import json
from operator import attrgetter

from django.conf import settings
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.cache import cache
from django.core.exceptions import ImproperlyConfigured, ObjectDoesNotExist, PermissionDenied
from django.db.models import Prefetch, Q
from django.http import Http404, HttpResponse, HttpResponseBadRequest, HttpResponseRedirect, JsonResponse
from django.shortcuts import get_object_or_404, render
from django.urls import reverse
from django.utils import timezone
from django.utils.functional import cached_property
from django.utils.html import escape, format_html
from django.utils.safestring import mark_safe
from django.utils.translation import gettext as _, gettext_lazy
from django.views.decorators.http import require_POST
from django.views.generic import DetailView, ListView

from judge import event_poster as event
from judge.highlight_code import highlight_code
from judge.models import Contest, Language, Problem, ProblemTranslation, Profile, Submission
from judge.utils.problems import get_result_data, user_authored_ids, user_completed_ids, user_editable_ids
from judge.utils.raw_sql import use_straight_join
from judge.utils.views import DiggPaginatorMixin, TitleMixin


def submission_related(queryset):
    return queryset.select_related('user__user', 'problem', 'language') \
        .only('id', 'user__user__username', 'user__display_rank', 'user__rating', 'problem__name',
              'problem__code', 'problem__is_public', 'language__short_name', 'language__key', 'date', 'time', 'memory',
              'points', 'result', 'status', 'case_points', 'case_total', 'current_testcase', 'contest_object')


class SubmissionMixin(object):
    model = Submission
    context_object_name = 'submission'
    pk_url_kwarg = 'submission'


class SubmissionDetailBase(LoginRequiredMixin, TitleMixin, SubmissionMixin, DetailView):
    def get_object(self, queryset=None):
        submission = super(SubmissionDetailBase, self).get_object(queryset)
        profile = self.request.profile
        problem = submission.problem
        if self.request.user.has_perm('judge.view_all_submission'):
            return submission
        if submission.user_id == profile.id:
            return submission
        if problem.is_editor(profile):
            return submission
        if problem.is_public or problem.testers.filter(id=profile.id).exists():
            if Submission.objects.filter(user_id=profile.id, result='AC', problem_id=problem.id,
                                         points=problem.points).exists():
                return submission
        raise PermissionDenied()

    def get_title(self):
        submission = self.object
        return _('Submission of %(problem)s by %(user)s') % {
            'problem': submission.problem.translated_name(self.request.LANGUAGE_CODE),
            'user': submission.user.user.username,
        }

    def get_content_title(self):
        submission = self.object
        return mark_safe(escape(_('Submission of %(problem)s by %(user)s')) % {
            'problem': format_html('<a href="{0}">{1}</a>',
                                   reverse('problem_detail', args=[submission.problem.code]),
                                   submission.problem.translated_name(self.request.LANGUAGE_CODE)),
            'user': format_html('<a href="{0}">{1}</a>',
                                reverse('user_page', args=[submission.user.user.username]),
                                submission.user.user.username),
        })


class SubmissionSource(SubmissionDetailBase):
    template_name = 'submission/source.html'

    def get_queryset(self):
        return super().get_queryset().select_related('source')

    def get_context_data(self, **kwargs):
        context = super(SubmissionSource, self).get_context_data(**kwargs)
        submission = self.object
        context['raw_source'] = submission.source.source.rstrip('\n')
        context['highlighted_source'] = highlight_code(submission.source.source, submission.language.pygments)
        return context


def make_batch(batch, cases):
    result = {'id': batch, 'cases': cases}
    if batch:
        result['points'] = min(map(attrgetter('points'), cases))
        result['total'] = max(map(attrgetter('total'), cases))
    return result


def group_test_cases(cases):
    result = []
    buf = []
    last = None
    for case in cases:
        if case.batch != last and buf:
            result.append(make_batch(last, buf))
            buf = []
        buf.append(case)
        last = case.batch
    if buf:
        result.append(make_batch(last, buf))
    return result


