Function ExtractForwardContext

internal/outbound/forward.go:36–57

ExtractForwardContext parses an RFC 5322 raw message and pulls out the fields needed to compose a forward quote. Parse failures degrade gracefully — the returned context's body fields stay empty so the caller still gets a usable header block to prepend.

(rawMessage []byte)

// gracefully — the returned context's body fields stay empty so the
// caller still gets a usable header block to prepend.
func ExtractForwardContext(rawMessage []byte) ForwardContext {
	ctx := ForwardContext{}
	if len(rawMessage) == 0 {
		return ctx
	}

	msg, err := mail.ReadMessage(bytes.NewReader(rawMessage))
	if err != nil {
		return ctx
	}

	ctx.From = strings.TrimSpace(msg.Header.Get("From"))
	ctx.Date = strings.TrimSpace(msg.Header.Get("Date"))
	ctx.Subject = strings.TrimSpace(msg.Header.Get("Subject"))
	ctx.To = strings.TrimSpace(msg.Header.Get("To"))
	ctx.Cc = strings.TrimSpace(msg.Header.Get("Cc"))

	contentType := msg.Header.Get("Content-Type")
	encoding := msg.Header.Get("Content-Transfer-Encoding")
	ctx.Text, ctx.HTML = extractBodyParts(msg.Body, contentType, encoding)
	return ctx
}

// extractBodyParts walks a message body looking for the text/plain and
// text/html parts. Recurses into multipart/alternative and