import json
import os.path
import zipfile
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
from django.core.exceptions import ObjectDoesNotExist
from django.core.exceptions import PermissionDenied
from django.db.models import Prefetch
from django.db.models import Q
from django.http import Http404
from django.http import HttpResponse
from django.http import HttpResponseBadRequest
from django.http import HttpResponseRedirect
from django.http import JsonResponse
from django.shortcuts import get_object_or_404
from django.shortcuts import render
from django.urls import reverse
from django.utils import timezone
from django.utils.functional import cached_property
from django.utils.html import escape
from django.utils.html import format_html
from django.utils.safestring import mark_safe
from django.utils.translation import gettext as _
from django.utils.translation import gettext_lazy
from django.views.decorators.http import require_POST
from django.views.generic import DetailView
from django.views.generic import ListView

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


def read_head_archive(archive, file):
    with archive.open(file) as f:
        return f.read(settings.TESTCASE_VISIBLE_LENGTH + 3)


def get_visible_content(data):
    data = data or b''
    data = data.replace(b'\r\n', b'\r').replace(b'\r', b'\n')
    if (len(data) > settings.TESTCASE_VISIBLE_LENGTH):
        data = data[:settings.TESTCASE_VISIBLE_LENGTH]
        data += b'.' * 3
    elif not data.endswith(b'\n'):
        data += b'\n'
    return data.decode('utf-8')


def get_input_answer(case, archive):
    result = {'input': '', 'answer': ''}
    if (len(case.input_file)):
        result['input'] = get_visible_content(read_head_archive(archive, case.input_file))
    if (len(case.output_file)):
        result['answer'] = get_visible_content(read_head_archive(archive, case.output_file))
    return result


def get_problem_data(submission):
    archive_path = os.path.join(settings.DMOJ_PROBLEM_DATA_ROOT,
                                str(submission.problem.data_files.zipfile))
    if not os.path.exists(archive_path):
        raise Exception(
            'archive file "%s" does not exist' % archive_path)
    try:
        archive = zipfile.ZipFile(archive_path, 'r')
    except zipfile.BadZipfile:
        raise Exception('bad archive: "%s"' % archive_path)
   
    testcases = ProblemTestCase.objects.filter(dataset=submission.problem)\
                               .order_by('order')

    if (submission.is_pretested):
        testcases = testcases.filter(is_pretest=True)

    problem_data = {}
    for count, case in enumerate(testcases):
        problem_data[count + 1] = get_input_answer(case, archive)

    return problem_data


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

        contest = submission.contest_or_none
        prefix_length = 0
        if (contest is not None):
            prefix_length = contest.problem.output_prefix_override
        if ((contest is None or prefix_length > 0) or self.request.user.is_superuser):
            context['cases_data'] = get_problem_data(submission)

        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]))