class SubmissionStatus(SubmissionDetailBase):
    template_name = 'submission/status.html'

    def get_context_data(self, **kwargs):
        context = super(SubmissionStatus, self).get_context_data(**kwargs)
        submission = self.object
        context['last_msg'] = event.last()
        context['batches'] = group_test_cases(submission.test_cases.all())
        context['time_limit'] = submission.problem.time_limit
        try:
            lang_limit = submission.problem.language_limits.get(language=submission.language)
        except ObjectDoesNotExist:
            pass
        else:
            context['time_limit'] = lang_limit.time_limit
        return context


class SubmissionTestCaseQuery(SubmissionStatus):
    template_name = 'submission/status-testcases.html'

    def get(self, request, *args, **kwargs):
        if 'id' not in request.GET or not request.GET['id'].isdigit():
            return HttpResponseBadRequest()
        self.kwargs[self.pk_url_kwarg] = kwargs[self.pk_url_kwarg] = int(request.GET['id'])
        return super(SubmissionTestCaseQuery, self).get(request, *args, **kwargs)


class SubmissionSourceRaw(SubmissionSource):
    def get(self, request, *args, **kwargs):
        submission = self.get_object()
        return HttpResponse(submission.source.source, content_type='text/plain')


@require_POST
def abort_submission(request, submission):
    submission = get_object_or_404(Submission, id=int(submission))
    if (not request.user.is_authenticated or (submission.was_rejudged or (request.profile != submission.user)) and
            not request.user.has_perm('abort_any_submission')):
        raise PermissionDenied()
    submission.abort()
    return HttpResponseRedirect(reverse('submission_status', args=(submission.id,)))


class SubmissionsListBase(DiggPaginatorMixin, TitleMixin, ListView):
    model = Submission
    paginate_by = 50
    show_problem = True
    title = gettext_lazy('All submissions')
    content_title = gettext_lazy('All submissions')
    tab = 'all_submissions_list'
    template_name = 'submission/list.html'
    context_object_name = 'submissions'
    first_page_href = None

    def get_result_data(self):
        result = self._get_result_data()
        for category in result['categories']:
            category['name'] = _(category['name'])
        return result

    def _get_result_data(self):
        return get_result_data(self.get_queryset().order_by())

    def access_check(self, request):
        pass

    @cached_property
    def in_contest(self):
        return self.request.user.is_authenticated and self.request.profile.current_contest is not None

    @cached_property
    def contest(self):
        return self.request.profile.current_contest.contest

    def _get_queryset(self):
        queryset = Submission.objects.all()
        use_straight_join(queryset)
        queryset = submission_related(queryset.order_by('-id'))
        if self.show_problem:
            queryset = queryset.prefetch_related(Prefetch('problem__translations',
                                                          queryset=ProblemTranslation.objects.filter(
                                                              language=self.request.LANGUAGE_CODE), to_attr='_trans'))
        if self.in_contest:
            queryset = queryset.filter(contest__participation__contest_id=self.contest.id)
            if self.contest.hide_scoreboard and self.contest.is_in_contest(self.request.user):
                queryset = queryset.filter(contest__participation__user=self.request.profile)
        else:
            queryset = queryset.select_related('contest_object').defer('contest_object__description')

            # This is not technically correct since contest organizers *should* see these, but
            # the join would be far too messy
            if not self.request.user.has_perm('judge.see_private_contest'):
                queryset = queryset.exclude(contest_object_id__in=Contest.objects.filter(hide_scoreboard=True))

        if self.selected_languages:
            queryset = queryset.filter(language_id__in=Language.objects.filter(key__in=self.selected_languages))
        if self.selected_statuses:
            queryset = queryset.filter(result__in=self.selected_statuses)

        return queryset

    def get_queryset(self):
        queryset = self._get_queryset()
        if not self.in_contest:
            if not self.request.user.has_perm('judge.see_private_problem'):
                queryset = queryset.filter(problem__is_public=True)
            if not self.request.user.has_perm('judge.see_organization_problem'):
                filter = Q(problem__is_organization_private=False)
                if self.request.user.is_authenticated:
                    filter |= Q(problem__organizations__in=self.request.profile.organizations.all())
                queryset = queryset.filter(filter)
        return queryset

