fef-questionnaire/questionnaire/views.py

#!/usr/bin/python
# vim: set fileencoding=utf-8
import json
import logging
from six import text_type as unicodestr
import tempfile

from compat import commit_on_success, commit, rollback
from hashlib import md5
from uuid import uuid4

from django.apps import apps
from django.http import HttpResponse, HttpResponseRedirect
from django.urls import reverse
from django.core.cache import cache
from django.contrib.auth.decorators import login_required, permission_required
from django.shortcuts import render, get_object_or_404
from django.views.generic.base import TemplateView
from django.conf import settings
from datetime import datetime
from django.utils import translation
from django.utils.translation import ugettext_lazy as _

from . import QuestionProcessors
from . import questionnaire_start, questionset_start, questionset_done, questionnaire_done
from . import AnswerException
from .emails import _send_email
from .models import (
    Answer, Landing, Question, Questionnaire, QuestionSet, Run, RunInfo, RunInfoHistory, Subject,
)
from .forms import NewLandingForm
from .parsers import BooleanParser
from .utils import numal_sort, split_numal, UnicodeWriter
from .run import (
    add_answer, delete_answer, get_runinfo, get_question,
    question_satisfies_checks, questionset_satisfies_checks,
    get_progress, make_partially_evaluated_js_exp_for_shownif_check, substitute_answer
)
from .dependency_checker import dep_check


try:
    use_session = settings.QUESTIONNAIRE_USE_SESSION
except AttributeError:
    use_session = False

try:
    debug_questionnaire = settings.QUESTIONNAIRE_DEBUG
except AttributeError:
    debug_questionnaire = False

try:
    (app_label, model_name) = settings.QUESTIONNAIRE_ITEM_MODEL.split('.', 1)
    item_model = apps.get_model(app_label=app_label, model_name=model_name)
except AttributeError:
    item_model = None


def r2r(tpl, request, **contextdict):
    "Shortcut to use RequestContext instead of Context in templates"
    contextdict['request'] = request
    return render(request, tpl, contextdict)

def get_async_progress(request, *args, **kwargs):
    """ Returns the progress as json for use with ajax """

    if 'runcode' in kwargs:
        runcode = kwargs['runcode']
    else:
        session_runcode = request.session.get('runcode', None)
        if session_runcode is not None:
            runcode = session_runcode

    runinfo = get_runinfo(runcode)
    response = dict(progress=get_progress(runinfo))

    cache.set('progress' + runinfo.random, response['progress'])
    response = HttpResponse(json.dumps(response),
                            content_type='application/javascript');
    response["Cache-Control"] = "no-cache"
    return response


def redirect_to_qs(runinfo, request=None):
    "Redirect to the correct and current questionset URL for this RunInfo"

    # cache current questionset
    qs = runinfo.questionset

    # skip questionsets that don't pass
    if not questionset_satisfies_checks(runinfo.questionset, runinfo):

        nxt = next(runinfo.questionset)

        while nxt and not questionset_satisfies_checks(nxt, runinfo):
            nxt = next(nxt)

        runinfo.questionset = nxt
        runinfo.save()

        hasquestionset = bool(nxt)
    else:
        hasquestionset = True

    # empty ?
    if not hasquestionset:
        logging.warn('no questionset in questionnaire which passes the check')
        return finish_questionnaire(request, runinfo, qs.questionnaire)

    if not use_session:
        args = [runinfo.random, runinfo.questionset.sortid]
        urlname = 'questionset'
    else:
        args = []
        request.session['qs'] = runinfo.questionset.sortid
        request.session['runcode'] = runinfo.random
        urlname = 'questionnaire'

    url = reverse(urlname, args=args)
    return HttpResponseRedirect(url)


def redirect_to_prev_questionnaire(request, runcode=None, qs=None):
    """
    Takes the questionnaire set in the session and redirects to the
    previous questionnaire if any. Used for linking to previous pages
    both when using sessions or not.
    """
    if use_session:
        runcode = request.session.get('runcode', None)

