from io import BytesIO
from zipfile import ZipFile

from corres2math.lists import get_sympa_client
from corres2math.matrix import Matrix
from corres2math.views import AdminMixin
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.exceptions import PermissionDenied
from django.core.mail import send_mail
from django.db import transaction
from django.http import HttpResponse
from django.shortcuts import redirect
from django.template.loader import render_to_string
from django.urls import reverse_lazy
from django.utils.translation import gettext_lazy as _
from django.views.generic import CreateView, DetailView, FormView, RedirectView, UpdateView
from django.views.generic.base import TemplateView
from django.views.generic.edit import FormMixin, ProcessFormView
from django_tables2 import SingleTableView
from magic import Magic
from registration.models import AdminRegistration

from .forms import JoinTeamForm, ParticipationForm, PhaseForm, ReceiveParticipationForm, RequestValidationForm,\
    TeamForm, UploadVideoForm, ValidateParticipationForm
from .models import Participation, Phase, Team, Video
from .tables import CalendarTable


class CreateTeamView(LoginRequiredMixin, CreateView):
    """
    Display the page to create a team for new users.
    """

    model = Team
    form_class = TeamForm
    extra_context = dict(title=_("Create team"))
    template_name = "participation/create_team.html"

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        registration = user.registration
        if not registration.participates:
            raise PermissionDenied(_("You don't participate, so you can't create a team."))
        elif registration.team:
            raise PermissionDenied(_("You are already in a team."))
        return super().dispatch(request, *args, **kwargs)

    @transaction.atomic
    def form_valid(self, form):
        """
        When a team is about to be created, the user automatically
        joins the team, a mailing list got created and the user is
        automatically subscribed to this mailing list, and finally
        a Matrix room is created and the user is invited in this room.
        """
        ret = super().form_valid(form)
        # The user joins the team
        user = self.request.user
        registration = user.registration
        registration.team = form.instance
        registration.save()

        # Subscribe the user mail address to the team mailing list
        get_sympa_client().subscribe(user.email, f"equipe-{form.instance.trigram.lower()}", False,
                                     f"{user.first_name} {user.last_name}")

        # Invite the user in the team Matrix room
        Matrix.invite(f"#team-{form.instance.trigram.lower()}:correspondances-maths.fr",
                      f"@{user.registration.matrix_username}:correspondances-maths.fr")
        return ret

    def get_success_url(self):
        return reverse_lazy("participation:team_detail", args=(self.object.pk,))


class JoinTeamView(LoginRequiredMixin, FormView):
    """
    Participants can join a team with the access code of the team.
    """
    model = Team
    form_class = JoinTeamForm
    extra_context = dict(title=_("Join team"))
    template_name = "participation/create_team.html"

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        registration = user.registration
        if not registration.participates:
            raise PermissionDenied(_("You don't participate, so you can't create a team."))
        elif registration.team:
            raise PermissionDenied(_("You are already in a team."))
        return super().dispatch(request, *args, **kwargs)

    @transaction.atomic
    def form_valid(self, form):
        """
        When a user joins a team, the user is automatically subscribed to
        the team mailing list,the user is invited in the team Matrix room.
        """
        self.object = form.instance
        ret = super().form_valid(form)

        # Join the team
        user = self.request.user
        registration = user.registration
        registration.team = form.instance
        registration.save()

        # Subscribe to the team mailing list
        get_sympa_client().subscribe(user.email, f"equipe-{form.instance.trigram.lower()}", False,
                                     f"{user.first_name} {user.last_name}")

        # Invite the user in the team Matrix room
        Matrix.invite(f"#team-{form.instance.trigram.lower()}:correspondances-maths.fr",
                      f"@{user.registration.matrix_username}:correspondances-maths.fr")
        return ret

    def get_success_url(self):
        return reverse_lazy("participation:team_detail", args=(self.object.pk,))


class MyTeamDetailView(LoginRequiredMixin, RedirectView):
    """
    Redirect to the detail of the team in which the user is.
    """

    def get_redirect_url(self, *args, **kwargs):
        user = self.request.user
        registration = user.registration
        if registration.participates:
            if registration.team:
                return reverse_lazy("participation:team_detail", args=(registration.team_id,))
            raise PermissionDenied(_("You are not in a team."))
        raise PermissionDenied(_("You don't participate, so you don't have any team."))