    def get_my_submissions_page(self):
        return None

    def get_all_submissions_page(self):
        return reverse('all_submissions')

    def get_searchable_status_codes(self):
        hidden_codes = ['SC']
        if not self.request.user.is_superuser and not self.request.user.is_staff:
            hidden_codes += ['IE']
        return [(key, value) for key, value in Submission.RESULT if key not in hidden_codes]

    def get_context_data(self, **kwargs):
        context = super(SubmissionsListBase, self).get_context_data(**kwargs)
        authenticated = self.request.user.is_authenticated
        context['dynamic_update'] = False
        context['show_problem'] = self.show_problem
        context['completed_problem_ids'] = user_completed_ids(self.request.profile) if authenticated else []
        context['authored_problem_ids'] = user_authored_ids(self.request.profile) if authenticated else []
        context['editable_problem_ids'] = user_editable_ids(self.request.profile) if authenticated else []

        context['all_languages'] = Language.objects.all().values_list('key', 'name')
        context['selected_languages'] = self.selected_languages

        context['all_statuses'] = self.get_searchable_status_codes()
        context['selected_statuses'] = self.selected_statuses

        context['results_json'] = mark_safe(json.dumps(self.get_result_data()))
        context['results_colors_json'] = mark_safe(json.dumps(settings.DMOJ_STATS_SUBMISSION_RESULT_COLORS))

        context['page_suffix'] = suffix = ('?' + self.request.GET.urlencode()) if self.request.GET else ''
        context['first_page_href'] = (self.first_page_href or '.') + suffix
        context['my_submissions_link'] = self.get_my_submissions_page()
        context['all_submissions_link'] = self.get_all_submissions_page()
        context['tab'] = self.tab
        return context

    def get(self, request, *args, **kwargs):
        check = self.access_check(request)
        if check is not None:
            return check

        self.selected_languages = set(request.GET.getlist('language'))
        self.selected_statuses = set(request.GET.getlist('status'))

        if 'results' in request.GET:
            return JsonResponse(self.get_result_data())

        return super(SubmissionsListBase, self).get(request, *args, **kwargs)


class UserMixin(object):
    def get(self, request, *args, **kwargs):
        if 'user' not in kwargs:
            raise ImproperlyConfigured('Must pass a user')
        self.profile = get_object_or_404(Profile, user__username=kwargs['user'])
        self.username = kwargs['user']
        return super(UserMixin, self).get(request, *args, **kwargs)


class ConditionalUserTabMixin(object):
    def get_context_data(self, **kwargs):
        context = super(ConditionalUserTabMixin, self).get_context_data(**kwargs)
        if self.request.user.is_authenticated and self.request.profile == self.profile:
            context['tab'] = 'my_submissions_tab'
        else:
            context['tab'] = 'user_submissions_tab'
            context['tab_username'] = self.profile.user.username
        return context


class AllUserSubmissions(ConditionalUserTabMixin, UserMixin, SubmissionsListBase):
    def get_queryset(self):
        return super(AllUserSubmissions, self).get_queryset().filter(user_id=self.profile.id)

    def get_title(self):
        if self.request.user.is_authenticated and self.request.profile == self.profile:
            return _('All my submissions')
        return _('All submissions by %s') % self.username

    def get_content_title(self):
        if self.request.user.is_authenticated and self.request.profile == self.profile:
            return format_html('All my submissions')
        return format_html('All submissions by <a href="{1}">{0}</a>', self.username,
                           reverse('user_page', args=[self.username]))

    def get_my_submissions_page(self):
        if self.request.user.is_authenticated:
            return reverse('all_user_submissions', kwargs={'user': self.request.user.username})