    if runcode is not None:
        runinfo = get_runinfo(runcode)
        if qs:
            qs = get_object_or_404(QuestionSet, sortid=qs, questionnaire=runinfo.questionset.questionnaire)
            prev_qs = qs.prev()
        else:
            prev_qs = runinfo.questionset.prev()

        while prev_qs and not questionset_satisfies_checks(prev_qs, runinfo):
            prev_qs = prev_qs.prev()

        if runinfo and prev_qs:
            if use_session:
                request.session['runcode'] = runinfo.random
                request.session['qs'] = prev_qs.sortid
                return HttpResponseRedirect(reverse('questionnaire'))

            else:
                runinfo.questionset = prev_qs
                runinfo.save()
                return HttpResponseRedirect(reverse('questionnaire', args=[runinfo.random]))

    return HttpResponseRedirect('/')

@commit_on_success
def questionnaire(request, runcode=None, qs=None):
    """
    Process submit answers (if present) and redirect to next page

    If this is a POST request, parse the submitted data in order to store
    all the submitted answers.  Then return to the next questionset or
    return a completed response.

    If this isn't a POST request, redirect to the main page.

    We only commit on success, to maintain consistency.  We also specifically
    rollback if there were errors processing the answers for this questionset.
    """

    if use_session:
        session_runcode = request.session.get('runcode', None)
        if session_runcode is not None:
            runcode = session_runcode

        session_qs = request.session.get('qs', None)
        if session_qs is not None:
            qs = session_qs

    # if runcode provided as query string, redirect to the proper page
    if not runcode:
        runcode = request.GET.get('runcode')
        if not runcode:
            return HttpResponseRedirect("/")
        else:
            if not use_session:
                args = [runcode, ]
            else:
                request.session['runcode'] = runcode
                args = []

            return HttpResponseRedirect(reverse("questionnaire", args=args))


    runinfo = get_runinfo(runcode)

    if not runinfo:
        commit()
        return HttpResponseRedirect('/')

    if runinfo.questionset.questionnaire.admin_access_only == 1:
        if not request.user.is_superuser:
            return HttpResponseRedirect(runinfo.questionset.questionnaire.redirect_url)

    # let the runinfo have a piggy back ride on the request
    # so we can easily use the runinfo in places like the question processor
    # without passing it around
    request.runinfo = runinfo

    if not qs:
        # Only change the language to the subjects choice for the initial
        # questionnaire page (may be a direct link from an email)
        if hasattr(request, 'session'):
            request.session[translation.LANGUAGE_SESSION_KEY] = runinfo.subject.language
            translation.activate(runinfo.subject.language)

    if 'lang' in request.GET:
        return set_language(request, runinfo, request.path)

    # --------------------------------
    # --- Handle non-POST requests ---
    # --------------------------------

    if request.method != "POST":
        if qs is not None:
            qs = get_object_or_404(QuestionSet, sortid=qs, questionnaire=runinfo.questionset.questionnaire)
            if runinfo.random.startswith('test:'):
                pass  # ok for testing
            elif qs.sortid > runinfo.questionset.sortid:
                # you may jump back, but not forwards
                return redirect_to_qs(runinfo, request)
            runinfo.questionset = qs
            runinfo.save()
            commit()
        # no questionset id in URL, so redirect to the correct URL
        if qs is None:
            return redirect_to_qs(runinfo, request)
        questionset_start.send(sender=None, runinfo=runinfo, questionset=qs)
        return show_questionnaire(request, runinfo)

    # -------------------------------------
    # --- Process POST with QuestionSet ---
    # -------------------------------------

    # if the submitted page is different to what runinfo says, update runinfo

    qs = request.POST.get('questionset_id', qs)
    try:
        qsobj = QuestionSet.objects.filter(pk=qs)[0]
        if qsobj.questionnaire == runinfo.questionset.questionnaire:
            if runinfo.questionset != qsobj:
                runinfo.questionset = qsobj
                runinfo.save()
    except:
        pass

    questionnaire = runinfo.questionset.questionnaire
    questionset = runinfo.questionset


