OpenSlides/openslides/assignments/views.py

from cgi import escape

from django.db import transaction
from django.utils.translation import ugettext as _
from django.utils.translation import ungettext
from reportlab.lib import colors
from reportlab.lib.units import cm
from reportlab.platypus import (PageBreak, Paragraph, SimpleDocTemplate, Spacer,
                                LongTable, Table, TableStyle)

from openslides.config.api import config
from openslides.users.models import Group, User  # TODO: remove this
from openslides.utils.pdf import stylesheet
from openslides.utils.rest_api import (
    DestroyModelMixin,
    GenericViewSet,
    ModelViewSet,
    Response,
    UpdateModelMixin,
    ValidationError,
    detail_route)
from openslides.utils.views import PDFView

from .models import Assignment, AssignmentPoll
from .serializers import (
    AssignmentAllPollSerializer,
    AssignmentFullSerializer,
    AssignmentShortSerializer
)


class AssignmentViewSet(ModelViewSet):
    """
    API endpoint to list, retrieve, create, update and destroy assignments
    and to manage candidatures.
    """
    queryset = Assignment.objects.all()

    def check_permissions(self, request):
        """
        Calls self.permission_denied() if the requesting user has not the
        permission to see assignments and in case of create, update,
        partial_update or destroy requests the permission to manage
        assignments.
        """
        if (not request.user.has_perm('assignments.can_see') or
                (self.action in ('create', 'update', 'partial_update', 'destroy') and
                 not request.user.has_perm('assignments.can_manage'))):
            self.permission_denied(request)

    def get_serializer_class(self):
        """
        Returns different serializer classes according to users permissions.
        """
        if self.request.user.has_perm('assignments.can_manage'):
            serializer_class = AssignmentFullSerializer
        else:
            serializer_class = AssignmentShortSerializer
        return serializer_class

    @detail_route(methods=['post', 'delete'])
    def candidature_self(self, request, pk=None):
        """
        View to nominate self as candidate (POST) or withdraw own
        candidature (DELETE).
        """
        if not request.user.has_perm('assignments.can_nominate_self'):
            self.permission_denied(request)
        assignment = self.get_object()
        if assignment.is_elected(request.user):
            raise ValidationError({'detail': _('You are already elected.')})
        if request.method == 'POST':
            message = self.nominate_self(request, assignment)
        else:
            # request.method == 'DELETE'
            message = self.withdraw_self(request, assignment)
        return Response({'detail': message})

    def nominate_self(self, request, assignment):
        if assignment.phase == assignment.PHASE_FINISHED:
            raise ValidationError({'detail': _('You can not candidate to this election because it is finished.')})
        if assignment.phase == assignment.PHASE_VOTING and not request.user.has_perm('assignments.can_manage'):
            # To nominate self during voting you have to be a manager.
            self.permission_denied(request)
        # If the request.user is already a candidate he can nominate himself nevertheless.
        assignment.set_candidate(request.user)
        return _('You were nominated successfully.')

    def withdraw_self(self, request, assignment):
        # Withdraw candidature and set self blocked.
        if assignment.phase == assignment.PHASE_FINISHED:
            raise ValidationError({'detail': _('You can not withdraw your candidature to this election because it is finished.')})
        if assignment.phase == assignment.PHASE_VOTING and not request.user.has_perm('assignments.can_manage'):
            # To withdraw self during voting you have to be a manager.
            self.permission_denied(request)
        if not assignment.is_candidate(request.user):
            raise ValidationError({'detail': _('You are not a candidate of this election.')})
        assignment.set_blocked(request.user)
        return _(
            'You have withdrawn your candidature successfully. '
            'You can not be nominated by other participants anymore.')

    def get_user_from_request_data(self, request):
        """
        Helper method to get a specific user from request data (not the
        request.user) so that the views self.candidature_other or
        self.mark_elected can play with him.
        """
        if not isinstance(request.data, dict):
            detail = _('Invalid data. Expected dictionary, got %s.') % type(request.data)
            raise ValidationError({'detail': detail})
        user_str = request.data.get('user', '')
        try:
            user_pk = int(user_str)
        except ValueError:
            raise ValidationError({'detail': _('Invalid data. Expected something like {"user": <id>}.')})
        try:
            user = User.objects.get(pk=user_pk)
        except User.DoesNotExist:
            raise ValidationError({'detail': _('Invalid data. User %d does not exist.') % user_pk})
        return user

