Stack Overflow question

<?php
	ini_set('display_errors',1);

	class MWSProduct{

		private $keys = array();

		private $serviceURL = "https://mws-eu.amazonservices.com/Products/2011-10-01";

		public function __construct($key, $secret, $name, $version, $merchant, $marketplace) {
			$this->keys = array('ACCESS_KEY'=>$key,
							  	'SECRET_KEY'=>$secret,
							  	'APP_NAME'=>$name,
							  	'APP_VERSION'=>$version,
							  	'MERCHANT_ID'=>$merchant,
							  	'MARKETPLACE_ID'=>$marketplace);
		}

		private function mwsRequestURL($request, $version = '2011-10-01') {
			// breaks the url appart into its components (query, host etc)
			$uri_elements = parse_url($request);
			// pulls the querystring out from the array of url elements
			$request = $uri_elements['query'];
			// parses the string as if it were a querystring and passes it into an array
			parse_str($request, $parameters);
			// Add the new required paramters
			$parameters['Timestamp'] = gmdate("Y-m-d\TH:i:s\Z");
			$parameters['Version'] = $version;
			//adds the access key if it hsa been sent
			$parameters['AWSAccessKeyId'] = $this->keys['ACCESS_KEY'];
		   // The new authentication requirements need the keys to be sorted (by byte value)
			ksort($parameters);
			// loops through the array, and breaks apart the parameter and key at the same time
			foreach ($parameters as $parameter => $value) {
				// We need to be sure we properly encode the value of our parameter
				$parameter = str_replace("%7E", "~", rawurlencode(str_replace('_', '.', $parameter)));
				$value = str_replace("%7E", "~", rawurlencode($value));
				$request_array[] = $parameter . '=' . $value;
			}
			// Put our & symbol at the beginning of each of our request variables and put it in a string
			$new_request = implode('&', $request_array);
			// Create our signature string
			$signature_string = "GET\n{$uri_elements['host']}\n{$uri_elements['path']}\n{$new_request}";
			// Create our signature using hash_hmac
			$signature = urlencode(base64_encode(hash_hmac('sha256', $signature_string, $this->keys['SECRET_KEY'], true)));
			// Return our new request
			return "https://{$uri_elements['host']}{$uri_elements['path']}?{$new_request}&Signature={$signature}";
		}



		public function cheapestPricing($asins) {
			$call = $this->serviceURL;
			$call.= "?AWSAccessKeyId=".$this->keys['ACCESS_KEY'];
			$call.= "&Action=GetLowestOfferListingsForASIN";
			$call.= "&SellerId=".$this->keys['MERCHANT_ID'];
			$call.= "&SignatureVersion=2";
			$call.= "&SignatureMethod=HmacSHA256";
			$call.= "&MarketplaceId=".$this->keys['MARKETPLACE_ID'];
			$call.= "&ExcludeMe=true";

			$count = 0;
			foreach($asins as $asin) {
				$count++;
				$call.= "&ASINList.ASIN.{$count}={$asin}";
			}

			$call = $this->mwsRequestURL($call);
			$response = file_get_contents($call);
			$response = simplexml_load_string($response);

			if(isset($response->GetLowestOfferListingsForASINResult->Error)) {
				return false;
			} else {

				$prices = array();

				foreach($response->GetLowestOfferListingsForASINResult as $product) {
					$asin = (string) $product->Product->Identifiers->MarketplaceASIN->ASIN;
					$prices[$asin] = array('new'=>array(),'used'=>array());
					foreach($product->Product->LowestOfferListings->LowestOfferListing as $price) {
						$cond = (string) strtolower($price->Qualifiers->ItemCondition);
						$sale = (float) $price->Price->ListingPrice->Amount;
						$ship = (float) $price->Price->Shipping->Amount;
						$landed = number_format($sale + $ship, 2, '.', '');
						$prices[$asin][$cond][] = array('landed'=>$landed, 'price'=>$sale, 'shipping'=>$ship);
					}
				}

				return $prices;
			}
		}

		public function getProduct($query) {
			$call = $this->serviceURL;
			$call.= "?AWSAccessKeyId=".$this->keys['ACCESS_KEY'];
			$call.= "&Action=ListMatchingProducts";
			$call.= "&SellerId=".$this->keys['MERCHANT_ID'];
			$call.= "&SignatureVersion=2";
			$call.= "&SignatureMethod=HmacSHA256";
			$call.= "&MarketplaceId=".$this->keys['MARKETPLACE_ID'];
			$call.= "&Query=".$query;

			$call = $this->mwsRequestURL($call);
			$response = str_replace('ns2:', '', file_get_contents($call));
			$response = new SimpleXmlElement($response);

			if(isset($response->ListMatchingProductsResult->Products->Product[0])) {
				$best = $response->ListMatchingProductsResult->Products->Product[0];

				$attributes = array();
				foreach($best->AttributeSets->ItemAttributes as $atts) {
					//preg_match_all('/[A-Z][^A-Z]*/',$str,$results);
					$atts = get_object_vars($atts);
					foreach($atts as $key => $value) {
						preg_match_all('/[A-Z][^A-Z]*/',$key,$name);
						$name = implode(' ', $name[0]);
						$attributes[$key] = array('name'=>$name, 'value'=>$value);
					}
				}

				$title = $attributes['Title']['value'];
				unset($attributes['Title']);

				$asin = (string) $best->Identifiers->MarketplaceASIN->ASIN;

				$imgSize = max((string)$attributes['SmallImage']['value']->Height, (string)$attributes['SmallImage']['value']->Width);
				$imgURL = (string)$attributes['SmallImage']['value']->URL;
				$imgURL = str_replace('._SL'.$imgSize.'_', '', $imgURL);
				unset($attributes['SmallImage']);

				unset($attributes['Languages']);
				unset($attributes['ListPrice']);

				$best = array('name'=>$title,
							  'asin'=>$asin,
							  'img'=>$imgURL,
							  'attributes'=>$attributes);


				return $best;
			} else {
				return false;
			}
		}


	}

?>