    # to confirm that we have the correct answers
    expected = questionset.questions()

    items = request.POST.items()
    extra = {}  # question_object => { "ANSWER" : "123", ... }

    # this will ensure that each question will be processed, even if we did not receive
    # any fields for it. Also works to ensure the user doesn't add extra fields in
    for x in expected:
        items.append((u'question_%s_Trigger953' % x.number, None))

    # generate the answer_dict for each question, and place in extra
    for item in items:
        key, value = item[0], item[1]
        if key.startswith('question_'):
            answer = key.split("_", 2)
            question = get_question(answer[1], questionset)
            if not question:
                logging.warn("Unknown question when processing: %s" % answer[1])
                continue
            extra[question] = ans = extra.get(question, {})
            if (len(answer) == 2):
                ans['ANSWER'] = value
            elif (len(answer) == 3):
                ans[answer[2]] = value
            else:
                logging.warn("Poorly formed form element name: %r" % answer)
                continue
            extra[question] = ans

    errors = {}
    for question, ans in extra.items():
        if not question_satisfies_checks(question, runinfo):
            continue
        if u"Trigger953" not in ans:
            logging.warn("User attempted to insert extra question (or it's a bug)")
            continue
        try:
            cd = question.getcheckdict()
            # requiredif is the new way
            depon = cd.get('requiredif', None) or cd.get('dependent', None)
            if depon:
                depparser = BooleanParser(dep_check, runinfo, extra)
                if not depparser.parse(depon):
                    # if check is not the same as answer, then we don't care
                    # about this question plus we should delete it from the DB
                    delete_answer(question, runinfo.subject, runinfo.run)
                    if cd.get('store', False):
                        runinfo.set_cookie(question.number, None)
                    continue
            add_answer(runinfo, question, ans)
            if cd.get('store', False):
                runinfo.set_cookie(question.number, ans['ANSWER'])
        except AnswerException as e:
            errors[question.number] = e
        except Exception:
            logging.exception("Unexpected Exception")
            rollback()
            raise

    if len(errors) > 0:
        res = show_questionnaire(request, runinfo, errors=errors)
        rollback()
        return res

    questionset_done.send(sender=None, runinfo=runinfo, questionset=questionset)

    nxt = next(questionset)
    while nxt and not questionset_satisfies_checks(nxt, runinfo):
        nxt = next(nxt)
    runinfo.questionset = nxt
    runinfo.save()
    if use_session:
        request.session['prev_runcode'] = runinfo.random

    if nxt is None:  # we are finished
        return finish_questionnaire(request, runinfo, questionnaire)

    commit()
    return redirect_to_qs(runinfo, request)


def finish_questionnaire(request, runinfo, questionnaire):
    hist = RunInfoHistory()
    hist.subject = runinfo.subject
    hist.run = runinfo.run
    hist.completed = datetime.now()
    hist.questionnaire = questionnaire
    hist.tags = runinfo.tags
    hist.skipped = runinfo.skipped
    hist.landing = runinfo.landing
    hist.save()

    questionnaire_done.send(sender=None, runinfo=runinfo,
                            questionnaire=questionnaire)
    lang = translation.get_language()
    redirect_url = questionnaire.redirect_url
    for x, y in (('$LANG', lang),
                 ('$SUBJECTID', runinfo.subject.id),
                 ('$RUNID', runinfo.run.runid),):
        redirect_url = redirect_url.replace(x, str(y))

    if runinfo.run.runid in ('12345', '54321') \
            or runinfo.run.runid.startswith('test:'):
        runinfo.questionset = QuestionSet.objects.filter(questionnaire=questionnaire).order_by('sortid')[0]
        runinfo.save()
    else:
        runinfo.delete()
    commit()
    if redirect_url:
        return HttpResponseRedirect(redirect_url)
    return r2r("questionnaire/complete.{}.html".format(lang), request, landing_object=hist.landing.content_object)


def show_questionnaire(request, runinfo, errors={}):
    """
    Return the QuestionSet template