    @detail_route(methods=['post', 'delete'])
    def candidature_other(self, request, pk=None):
        """
        View to nominate other users (POST) or delete their candidature
        status (DELETE). The client has to send {'user': <id>}.
        """
        if not request.user.has_perm('assignments.can_nominate_other'):
            self.permission_denied(request)
        user = self.get_user_from_request_data(request)
        assignment = self.get_object()
        if assignment.is_elected(user):
            raise ValidationError({'detail': _('User %s is already elected.') % user})
        if request.method == 'POST':
            message = self.nominate_other(request, user, assignment)
        else:
            # request.method == 'DELETE'
            message = self.delete_other(request, user, assignment)
        return Response({'detail': message})

    def nominate_other(self, request, user, assignment):
        if assignment.phase == assignment.PHASE_FINISHED:
            detail = _('You can not nominate someone to this election because it is finished.')
            raise ValidationError({'detail': detail})
        if assignment.phase == assignment.PHASE_VOTING and not request.user.has_perm('assignments.can_manage'):
            # To nominate other during voting you have to be a manager.
            self.permission_denied(request)
        if not request.user.has_perm('assignments.can_manage'):
            if assignment.is_blocked(user):
                raise ValidationError({'detail': _('User %s does not want to be an candidate.') % user})
            if assignment.is_elected(user):
                raise ValidationError({'detail': _('User %s is already elected.') % user})
        # If the user is already a candidate he can be nominated nevertheless.
        assignment.set_candidate(user)
        return _('User %s was nominated successfully.') % user

    def delete_other(self, request, user, assignment):
        # To delete candidature status you have to be a manager.
        if not request.user.has_perm('assignments.can_manage'):
            self.permission_denied(request)
        if assignment.phase == assignment.PHASE_FINISHED:
            detail = _('You can not delete someones candidature to this election because it is finished.')
            raise ValidationError({'detail': detail})
        if not assignment.is_candidate(user) and not assignment.is_blocked(user):
            raise ValidationError({'detail': _('User %s has no status in this election.') % user})
        assignment.delete_related_user(user)
        return _('Candidate %s was withdrawn/unblocked successfully.') % user

    @detail_route(methods=['post', 'delete'])
    def mark_elected(self, request, pk=None):
        """
        View to mark other users as elected (POST) or undo this (DELETE).
        The client has to send {'user': <id>}.
        """
        if not request.user.has_perm('assignments.can_manage'):
            self.permission_denied(request)
        user = self.get_user_from_request_data(request)
        assignment = self.get_object()
        if request.method == 'POST':
            if not assignment.is_candidate(user):
                raise ValidationError({'detail': _('User %s is not a candidate of this election.') % user})
            assignment.set_elected(user)
            message = _('User %s was successfully elected.') % user
        else:
            # request.method == 'DELETE'
            if not assignment.is_elected(user):
                detail = _('User %s is not an elected candidate of this election.') % user
                raise ValidationError({'detail': detail})
            assignment.set_candidate(user)
            message = _('User %s was successfully unelected.') % user
        return Response({'detail': message})

    @detail_route(methods=['post'])
    def create_poll(self, request, pk=None):
        """
        View to create a poll. It is a POST request without any data.
        """
        if not request.user.has_perm('assignments.can_manage'):
            self.permission_denied(request)
        assignment = self.get_object()
        if not assignment.candidates.exists():
            raise ValidationError({'detail': _('Can not create poll because there are no candidates.')})
        with transaction.atomic():
            assignment.create_poll()
        return Response({'detail': _(' Poll created successfully.')})


class AssignmentPollViewSet(UpdateModelMixin, DestroyModelMixin, GenericViewSet):
    """
    API endpoint to update and destroy assignment polls.
    """
    queryset = AssignmentPoll.objects.all()
    serializer_class = AssignmentAllPollSerializer

    def check_permissions(self, request):
        """
        Calls self.permission_denied() if the requesting user has not the
        permission to see assignments and to manage assignments.
        """
        if (not request.user.has_perm('assignments.can_see') or
                not request.user.has_perm('assignments.can_manage')):
            self.permission_denied(request)


