import os
import datetime
import pytz

from django import forms
from django.conf import settings
from django.utils.html import mark_safe
from django.core.urlresolvers import reverse as urlreverse

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 SearchableDocAliasesField
from ietf.meeting.models import Meeting
from ietf.submit.models import Submission, Preapproval
from ietf.submit.utils import validate_submission_rev, validate_submission_document_date
from ietf.submit.parsers.pdf_parser import PDFParser
from ietf.submit.parsers.plain_parser import PlainParser
from ietf.submit.parsers.ps_parser import PSParser
from ietf.submit.parsers.xml_parser import XMLParser
from ietf.utils.draft import Draft


class UploadForm(forms.Form):
    txt = forms.FileField(label=u'.txt format', required=True)
    xml = forms.FileField(label=u'.xml format', required=False)
    pdf = forms.FileField(label=u'.pdf format', required=False)
    ps = forms.FileField(label=u'.ps format', required=False)

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

        self.remote_ip = request.META.get('REMOTE_ADDR', None)

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

        self.group = None
        self.parsed_draft = None

    def set_cutoff_warnings(self):
        now = datetime.datetime.now(pytz.utc)
        meeting = Meeting.get_current_meeting()
        #
        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")
        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 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

        parsed_info = parser_class(f).critical_parse()
        if parsed_info.errors:
            raise forms.ValidationError(parsed_info.errors)

        return f


    def clean_txt(self):
        return self.clean_file("txt", PlainParser)

    def clean_pdf(self):
        return self.clean_file("pdf", PDFParser)

    def clean_ps(self):
        return self.clean_file("ps", PSParser)

    def clean_xml(self):
        return self.clean_file("xml", XMLParser)

    def clean(self):
        if self.shutdown and not has_role(self.request.user, "Secretariat"):
            raise forms.ValidationError('The tool is shut down')

        # sanity check that paths exist (for development servers)
        for s in ("IDSUBMIT_STAGING_PATH", "IDSUBMIT_IDNITS_BINARY",
                  "IDSUBMIT_REPOSITORY_PATH", "INTERNET_DRAFT_ARCHIVE_DIR"):
            if not os.path.exists(getattr(settings, s)):
                raise forms.ValidationError('%s defined in settings.py does not exist' % s)

        if self.cleaned_data.get('txt'):
            # try to parse it
            txt_file = self.cleaned_data['txt']
            txt_file.seek(0)
            self.parsed_draft = Draft(txt_file.read(), txt_file.name)
            txt_file.seek(0)

            if not self.parsed_draft.filename:
                raise forms.ValidationError("Draft parser could not extract a valid draft name from the .txt file")

            if not self.parsed_draft.get_title():
                raise forms.ValidationError("Draft parser could not extract a valid title from the .txt file")

            # check group
            self.group = self.deduce_group()

            # check existing
            existing = Submission.objects.filter(name=self.parsed_draft.filename, rev=self.parsed_draft.revision).exclude(state__in=("posted", "cancel"))
            if existing:
                raise forms.ValidationError(mark_safe('Submission with same name and revision is currently being processed. <a href="%s">Check the status here.</a>' % urlreverse("submit_submission_status", kwargs={ 'submission_id': existing[0].pk })))

            # cut-off
            if self.parsed_draft.revision == '00' and self.in_first_cut_off:
                raise forms.ValidationError(mark_safe(self.cutoff_warning))

            # check thresholds
            today = datetime.date.today()

            self.check_submissions_tresholds(
                "for the draft %s" % self.parsed_draft.filename,
                dict(name=self.parsed_draft.filename, rev=self.parsed_draft.revision, submission_date=today),
                settings.IDSUBMIT_MAX_DAILY_SAME_DRAFT_NAME, settings.IDSUBMIT_MAX_DAILY_SAME_DRAFT_NAME_SIZE,
            )
            self.check_submissions_tresholds(
                "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,
            )
            if self.group:
                self.check_submissions_tresholds(
                    "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,
                )
            self.check_submissions_tresholds(
                "across all submitters",
                dict(submission_date=today),
                settings.IDSUBMIT_MAX_DAILY_SUBMISSIONS, settings.IDSUBMIT_MAX_DAILY_SUBMISSIONS_SIZE,
            )

        return super(UploadForm, self).clean()

    def check_submissions_tresholds(self, 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) > max_size * 1024 * 1024:
            raise forms.ValidationError("Max uploaded amount %s has been reached for today (maximum is %s MB)." % (which, max_size))

    def deduce_group(self):
        """Figure out group from name or previously submitted draft, returns None if individual."""
        name = self.parsed_draft.filename
        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:
            if name.startswith('draft-ietf-') or name.startswith("draft-irtf-"):
                components = name.split("-")
                if len(components) < 3:
                    raise forms.ValidationError(u"The draft name \"%s\" is missing a third part, please rename it" % name)

                if components[1] == "ietf":
                    group_type = "wg"
                elif components[1] == "irtf":
                    group_type = "rg"

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

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

            elif name.startswith("draft-rfc-"):
                return Group.objects.get(acronym="iesg")

            elif name.startswith("draft-irtf-"):
                return Group.objects.get(acronym="irtf")

            elif name.startswith("draft-iab-"):
                return Group.objects.get(acronym="iab")

            elif name.startswith("draft-iana-"):
                return Group.objects.get(acronym="iana")

            elif name.startswith("draft-rfc-editor-") or name.startswith("draft-rfced-") or name.startswith("draft-rfceditor-"):
                return Group.objects.get(acronym="rfceditor")

            else:
                return None

class NameEmailForm(forms.Form):
    """For validating supplied submitter and author information."""
    name = forms.CharField(required=True)
    email = forms.EmailField(label=u'Email address')

    def __init__(self, *args, **kwargs):
        email_required = kwargs.pop("email_required", True)
        super(NameEmailForm, self).__init__(*args, **kwargs)

        self.fields["email"].required = email_required
        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()

    def cleaned_line(self):
        line = self.cleaned_data["name"]
        email = self.cleaned_data.get("email")
        if email:
            line += u" <%s>" % email
        return line

class ReplacesForm(forms.Form):
    replaces = SearchableDocAliasesField(required=False, help_text="Any drafts that this document replaces (approval required for replacing a draft you are not the author of)")

class EditSubmissionForm(forms.ModelForm):
    title = forms.CharField(required=True, max_length=255)
    rev = forms.CharField(label=u'Revision', max_length=2, required=True)
    document_date = forms.DateField(required=True)
    pages = forms.IntegerField(required=True)
    abstract = forms.CharField(widget=forms.Textarea, required=True)

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

    class Meta:
        model = Submission
        fields = ['title', 'rev', 'document_date', 'pages', '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()

        if not n.startswith("draft-"):
            raise forms.ValidationError("Name doesn't start with \"draft-\".")
        if len(n.split(".")) > 1 and len(n.split(".")[-1]) == 3:
            raise forms.ValidationError("Name appears to end with a file extension .%s - do not include an extension." % n.split(".")[-1])

        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 draft name.")
        if not components[-1]:
            raise forms.ValidationError("Name ends with a dash.")
        acronym = components[2]
        if acronym not in self.groups.values_list('acronym', flat=True):
            raise forms.ValidationError("Group acronym not recognized as one you can approve 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("A draft with this name has already been submitted and accepted. A pre-approval would not make any difference.")

        return n