forms.py

# Copyright The IETF Trust 2011-2023, All Rights Reserved
# -*- coding: utf-8 -*-


import os
import re
import datetime
import email
import sys
import tempfile
from contextlib import ExitStack

from email.utils import formataddr
from typing import Tuple

from django import forms
from django.conf import settings
from django.utils.html import mark_safe, format_html # type:ignore
from django.urls import reverse as urlreverse
from django.utils import timezone
from django.utils.encoding import force_str

import debug                            # pyflakes:ignore

from ietf.doc.models import Document
from ietf.group.models import Group
from ietf.ietfauth.utils import has_role
from ietf.doc.fields import SearchableDocumentsField
from ietf.ipr.mail import utc_from_string
from ietf.meeting.models import Meeting
from ietf.message.models import Message
from ietf.name.models import FormalLanguageName, GroupTypeName
from ietf.submit.models import Submission, Preapproval
from ietf.submit.utils import validate_submission_name, validate_submission_rev, validate_submission_document_date, remote_ip
from ietf.submit.parsers.plain_parser import PlainParser
from ietf.submit.parsers.xml_parser import XMLParser
from ietf.utils.draft import PlaintextDraft
from ietf.utils.fields import ModelMultipleChoiceField
from ietf.utils.timezone import date_today
from ietf.utils.xmldraft import InvalidXMLError, XMLDraft, XMLParseError


class SubmissionBaseUploadForm(forms.Form):
    xml = forms.FileField(label='.xml format', required=True)

    formats: Tuple[str, ...] = ('xml',)  # allowed formats
    base_formats: Tuple[str, ...] = ('xml',)  # at least one of these is required

    def __init__(self, request, *args, **kwargs):
        super(SubmissionBaseUploadForm, self).__init__(*args, **kwargs)

        self.remote_ip = remote_ip(request)

        self.request = request
        self.in_first_cut_off = False
        self.cutoff_warning = ""
        self.shutdown = False
        self.set_cutoff_warnings()

        self.group = None
        self.filename = None
        self.revision = None
        self.title = None
        self.abstract = None
        self.authors = []
        self.file_types = []
        self.file_info = {}             # indexed by file field name, e.g., 'txt', 'xml', ...
        self.xml_version = None

        self._extracted_filenames_and_revisions = {}

    def set_cutoff_warnings(self):
        now = timezone.now()
        meeting = Meeting.get_current_meeting()
        if not meeting:
            return
        #
        cutoff_00 = meeting.get_00_cutoff()
        cutoff_01 = meeting.get_01_cutoff()
        reopen    = meeting.get_reopen_time()
        #
        cutoff_00_str = cutoff_00.strftime("%Y-%m-%d %H:%M %Z")
        cutoff_01_str = cutoff_01.strftime("%Y-%m-%d %H:%M %Z")
        reopen_str    = reopen.strftime("%Y-%m-%d %H:%M %Z")

        # Workaround for IETF107. This would be better handled by a refactor that allowed meetings to have no cutoff period.
        if cutoff_01 >= reopen:
            return

