<?php

// $Id:

function createfromweb_operator_amazon_keywords_name() {
        return "amazon via keywords";
}

/*
 * Inspiration and most of the code is from here:
 * http://manas.tungare.name/blog/howto-obtain-metadata-for-a-book-given-its-isbn-using-amazon-web-services-in-php/
 */

function createfromweb_operator_amazon_keywords_execute($keywords) {

$awsAccessKeyID = 'YOUR ACCESS KEY ID HERE';
    $awsSecretKey = 'YOUR SECRET KEY HERE'; #this is the longer string


    $host = 'ecs.amazonaws.com';
    $path = '/onca/xml';


    $args = array(
      'Service' => 'AWSECommerceService',
      'AWSAccessKeyId' => $awsAccessKeyID,
      'Timestamp' => gmdate('Y-m-d\TH:i:s\Z'),
#      'IdType' => 'ISBN',
#      'ItemId' => $isbn,
#      'Operation' => 'ItemLookup',
      'ResponseGroup' => 'ItemAttributes',
      'SearchIndex' => 'Books',
      'Operation' => 'ItemSearch',
      'SearchIndex' => 'Books',
      'Keywords' => urlencode($keywords),
    );


    ksort($args);
    $parts = array();
    foreach(array_keys($args) as $key) {
      $parts[] = $key . "=" . $args[$key];
    }


    // Construct the string to sign
    $stringToSign = "GET\n" . $host . "\n" . $path . "\n" . implode("&", $parts);
    $stringToSign = str_replace('+', '%20', $stringToSign);
    $stringToSign = str_replace(':', '%3A', $stringToSign);
    $stringToSign = str_replace(';', urlencode(';'), $stringToSign);

    // Sign the request
    $signature = hash_hmac("sha256", $stringToSign, $awsSecretKey, TRUE);

    // Base64 encode the signature and make it URL safe
    $signature = base64_encode($signature);
    $signature = str_replace('+', '%2B', $signature);
    $signature = str_replace('=', '%3D', $signature);
    $signature = str_replace(' ', '%20', $signature);


    // Construct the URL
    $url = 'http://' . $host . $path . '?' . implode("&", $parts) . "&Signature=" . $signature;


    //Catch the response in the $parsed_xml object
    $parsed_xml = simplexml_load_file($url)
      or drupal_set_message ("amazon: book search failed",error);

    //$parsed_xml = simplexml_load_string($response);
    //printSearchResults($parsed_xml, $SearchIndex);

    $amazonresults = array();
        foreach($parsed_xml->Items->Item as $current){
            $year_pattern = "/[0-9]{4}/";
            $raw_date = utf8_decode((string)$current->ItemAttributes->PublicationDate);
            if( preg_match( $year_pattern, $raw_date, $matches ) ) {
                $publication_year = $matches[0];
            } else {
                $publication_year = $raw_date;
            }
            foreach($current->ItemAttributes->Author as $author) {
              $authors[] = utf8_decode((string)$author);
            }
            $author_s = implode(', ', $authors);
            $amazonresults[] = array(
                "title" => utf8_decode((string)$current->ItemAttributes->Title),
                "authors" => $author_s,
                "publisher" => utf8_decode((string)$current->ItemAttributes->Publisher),
                "isbn" => utf8_decode((string)$current->ItemAttributes->ISBN),
                "year" => $publication_year,
                "date" => $raw_date,
                "item_link" => utf8_decode((string)$current->DetailPageURL),
                "query_url" => $url,
                //"SmallImageURL" => utf8_decode((string)$current->ItemAttributes->SmallImageURL),
            );
        }
    #print_r($amazonresults); die();
    return $amazonresults;
}