class AssignmentPDF(PDFView):
    required_permission = 'assignments.can_see'
    top_space = 0

    def get_filename(self):
        try:
            assignment = Assignment.objects.get(pk=self.kwargs['pk'])
            filename = u'%s-%s' % (
                _("Assignment"),
                assignment.title.replace(' ', '_'))
        except:
            filename = _("Elections")
        return filename

    def append_to_pdf(self, story):
        try:
            assignment_pk = self.kwargs['pk']
        except KeyError:
            assignment_pk = None

        if assignment_pk is None:  # print all assignments
            title = escape(config["assignment_pdf_title"])
            story.append(Paragraph(title, stylesheet['Heading1']))
            preamble = escape(config["assignment_pdf_preamble"])
            if preamble:
                story.append(Paragraph(
                    "%s" % preamble.replace('\r\n', '<br/>'),
                    stylesheet['Paragraph']))
            story.append(Spacer(0, 0.75 * cm))
            assignments = Assignment.objects.all()
            if not assignments:  # No assignments existing
                story.append(Paragraph(
                    _("No assignments available."), stylesheet['Heading3']))
            else:  # Print all assignments
                # List of assignments
                for assignment in assignments:
                    story.append(Paragraph(
                        escape(assignment.title), stylesheet['Heading3']))
                # Assignment details (each assignment on single page)
                for assignment in assignments:
                    story.append(PageBreak())
                    # append the assignment to the story-object
                    self.get_assignment(assignment, story)
        else:  # print selected assignment
            assignment = Assignment.objects.get(pk=assignment_pk)
            # append the assignment to the story-object
            self.get_assignment(assignment, story)

    def get_assignment(self, assignment, story):
        # title
        story.append(Paragraph(
            _("Election: %s") % escape(assignment.title), stylesheet['Heading1']))
        story.append(Spacer(0, 0.5 * cm))

        # Filling table rows...
        data = []
        polls = assignment.polls.filter(published=True)
        # 1. posts
        data.append([
            Paragraph("%s:" %
                      _("Number of members to be elected"), stylesheet['Bold']),
            Paragraph(str(assignment.open_posts), stylesheet['Paragraph'])])

        # 2a. if no polls available print candidates
        if not polls:
            data.append([
                Paragraph("%s:<seqreset id='counter'>" %
                          _("Candidates"), stylesheet['Heading4']),
                []])
            for candidate in assignment.candidates:
                data.append([
                    [],
                    Paragraph("<seq id='counter'/>.&nbsp; %s" % candidate,
                              stylesheet['Signaturefield'])])
            if assignment.phase == assignment.PHASE_SEARCH:
                for x in range(0, 7):
                    data.append([
                        [],
                        Paragraph("<seq id='counter'/>.&nbsp; "
                                  "__________________________________________",
                                  stylesheet['Signaturefield'])])

        # 2b. if polls available print election result
        if polls:
            # Preparing
            vote_results = assignment.vote_results(only_published=True)
            data_votes = []

            # Left side
            cell = []
            cell.append(Paragraph(
                "%s:" % (_("Election result")), stylesheet['Heading4']))

            # Add table head row
            headrow = []
            headrow.append(_("Candidates"))
            for poll in polls:
                headrow.append("%s. %s" % (poll.get_ballot(), _("ballot")))
            data_votes.append(headrow)

            # Add result rows
            elected_candidates = list(assignment.elected)
            length = len(vote_results)
            for candidate, poll_list in vote_results.iteritems():
                row = []
                candidate_string = candidate.clean_name
                if candidate in elected_candidates:
                    candidate_string = "* " + candidate_string
                if candidate.name_suffix and length < 20:
                    candidate_string += "\n(%s)" % candidate.name_suffix
                row.append(candidate_string)
                for vote in poll_list:
                    if vote is None:
                        row.append('–')
                    elif 'Yes' in vote and 'No' in vote and 'Abstain' in vote:
                        row.append(
                            _("Y: %(YES)s\nN: %(NO)s\nA: %(ABSTAIN)s")
                            % {'YES': vote['Yes'], 'NO': vote['No'],
                               'ABSTAIN': vote['Abstain']})
                    elif 'Votes' in vote:
                        row.append(vote['Votes'])
                    else:
                        pass
                data_votes.append(row)