        if cutoff_00 == cutoff_01:
            if now.date() >= (cutoff_00.date() - meeting.idsubmit_cutoff_warning_days) and now.date() < cutoff_00.date():
                self.cutoff_warning = ( 'The last submission time for Internet-Drafts before %s is %s.<br><br>' % (meeting, cutoff_00_str))
            elif now <= cutoff_00:
                self.cutoff_warning = (
                    'The last submission time for new Internet-Drafts before the meeting is %s.<br>'
                    'After that, you will not be able to submit Internet-Drafts until after %s (IETF-meeting local time)' % (cutoff_00_str, reopen_str, ))
        else:
            if now.date() >= (cutoff_00.date() - meeting.idsubmit_cutoff_warning_days) and now.date() < cutoff_00.date():
                self.cutoff_warning = ( 'The last submission time for new documents (i.e., version -00 Internet-Drafts) before %s is %s.<br><br>' % (meeting, cutoff_00_str) +
                                        'The last submission time for revisions to existing documents before %s is %s.<br>' % (meeting, cutoff_01_str) )
            elif now.date() >= cutoff_00.date() and now <= cutoff_01:
                # We are in the first_cut_off
                if now < cutoff_00:
                    self.cutoff_warning = (
                        'The last submission time for new documents (i.e., version -00 Internet-Drafts) before the meeting is %s.<br>'
                        'After that, you will not be able to submit a new document until after %s (IETF-meeting local time)' % (cutoff_00_str, reopen_str, ))
                else:  # No 00 version allowed
                    self.cutoff_warning = (
                        'The last submission time for new documents (i.e., version -00 Internet-Drafts) was %s.<br>'
                        'You will not be able to submit a new document until after %s (IETF-meeting local time).<br><br>'
                        'You can still submit a version -01 or higher Internet-Draft until %s' % (cutoff_00_str, reopen_str, cutoff_01_str, ))
                    self.in_first_cut_off = True
        if now > cutoff_01 and now < reopen:
            self.cutoff_warning = (
                'The last submission time for the I-D submission was %s.<br><br>'
                'The I-D submission tool will be reopened after %s (IETF-meeting local time).' % (cutoff_01_str, reopen_str))
            self.shutdown = True

    def _clean_file(self, field_name, parser_class):
        f = self.cleaned_data[field_name]
        if not f:
            return f

        self.file_info[field_name] = parser_class(f).critical_parse()
        if self.file_info[field_name].errors:
            raise forms.ValidationError(self.file_info[field_name].errors, code="critical_error")
        return f

    def clean_xml(self):
        def format_messages(where, e, log_msgs):
            m = str(e)
            if m:
                m = [m]
            else:
                import traceback
                typ, val, tb = sys.exc_info()
                m = traceback.format_exception(typ, val, tb)
                m = [l.replace('\n ', ':\n ') for l in m]
            msgs = [s for s in ([f"Error from xml2rfc ({where}):"] + m + log_msgs) if s]
            return msgs

        xml_file = self._clean_file("xml", XMLParser)
        if xml_file:
            tfn = None
            with ExitStack() as stack:
                @stack.callback
                def cleanup():  # called when context exited, even in case of exception
                    if tfn is not None:
                        os.unlink(tfn)

                # We need to write the xml file to disk in order to hand it
                # over to the xml parser.  XXX FIXME: investigate updating
                # xml2rfc to be able to work with file handles to in-memory
                # files.
                name, ext = os.path.splitext(os.path.basename(xml_file.name))
                with tempfile.NamedTemporaryFile(prefix=name+'-',
                                                 suffix='.xml',
                                                 mode='wb+',
                                                 delete=False) as tf:
                    tfn = tf.name
                    for chunk in xml_file.chunks():
                        tf.write(chunk)

                try:
                    xml_draft = XMLDraft(tfn)
                except InvalidXMLError:
                    raise forms.ValidationError(
                        "The uploaded file is not valid XML. Please make sure you are uploading the correct file.",
                        code="invalid_xml_error",
                    )
                except XMLParseError as e:
                    msgs = format_messages('xml', e, e.parser_msgs())
                    raise forms.ValidationError(msgs, code="xml_parse_error")
                except Exception as e:
                    raise forms.ValidationError(f"Error parsing XML Internet-Draft: {e}", code="parse_exception")
                if not xml_draft.filename:
                    raise forms.ValidationError(
                        "Could not extract a valid Internet-Draft name from the XML.  "
                        "Please make sure that the top-level <rfc/> "
                        "element has a docName attribute which provides the full Internet-Draft name including "
                        "revision number.", 
                        code="parse_error_filename",
                    )
                if not xml_draft.revision:
                    raise forms.ValidationError(
                        "Could not extract a valid Internet-Draft revision from the XML.  "
                        "Please make sure that the top-level <rfc/> "
                        "element has a docName attribute which provides the full Internet-Draft name including "
                        "revision number.", 
                        code="parse_error_revision",
                    )
                self._extracted_filenames_and_revisions['xml'] = (xml_draft.filename, xml_draft.revision)
        return xml_file

    def clean(self):
        if self.shutdown and not has_role(self.request.user, "Secretariat"):
            raise forms.ValidationError(self.cutoff_warning)

