static bool TryGetMultipartAlternativeBody(BodyPartMultipart multipart, bool html, out BodyPartText body)
{
// walk the multipart/alternative children backwards from greatest level of faithfulness to the least faithful
for (int i = multipart.BodyParts.Count - 1; i >= 0; i--)
{
var multi = multipart.BodyParts[i] as BodyPartMultipart;
BodyPartText text = null;
if (multi != null)
{
if (multi.ContentType.IsMimeType("multipart", "related"))
{
text = GetMultipartRelatedRoot(multi) as BodyPartText;
}
else if (multi.ContentType.IsMimeType("multipart", "alternative"))
{
// Note: nested multipart/alternatives make no sense... yet here we are.
if (TryGetMultipartAlternativeBody(multi, html, out body))
{
return(true);
}
}
}
else
{
text = multipart.BodyParts[i] as BodyPartText;
}
if (text != null && (html ? text.IsHtml : text.IsPlain))
{
body = text;
return(true);
}
}
body = null;
return(false);
}
static BodyPart GetMultipartRelatedRoot(BodyPartMultipart related)
{
string start = related.ContentType.Parameters["start"];
string contentId;
if (start == null)
{
return(related.BodyParts.Count > 0 ? related.BodyParts[0] : null);
}
if ((contentId = MimeUtils.EnumerateReferences(start).FirstOrDefault()) == null)
{
contentId = start;
}
var cid = new Uri(string.Format("cid:{0}", contentId));
for (int i = 0; i < related.BodyParts.Count; i++)
{
var basic = related.BodyParts[i] as BodyPartBasic;
if (basic != null && (basic.ContentId == contentId || basic.ContentLocation == cid))
{
return(basic);
}
var multipart = related.BodyParts[i] as BodyPartMultipart;
if (multipart != null && multipart.ContentLocation == cid)
{
return(multipart);
}
}
return(null);
}
static bool TryParse(string text, ref int index, string path, out BodyPart part)
{
ContentDisposition disposition;
ContentType contentType;
string[] array;
string nstring;
Uri location;
uint number;
part = null;
while (index < text.Length && text[index] == ' ')
{
index++;
}
if (index >= text.Length || text[index] != '(')
{
if (index + 3 <= text.Length && text.Substring(index, 3) == "NIL")
{
index += 3;
return(true);
}
return(false);
}
index++;
if (index >= text.Length)
{
return(false);
}
if (text[index] == '(')
{
var prefix = path.Length > 0 ? path + "." : string.Empty;
var multipart = new BodyPartMultipart();
IList <BodyPart> children;
if (!TryParse(text, ref index, prefix, out children))
{
return(false);
}
foreach (var child in children)
{
multipart.BodyParts.Add(child);
}
if (!TryParse(text, ref index, true, out contentType))
{
return(false);
}
multipart.ContentType = contentType;
if (!TryParse(text, ref index, out disposition))
{
return(false);
}
multipart.ContentDisposition = disposition;
if (!TryParse(text, ref index, out array))
{
return(false);
}
multipart.ContentLanguage = array;
if (!TryParse(text, ref index, out location))
{
return(false);
}
multipart.ContentLocation = location;
part = multipart;
}
else
{
BodyPartMessage message = null;
BodyPartText txt = null;
BodyPartBasic basic;
if (!TryParse(text, ref index, false, out contentType))
{
return(false);
}
if (contentType.IsMimeType("message", "rfc822"))
{
basic = message = new BodyPartMessage();
}
else if (contentType.IsMimeType("text", "*"))
{
basic = txt = new BodyPartText();
}
else
{
basic = new BodyPartBasic();
}
basic.ContentType = contentType;
if (!TryParse(text, ref index, out nstring))
{
return(false);
}
basic.ContentId = nstring;
if (!TryParse(text, ref index, out nstring))
{
return(false);
}
basic.ContentDescription = nstring;
if (!TryParse(text, ref index, out nstring))
{
return(false);
}
basic.ContentTransferEncoding = nstring;
if (!TryParse(text, ref index, out number))
{
return(false);
}
basic.Octets = number;
if (!TryParse(text, ref index, out nstring))
{
return(false);
}
basic.ContentMd5 = nstring;
if (!TryParse(text, ref index, out disposition))
{
return(false);
}
basic.ContentDisposition = disposition;
if (!TryParse(text, ref index, out array))
{
return(false);
}
basic.ContentLanguage = array;
if (!TryParse(text, ref index, out location))
{
return(false);
}
basic.ContentLocation = location;
if (message != null)
{
Envelope envelope;
BodyPart body;
if (!Envelope.TryParse(text, ref index, out envelope))
{
return(false);
}
message.Envelope = envelope;
if (!TryParse(text, ref index, path, out body))
{
return(false);
}
message.Body = body;
if (!TryParse(text, ref index, out number))
{
return(false);
}
message.Lines = number;
}
else if (txt != null)
{
if (!TryParse(text, ref index, out number))
{
return(false);
}
txt.Lines = number;
}
part = basic;
}
part.PartSpecifier = path;
if (index >= text.Length || text[index] != ')')
{
return(false);
}
index++;
return(true);
}
static bool TryGetMessageBody (BodyPartMultipart multipart, bool html, out BodyPartText body)
{
BodyPartMultipart multi;
BodyPartText text;
if (multipart.ContentType.IsMimeType ("multipart", "alternative"))
return TryGetMultipartAlternativeBody (multipart, html, out body);
if (!multipart.ContentType.IsMimeType ("multipart", "related")) {
// Note: This is probably a multipart/mixed... and if not, we can still treat it like it is.