    Also add the javascript dependency code.
    """

    request.runinfo = runinfo

    if request.GET.get('show_all') == '1':  # for debugging purposes.
        questions = runinfo.questionset.questionnaire.questions()
    else:
        questions = runinfo.questionset.questions()

    show_all = request.GET.get('show_all') == '1'  # for debugging purposes in some cases we may want to show all questions on one screen.
    questionset = runinfo.questionset
    questions = questionset.questionnaire.questions() if show_all else questionset.questions()

    qlist = []
    jsinclude = []  # js files to include
    cssinclude = []  # css files to include
    jstriggers = []
    qvalues = {}

    # initialize qvalues
    cookiedict = runinfo.get_cookiedict()

    for k, v in cookiedict.items():
        qvalues[k] = v

    substitute_answer(qvalues, runinfo.questionset)

    #we make it clear to the user that we're going to sort by sort id then number, so why wasn't it doing that?
    questions = sorted(questions, key=lambda question: (question.sort_id, question.number))

    for question in questions:
        # if we got here the questionset will at least contain one question
        # which passes, so this is all we need to check for
        question_visible = question_satisfies_checks(question, runinfo) or show_all
        Type = question.get_type()
        _qnum, _qalpha = split_numal(question.number)

        qdict = {
            'css_style': '' if question_visible else 'display:none;',
            'template': 'questionnaire/%s.html' % (Type),
            'qnum': _qnum,
            'qalpha': _qalpha,
            'qtype': Type,
            'qnum_class': (_qnum % 2 == 0) and " qeven" or " qodd",
            'qalpha_class': _qalpha and (ord(_qalpha[-1]) % 2 \
                                         and ' alodd' or ' aleven') or '',
        }

        # substitute answer texts
        substitute_answer(qvalues, question)

        # add javascript dependency checks
        cd = question.getcheckdict()

        # Note: dep_check() is showing up on pages where questions rely on previous pages' questions -
        # this causes disappearance of questions, since there are no qvalues for questions on previous
        # pages. BUT depon will be false if the question is a SAMEAS of another question with no off-page
        # checks. This will make no bad dep_check()s appear for these SAMEAS questions, circumventing the
        # problem. Eventually need to fix either getcheckdict() (to screen out questions on previous pages)
        # or prevent JavaScript from hiding questions when check_dep() cannot find a key in qvalues.
        depon = cd.get('requiredif', None) or cd.get('dependent', None) or cd.get('shownif', None)
        if depon:
            willberequiredif = bool(cd.get("requiredif", None) )
            willbedependent = bool(cd.get("dependent", None) )
            willbe_shownif = (not willberequiredif) and (not willbedependent) and bool(cd.get("shownif", None))

            # jamie and mark funkyness to be only done if depon is shownif, some similar thought is due to requiredif
            # for shownon, we have to deal with the fact that only the answers from this page are available to the JS
            # so we do a partial parse to form the checks="" attribute
            if willbe_shownif:
                qdict['checkstring'] = ' checks="%s"' % make_partially_evaluated_js_exp_for_shownif_check(
                    depon, runinfo, question
                )

            else:
                # extra args to BooleanParser are not required for toString
                parser = BooleanParser(dep_check)
                qdict['checkstring'] = ' checks="%s"' % parser.toString(depon)
            jstriggers.append('qc_%s' % question.number)

        footerdep = cd.get('footerif', None)
        if footerdep:
            parser = BooleanParser(dep_check)
            qdict['footerchecks'] = ' checks="%s"' % parser.toString(footerdep)
            jstriggers.append('qc_%s_footer' % question.number)

        if 'default' in cd and not question.number in cookiedict:
            qvalues[question.number] = cd['default']
        if Type in QuestionProcessors:
            qdict.update(QuestionProcessors[Type](request, question))
            if 'jsinclude' in qdict:
                if qdict['jsinclude'] not in jsinclude:
                    jsinclude.extend(qdict['jsinclude'])
            if 'cssinclude' in qdict:
                if qdict['cssinclude'] not in cssinclude:
                    cssinclude.extend(qdict['jsinclude'])
            if 'jstriggers' in qdict:
                jstriggers.extend(qdict['jstriggers'])
            if 'qvalue' in qdict and not question.number in cookiedict:
                qvalues[question.number] = qdict['qvalue']
            if 'qvalues' in qdict:
            # for multiple selection
                for choice in qdict['qvalues']:
                    qvalues[choice] = 'true'