        # check general submission rate thresholds before doing any more work
        today = date_today()
        self.check_submissions_thresholds(
            "for the same submitter",
            dict(remote_ip=self.remote_ip, submission_date=today),
            settings.IDSUBMIT_MAX_DAILY_SAME_SUBMITTER, settings.IDSUBMIT_MAX_DAILY_SAME_SUBMITTER_SIZE,
        )
        self.check_submissions_thresholds(
            "across all submitters",
            dict(submission_date=today),
            settings.IDSUBMIT_MAX_DAILY_SUBMISSIONS, settings.IDSUBMIT_MAX_DAILY_SUBMISSIONS_SIZE,
        )

        for ext in self.formats:
            f = self.cleaned_data.get(ext, None)
            if not f:
                continue
            self.file_types.append('.%s' % ext)
        if not any(f".{bt}" in self.file_types for bt in self.base_formats):
            if not self.errors:
                raise forms.ValidationError(
                    "Unexpected submission file types; found {}, but {} is required".format(
                        ", ".join(ft.lstrip(".") for ft in self.file_types),
                        " or ".join(self.base_formats),
                    )
                )

        # The following errors are likely noise if we have previous field
        # errors:
        if self.errors:
            raise forms.ValidationError('')

        # Check that all formats agree on draft name/rev
        filename_from = None
        for fmt, (extracted_name, extracted_rev) in self._extracted_filenames_and_revisions.items():
            if self.filename is None:
                filename_from = fmt
                self.filename = extracted_name
                self.revision = extracted_rev
            elif self.filename != extracted_name:
                raise forms.ValidationError(
                    {fmt: f"Extracted filename '{extracted_name}' does not match filename '{self.filename}' from {filename_from} format"},
                    code="filename_mismatch",
                )
            elif self.revision != extracted_rev:
                raise forms.ValidationError(
                    {fmt: f"Extracted revision ({extracted_rev}) does not match revision from {filename_from} format ({self.revision})"},
                    code="revision_mismatch",
                )
        # Not expected to encounter missing filename/revision here because
        # the individual fields should fail validation, but just in case
        if not self.filename:
            raise forms.ValidationError(
                "Unable to extract a filename from any uploaded format.",
                code="no_filename",
            )
        if not self.revision:
            raise forms.ValidationError(
                "Unable to extract a revision from any uploaded format.",
                code="no_revision",
            )

        name_error = validate_submission_name(self.filename)
        if name_error:
            raise forms.ValidationError(name_error)

        rev_error = validate_submission_rev(self.filename, self.revision)
        if rev_error:
            raise forms.ValidationError(rev_error)

        self.check_for_old_uppercase_collisions(self.filename)    

        # check group
        self.group = self.deduce_group(self.filename)
        # check existing
        existing = Submission.objects.filter(name=self.filename, rev=self.revision).exclude(state__in=("posted", "cancel", "waiting-for-draft"))
        if existing:
            raise forms.ValidationError(
                format_html(
                    'A submission with same name and revision is currently being processed. <a href="{}">Check the status here.</a>',
                    urlreverse("ietf.submit.views.submission_status", kwargs={'submission_id': existing[0].pk}),
                )
            )