class TeamDetailView(LoginRequiredMixin, FormMixin, ProcessFormView, DetailView):
    """
    Display the detail of a team.
    """
    model = Team

    def get(self, request, *args, **kwargs):
        user = request.user
        self.object = self.get_object()
        # Ensure that the user is an admin or a member of the team
        if user.registration.is_admin or user.registration.participates and user.registration.team.pk == kwargs["pk"]:
            return super().get(request, *args, **kwargs)
        raise PermissionDenied

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

        team = self.get_object()
        context["request_validation_form"] = RequestValidationForm(self.request.POST or None)
        context["validation_form"] = ValidateParticipationForm(self.request.POST or None)
        # A team is complete when there are at least 3 members that have sent their photo authorization
        # and confirmed their email address
        context["can_validate"] = team.students.count() >= 3 and \
            all(r.email_confirmed for r in team.students.all()) and \
            all(r.photo_authorization for r in team.students.all()) and \
            team.participation.problem

        return context

    def get_form_class(self):
        if not self.request.POST:
            return RequestValidationForm
        elif self.request.POST["_form_type"] == "RequestValidationForm":
            return RequestValidationForm
        elif self.request.POST["_form_type"] == "ValidateParticipationForm":
            return ValidateParticipationForm
        return None

    def form_valid(self, form):
        self.object = self.get_object()
        if isinstance(form, RequestValidationForm):
            if not self.request.user.registration.participates:
                form.add_error(None, _("You don't participate, so you can't request the validation of the team."))
                return self.form_invalid(form)
            if self.object.participation.valid is not None:
                form.add_error(None, _("The validation of the team is already done or pending."))
                return self.form_invalid(form)

            self.object.participation.valid = False
            self.object.participation.save()

            for admin in AdminRegistration.objects.all():
                mail_context = dict(user=admin.user, team=self.object)
                mail_plain = render_to_string("participation/mails/request_validation.txt", mail_context)
                mail_html = render_to_string("participation/mails/request_validation.html", mail_context)
                admin.user.email_user("[Corres2math] Validation d'équipe", mail_plain, html_message=mail_html)
        elif isinstance(form, ValidateParticipationForm):
            if not self.request.user.registration.is_admin:
                form.add_error(None, _("You are not an administrator."))
                return self.form_invalid(form)
            elif self.object.participation.valid is not False:
                form.add_error(None, _("This team has no pending validation."))
                return self.form_invalid(form)

            if "validate" in self.request.POST:
                self.object.participation.valid = True
                self.object.participation.save()
                mail_context = dict(team=self.object, message=form.cleaned_data["message"])
                mail_plain = render_to_string("participation/mails/team_validated.txt", mail_context)
                mail_html = render_to_string("participation/mails/team_validated.html", mail_context)
                send_mail("[Corres2math] Équipe validée", mail_plain, None, [self.object.email], html_message=mail_html)
            elif "invalidate" in self.request.POST:
                self.object.participation.valid = None
                self.object.participation.save()
                mail_context = dict(team=self.object, message=form.cleaned_data["message"])
                mail_plain = render_to_string("participation/mails/team_not_validated.txt", mail_context)
                mail_html = render_to_string("participation/mails/team_not_validated.html", mail_context)
                send_mail("[Corres2math] Équipe non validée", mail_plain, None, [self.object.email],
                          html_message=mail_html)
            else:
                form.add_error(None, _("You must specify if you validate the registration or not."))
                return self.form_invalid(form)

        return super().form_invalid(form)

    def get_success_url(self):
        return self.request.path


class TeamUpdateView(LoginRequiredMixin, UpdateView):
    """
    Update the detail of a team
    """
    model = Team
    form_class = TeamForm
    template_name = "participation/update_team.html"

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        if user.registration.is_admin or user.registration.participates and user.registration.team.pk == kwargs["pk"]:
            return super().dispatch(request, *args, **kwargs)
        raise PermissionDenied