for (int i = 0; i < multipart.BodyParts.Count; i++) {
multi = multipart.BodyParts[i] as BodyPartMultipart;
// descend into nested multiparts, if there are any...
if (multi != null) {
if (TryGetMessageBody (multi, html, out body))
return true;
// The text body should never come after a multipart.
break;
}
text = multipart.BodyParts[i] as BodyPartText;
// Look for the first non-attachment text part (realistically, the body text will
// preceed any attachments, but I'm not sure we can rely on that assumption).
if (text != null && !text.IsAttachment) {
if (html ? text.IsHtml : text.IsPlain) {
body = text;
return true;
}
// Note: the first text/* part in a multipart/mixed is the text body.
// If it's not in the format we're looking for, then it doesn't exist.
break;
}
}
} else {
// Note: If the multipart/related root document is HTML, then this is the droid we are looking for.
var root = GetMultipartRelatedRoot (multipart);
text = root as BodyPartText;
if (text != null) {
body = (html ? text.IsHtml : text.IsPlain) ? text : null;
return body != null;
}
// maybe the root is another multipart (like multipart/alternative)?
multi = root as BodyPartMultipart;
if (multi != null)
return TryGetMessageBody (multi, html, out body);
}
body = null;
return false;
}
static bool TryGetMultipartAlternativeBody (BodyPartMultipart multipart, bool html, out BodyPartText body)
{
// walk the multipart/alternative children backwards from greatest level of faithfulness to the least faithful
for (int i = multipart.BodyParts.Count - 1; i >= 0; i--) {
var multi = multipart.BodyParts[i] as BodyPartMultipart;
BodyPartText text = null;
if (multi != null) {
if (multi.ContentType.IsMimeType ("multipart", "related")) {
text = GetMultipartRelatedRoot (multi) as BodyPartText;
} else if (multi.ContentType.IsMimeType ("multipart", "alternative")) {
// Note: nested multipart/alternatives make no sense... yet here we are.
if (TryGetMultipartAlternativeBody (multi, html, out body))
return true;
}
} else {
text = multipart.BodyParts[i] as BodyPartText;
}
if (text != null && (html ? text.IsHtml : text.IsPlain)) {
body = text;
return true;
}
}
body = null;
return false;
}
static BodyPart GetMultipartRelatedRoot (BodyPartMultipart related)
{
string start = related.ContentType.Parameters["start"];
string contentId;
if (start == null)
return related.BodyParts.Count > 0 ? related.BodyParts[0] : null;
if ((contentId = MimeUtils.EnumerateReferences (start).FirstOrDefault ()) == null)
contentId = start;
var cid = new Uri (string.Format ("cid:{0}", contentId));
for (int i = 0; i < related.BodyParts.Count; i++) {
var basic = related.BodyParts[i] as BodyPartBasic;
if (basic != null && (basic.ContentId == contentId || basic.ContentLocation == cid))
return basic;
var multipart = related.BodyParts[i] as BodyPartMultipart;
if (multipart != null && multipart.ContentLocation == cid)
return multipart;
}
return null;
}
static bool TryGetMessageBody(BodyPartMultipart multipart, bool html, out BodyPartText body)
{
BodyPartMultipart multi;
BodyPartText text;
if (multipart.ContentType.IsMimeType("multipart", "alternative"))
{
return(TryGetMultipartAlternativeBody(multipart, html, out body));
}
if (!multipart.ContentType.IsMimeType("multipart", "related"))
{
// Note: This is probably a multipart/mixed... and if not, we can still treat it like it is.