        # cut-off
        if self.revision == '00' and self.in_first_cut_off:
            raise forms.ValidationError(mark_safe(self.cutoff_warning))
        # check thresholds that depend on the draft / group
        self.check_submissions_thresholds(
            "for the Internet-Draft %s" % self.filename,
            dict(name=self.filename, rev=self.revision, submission_date=today),
            settings.IDSUBMIT_MAX_DAILY_SAME_DRAFT_NAME, settings.IDSUBMIT_MAX_DAILY_SAME_DRAFT_NAME_SIZE,
        )
        if self.group:
            self.check_submissions_thresholds(
                "for the group \"%s\"" % (self.group.acronym),
                dict(group=self.group, submission_date=today),
                settings.IDSUBMIT_MAX_DAILY_SAME_GROUP, settings.IDSUBMIT_MAX_DAILY_SAME_GROUP_SIZE,
            )
        return super().clean()

    @staticmethod
    def check_for_old_uppercase_collisions(name):
        possible_collision = Document.objects.filter(name__iexact=name).first()
        if possible_collision and possible_collision.name != name:
            raise forms.ValidationError(
                f"Case-conflicting draft name found: {possible_collision.name}. "
                "Please choose a different draft name. Case-conflicting names with "
                "the small number of legacy Internet-Drafts with names containing "
                "upper-case letters are not permitted."
            )

    @staticmethod
    def check_submissions_thresholds(which, filter_kwargs, max_amount, max_size):
        submissions = Submission.objects.filter(**filter_kwargs)

        if len(submissions) > max_amount:
            raise forms.ValidationError("Max submissions %s has been reached for today (maximum is %s submissions)." % (which, max_amount))
        if sum(s.file_size for s in submissions if s.file_size) > max_size * 1024 * 1024:
            raise forms.ValidationError("Max uploaded amount %s has been reached for today (maximum is %s MB)." % (which, max_size))

    @staticmethod
    def deduce_group(name):
        """Figure out group from name or previously submitted draft, returns None if individual."""
        existing_draft = Document.objects.filter(name=name, type="draft")
        if existing_draft:
            group = existing_draft[0].group
            if group and group.type_id not in ("individ", "area"):
                return group
            else:
                return None
        else:
            name_parts = name.split("-")
            if len(name_parts) < 3:
                raise forms.ValidationError("The Internet-Draft name \"%s\" is missing a third part, please rename it" % name)

            if name.startswith('draft-ietf-') or name.startswith("draft-irtf-"):
                if name_parts[1] == "ietf":
                    group_type = "wg"
                elif name_parts[1] == "irtf":
                    group_type = "rg"
                else:
                    group_type = None

                # first check groups with dashes
                for g in Group.objects.filter(acronym__contains="-", type=group_type):
                    if name.startswith('draft-%s-%s-' % (name_parts[1], g.acronym)):
                        return g

                try:
                    return Group.objects.get(acronym=name_parts[2], type=group_type)
                except Group.DoesNotExist:
                    raise forms.ValidationError('There is no active group with acronym \'%s\', please rename your Internet-Draft' % name_parts[2])

            elif name.startswith("draft-rfc-"):
                return Group.objects.get(acronym="iesg")
            elif name.startswith("draft-rfc-editor-") or name.startswith("draft-rfced-") or name.startswith("draft-rfceditor-"):
                return Group.objects.get(acronym="rfceditor")
            else:
                ntype = name_parts[1].lower()
                # This covers group types iesg, iana, iab, ise, and others:
                if GroupTypeName.objects.filter(slug=ntype).exists():
                    group = Group.objects.filter(acronym=ntype).first()
                    if group:
                        return group
                    else:
                        raise forms.ValidationError('Internet-Draft names starting with draft-%s- are restricted, please pick a different name' % ntype)
            return None


class SubmissionManualUploadForm(SubmissionBaseUploadForm):
    txt = forms.FileField(label='.txt format', required=False)
    formats = SubmissionBaseUploadForm.formats + ('txt',)
    base_formats =  SubmissionBaseUploadForm.base_formats + ('txt',)

    def __init__(self, request, *args, **kwargs):
        super().__init__(request, *args, **kwargs)
        self.fields['xml'].required = False

