import os
import re
import datetime

from django.conf import settings
from django.contrib.sites.models import Site
from django.core.urlresolvers import reverse as urlreverse

from ietf.idtracker.models import (InternetDraft, PersonOrOrgInfo, IETFWG,
                                   IDAuthor, EmailAddress, IESGLogin, BallotInfo)
from ietf.submit.models import TempIdAuthors
from ietf.utils.mail import send_mail
from ietf.utils import unaccent

from ietf.doc.models import *
from ietf.person.models import Person, Alias, Email
from ietf.doc.utils import active_ballot_positions

# Some useful states
UPLOADED = 1
WAITING_AUTHENTICATION = 4
MANUAL_POST_REQUESTED = 5
POSTED = -1
POSTED_BY_SECRETARIAT = -2
CANCELED = -4
INITIAL_VERSION_APPROVAL_REQUESTED = 10


# Not a real WG
NONE_WG = 1027


def request_full_url(request, submission):
    subject = 'Full URL for managing submission of draft %s' % submission.filename
    from_email = settings.IDSUBMIT_FROM_EMAIL
    to_email = list(set(u'%s <%s>' % i.email() for i in submission.tempidauthors_set.all()))
    url = settings.IDTRACKER_BASE_URL + urlreverse('draft_status_by_hash',
                                                   kwargs=dict(submission_id=submission.submission_id,
                                                               submission_hash=submission.get_hash()))
    send_mail(request, to_email, from_email, subject, 'submit/request_full_url.txt',
              {'submission': submission,
               'url': url})


def perform_post(request, submission):
    group_id = submission.group_acronym and submission.group_acronym.pk or NONE_WG
    state_change_msg = ''
    try:
        draft = InternetDraft.objects.get(filename=submission.filename)
        draft.title = submission.id_document_name
        draft.group_id = group_id
        draft.filename = submission.filename
        draft.revision = submission.revision
        draft.revision_date = submission.submission_date
        draft.file_type = submission.file_type
        draft.txt_page_count = submission.txt_page_count
        draft.last_modified_date = datetime.date.today()
        draft.abstract = submission.abstract
        draft.status_id = 1  # Active
        draft.expired_tombstone = 0
        draft.save()
    except InternetDraft.DoesNotExist:
        draft = InternetDraft.objects.create(
            title=submission.id_document_name,
            group_id=group_id,
            filename=submission.filename,
            revision=submission.revision,
            revision_date=submission.submission_date,
            file_type=submission.file_type,
            txt_page_count=submission.txt_page_count,
            start_date=datetime.date.today(),
            last_modified_date=datetime.date.today(),
            abstract=submission.abstract,
            status_id=1,  # Active
            intended_status_id=8,  # None
        )
    update_authors(draft, submission)
    if draft.idinternal:
        from ietf.idrfc.utils import add_document_comment
        add_document_comment(None, draft, "New version available")
        if draft.idinternal.cur_sub_state_id == 5 and draft.idinternal.rfc_flag == 0:  # Substate 5 Revised ID Needed
            draft.idinternal.prev_sub_state_id = draft.idinternal.cur_sub_state_id
            draft.idinternal.cur_sub_state_id = 2  # Substate 2 AD Followup
            draft.idinternal.save()
            state_change_msg = "Sub state has been changed to AD Follow up from New Id Needed"
            add_document_comment(None, draft, state_change_msg)
    move_docs(submission)
    submission.status_id = POSTED
    send_announcements(submission, draft, state_change_msg)
    submission.save()

def perform_postREDESIGN(request, submission):
    system = Person.objects.get(name="(System)")

    group_id = submission.group_acronym_id or NONE_WG
    try:
        draft = Document.objects.get(name=submission.filename)
        save_document_in_history(draft)
    except Document.DoesNotExist:
        draft = Document(name=submission.filename)
        draft.intended_std_level = None

    prev_rev = draft.rev

    draft.type_id = "draft"
    draft.time = datetime.datetime.now()
    draft.title = submission.id_document_name
    draft.group_id = group_id
    draft.rev = submission.revision
    draft.pages = submission.txt_page_count
    draft.abstract = submission.abstract
    was_rfc = draft.get_state_slug() == "rfc"

    if not draft.stream:
        if draft.name.startswith("draft-iab-"):
            stream_slug = "iab"
        elif draft.name.startswith("draft-irtf-"):
            stream_slug = "irtf"
        elif draft.name.startswith("draft-ietf-") and (draft.group.type_id != "individ" or was_rfc):
            stream_slug = "ietf"

        if stream_slug:
            draft.stream = StreamName.objects.get(slug=stream_slug)

    draft.expires = datetime.datetime.now() + datetime.timedelta(settings.INTERNET_DRAFT_DAYS_TO_EXPIRE)
    draft.save()

    draft.set_state(State.objects.get(type="draft", slug="active"))
    if draft.stream_id == "ietf" and draft.group.type_id != "individ":
        # automatically set state "WG Document"
        draft.set_state(State.objects.get(type="draft-stream-%s" % draft.stream_id, slug="wg-doc"))