        qlist.append((question, qdict))

    try:
        has_progress = settings.QUESTIONNAIRE_PROGRESS in ('async', 'default')
        async_progress = settings.QUESTIONNAIRE_PROGRESS == 'async'
    except AttributeError:
        has_progress = True
        async_progress = False

    if has_progress:
        if async_progress:
            progress = cache.get('progress' + runinfo.random, 1)
        else:
            progress = get_progress(runinfo)
    else:
        progress = 0

    if request.POST:
        for k, v in request.POST.items():
            if k.startswith("question_"):
                s = k.split("_")
                if s[-1] == "value":    # multiple checkboxes with value boxes
                    qvalues["_".join(s[1:])] = v
                elif len(s) == 4:
                    qvalues[s[1] + '_' + v] = '1'  # evaluates true in JS
                elif len(s) == 3 and s[2] == 'comment':
                    qvalues[s[1] + '_' + s[2]] = v
                else:
                    qvalues[s[1]] = v

    if use_session:
        prev_url = reverse('redirect_to_prev_questionnaire')
    else:
        prev_url = reverse('redirect_to_prev_questionnaire', args=[runinfo.random, runinfo.questionset.sortid])

    current_answers = []
    if debug_questionnaire:
        current_answers = Answer.objects.filter(subject=runinfo.subject, run=runinfo.run).order_by('id')


    r = r2r("questionnaire/questionset.html", request,
            questionset=runinfo.questionset,
            runinfo=runinfo,
            errors=errors,
            qlist=qlist,
            progress=progress,
            triggers=jstriggers,
            qvalues=qvalues,
            jsinclude=jsinclude,
            cssinclude=cssinclude,
            async_progress=async_progress,
            async_url=reverse('progress', args=[runinfo.random]),
            prev_url=prev_url,
            current_answers=current_answers,
    )
    r['Cache-Control'] = 'no-cache'
    r['Expires'] = "Thu, 24 Jan 1980 00:00:00 GMT"
    r.set_cookie('questionset_id', str(questionset.id))
    return r


def set_language(request, runinfo=None, nxt=None):
    """
    Change the language, save it to runinfo if provided, and
    redirect to the provided URL (or the last URL).
    Can also be used by a url handler, w/o runinfo & next.
    """
    if not nxt:
        nxt = request.GET.get('next', request.POST.get('next', None))
    if not nxt:
        nxt = request.META.get('HTTP_REFERER', None)
        if not nxt:
            nxt = '/'
    response = HttpResponseRedirect(nxt)
    response['Expires'] = "Thu, 24 Jan 1980 00:00:00 GMT"
    if request.method == 'GET':
        lang_code = request.GET.get('lang', None)
        if lang_code and translation.check_for_language(lang_code):
            if hasattr(request, 'session'):
                request.session[translation.LANGUAGE_SESSION_KEY] = lang_code
            else:
                response.set_cookie(settings.LANGUAGE_COOKIE_NAME, lang_code)
            if runinfo:
                runinfo.subject.language = lang_code
                runinfo.subject.save()
    return response



@permission_required("questionnaire.management")
def send_email(request, runinfo_id):
    if request.method != "POST":
        return HttpResponse("This page MUST be called as a POST request.")
    runinfo = get_object_or_404(RunInfo, pk=int(runinfo_id))
    successful = _send_email(runinfo)
    return r2r("emailsent.html", request, runinfo=runinfo, successful=successful)


def generate_run(request, questionnaire_id, subject_id=None, context={}):
    """
    A view that can generate a RunID instance anonymously,
    and then redirect to the questionnaire itself.

    It uses a Subject with the givenname of 'Anonymous' and the
    surname of 'User'.  If this Subject does not exist, it will
    be created.