    def clean_txt(self):
        txt_file = self._clean_file("txt", PlainParser)
        if txt_file is not None:
            txt_file.seek(0)
            bytes = txt_file.read()
            try:
                text = bytes.decode(PlainParser.encoding)
                parsed_draft = PlaintextDraft(text, txt_file.name)
                self._extracted_filenames_and_revisions["txt"] = (parsed_draft.filename, parsed_draft.revision)
            except (UnicodeDecodeError, LookupError) as e:
                raise forms.ValidationError(f'Failed decoding the uploaded file: "{str(e)}"', code="decode_failed")
            if not parsed_draft.filename:
                raise forms.ValidationError(
                    "Could not extract a valid Internet-Draft name from the plaintext.  "
                    "Please make sure that the full Internet-Draft name including "
                    "revision number appears centered on its own line below the document title on the "
                    "first page.", 
                    code="parse_error_filename",
                )
            if not parsed_draft.revision:
                raise forms.ValidationError(
                    "Could not extract a valid Internet-Draft revision from the plaintext.  "
                    "Please make sure that the full Internet-Draft name including "
                    "revision number appears centered on its own line below the document title on the "
                    "first page.", 
                    code="parse_error_revision",
                )
        return txt_file


class SubmissionAutoUploadForm(SubmissionBaseUploadForm):
    user = forms.EmailField(required=True)
    replaces = forms.CharField(required=False, max_length=1000, strip=True)

    def clean(self):
        cleaned_data = super().clean()

        # Clean the replaces field after the rest of the cleaning so we know the name of the
        # uploaded draft via self.filename
        if self.cleaned_data['replaces']:
            names_replaced = [s.strip() for s in self.cleaned_data['replaces'].split(',')]
            self.cleaned_data['replaces'] = ','.join(names_replaced)
            documents_replaced = Document.objects.filter(name__in=names_replaced)
            if len(names_replaced) != len(documents_replaced):
                known_names = documents_replaced.values_list('name', flat=True)
                unknown_names = [n for n in names_replaced if n not in known_names]
                self.add_error(
                    'replaces',
                    forms.ValidationError(
                        'Unknown Internet-Draft name(s): ' + ', '.join(unknown_names)
                    ),
                )
            for doc in documents_replaced:
                if doc.name == self.filename:
                    self.add_error(
                        'replaces',
                        forms.ValidationError("An Internet-Draft cannot replace itself"),
                    )
                elif doc.type_id != "draft":
                    self.add_error(
                        'replaces',
                        forms.ValidationError("An Internet-Draft can only replace another Internet-Draft"),
                    )
                elif doc.get_state_slug() == "rfc":
                    self.add_error(
                        'replaces',
                        forms.ValidationError("An Internet-Draft cannot replace another Internet-Draft that has become an RFC"),
                    )
                elif doc.get_state_slug('draft-iesg') in ('approved', 'ann', 'rfcqueue'):
                    self.add_error(
                        'replaces',
                        forms.ValidationError(
                            doc.name + " is approved by the IESG and cannot be replaced"
                        ),
                    )
            return cleaned_data


class NameEmailForm(forms.Form):
    name = forms.CharField(required=True)
    email = forms.EmailField(label='Email address', required=True)

    def __init__(self, *args, **kwargs):
        super(NameEmailForm, self).__init__(*args, **kwargs)

        self.fields["name"].widget.attrs["class"] = "name"
        self.fields["email"].widget.attrs["class"] = "email"

    def clean_name(self):
        return self.cleaned_data["name"].replace("\n", "").replace("\r", "").replace("<", "").replace(">", "").strip()

    def clean_email(self):
        return self.cleaned_data["email"].replace("\n", "").replace("\r", "").replace("<", "").replace(">", "").strip()

class AuthorForm(NameEmailForm):
    affiliation = forms.CharField(max_length=100, required=False)
    country = forms.CharField(max_length=255, required=False)

    def __init__(self, *args, **kwargs):
        super(AuthorForm, self).__init__(*args, **kwargs)