    DocAlias.objects.get_or_create(name=submission.filename, document=draft)

    update_authors(draft, submission)

    # new revision event
    try:
        a = submission.tempidauthors_set.get(author_order=0)
        submitter = ensure_person_email_info_exists(a).person
    except TempIdAuthors.DoesNotExist:
        submitter = system

    e = NewRevisionDocEvent(type="new_revision", doc=draft, rev=draft.rev)
    e.time = draft.time #submission.submission_date
    e.by = submitter
    e.desc = "New revision available"
    e.save()

    # clean up old files
    from ietf.idrfc.expire import move_draft_files_to_archive
    move_draft_files_to_archive(draft, prev_rev)

    # automatic state changes
    state_change_msg = ""

    if not was_rfc and draft.tags.filter(slug="need-rev"):
        draft.tags.remove("need-rev")
        draft.tags.add("ad-f-up")

        e = DocEvent(type="changed_document", doc=draft)
        e.desc = "Sub state has been changed to <b>AD Followup</b> from <b>Revised ID Needed</b>"
        e.by = system
        e.save()

        state_change_msg = e.desc

    move_docs(submission)
    submission.status_id = POSTED

    announce_to_lists(request, submission)
    if draft.get_state("draft-iesg") != None and not was_rfc:
        announce_new_version(request, submission, draft, state_change_msg)
    announce_to_authors(request, submission)

    submission.save()

if settings.USE_DB_REDESIGN_PROXY_CLASSES:
    perform_post = perform_postREDESIGN

def send_announcements(submission, draft, state_change_msg):
    announce_to_lists(request, submission)
    if draft.idinternal and not draft.idinternal.rfc_flag:
        announce_new_version(request, submission, draft, state_change_msg)
    announce_to_authors(request, submission)


def announce_to_lists(request, submission):
    subject = 'I-D Action: %s-%s.txt' % (submission.filename, submission.revision)
    from_email = settings.IDSUBMIT_ANNOUNCE_FROM_EMAIL
    to_email = [settings.IDSUBMIT_ANNOUNCE_LIST_EMAIL]
    authors = []
    for i in submission.tempidauthors_set.order_by('author_order'):
        if not i.author_order:
            continue
        authors.append(i.get_full_name())
    if submission.group_acronym:
        cc = [submission.group_acronym.email_address]
    else:
        cc = None
    send_mail(request, to_email, from_email, subject, 'submit/announce_to_lists.txt',
              {'submission': submission,
               'authors': authors}, cc=cc)


def announce_new_version(request, submission, draft, state_change_msg):
    to_email = []
    if draft.idinternal.state_change_notice_to:
        to_email.append(draft.idinternal.state_change_notice_to)
    if draft.idinternal.job_owner:
        to_email.append(draft.idinternal.job_owner.person.email()[1])
    try:
        if draft.idinternal.ballot:
            for p in draft.idinternal.ballot.positions.all():
                if p.discuss == 1 and p.ad.user_level == IESGLogin.AD_LEVEL:
                    to_email.append(p.ad.person.email()[1])
    except BallotInfo.DoesNotExist:
        pass
    subject = 'New Version Notification - %s-%s.txt' % (submission.filename, submission.revision)
    from_email = settings.IDSUBMIT_ANNOUNCE_FROM_EMAIL
    send_mail(request, to_email, from_email, subject, 'submit/announce_new_version.txt',
              {'submission': submission,
               'msg': state_change_msg})


def announce_new_versionREDESIGN(request, submission, draft, state_change_msg):
    to_email = []
    if draft.notify:
        to_email.append(draft.notify)
    if draft.ad:
        to_email.append(draft.ad.role_email("ad").address)

    for ad, pos in active_ballot_positions(draft).iteritems():
        if pos and pos.pos_id == "discuss":
            to_email.append(ad.role_email("ad").address)

    subject = 'New Version Notification - %s-%s.txt' % (submission.filename, submission.revision)
    from_email = settings.IDSUBMIT_ANNOUNCE_FROM_EMAIL
    send_mail(request, to_email, from_email, subject, 'submit/announce_new_version.txt',
              {'submission': submission,
               'msg': state_change_msg})

if settings.USE_DB_REDESIGN_PROXY_CLASSES:
    announce_new_version = announce_new_versionREDESIGN

