/// <summary>
/// Extract the header part and body part of a message.<br/>
/// The headers are then parsed to a strongly typed <see cref="MessageHeader"/> object.
/// </summary>
/// <param name="fullRawMessage">The full message in bytes where header and body needs to be extracted from</param>
/// <param name="headers">The extracted header parts of the message</param>
/// <param name="body">The body part of the message</param>
/// <exception cref="ArgumentNullException">If <paramref name="fullRawMessage"/> is <see langword="null"/></exception>
public static void ExtractHeadersAndBody(byte[] fullRawMessage, out MessageHeader headers, out byte[] body)
{
if(fullRawMessage == null)
throw new ArgumentNullException("fullRawMessage");
// Find the end location of the headers
int endOfHeaderLocation = FindHeaderEndPosition(fullRawMessage);
// The headers are always in ASCII - therefore we can convert the header part into a string
// using US-ASCII encoding
string headersString = Encoding.ASCII.GetString(fullRawMessage, 0, endOfHeaderLocation);
// Now parse the headers to a NameValueCollection
NameValueCollection headersUnparsedCollection = ExtractHeaders(headersString);
// Use the NameValueCollection to parse it into a strongly-typed MessageHeader header
headers = new MessageHeader(headersUnparsedCollection);
// Since we know where the headers end, we also know where the body is
// Copy the body part into the body parameter
body = new byte[fullRawMessage.Length - endOfHeaderLocation];
Array.Copy(fullRawMessage, endOfHeaderLocation, body, 0, body.Length);
}
/// <summary>
/// Used to construct the topmost message part
/// </summary>
/// <param name="rawBody">The body that needs to be parsed</param>
/// <param name="headers">The headers that should be used from the message</param>
/// <exception cref="ArgumentNullException">If <paramref name="rawBody"/> or <paramref name="headers"/> is <see langword="null"/></exception>
internal MessagePart(byte[] rawBody, MessageHeader headers)
{
if(rawBody == null)
throw new ArgumentNullException("rawBody");
if(headers == null)
throw new ArgumentNullException("headers");
ContentType = headers.ContentType;
ContentDescription = headers.ContentDescription;
ContentTransferEncoding = headers.ContentTransferEncoding;
ContentId = headers.ContentId;
ContentDisposition = headers.ContentDisposition;
FileName = FindFileName(ContentType, ContentDisposition, "(no name)");
BodyEncoding = ParseBodyEncoding(ContentType.CharSet);
ParseBody(rawBody);
}