for (int i = 0; i < multipart.BodyParts.Count; i++)
{
multi = multipart.BodyParts[i] as BodyPartMultipart;
// descend into nested multiparts, if there are any...
if (multi != null)
{
if (TryGetMessageBody(multi, html, out body))
{
return(true);
}
// The text body should never come after a multipart.
break;
}
text = multipart.BodyParts[i] as BodyPartText;
// Look for the first non-attachment text part (realistically, the body text will
// preceed any attachments, but I'm not sure we can rely on that assumption).
if (text != null && !text.IsAttachment)
{
if (html ? text.IsHtml : text.IsPlain)
{
body = text;
return(true);
}
// Note: the first text/* part in a multipart/mixed is the text body.
// If it's not in the format we're looking for, then it doesn't exist.
break;
}
}
}
else
{
// Note: If the multipart/related root document is HTML, then this is the droid we are looking for.
var root = GetMultipartRelatedRoot(multipart);
text = root as BodyPartText;
if (text != null)
{
body = (html ? text.IsHtml : text.IsPlain) ? text : null;
return(body != null);
}
// maybe the root is another multipart (like multipart/alternative)?
multi = root as BodyPartMultipart;
if (multi != null)
{
return(TryGetMessageBody(multi, html, out body));
}
}
body = null;
return(false);
}
static BodyPartMultipart CreateMultipart (string type, string subtype, string partSpecifier, params BodyPart[] bodyParts)
{
var multipart = new BodyPartMultipart { ContentType = CreateContentType (type, subtype, partSpecifier) };
foreach (var bodyPart in bodyParts)
multipart.BodyParts.Add (bodyPart);
return multipart;
}
static bool TryParse (string text, ref int index, string path, out BodyPart part)
{
ContentDisposition disposition;
ContentType contentType;
string[] array;
string nstring;
Uri location;
uint number;
part = null;
while (index < text.Length && text[index] == ' ')
index++;
if (index >= text.Length || text[index] != '(') {
if (index + 3 <= text.Length && text.Substring (index, 3) == "NIL") {
index += 3;
return true;
}
return false;
}
index++;
if (index >= text.Length)
return false;
if (text[index] == '(') {
var prefix = path.Length > 0 ? path + "." : string.Empty;
var multipart = new BodyPartMultipart ();
IList<BodyPart> children;
if (!TryParse (text, ref index, prefix, out children))
return false;
foreach (var child in children)
multipart.BodyParts.Add (child);
if (!TryParse (text, ref index, true, out contentType))
return false;
multipart.ContentType = contentType;
if (!TryParse (text, ref index, out disposition))
return false;
multipart.ContentDisposition = disposition;
if (!TryParse (text, ref index, out array))
return false;
multipart.ContentLanguage = array;
if (!TryParse (text, ref index, out location))
return false;
multipart.ContentLocation = location;
part = multipart;
} else {
BodyPartMessage message = null;
BodyPartText txt = null;
BodyPartBasic basic;
if (!TryParse (text, ref index, false, out contentType))
return false;
if (contentType.Matches ("message", "rfc822"))
basic = message = new BodyPartMessage ();
else if (contentType.Matches ("text", "*"))
basic = txt = new BodyPartText ();
else
basic = new BodyPartBasic ();
basic.ContentType = contentType;
if (!TryParse (text, ref index, out nstring))
return false;
basic.ContentId = nstring;
if (!TryParse (text, ref index, out nstring))
return false;
basic.ContentDescription = nstring;
if (!TryParse (text, ref index, out nstring))
return false;
basic.ContentTransferEncoding = nstring;
if (!TryParse (text, ref index, out number))
return false;
basic.Octets = number;
if (!TryParse (text, ref index, out nstring))
return false;
basic.ContentMd5 = nstring;
if (!TryParse (text, ref index, out disposition))
return false;
basic.ContentDisposition = disposition;
if (!TryParse (text, ref index, out array))
return false;
basic.ContentLanguage = array;
if (!TryParse (text, ref index, out location))
return false;
basic.ContentLocation = location;
if (message != null) {
Envelope envelope;
BodyPart body;
if (!Envelope.TryParse (text, ref index, out envelope))
return false;
message.Envelope = envelope;
if (!TryParse (text, ref index, path, out body))
return false;
message.Body = body;
if (!TryParse (text, ref index, out number))
return false;
message.Lines = number;
} else if (txt != null) {
if (!TryParse (text, ref index, out number))
return false;
txt.Lines = number;
}
part = basic;
}
part.PartSpecifier = path;
if (index >= text.Length || text[index] != ')')
return false;
index++;
return true;
}
async void RenderRelated (IMailFolder folder, UniqueId uid, BodyPartMultipart related)
{
var start = related.ContentType.Parameters["start"];
BodyPartText root = null;
if (!string.IsNullOrEmpty (start)) {
// if the 'start' parameter is set, it overrides the default behavior of using the first
// body part as the main document.
