/// <summary>
/// Creates a string that includes the information from the request in a
/// standardized (canonical) format.
/// </summary>
/// <param name="uri"></param>
/// <param name="httpMethodName"></param>
/// <param name="parameters"></param>
/// <param name="preSignedHeaders"></param>
/// <param name="requestPayload"></param>
/// <returns>canonical request string</returns>
/// <seealso cref="http://amazonpaycheckoutintegrationguide.s3.amazonaws.com/amazon-pay-api-v2/signing-requests.html"/>
public string CreateCanonicalRequest(ApiRequest apiRequest, Dictionary <String, List <String> > preSignedHeaders)
{
string path = apiRequest.Path.AbsolutePath;
StringBuilder canonicalRequestBuilder = new StringBuilder();
// if a body was passed to the request, convert it into a JSON string
string body = string.Empty;
if (apiRequest.Body != null)
{
body = apiRequest.BodyAsJsonString;
}
canonicalRequestBuilder.Append(apiRequest.HttpMethod.ToString())
.Append(LineSeparator)
.Append(canonicalBuilder.GetCanonicalizedURI(path))
.Append(LineSeparator)
.Append(canonicalBuilder.GetCanonicalizedQueryString(apiRequest.QueryParameters))
.Append(LineSeparator)
.Append(canonicalBuilder.GetCanonicalizedHeaderString(preSignedHeaders))
.Append(LineSeparator)
.Append(canonicalBuilder.GetSignedHeadersString(preSignedHeaders))
.Append(LineSeparator)
.Append(canonicalBuilder.HashThenHexEncode(body));
return(canonicalRequestBuilder.ToString());
}
