public class Amazon_Integration {
    
    public String action = 'SubmitFeed';
    public String FeedType ='_POST_PRODUCT_DATA_';
    Public string accessKey = 'AKIexampleOKHWA';
    Public string MarketplaceId = 'AexampleDER';
    Public string SellerId = 'AUexampleRCX';
    Public string SignatureMethod='HmacSHA256';
    Public string SignatureVersion='2';    
    Public string version='2009-01-01';
    Public string amazonSecretKey='9YexampleWQMeM';
    Public string mwstoken = 'amzn.mws.example.9f650';
    public string endpoint = 'https://mws.amazonservices.com/Feeds/2009-01-01';        
    
    //Prepare the feed 
	public String prepare_body(String sellerId){
        
       String xmlBody = '<?xml version="1.0" encoding="UTF-8"?>' + 
                     '<AmazonEnvelope xmlns:xsi=http://www.w3.org/2001/XMLSchema-instance xsi:noNamespaceSchemaLocation="amzn-envelope.xsd">'+
                         '<Header>' +
                         '<DocumentVersion>1.01</DocumentVersion>' +
                         '<MerchantIdentifier>' + sellerId + '</MerchantIdentifier>' +
                         '</Header>' +
                         '<MessageType>Product</MessageType>' +                         
                         '<Message>' +
                             '<MessageID>1</MessageID>' +
                             '<OperationType>Update</OperationType>' +
                             '<Product>' +
                                 '<SKU>56789</SKU>' +
                                 '<StandardProductID>' +
                                 '<Type>ASIN</Type>' +
                                 '<Value>B0EXAMPLEG</Value>' +
                                 '</StandardProductID>' +
                                 '<ProductTaxCode>A_GEN_NOTAX</ProductTaxCode>' +
                                 '<DescriptionData>' +
                                     '<Title>Example Product Title</Title>' +
                                     '<Brand>Example Product Brand</Brand>' +
                                     '<Description>This is an example product description.</Description>' +
                                     '<BulletPoint>Example Bullet Point 1</BulletPoint>' +
                                     '<BulletPoint>Example Bullet Point 2</BulletPoint>' +
                                     '<MSRP currency="USD">25.19</MSRP>' +
                                     '<Manufacturer>Example Product Manufacturer</Manufacturer>' +
                                     '<ItemType>example-item-type</ItemType>' +
                                  '</DescriptionData>' +
                                  '<ProductData>' +
                                    '<Health>' +
                                      '<ProductType>' +
                                        '<HealthMisc>' +
                                          '<Ingredients>Example Ingredients</Ingredients>' +
                                          '<Directions>Example Directions</Directions>' +
                                        '</HealthMisc>' +
                                      '</ProductType>' +
                                     '</Health>' +
                                   '</ProductData>' +
                                '</Product>' +
                             '</Message>' +
                           '</AmazonEnvelope>';                                              
            
            return xmlBody;
    }
    
    public String get_contentmd5(String xmlBody){
        	Blob targetBlob = Blob.valueOf(xmlBody);
        	Blob hash = Crypto.generateDigest('MD5', targetBlob);    
        	String contentMD5 = EncodingUtil.base64Encode(hash);
        	contentMD5 =  EncodingUtil.URLENCODE(contentMD5,'UTF-8');                    
        	return contentMD5;
    }
    
    public string send_feed_to_amazon(String xmlBody, String ContentMD5){

        String timestamp = datetime.now().formatGMT('yyyy-MM-dd\'T\'HH:mm:ss.SSS\'Z\'');
        timestamp = EncodingUtil.urlEncode(timestamp,'UTF-8');
        
        //Construct a query string with the query information
        String queryString = 'AWSAccessKeyId=' + accessKey + 
            '&Action=SubmitFeed'+
            '&ContentMD5Value=' + ContentMD5 +
            '&FeedType=_POST_PRODUCT_DATA_'+
            '&MWSAuthToken=' + mwstoken +   
            '&MarketplaceId.Id.1=' + MarketplaceId  +
            '&SellerId=' + SellerId +                                         
            '&SignatureMethod=' + SignatureMethod  +
            '&SignatureVersion=' + SignatureVersion  +
            '&Timestamp=' + timestamp  +
            '&Version=' + version;

        String stringtoSign = 'POST' + '\n' +
            'mws.amazonservices.com' + '\n' +
            '/Feeds/2009-01-01' + '\n' +
            queryString;               
        
        //Covert query string to signature using Amazon secret key as key
        Blob mac = Crypto.generateMac('HMacSHA256', 
        blob.valueof(stringtoSign),blob.valueof(amazonSecretKey));

        String signature = EncodingUtil.base64Encode(mac);
        signature = EncodingUtil.urlEncode(signature,'UTF-8');        

       //Create a new request
       HttpRequest request = new HttpRequest();    
        
       request.setEndpoint(endpoint +'?AWSAccessKeyId=' + accessKey +
                		   '&Action=SubmitFeed'+                                                                                 
                           '&FeedType=_POST_PRODUCT_DATA_'+                                                      
                           '&MWSAuthToken=' + mwstoken +
                           '&MarketplaceIdList.Id.1=' + marketplaceId +
                           '&SellerId=' + sellerId +
                           '&ContentMD5Value=' + ContentMD5 +
                           '&SignatureMethod='+ signatureMethod +
                           '&SignatureVersion=2' +
                           '&Timestamp=' + timestamp +
                           '&Version=' + version +                           
                           '&Signature=' + signature);
        
        request.setMethod('POST');
        request.setHeader('Content-type', 'text/xml');        
        request.setBody(xmlBody);        
        
        Http http = new Http();
        try {
            HttpResponse response = http.send(request);
            string status=response.getStatus();           
            System.debug(response.getStatus());
            System.debug(response.getStatusCode());            
            System.debug(response.getBody());            
            return status;
        } 
        catch(System.CalloutException e) {
            System.debug(e);
            return string.valueOf(e);
        }        
	}
}