class SubmitterForm(NameEmailForm):
    #Fields for secretariat only
    approvals_received = forms.BooleanField(label='Approvals received', required=False, initial=False)

    def cleaned_line(self):
        line = self.cleaned_data["name"]
        email = self.cleaned_data.get("email")
        if email:
            line = formataddr((line, email))
        return line

    def clean_name(self):
        name = super(SubmitterForm, self).clean_name()
        if name.startswith('=?'):
            msg = f'"{name}" appears to be a MIME-encoded string.'
            try:
                import email.header
                text, encoding = email.header.decode_header(name)[0]
                decoded_name = text.decode(encoding)
                msg += f' Did you mean "{decoded_name}"?'
            except:
                pass
            raise forms.ValidationError(msg)
        return name

class ReplacesForm(forms.Form):
    replaces = SearchableDocumentsField(required=False, help_text='Do not enter anything here if you are only submitting the next version of your Internet-Draft. Only enter items here if this submission is intended to replace an I-D with a different name. A typical use of this field is to note what individual I-Ds are replaced by a new -00 Working group I-D. Note that additional approval will be required to replace an I-D for which you are not an author.')

    def __init__(self, *args, **kwargs):
        self.name = kwargs.pop("name")
        super(ReplacesForm, self).__init__(*args, **kwargs)

    def clean_replaces(self):
        for doc in self.cleaned_data['replaces']:
            if doc.name == self.name:
                raise forms.ValidationError("An Internet-Draft cannot replace itself.")
            if doc.type_id != "draft":
                raise forms.ValidationError("An Internet-Draft can only replace another Internet-Draft")
            if doc.get_state_slug('draft-iesg') in ('approved','ann','rfcqueue'):
                raise forms.ValidationError(doc.name+" is approved by the IESG and cannot be replaced")
        return self.cleaned_data['replaces']

class EditSubmissionForm(forms.ModelForm):
    title = forms.CharField(required=True, max_length=255)
    rev = forms.CharField(label='Revision', max_length=2, required=True)
    document_date = forms.DateField(required=True)
    pages = forms.IntegerField(required=True)
    formal_languages = ModelMultipleChoiceField(queryset=FormalLanguageName.objects.filter(used=True), widget=forms.CheckboxSelectMultiple, required=False)
    abstract = forms.CharField(widget=forms.Textarea, required=True, strip=False)

    note = forms.CharField(label=mark_safe('Comment to the Secretariat'), widget=forms.Textarea, required=False, strip=False)

    class Meta:
        model = Submission
        fields = ['title', 'rev', 'document_date', 'pages', 'formal_languages', 'abstract', 'note']

    def clean_rev(self):
        rev = self.cleaned_data["rev"]

        if len(rev) == 1:
            rev = "0" + rev

        error = validate_submission_rev(self.instance.name, rev)
        if error:
            raise forms.ValidationError(error)

        return rev

    def clean_document_date(self):
        document_date = self.cleaned_data['document_date']
        error = validate_submission_document_date(self.instance.submission_date, document_date)
        if error:
            raise forms.ValidationError(error)

        return document_date

class PreapprovalForm(forms.Form):
    name = forms.CharField(max_length=255, required=True, label="Pre-approved name", initial="draft-")

    def clean_name(self):
        n = self.cleaned_data['name'].strip().lower()
        error_msg = validate_submission_name(n)
        if error_msg:
            raise forms.ValidationError(error_msg)

        components = n.split("-")
        if components[-1] == "00":
            raise forms.ValidationError("Name appears to end with a revision number -00 - do not include the revision.")
        if len(components) < 4:
            raise forms.ValidationError("Name has less than four dash-delimited components - can't form a valid group Internet-Draft name.")
        acronym = components[2]
        if acronym not in [ g.acronym for g in self.groups ]:
            raise forms.ValidationError("Group acronym not recognized as one you can approve Internet-Drafts for.")