    This can be used with a URL pattern like:
    (r'^take/(?P<questionnaire_id>[0-9]+)/$', 'questionnaire.views.generate_run'),
    """
    qu = get_object_or_404(Questionnaire, id=questionnaire_id)
    qs = qu.questionsets()[0]

    if subject_id is not None:
        su = get_object_or_404(Subject, pk=subject_id)
    else:
        su = Subject(anonymous=True, ip_address=request.META['REMOTE_ADDR'])
        su.save()

#    str_to_hash = "".join(map(lambda i: chr(random.randint(0, 255)), range(16)))
    str_to_hash = str(uuid4())
    str_to_hash += settings.SECRET_KEY
    key = md5(bytes(str_to_hash, 'utf-8')).hexdigest()
    landing = context.get('landing', None)
    r = Run.objects.create(runid=key)
    run = RunInfo.objects.create(subject=su, random=key, run=r, questionset=qs, landing=landing)
    if not use_session:
        kwargs = {'runcode': key}
    else:
        kwargs = {}
        request.session['runcode'] = key

    questionnaire_start.send(sender=None, runinfo=run, questionnaire=qu)
    response = HttpResponseRedirect(reverse('questionnaire', kwargs=kwargs))
    response.set_cookie('next', context.get('next',''))
    return response

def generate_error(request):
    return 400/0

class QuestionnaireView(TemplateView):
    template_name = "pages/generic.html"

    def get_context_data(self, **kwargs):
        context = super(QuestionnaireView, self).get_context_data(**kwargs)

        nonce = self.kwargs['nonce']
        landing = get_object_or_404(Landing, nonce=nonce)
        context["landing"] = landing
        context["next"] = self.request.GET.get('next', '')


        return context

    def get(self, request, *args, **kwargs):
        context = self.get_context_data(**kwargs)
        if context['landing'].questionnaire:
            return generate_run(request, context['landing'].questionnaire.id, context=context)
        return self.render_to_response(context)

try:
    (app_label, model_name) = settings.QUESTIONNAIRE_ITEM_MODEL.split('.', 1)
    item_model = apps.get_model(app_label=app_label, model_name=model_name)
except AttributeError:
    item_model = None


@login_required
def new_questionnaire(request, item_id):
    if item_id:
        item = get_object_or_404(item_model, id=item_id)
        form = NewLandingForm()
    else:
        item = None
        form = NewLandingForm()
    if  request.method == 'POST':
        form = NewLandingForm(data=request.POST)
        if form.is_valid():
            if not item and form.item:
                item = form.item
            landing = Landing.objects.create(label=form.cleaned_data['label'], questionnaire=form.cleaned_data['questionnaire'], content_object=item)
            return HttpResponseRedirect(reverse('questionnaires'))
    return render(request, "manage_questionnaire.html", {"item":item, "form":form})



def questionnaires(request):
    if not request.user.is_authenticated() :
        return render(request, "questionnaires.html")
    items = item_model.objects.all()
    questionnaires = Questionnaire.objects.all()
    return render(request, "questionnaires.html", {"items":items, "questionnaires":questionnaires})


def _table_headers(questions):
    """
    Return the header labels for a set of questions as a list of strings.

    This will create separate columns for each multiple-choice possiblity
    and freeform options, to avoid mixing data types and make charting easier.
    """
    ql = list(questions.order_by(
         'questionset__sortid', 'number')
        )
    #ql.sort(lambda x, y: numal_sort(x.number, y.number))
    columns = []
    for q in ql:
        qnum = '{}.{}'.format(q.questionset.sortid, q.number)
        if q.type.startswith('choice-yesnocomment'):
            columns.extend([qnum, qnum + "-freeform"])
        elif q.type.startswith('choice-freeform'):
            columns.extend([qnum, qnum + "-freeform"])
        elif q.type.startswith('choice-multiple'):
            cl = [c.value for c in q.choice_set.all()]
            cl.sort(numal_sort)
            columns.extend([qnum + '-' + value for value in cl])
            if q.type == 'choice-multiple-freeform':
                columns.append(qnum + '-freeform')
        else:
            columns.append(qnum)
    return columns


default_extra_headings = [u'subject', u'run id']


def default_extra_entries(subject, run):
    return ["%s/%s" % (subject.id, subject.ip_address), run.id]


