From b359b15cdb646834771647297d3b1a4aefa2992a Mon Sep 17 00:00:00 2001
From: Christian Herdtweck <christian.herdtweck@intra2net.com>
Date: Thu, 24 Jan 2019 16:43:08 +0100
Subject: [PATCH] Create new mail_utils option: get headers+attachments

Often I parse and transfer big email message when actually
I only want the headers plus the attachment file names.

Create an option for this in mail_utils.parse_mail_file
---
 src/mail_utils.py |   42 ++++++++++++++++++++++++++++++++++--------
 1 files changed, 34 insertions(+), 8 deletions(-)

diff --git a/src/mail_utils.py b/src/mail_utils.py
index fde7a4b..75c4bb5 100644
--- a/src/mail_utils.py
+++ b/src/mail_utils.py
@@ -688,21 +688,32 @@ def create_users(usernames, config_file, params):
     log.info("%s users successfully created!", len(usernames))
 
 
-def parse_mail_file(file_name, headers_only=True):
+def parse_mail_file(file_name, headers_only=True, attachment_filenames=False):
     """
     Parse given email file (e.g. a banned message).
 
-    :param str file_name: file name for the email
-    :param bool headers_only: whether to parse only the email headers; set this
-                              to False, e.g. if you want to check for
-                              attachments using message.walk()
-    :returns: parsed email
-    :rtype: root message object (of class :py:class:`email.message.Message`)
+    This is basically a `email.parser.Parser().parse(...)` with given
+    `headers_only`, that can handle BSMTP. As an extra bonus, you can just
+    request headers plus the names of attached files.
 
     Removes the SMTP envelope surrounding the email if present. Only left-over
     might be a line with a '.' at end of non-multipart messages if
      `headers_only` is False.
+
+    :param str file_name: file name for the email
+    :param bool headers_only: whether to parse only the email headers; set this
+                              to False, e.g. if you want to check for
+                              attachments using message.walk()
+    :param bool attachment_filenames: if you just want headers and names of
+                                      attached files, set `headers_only` and
+                                      this to True.
+    :returns: either msg or 2-tuple `(msg, filenames)` if requested per arg
+              `attachment_filenames`
+    :rtype: :py:class:`email.message.Message` or
+             (:py:class:`email.message.Message`, (str))
     """
+    msg = None
+    start_pos = 0
     with open(file_name, 'r') as read_handle:
         line = read_handle.readline()
         if line.startswith('EHLO'):
@@ -713,7 +724,22 @@ def parse_mail_file(file_name, headers_only=True):
             # multipart)
         else:
             read_handle.seek(0)  # forget we read the first line already
-        return Parser().parse(read_handle, headersonly=headers_only)
+        start_pos = read_handle.tell()
+        msg = Parser().parse(read_handle, headersonly=headers_only)
+
+    if not attachment_filenames:
+        return msg
+
+    # otherwise need to parse complete message to get attachment file names
+    if headers_only:
+        with open(file_name, 'r') as read_handle:
+            read_handle.seek(start_pos)
+            full_msg = Parser().parse(read_handle, headersonly=False)
+    else:
+        full_msg = msg
+    filenames = [get_filename(part) for part in full_msg.walk()]
+    return msg, tuple(filename for filename in filenames
+                      if filename is not None)
 
 
 def get_user_mail(user, mailbox='INBOX', **kwargs):
-- 
1.7.1