public function setMethod( $method )
	{
		$method = strtoupper(trim($method));
		if( !in_array( $method , self::$SUPPORTED_HTTP_METHODS ) ) {
			throw new InvalidArgumentException( $method );
		}
		$this->method = $method;
	}

	public function setTimeout( $timeout )
	{
		$this->timeout = (int)$timeout;
	}

	public function getTimeout()
	{
		if( is_null( $this->timeout ) ) {
			return self::DEFAULT_TIMEOUT;
		}
		return $this->timeout;
	}

	public function addParam( $key, $value )
	{
		$this->params[ $key ] = $value;
	}

	public function addHeader( $key, $value )
	{
		$this->headers[] = $key . ': ' . $value;
	}

	public function reset( $resetEndpoint=true )
	{
		if( $resetEndpoint ) {
			$this->endpoint = null;
		}
		$this->headers = array();
		$this->params = array();
		$this->method = self::HTTP_METHOD_GET;
	}

	public function sendRequest()
	{
		$ch = curl_init();
		if (! is_resource($ch) ) {
			return false;
		}
		curl_setopt( $ch , CURLOPT_SSL_VERIFYPEER , 0 );
		curl_setopt( $ch , CURLOPT_FOLLOWLOCATION , 0 );
		curl_setopt( $ch , CURLOPT_URL , $this->getEndpoint() );
		switch( $this->method ) {
			case self::HTTP_METHOD_GET:
				curl_setopt( $ch , CURLOPT_HTTPGET , 1 );
				if( count($this->params) > 0 ) {
					curl_setopt( $ch , CURLOPT_URL ,
					$this->getEndpoint() . '?' . http_build_query($this->params)
					);
				}
				break;
			case self::HTTP_METHOD_POST:
				curl_setopt( $ch , CURLOPT_POST , 1 );
				if( count($this->params) > 0 ) {
					curl_setopt( $ch , CURLOPT_POSTFIELDS , http_build_query($this->params) );
				}
				break;
		}
		curl_setopt( $ch , CURLOPT_TIMEOUT , $this->getTimeout() );
		curl_setopt( $ch , CURLOPT_RETURNTRANSFER , 1 );
		curl_setopt( $ch , CURLOPT_HTTPHEADER , $this->headers );
		curl_setopt( $ch , CURLOPT_VERBOSE , 0 );
		$response = curl_exec($ch);
		curl_close($ch);
		return $response;
	}

}

$rest = new RestInterface();
$rest->setMethod( RestInterface::HTTP_METHOD_GET );
$rest->setEndpoint( 'http://www.openlinksw.com/dataspace/person/kidehen@openlinksw.com' );
$rest->addHeader( 'Accept' , 'application/rdf+xml, text/n3, text/rdf+n3, text/turtle, application/x-turtle, application/turtle, text/plain' );
echo $rest->sendRequest();