@login_required
def export_csv(request, qid,
        extra_headings=default_extra_headings,
        extra_entries=default_extra_entries,
        answer_filter=None,
        filecode=0,
    ):
    """
    For a given questionnaire id, generate a CSV containing all the
    answers for all subjects.
    qid -- questionnaire_id
    extra_headings -- customize the headings for extra columns,
    extra_entries -- function returning a list of extra column entries,
    answer_filter -- custom filter for the answers. If this is present, the filter must manage access.
    filecode -- code for filename
    """
    if answer_filter is None and not request.user.has_perm("questionnaire.export"):
        return HttpResponse('Sorry, you do not have export permissions', content_type="text/plain")

    fd = tempfile.TemporaryFile()

    questionnaire = get_object_or_404(Questionnaire, pk=int(qid))
    headings, answers = answer_export(questionnaire, answer_filter=answer_filter)

    writer = UnicodeWriter(fd)
    writer.writerow(extra_headings + headings)
    for subject, run, answer_row in answers:
        row = extra_entries(subject, run) + [
            a if a else '--' for a in answer_row]
        writer.writerow(row)
    fd.seek(0)

    response = HttpResponse(fd, content_type="text/csv")
    response['Content-Length'] = fd.tell()
    response['Content-Disposition'] = 'attachment; filename="answers-%s-%s.csv"' % (qid, filecode)
    return response


def item_answer_filter(item_id):
    def item_filter(answers):
        if item_model:
            items = item_model.objects.filter(id=item_id)
            return answers.filter(run__run_info_histories__landing__items__in=items)
        else:
            return answers.none()
    return item_filter


# wrapper for export_csv to customize the report table
@login_required
def export_item_csv(request, qid, item_id):
    def extra_entries(subject, run):
        landing = completed = None
        try:
            landing = run.run_info_histories.all()[0].landing
            completed = run.run_info_histories.all()[0].completed
        except IndexError:
            try:
                landing = run.run_infos.all()[0].landing
                completed = run.run_infos.all()[0].created
            except IndexError:
                label = wid = "error"
        if landing:
            label = landing.label
            wid = landing.object_id
        return [wid, subject.ip_address, run.id, completed, label]

    extra_headings = [u'item id', u'subject ip address', u'run id', u'date completed', u'landing label']
    return export_csv(request, qid,
        extra_entries=extra_entries,
        extra_headings=extra_headings,
        answer_filter=item_answer_filter(item_id),
        filecode=item_id)


def answer_export(questionnaire, answers=None, answer_filter=None):
    """
    questionnaire -- questionnaire model for export
    answers -- query set of answers to include in export, defaults to all
    answer_filter -- filter for the answers

    Return a flat dump of column headings and all the answers for a
    questionnaire (in query set answers) in the form (headings, answers)
    where headings is:
        ['question1 number', ...]
    and answers is:
        [(subject1, 'runid1', ['answer1.1', ...]), ... ]

    The headings list might include items with labels like
    'questionnumber-freeform'.  Those columns will contain all the freeform
    answers for that question (separated from the other answer data).

    Multiple choice questions will have one column for each choice with
    labels like 'questionnumber-choice'.