root = related.BodyParts.OfType<BodyPartText> ().FirstOrDefault (x => x.ContentId == start);
} else if (related.BodyParts.Count > 0) {
// this will generally either be a text/html part (which is what we are looking for) or a multipart/alternative
var multipart = related.BodyParts[0] as BodyPartMultipart;
if (multipart != null) {
if (multipart.ContentType.Matches ("multipart", "alternative") && multipart.BodyParts.Count > 0) {
// find the last text/html part (which will be the closest to what the sender saw in their WYSIWYG editor)
// or, failing that, the last text part.
for (int i = multipart.BodyParts.Count; i > 0; i--) {
var bodyPart = multipart.BodyParts[i - 1] as BodyPartText;
if (bodyPart == null)
continue;
if (bodyPart.ContentType.Matches ("text", "html")) {
root = bodyPart;
break;
}
if (root == null)
root = bodyPart;
}
}
} else {
root = related.BodyParts[0] as BodyPartText;
}
}
if (root == null)
return;
var text = await folder.GetBodyPartAsync (uid, root) as TextPart;
if (text != null && text.ContentType.Matches ("text", "html")) {
var doc = new HtmlAgilityPack.HtmlDocument ();
var saved = new Dictionary<MimePart, string> ();
TextPart html;
doc.LoadHtml (text.Text);
// find references to related MIME parts and replace them with links to links to the saved attachments
foreach (var img in doc.DocumentNode.SelectNodes ("//img[@src]")) {
var src = img.Attributes["src"];
int index;
Uri uri;
if (src == null || src.Value == null)
continue;
// parse the <img src=...> attribute value into a Uri
if (Uri.IsWellFormedUriString (src.Value, UriKind.Absolute))
uri = new Uri (src.Value, UriKind.Absolute);
else
uri = new Uri (src.Value, UriKind.Relative);
// locate the index of the attachment within the multipart/related (if it exists)
if ((index = related.BodyParts.IndexOf (uri)) != -1) {
var bodyPart = related.BodyParts[index] as BodyPartBasic;
if (bodyPart == null) {
// the body part is not a basic leaf part (IOW it's a multipart or message-part)
continue;
}
var attachment = await folder.GetBodyPartAsync (uid, bodyPart) as MimePart;
// make sure the referenced part is a MimePart (as opposed to another Multipart or MessagePart)
if (attachment == null)
continue;
string fileName;
// save the attachment (if we haven't already saved it)
if (!saved.TryGetValue (attachment, out fileName)) {
fileName = attachment.FileName;
if (string.IsNullOrEmpty (fileName))
fileName = Guid.NewGuid ().ToString ();
if (!Directory.Exists (uid.ToString ()))
Directory.CreateDirectory (uid.ToString ());
fileName = Path.Combine (uid.ToString (), fileName);
using (var stream = File.Create (fileName))
attachment.ContentObject.DecodeTo (stream);
saved.Add (attachment, fileName);
}
// replace the <img src=...> value with the local file name
src.Value = "file://" + Path.GetFullPath (fileName);
}
}
if (saved.Count > 0) {
// we had to make some modifications to the original html part, so create a new
// (temporary) text/html part to render
html = new TextPart ("html");
using (var writer = new StringWriter ()) {
doc.Save (writer);
html.Text = writer.GetStringBuilder ().ToString ();
}
} else {
html = text;
}
RenderText (html);
} else if (text != null) {
RenderText (text);
}
}
async void RenderMultipartRelated (IMailFolder folder, UniqueId uid, BodyPartMultipart bodyPart)
{
// download the entire multipart/related for simplicity since we'll probably end up needing all of the image attachments anyway...
var related = await folder.GetBodyPartAsync (uid, bodyPart) as MultipartRelated;
RenderMultipartRelated (related);
}