            # Add valid votes row
            footrow_one = []
            footrow_one.append(_("Valid votes"))
            votesvalid_is_used = False
            for poll in polls:
                footrow_one.append(poll.print_votesvalid())
                if poll.votesvalid is not None:
                    votesvalid_is_used = True
            if votesvalid_is_used:
                data_votes.append(footrow_one)

            # Add invalid votes row
            footrow_two = []
            footrow_two.append(_("Invalid votes"))
            votesinvalid_is_used = False
            for poll in polls:
                footrow_two.append(poll.print_votesinvalid())
                if poll.votesinvalid is not None:
                    votesinvalid_is_used = True
            if votesinvalid_is_used:
                data_votes.append(footrow_two)

            # Add votes cast row
            footrow_three = []
            footrow_three.append(_("Votes cast"))
            votescast_is_used = False
            for poll in polls:
                footrow_three.append(poll.print_votescast())
                if poll.votescast is not None:
                    votescast_is_used = True
            if votescast_is_used:
                data_votes.append(footrow_three)

            table_votes = Table(data_votes)
            table_votes.setStyle(
                TableStyle([
                    ('GRID', (0, 0), (-1, -1), 0.5, colors.grey),
                    ('VALIGN', (0, 0), (-1, -1), 'TOP'),
                    ('LINEABOVE', (0, 0), (-1, 0), 2, colors.black),
                    ('LINEABOVE', (0, 1), (-1, 1), 1, colors.black),
                    ('LINEBELOW', (0, -1), (-1, -1), 2, colors.black),
                    ('ROWBACKGROUNDS', (0, 1), (-1, -1), (colors.white, (.9, .9, .9)))
                ])
            )
            data.append([cell, table_votes])
            if elected_candidates:
                data.append(['', '* = ' + _('elected')])

        # table style
        data.append(['', ''])
        t = LongTable(data)
        t._argW[0] = 4.5 * cm
        t._argW[1] = 11 * cm
        t.setStyle(TableStyle([
            ('BOX', (0, 0), (-1, -1), 1, colors.black),
            ('VALIGN', (0, 0), (-1, -1), 'TOP')]))
        story.append(t)
        story.append(Spacer(0, 1 * cm))

        # election description
        story.append(
            Paragraph("%s" % escape(assignment.description).replace('\r\n', '<br/>'),
                      stylesheet['Paragraph']))


class AssignmentPollPDF(PDFView):
    required_permission = 'assignments.can_manage'
    top_space = 0

    def get(self, request, *args, **kwargs):
        self.poll = AssignmentPoll.objects.get(pk=self.kwargs['poll_pk'])
        return super().get(request, *args, **kwargs)

    def get_filename(self):
        filename = u'%s-%s_%s' % (
            _("Election"), self.poll.assignment.title.replace(' ', '_'),
            self.poll.get_ballot())
        return filename

    def get_template(self, buffer):
        return SimpleDocTemplate(
            buffer, topMargin=-6, bottomMargin=-6, leftMargin=0, rightMargin=0,
            showBoundary=False)

    def build_document(self, pdf_document, story):
        pdf_document.build(story)

    def append_to_pdf(self, story):
        circle = "*"  # = Unicode Character 'HEAVY LARGE CIRCLE' (U+2B55)
        cell = []
        cell.append(Spacer(0, 0.8 * cm))
        cell.append(Paragraph(
            _("Election") + ": " + self.poll.assignment.title,
            stylesheet['Ballot_title']))
        cell.append(Paragraph(
            self.poll.description or '',
            stylesheet['Ballot_subtitle']))
        options = self.poll.get_options()

        ballot_string = _("%d. ballot") % self.poll.get_ballot()
        candidate_string = ungettext(
            "%d candidate", "%d candidates", len(options)) % len(options)
        available_posts_string = ungettext(
            "%d available post", "%d available posts",
            self.poll.assignment.open_posts) % self.poll.assignment.open_posts
        cell.append(Paragraph(
            "%s, %s, %s" % (ballot_string, candidate_string, available_posts_string),
            stylesheet['Ballot_description']))
        cell.append(Spacer(0, 0.4 * cm))

        data = []
        # get ballot papers config values
        ballot_papers_selection = config["assignment_pdf_ballot_papers_selection"]
        ballot_papers_number = config["assignment_pdf_ballot_papers_number"]

