From: W. Trevor King Date: Fri, 31 Aug 2012 18:34:16 +0000 (-0400) Subject: mailpipe: split initial _parse_message processing into sub-functions. X-Git-Tag: v0.3~51 X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=c76cc1a92e0d45605ca7e73e1f6e14156191c0c7;p=pygrader.git mailpipe: split initial _parse_message processing into sub-functions. New functions: * _get_message_person_and_subject (which calls the others internally) * _get_message_person * _get_decoded_message * _get_message_subject With the previous implementation, all the inline error handling was making the intended logic of _parse_message difficult to follow. --- diff --git a/pygrader/mailpipe.py b/pygrader/mailpipe.py index c8f4550..3f44ffe 100644 --- a/pygrader/mailpipe.py +++ b/pygrader/mailpipe.py @@ -596,88 +596,22 @@ def _load_messages(course, stream, mailbox=None, input_=None, output=None, yield ret def _parse_message(course, msg, respond=None, use_color=None): + """Parse an incoming email and respond if neccessary. + + Return ``(msg, person, assignment, time)`` on successful parsing. + Return ``None`` on failure. + """ highlight,lowlight,good,bad = _standard_colors(use_color=use_color) + original = msg mid = msg['Message-ID'] - sender = msg['Return-Path'] # RFC 822 - if sender is None: - _LOG.debug(_color_string( - string='no Return-Path in {}'.format(mid), color=lowlight)) - return None - sender = sender[1:-1] # strip wrapping '<' and '>' - - people = list(course.find_people(email=sender)) - if len(people) == 0: - _LOG.warn(_color_string( - string='no person found to match {}'.format(sender), - color=bad)) - if respond: - person = _Person(name=sender, emails=[sender]) - response_subject = 'unregistered address {}'.format(sender) - response_text = ( - '{},\n\n' - 'Your email address is not registered with pygrader for\n' - '{}. If you feel it should be, contact your professor\n' - 'or TA.\n\n' - 'Yours,\n{}').format( - sender, course.name, course.robot.alias()) - response = _construct_response( - author=course.robot, targets=[person], - subject=response_subject, text=response_text, original=msg) - respond(response) - return None - if len(people) > 1: - _LOG.warn(_color_string( - string='multiple people match {} ({})'.format( - sender, ', '.join(str(p) for p in people)), - color=bad)) - return None - person = people[0] - - if person.pgp_key: - original = msg - msg = _get_verified_message(msg, person.pgp_key, use_color=use_color) - if msg is None: - if respond: - response_subject = 'unsigned message {}'.format(mid) - response_text = ( - '{},\n\n' - 'We received an email message from you without a valid\n' - 'PGP signature.\n\n' - 'Yours,\n{}').format( - person.alias(), course.robot.alias()) - response = _construct_response( - author=course.robot, targets=[person], - subject=response_subject, text=response_text, - original=original) - respond(response) - return None - - if msg['Subject'] is None: - _LOG.warn(_color_string( - string='no subject in {}'.format(mid), color=bad)) - if respond: - response_subject = 'no subject in {}'.format(mid) - response_text = ( - '{},\n\n' - 'We received an email message from you without a subject.\n\n' - 'Yours,\n{}').format( - person.alias(), course.robot.alias()) - response = _construct_response( - author=course.robot, targets=[person], - subject=response_subject, text=response_text, original=msg) - respond(response) - return None - parts = _decode_header(msg['Subject']) - if len(parts) != 1: - _LOG.warn(_color_string( - string='multi-part header {}'.format(parts), color=bad)) + try: + msg,person,subject = _get_message_person_and_subject( + course=course, message=msg, original=original, respond=respond, + use_color=use_color) + except ValueError as error: + _LOG.debug(_color_string(string=str(error), color=bad)) return None - subject,encoding = parts[0] - if encoding is None: - encoding = 'ascii' - _LOG.debug('decoded header {} -> {}'.format(parts[0], subject)) - subject = subject.lower().replace('#', '') for assignment in course.assignments: if _match_assignment(assignment, subject): break @@ -748,6 +682,100 @@ def _parse_message(course, msg, respond=None, use_color=None): respond(response) return (msg, person, assignment, time) +def _get_message_person(course, message, original, respond=None, + use_color=None): + mid = message['Message-ID'] + sender = message['Return-Path'] # RFC 822 + if sender is None: + raise ValueError('no Return-Path in {}'.format(mid)) + sender = sender[1:-1] # strip wrapping '<' and '>' + people = list(course.find_people(email=sender)) + if len(people) == 0: + if respond: + person = _Person(name=sender, emails=[sender]) + response_subject = 'unregistered address {}'.format(sender) + response_text = ( + '{},\n\n' + 'Your email address is not registered with pygrader for\n' + '{}. If you feel it should be, contact your professor\n' + 'or TA.\n\n' + 'Yours,\n{}').format( + sender, course.name, course.robot.alias()) + response = _construct_response( + author=course.robot, targets=[person], + subject=response_subject, text=response_text, + original=original) + respond(response) + raise ValueError('no person found to match {}'.format(sender)) + if len(people) > 1: + raise ValueError('multiple people match {} ({})'.format( + sender, ', '.join(str(p) for p in people))) + return people[0] + +def _get_decoded_message(course, message, original, person, + respond=None, use_color=None): + message = _get_verified_message( + message, person.pgp_key, use_color=use_color) + if message is None: + if respond: + mid = original['Message-ID'] + response_subject = 'unsigned message {}'.format(mid) + response_text = ( + '{},\n\n' + 'We received an email message from you without a valid\n' + 'PGP signature.\n\n' + 'Yours,\n{}').format( + person.alias(), course.robot.alias()) + response = _construct_response( + author=course.robot, targets=[person], + subject=response_subject, text=response_text, + original=original) + respond(response) + raise ValueError('unsigned message from {}'.format(person.alias())) + return message + +def _get_message_subject(course, message, original, person, + respond=None, use_color=None): + if message['Subject'] is None: + mid = message['Message-ID'] + response_subject = 'no subject in {}'.format(mid) + if respond: + response_text = ( + '{},\n\n' + 'We received an email message from you without a subject.\n\n' + 'Yours,\n{}').format( + person.alias(), course.robot.alias()) + response = _construct_response( + author=course.robot, targets=[person], + subject=response_subject, text=response_text, + original=original) + respond(response) + raise ValueError(response_subject) + + parts = _decode_header(message['Subject']) + if len(parts) != 1: + raise ValueError('multi-part header {}'.format(parts)) + subject,encoding = parts[0] + if encoding is None: + encoding = 'ascii' + _LOG.debug('decoded header {} -> {}'.format(parts[0], subject)) + return subject.lower().replace('#', '') + +def _get_message_person_and_subject(course, message, original, + respond=None, use_color=None): + original = message + person = _get_message_person( + course=course, message=message, original=original, + respond=respond, use_color=use_color) + if person.pgp_key: + message = _get_decoded_message( + course=course, message=message, original=original, person=person, + respond=respond, use_color=use_color) + subject = _get_message_subject( + course=course, message=message, original=original, person=person, + respond=respond, use_color=use_color) + return (message, person, subject) + def _match_assignment(assignment, subject): return assignment.name.lower() in subject