def announce_to_authors(request, submission):
    authors = submission.tempidauthors_set.order_by('author_order')
    cc = list(set(i.email()[1] for i in authors if i.email() != authors[0].email()))
    to_email = [authors[0].email()[1]]  # First TempIdAuthor is submitter
    from_email = settings.IDSUBMIT_ANNOUNCE_FROM_EMAIL
    subject = 'New Version Notification for %s-%s.txt' % (submission.filename, submission.revision)
    if submission.group_acronym:
        wg = submission.group_acronym.group_acronym.acronym
    elif submission.filename.startswith('draft-iesg'):
        wg = 'IESG'
    else:
        wg = 'Individual Submission'
    send_mail(request, to_email, from_email, subject, 'submit/announce_to_authors.txt',
              {'submission': submission,
               'submitter': authors[0].get_full_name(),
               'wg': wg}, cc=cc)


def find_person(first_name, last_name, middle_initial, name_suffix, email):
    person_list = None
    if email:
        person_list = PersonOrOrgInfo.objects.filter(emailaddress__address=email).distinct()
        if person_list and len(person_list) == 1:
            return person_list[0]
    if not person_list:
        person_list = PersonOrOrgInfo.objects.all()
    person_list = person_list.filter(first_name=first_name,
                                     last_name=last_name)
    if middle_initial:
        person_list = person_list.filter(middle_initial=middle_initial)
    if name_suffix:
        person_list = person_list.filter(name_suffix=name_suffix)
    if person_list:
        return person_list[0]
    return None


def update_authors(draft, submission):
    # TempAuthor of order 0 is submitter
    new_authors = list(submission.tempidauthors_set.filter(author_order__gt=0))
    person_pks = []
    for author in new_authors:
        person = find_person(author.first_name, author.last_name,
                             author.middle_initial, author.name_suffix,
                             author.email_address)
        if not person:
            person = PersonOrOrgInfo(
                first_name=author.first_name,
                last_name=author.last_name,
                middle_initial=author.middle_initial or '',
                name_suffix=author.name_suffix or '',
                )
            person.save()
            if author.email_address:
                EmailAddress.objects.create(
                    address=author.email_address,
                    priority=1,
                    type='INET',
                    person_or_org=person,
                    )
        person_pks.append(person.pk)
        try:
            idauthor = IDAuthor.objects.get(
                document=draft,
                person=person,
                )
            idauthor.author_order = author.author_order
        except IDAuthor.DoesNotExist:
            idauthor = IDAuthor(
                document=draft,
                person=person,
                author_order=author.author_order,
                )
        idauthor.save()
    draft.authors.exclude(person__pk__in=person_pks).delete()

def get_person_from_author(author):
    persons = None

    # try email
    if author.email_address:
        persons = Person.objects.filter(email__address=author.email_address).distinct()
        if len(persons) == 1:
            return persons[0]

    if not persons:
        persons = Person.objects.all()

    # try full name
    p = persons.filter(alias__name=author.get_full_name()).distinct()
    if p:
        return p[0]

    return None

def ensure_person_email_info_exists(author):
    person = get_person_from_author(author)

    # make sure we got a person
    if not person:
        person = Person()
        person.name = author.get_full_name()
        person.ascii = unaccent.asciify(person.name)
        person.save()

        Alias.objects.create(name=person.name, person=person)
        if person.name != person.ascii:
            Alias.objects.create(name=ascii, person=person)

    # make sure we got an email address
    if author.email_address:
        addr = author.email_address.lower()
    else:
        # we're in trouble, use a fake one
        addr = u"unknown-email-%s" % person.name.replace(" ", "-")

    try:
        email = person.email_set.get(address=addr)
    except Email.DoesNotExist:
        try:
            # maybe it's pointing to someone else
            email = Email.objects.get(address=addr)
        except Email.DoesNotExist:
            # most likely we just need to create it
            email = Email(address=addr)
            email.active = False

        email.person = person
        email.save()

    return email


def update_authorsREDESIGN(draft, submission):
    # order 0 is submitter
    authors = []
    for author in submission.tempidauthors_set.exclude(author_order=0).order_by('author_order'):
        email = ensure_person_email_info_exists(author)

        try:
            a = DocumentAuthor.objects.get(document=draft, author=email)
        except DocumentAuthor.DoesNotExist:
            a = DocumentAuthor(document=draft, author=email)

        a.order = author.author_order
        a.save()

        authors.append(email)

    draft.documentauthor_set.exclude(author__in=authors).delete()


if settings.USE_DB_REDESIGN_PROXY_CLASSES:
    update_authors = update_authorsREDESIGN


def get_person_for_user(user):
    try:
        return user.get_profile().person()
    except:
        return None