        # set number of ballot papers
        if ballot_papers_selection == "NUMBER_OF_DELEGATES":
            try:
                if Group.objects.get(pk=3):
                    number = User.objects.filter(groups__pk=3).count()
            except Group.DoesNotExist:
                number = 0
        elif ballot_papers_selection == "NUMBER_OF_ALL_PARTICIPANTS":
            number = int(User.objects.count())
        else:  # ballot_papers_selection == "CUSTOM_NUMBER"
            number = int(ballot_papers_number)
        number = max(1, number)

        counter = 0
        cellcolumnA = []
        # Choose kind of ballot paper (YesNoAbstain or Yes)
        if self.poll.yesnoabstain:  # YesNoAbstain ballot: max 27 candidates
            for option in options:
                counter += 1
                candidate = option.candidate
                cell.append(Paragraph(
                    candidate.get_short_name(), stylesheet['Ballot_option_name_YNA']))
                if candidate.structure_level:
                    cell.append(Paragraph(
                        "(%s)" % candidate.structure_level,
                        stylesheet['Ballot_option_suffix_YNA']))
                else:
                    cell.append(Paragraph(
                        "&nbsp;", stylesheet['Ballot_option_suffix_YNA']))
                cell.append(Paragraph("<font name='circlefont' size='15'>%(circle)s</font> \
                    <font name='Ubuntu'>%(yes)s &nbsp;&nbsp;&nbsp;</font> \
                    <font name='circlefont' size='15'>%(circle)s</font> \
                    <font name='Ubuntu'>%(no)s &nbsp;&nbsp;&nbsp;</font> \
                    <font name='circlefont' size='15'>%(circle)s</font> \
                    <font name='Ubuntu'>%(abstain)s</font>" %
                            {'circle': circle,
                             'yes': _("Yes"),
                             'no': _("No"),
                             'abstain': _("Abstention")},
                            stylesheet['Ballot_option_circle_YNA']))
                if counter == 13:
                    cellcolumnA = cell
                    cell = []
                    cell.append(Spacer(0, 1.3 * cm))

            # print ballot papers
            for user in range(number // 2):
                if len(options) > 13:
                    data.append([cellcolumnA, cell])
                else:
                    data.append([cell, cell])
            rest = number % 2
            if rest:
                data.append([cell, ''])
            if len(options) <= 2:
                t = Table(data, 10.5 * cm, 7.42 * cm)
            elif len(options) <= 5:
                t = Table(data, 10.5 * cm, 14.84 * cm)
            else:
                t = Table(data, 10.5 * cm, 29.7 * cm)
        else:  # Yes ballot: max 46 candidates
            for option in options:
                counter += 1
                candidate = option.candidate
                cell.append(Paragraph("<font name='circlefont' size='15'>%s</font> \
                            <font name='Ubuntu'>%s</font>" %
                            (circle, candidate.clean_name), stylesheet['Ballot_option_name']))
                if candidate.structure_level:
                    cell.append(Paragraph(
                        "(%s)" % candidate.structure_level,
                        stylesheet['Ballot_option_suffix']))
                else:
                    cell.append(Paragraph(
                        "&nbsp;", stylesheet['Ballot_option_suffix']))
                if counter == 22:
                    cellcolumnA = cell
                    cell = []
                    cell.append(Spacer(0, 0.75 * cm))

            # print ballot papers
            for user in range(number // 2):
                if len(options) > 22:
                    data.append([cellcolumnA, cell])
                else:
                    data.append([cell, cell])
            rest = number % 2
            if rest:
                data.append([cell, ''])
            if len(options) <= 4:
                t = Table(data, 10.5 * cm, 7.42 * cm)
            elif len(options) <= 8:
                t = Table(data, 10.5 * cm, 14.84 * cm)
            else:
                t = Table(data, 10.5 * cm, 29.7 * cm)

        t.setStyle(TableStyle([
            ('GRID', (0, 0), (-1, -1), 0.25, colors.grey),
            ('VALIGN', (0, 0), (-1, -1), 'TOP')]))
        story.append(t)