    def get_context_data(self, **kwargs):
        context = super(AllUserSubmissions, self).get_context_data(**kwargs)
        context['dynamic_update'] = context['page_obj'].number == 1
        context['dynamic_user_id'] = self.profile.id
        context['last_msg'] = event.last()
        return context


class ProblemSubmissionsBase(SubmissionsListBase):
    show_problem = False
    dynamic_update = True
    check_contest_in_access_check = True

    def get_queryset(self):
        if self.in_contest and not self.contest.contest_problems.filter(problem_id=self.problem.id).exists():
            raise Http404()
        return super(ProblemSubmissionsBase, self)._get_queryset().filter(problem_id=self.problem.id)

    def get_title(self):
        return _('All submissions for %s') % self.problem_name

    def get_content_title(self):
        return format_html('All submissions for <a href="{1}">{0}</a>', self.problem_name,
                           reverse('problem_detail', args=[self.problem.code]))

    def access_check_contest(self, request):
        if self.in_contest and not self.contest.can_see_scoreboard(request.user):
            raise Http404()

    def access_check(self, request):
        if not self.problem.is_accessible_by(request.user):
            raise Http404()

        if self.check_contest_in_access_check:
            self.access_check_contest(request)

    def get(self, request, *args, **kwargs):
        if 'problem' not in kwargs:
            raise ImproperlyConfigured(_('Must pass a problem'))
        self.problem = get_object_or_404(Problem, code=kwargs['problem'])
        self.problem_name = self.problem.translated_name(self.request.LANGUAGE_CODE)
        return super(ProblemSubmissionsBase, self).get(request, *args, **kwargs)

    def get_all_submissions_page(self):
        return reverse('chronological_submissions', kwargs={'problem': self.problem.code})

    def get_context_data(self, **kwargs):
        context = super(ProblemSubmissionsBase, self).get_context_data(**kwargs)
        if self.dynamic_update:
            context['dynamic_update'] = context['page_obj'].number == 1
            context['dynamic_problem_id'] = self.problem.id
            context['last_msg'] = event.last()
        context['best_submissions_link'] = reverse('ranked_submissions', kwargs={'problem': self.problem.code})
        return context


class ProblemSubmissions(ProblemSubmissionsBase):
    def get_my_submissions_page(self):
        if self.request.user.is_authenticated:
            return reverse('user_submissions', kwargs={'problem': self.problem.code,
                                                       'user': self.request.user.username})


class UserProblemSubmissions(ConditionalUserTabMixin, UserMixin, ProblemSubmissions):
    check_contest_in_access_check = False

    @cached_property
    def is_own(self):
        return self.request.user.is_authenticated and self.request.profile == self.profile

    def access_check(self, request):
        super(UserProblemSubmissions, self).access_check(request)

        if not self.is_own:
            self.access_check_contest(request)

    def get_queryset(self):
        return super(UserProblemSubmissions, self).get_queryset().filter(user_id=self.profile.id)

    def get_title(self):
        if self.is_own:
            return _("My submissions for %(problem)s") % {'problem': self.problem_name}
        return _("%(user)s's submissions for %(problem)s") % {'user': self.username, 'problem': self.problem_name}

    def get_content_title(self):
        if self.request.user.is_authenticated and self.request.profile == self.profile:
            return format_html('''My submissions for <a href="{3}">{2}</a>''',
                               self.username, reverse('user_page', args=[self.username]),
                               self.problem_name, reverse('problem_detail', args=[self.problem.code]))
        return format_html('''<a href="{1}">{0}</a>'s submissions for <a href="{3}">{2}</a>''',
                           self.username, reverse('user_page', args=[self.username]),
                           self.problem_name, reverse('problem_detail', args=[self.problem.code]))

    def get_context_data(self, **kwargs):
        context = super(UserProblemSubmissions, self).get_context_data(**kwargs)
        context['dynamic_user_id'] = self.profile.id
        return context


def single_submission(request, submission_id, show_problem=True):
    request.no_profile_update = True
    authenticated = request.user.is_authenticated
    submission = get_object_or_404(submission_related(Submission.objects.all()), id=int(submission_id))