def is_secretariat(user):
    if not user or not user.is_authenticated():
        return False
    return bool(user.groups.filter(name='Secretariat'))

if settings.USE_DB_REDESIGN_PROXY_CLASSES:
    from ietf.liaisons.accounts import is_secretariat, get_person_for_user

def move_docs(submission):
    for ext in submission.file_type.split(','):
        source = os.path.join(settings.IDSUBMIT_STAGING_PATH, '%s-%s%s' % (submission.filename, submission.revision, ext))
        dest = os.path.join(settings.IDSUBMIT_REPOSITORY_PATH, '%s-%s%s' % (submission.filename, submission.revision, ext))
        os.rename(source, dest)


def remove_docs(submission):
    for ext in submission.file_type.split(','):
        source = os.path.join(settings.IDSUBMIT_STAGING_PATH, '%s-%s%s' % (submission.filename, submission.revision, ext))
        if os.path.exists(source):
            os.unlink(source)


class DraftValidation(object):

    def __init__(self, draft):
        self.draft = draft
        self.warnings = {}
        self.passes_idnits = self.passes_idnits()
        self.wg = self.get_working_group()
        self.authors = self.get_authors()
        self.submitter = self.get_submitter()

    def passes_idnits(self):
        passes_idnits = self.check_idnits_success(self.draft.idnits_message)
        return passes_idnits

    def get_working_group(self):
        if self.draft.group_acronym and self.draft.group_acronym.pk == NONE_WG:
            return None
        return self.draft.group_acronym

    def check_idnits_success(self, idnits_message):
        if not idnits_message:
            return False
        success_re = re.compile('\s+Summary:\s+0\s+|No nits found')
        if success_re.search(idnits_message):
            return True
        return False

    def is_valid_attr(self, key):
        if key in self.warnings.keys():
            return False
        return True

    def is_valid(self):
        self.validate_metadata()
        return not bool(self.warnings.keys()) and self.passes_idnits

    def validate_metadata(self):
        self.validate_revision()
        self.validate_title()
        self.validate_authors()
        self.validate_abstract()
        self.validate_creation_date()
        self.validate_wg()
        self.validate_files()

    def validate_files(self):
        if self.draft.status_id in [POSTED, POSTED_BY_SECRETARIAT]:
            return
        for ext in self.draft.file_type.split(','):
            source = os.path.join(settings.IDSUBMIT_STAGING_PATH, '%s-%s%s' % (self.draft.filename, self.draft.revision, ext))
            if not os.path.exists(source):
                self.add_warning('document_files', '"%s" were not found in the staging area.<br />We recommend you that you cancel this submission and upload your files again.' % os.path.basename(source))
                break

    def validate_title(self):
        if not self.draft.id_document_name:
            self.add_warning('title', 'Title is empty or was not found')

    def validate_wg(self):
        if self.wg and not self.wg.status_id == IETFWG.ACTIVE:
            self.add_warning('group', 'Working Group exists but is not an active WG')

    def validate_abstract(self):
        if not self.draft.abstract:
            self.add_warning('abstract', 'Abstract is empty or was not found')

    def add_warning(self, key, value):
        self.warnings.update({key: value})

    def validate_revision(self):
        if self.draft.status_id in [POSTED, POSTED_BY_SECRETARIAT]:
            return
        revision = self.draft.revision
        existing_revisions = [int(i.revision_display()) for i in InternetDraft.objects.filter(filename=self.draft.filename)]
        expected = 0
        if existing_revisions:
            expected = max(existing_revisions) + 1
        try:
            if int(revision) != expected:
                self.add_warning('revision', 'Invalid Version Number (Version %02d is expected)' % expected)
        except ValueError:
            self.add_warning('revision', 'Revision not found')

    def validate_authors(self):
        if not self.authors:
            self.add_warning('authors', 'No authors found')
            return

    def validate_creation_date(self):
        date = self.draft.creation_date
        if not date:
            self.add_warning('creation_date', 'Creation Date field is empty or the creation date is not in a proper format')
            return
        submit_date = self.draft.submission_date
        if (date + datetime.timedelta(days=3) < submit_date or
            date - datetime.timedelta(days=3) > submit_date):
            self.add_warning('creation_date', 'Creation Date must be within 3 days of submission date')

    def get_authors(self):
        return self.draft.tempidauthors_set.exclude(author_order=0).order_by('author_order')

    def get_submitter(self):
        submitter = self.draft.tempidauthors_set.filter(author_order=0)
        if submitter:
            return submitter[0]
        elif self.draft.submitter_tag:
            try:
                return PersonOrOrgInfo.objects.get(pk=self.draft.submitter_tag)
            except PersonOrOrgInfo.DoesNotExist:
                return False
        return None