var azure = require('azure'); 
var qs = require('querystring');

function insert(item, user, request) {  
        var accountName = '<replace with your storage account name>';
        var accountKey = '<replace with your storage account key>';         
        var host =   accountName + '.blob.core.windows.net';
        var canonicalizedResource = '/' +  item.containerName + '/' + item.resourceName;
        //Must be lowercase
        item.containerName = item.containerName.toLowerCase();
        
        //Create the container if it does not exist
        //we will use public read access for the blobs and will use a SAS to upload        
        var blobService = azure.createBlobService(accountName, accountKey, host);
        blobService.createContainerIfNotExists(item.containerName, {publicAccessLevel : 'blob'}, function(error){            
            if(!error){
                // Container exists now define a policy that provides write access                      
                // that starts immediately and expires in 5 mins        
                var sharedAccessPolicy = {
                  AccessPolicy:{
                        Permissions: azure.Constants.BlobConstants.SharedAccessPermissions.WRITE,
                        //Start: //use for start time in future, beware of server time skew 
                        Expiry: formatDate(new Date(new Date().getTime() + 5 * 60 * 1000)) //5 minutes from now
                    }
                };
                
                //Generate the SAS for your BLOB
                var sasQueryString = getSAS(accountName,
                                  accountKey, 
                                  canonicalizedResource,
                                  azure.Constants.BlobConstants.ResourceTypes.BLOB,
                                  sharedAccessPolicy);
                
                //full path for resource with sas
                item.sas =  'https://' + host + canonicalizedResource + '?' + sasQueryString;                                         
            }
            else{
                console.error(error);
            }
            
            request.execute();
        });                       
}

function getSAS(accountName, accountKey, path, resourceType, sharedAccessPolicy) {                         
     return qs.encode(new azure.SharedAccessSignature(accountName, accountKey)
                                    .generateSignedQueryString(path, {}, resourceType, sharedAccessPolicy));                           
}

function formatDate(date){ 
        var raw = date.toJSON();
        //blob service does not like milliseconds on the end of the time so strip
        return raw.substr(0, raw.lastIndexOf('.')) + 'Z'; 
}