    The items in the answers list are unicode strings or empty strings
    if no answer was given.  The number of elements in each answer list will
    always match the number of headings.
    """
    if answers is None:
        answers = Answer.objects.all()
    if answer_filter:
        answers = answer_filter(answers)
    answers = answers.filter(
        question__questionset__questionnaire=questionnaire).order_by(
        'subject', 'run__runid', 'question__questionset__sortid', 'question__number')
    answers = answers.select_related()
    questions = Question.objects.filter(
        questionset__questionnaire=questionnaire)
    headings = _table_headers(questions)

    coldict = {}
    for num, col in enumerate(headings):  # use coldict to find column indexes
        coldict[col] = num
    # collect choices for each question
    qchoicedict = {}
    for q in questions:
        qchoicedict[q.id] = [x[0] for x in q.choice_set.values_list('value')]

    runid = subject = None
    out = []
    row = []
    run = None
    for answer in answers:
        if answer.run != run or answer.subject != subject:
            if row:
                out.append((subject, run, row))
            run = answer.run
            subject = answer.subject
            row = [""] * len(headings)
        ans = answer.split_answer()
        if type(ans) == int:
            ans = str(ans)
        for choice in ans:
            col = None
            qnum = '{}.{}'.format(answer.question.questionset.sortid, answer.question.number)
            if type(choice) == list:
                # freeform choice
                choice = choice[0]
                col = coldict.get(qnum + '-freeform', None)
            if col is None:  # look for enumerated choice column (multiple-choice)
                col = coldict.get(qnum + '-' + unicodestr(choice), None)
            if col is None:  # single-choice items
                if ((not qchoicedict[answer.question.id]) or
                            choice in qchoicedict[answer.question.id]):
                    col = coldict.get(qnum, None)
            if col is None:  # last ditch, if not found throw it in a freeform column
                col = coldict.get(qnum + '-freeform', None)
            if col is not None:
                row[col] = choice
    # and don't forget about the last one
    if row:
        out.append((subject, run, row))
    return headings, out


def answer_summary(questionnaire, answers=None, answer_filter=None):
    """
    questionnaire -- questionnaire model for summary
    answers -- query set of answers to include in summary, defaults to all

    Return a summary of the answer totals in answer_qs in the form:
    [('q1', 'question1 text',
        [('choice1', 'choice1 text', num), ...],
        ['freeform1', ...]), ...]

    questions are returned in questionnaire order
    choices are returned in question order
    freeform options are case-insensitive sorted
    """

    if answers is None:
        answers = Answer.objects.all()
    if answer_filter:
        answers = answer_filter(answers)
    answers = answers.filter(question__questionset__questionnaire=questionnaire)
    questions = Question.objects.filter(
        questionset__questionnaire=questionnaire).order_by(
        'questionset__sortid', 'number')

    summary = []
    for question in questions:
        q_type = question.get_type()
        if q_type.startswith('choice-yesno'):
            choices = [('yes', _('Yes')), ('no', _('No'))]
            if 'dontknow' in q_type:
                choices.append(('dontknow', _("Don't Know")))
        elif q_type.startswith('choice'):
            choices = [(c.value, c.text) for c in question.choices()]
        else:
            choices = []
        choice_totals = dict([(k, 0) for k, v in choices])
        freeforms = []
        for a in answers.filter(question=question):
            ans = a.split_answer()
            for choice in ans:
                if type(choice) == list:
                    freeforms.extend(choice)
                elif choice in choice_totals:
                    choice_totals[choice] += 1
                else:
                    # be tolerant of improperly marked data
                    freeforms.append(choice)
        freeforms.sort(numal_sort)
        summary.append((question.number, question.text, [
            (n, t, choice_totals[n]) for (n, t) in choices], freeforms))
    return summary


@login_required
def export_summary(request, qid, answer_filter=None):
    """
    For a given questionnaire id, generate a CSV containing a summary of
    answers for all subjects.
    qid -- questionnaire_id
    answer_filter -- custom filter for the answers. If this is present, the filter must manage access.
    """
    if answer_filter is None and not request.user.has_perm("questionnaire.export"):
        return HttpResponse('Sorry, you do not have export permissions', content_type="text/plain")


    questionnaire = get_object_or_404(Questionnaire, pk=int(qid))
    summaries = answer_summary(questionnaire, answer_filter=answer_filter)

    return render(request, "pages/summaries.html", {'summaries':summaries})


@login_required
def export_item_summary(request, qid, item_id):
    """
    wrapper without filter
    """
    return export_summary(
        request,
        qid,
        answer_filter=item_answer_filter(item_id),
    )