        if Preapproval.objects.filter(name=n):
            raise forms.ValidationError("Pre-approval for this name already exists.")
        if Submission.objects.filter(state="posted", name=n):
            raise forms.ValidationError("An Internet-Draft with this name has already been submitted and accepted. A pre-approval would not make any difference.")

        return n


class SubmissionEmailForm(forms.Form):
    '''
    Used to add a message to a submission or to create a new submission.
    This message is NOT a reply to a previous message but has arrived out of band
    
    if submission_pk is None we are starting a new submission and name
    must be unique. Otherwise the name must match the submission.name.
    '''
    name = forms.CharField(required=True, max_length=255, label="Internet-Draft name")
    submission_pk = forms.IntegerField(required=False, widget=forms.HiddenInput())
    direction = forms.ChoiceField(choices=(("incoming", "Incoming"), ("outgoing", "Outgoing")),
                                  widget=forms.RadioSelect)
    message = forms.CharField(required=True, widget=forms.Textarea, strip=False,
                              help_text="Copy the entire message including headers. To do so, view the source, select all, copy then paste into the text area above")
    #in_reply_to = MessageModelChoiceField(queryset=Message.objects,label="In Reply To",required=False)

    def __init__(self, *args, **kwargs):
        super(SubmissionEmailForm, self).__init__(*args, **kwargs)

    def clean_message(self):
        '''Returns a ietf.message.models.Message object'''
        self.message_text = self.cleaned_data['message']
        try:
            message = email.message_from_string(force_str(self.message_text))
        except Exception as e:
            self.add_error('message', e)
            return None
            
        for field in ('to','from','subject','date'):
            if not message[field]:
                raise forms.ValidationError('Error parsing email: {} field not found.'.format(field))
        date = utc_from_string(message['date'])
        if not isinstance(date,datetime.datetime):
            raise forms.ValidationError('Error parsing email date field')
        return message

    def clean(self):
        if any(self.errors):
            return self.cleaned_data
        super(SubmissionEmailForm, self).clean()
        name = self.cleaned_data['name']
        match = re.search(r"(draft-[a-z0-9-]*)-(\d\d)", name)
        if not match:
            self.add_error('name', 
                           "Submission name {} must start with 'draft-' and only contain digits, lowercase letters and dash characters and end with revision.".format(name))
        else:
            self.draft_name = match.group(1)    
            self.revision = match.group(2)

            error = validate_submission_rev(self.draft_name, self.revision)
            if error:
                raise forms.ValidationError(error)

        #in_reply_to = self.cleaned_data['in_reply_to']
        #message = self.cleaned_data['message']
        direction = self.cleaned_data['direction']
        if direction != 'incoming' and direction != 'outgoing':
            self.add_error('direction', "Must be one of 'outgoing' or 'incoming'")

        #if in_reply_to:
        #    if direction != 'incoming':
        #        raise forms.ValidationError('Only incoming messages can have In Reply To selected')
        #    date = utc_from_string(message['date'])
        #    if date < in_reply_to.time:
        #        raise forms.ValidationError('The incoming message must have a date later than the message it is replying to')

        return self.cleaned_data

class MessageModelForm(forms.ModelForm):
    in_reply_to_id = forms.CharField(required=False, widget=forms.HiddenInput())
    
    class Meta:
        model = Message
        fields = ['to','frm','cc','bcc','reply_to','subject','body']
        exclude = ['time','by','content_type','related_groups','related_docs']

    def __init__(self, *args, **kwargs):
        super(MessageModelForm, self).__init__(*args, **kwargs)
        self.fields['frm'].label='From'
        self.fields['frm'].widget.attrs['readonly'] = True
        self.fields['reply_to'].widget.attrs['readonly'] = True


class SubmissionSearchForm(forms.Form):
    """Form used for search_submission"""

    name = forms.CharField(max_length=255, required=True, label="I-D name")

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields["name"].widget.attrs["placeholder"] = "draft-..."