    if not submission.problem.is_accessible_by(request.user):
        raise Http404()

    return render(request, 'submission/row.html', {
        'submission': submission,
        'authored_problem_ids': user_authored_ids(request.profile) if authenticated else [],
        'completed_problem_ids': user_completed_ids(request.profile) if authenticated else [],
        'editable_problem_ids': user_editable_ids(request.profile) if authenticated else [],
        'show_problem': show_problem,
        'problem_name': show_problem and submission.problem.translated_name(request.LANGUAGE_CODE),
        'profile_id': request.profile.id if authenticated else 0,
    })


def single_submission_query(request):
    request.no_profile_update = True
    if 'id' not in request.GET or not request.GET['id'].isdigit():
        return HttpResponseBadRequest()
    try:
        show_problem = int(request.GET.get('show_problem', '1'))
    except ValueError:
        return HttpResponseBadRequest()
    return single_submission(request, int(request.GET['id']), bool(show_problem))


class AllSubmissions(SubmissionsListBase):
    stats_update_interval = 3600

    def get_my_submissions_page(self):
        if self.request.user.is_authenticated:
            return reverse('all_user_submissions', kwargs={'user': self.request.user.username})

    def get_context_data(self, **kwargs):
        context = super(AllSubmissions, self).get_context_data(**kwargs)
        context['dynamic_update'] = context['page_obj'].number == 1
        context['last_msg'] = event.last()
        context['stats_update_interval'] = self.stats_update_interval
        return context

    def _get_result_data(self):
        if self.in_contest or self.selected_languages or self.selected_statuses:
            return super(AllSubmissions, self)._get_result_data()

        key = 'global_submission_result_data'
        result = cache.get(key)
        if result:
            return result
        result = super(AllSubmissions, self)._get_result_data()
        cache.set(key, result, self.stats_update_interval)
        return result


class ForceContestMixin(object):
    @property
    def in_contest(self):
        return True

    @property
    def contest(self):
        return self._contest

    def access_check(self, request):
        super(ForceContestMixin, self).access_check(request)

        if not request.user.has_perm('judge.see_private_contest'):
            if not self.contest.is_visible:
                raise Http404()
            if self.contest.start_time is not None and self.contest.start_time > timezone.now():
                raise Http404()

    def get_problem_number(self, problem):
        return self.contest.contest_problems.select_related('problem').get(problem=problem).order

    def get(self, request, *args, **kwargs):
        if 'contest' not in kwargs:
            raise ImproperlyConfigured(_('Must pass a contest'))
        self._contest = get_object_or_404(Contest, key=kwargs['contest'])
        return super(ForceContestMixin, self).get(request, *args, **kwargs)


class UserContestSubmissions(ForceContestMixin, UserProblemSubmissions):
    def get_title(self):
        if self.problem.is_accessible_by(self.request.user):
            return "%s's submissions for %s in %s" % (self.username, self.problem_name, self.contest.name)
        return "%s's submissions for problem %s in %s" % (
            self.username, self.get_problem_number(self.problem), self.contest.name)

    def access_check(self, request):
        super(UserContestSubmissions, self).access_check(request)
        if not self.contest.users.filter(user_id=self.profile.id).exists():
            raise Http404()

    def get_content_title(self):
        if self.problem.is_accessible_by(self.request.user):
            return format_html(_('<a href="{1}">{0}</a>\'s submissions for '
                                 '<a href="{3}">{2}</a> in <a href="{5}">{4}</a>'),
                               self.username, reverse('user_page', args=[self.username]),
                               self.problem_name, reverse('problem_detail', args=[self.problem.code]),
                               self.contest.name, reverse('contest_view', args=[self.contest.key]))
        return format_html(_('<a href="{1}">{0}</a>\'s submissions for '
                             'problem {2} in <a href="{4}">{3}</a>'),
                           self.username, reverse('user_page', args=[self.username]),
                           self.get_problem_number(self.problem),
                           self.contest.name, reverse('contest_view', args=[self.contest.key]))