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["participation_form"] = ParticipationForm(data=self.request.POST or None,
                                                          instance=self.object.participation)
        return context

    @transaction.atomic
    def form_valid(self, form):
        participation_form = ParticipationForm(data=self.request.POST or None, instance=self.object.participation)
        if not participation_form.is_valid():
            return self.form_invalid(form)

        participation_form.save()
        return super().form_valid(form)

    def get_success_url(self):
        return reverse_lazy("participation:team_detail", args=(self.object.pk,))


class TeamAuthorizationsView(LoginRequiredMixin, DetailView):
    """
    Get as a ZIP archive all the authorizations that are sent
    """
    model = Team

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        if user.registration.is_admin or user.registration.participates and user.registration.team.pk == kwargs["pk"]:
            return super().dispatch(request, *args, **kwargs)
        raise PermissionDenied

    def get(self, request, *args, **kwargs):
        team = self.get_object()
        output = BytesIO()
        zf = ZipFile(output, "w")
        for student in team.students.all():
            magic = Magic(mime=True)
            mime_type = magic.from_file("media/" + student.photo_authorization.name)
            ext = mime_type.split("/")[1].replace("jpeg", "jpg")
            zf.write("media/" + student.photo_authorization.name,
                     _("Photo authorization of {student}.{ext}").format(student=str(student), ext=ext))
        zf.close()
        response = HttpResponse(content_type="application/zip")
        response["Content-Disposition"] = "attachment; filename=\"{filename}\"" \
            .format(filename=_("Photo authorizations of team {trigram}.zip").format(trigram=team.trigram))
        response.write(output.getvalue())
        return response


class TeamLeaveView(LoginRequiredMixin, TemplateView):
    """
    A team member leaves a team
    """

    template_name = "participation/team_leave.html"

    def dispatch(self, request, *args, **kwargs):
        if not request.user.is_authenticated:
            return self.handle_no_permission()
        if not request.user.registration.team:
            raise PermissionDenied(_("You are not in a team."))
        if request.user.registration.team.participation.valid is not None:
            raise PermissionDenied(_("The team is already validated or the validation is pending."))
        return super().dispatch(request, *args, **kwargs)

    @transaction.atomic()
    def post(self, request, *args, **kwargs):
        """
        When the team is left, the user is unsubscribed from the team mailing list
        and kicked from the team room.
        """
        team = request.user.registration.team
        request.user.registration.team = None
        request.user.registration.save()
        get_sympa_client().unsubscribe(request.user.email, f"equipe-{team.trigram.lower()}", False)
        Matrix.kick(f"#team-{team.trigram.lower()}:correspondances-maths.fr",
                    f"@{request.user.registration.matrix_username}:correspondances-maths.fr",
                    "Équipe quittée")
        if team.students.count() + team.coachs.count() == 0:
            team.delete()
        return redirect(reverse_lazy("index"))


class MyParticipationDetailView(LoginRequiredMixin, RedirectView):
    """
    Redirects to the detail view of the participation of the team.
    """
    def get_redirect_url(self, *args, **kwargs):
        user = self.request.user
        registration = user.registration
        if registration.participates:
            if registration.team:
                return reverse_lazy("participation:participation_detail", args=(registration.team.participation.id,))
            raise PermissionDenied(_("You are not in a team."))
        raise PermissionDenied(_("You don't participate, so you don't have any team."))


class ParticipationDetailView(LoginRequiredMixin, DetailView):
    """
    Display detail about the participation of a team, and manage the video submission.
    """
    model = Participation

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        if not self.get_object().valid:
            raise PermissionDenied(_("The team is not validated yet."))
        if user.registration.is_admin or user.registration.participates \
                and user.registration.team.participation.pk == kwargs["pk"]:
            return super().dispatch(request, *args, **kwargs)
        raise PermissionDenied

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

        context["title"] = lambda: _("Participation of team {trigram}").format(trigram=self.object.team.trigram)
        context["current_phase"] = Phase.current_phase()

        return context


class SetParticipationReceiveParticipationView(AdminMixin, UpdateView):
    """
    Define the solution that a team will receive.
    """
    model = Participation
    form_class = ReceiveParticipationForm
    template_name = "participation/receive_participation_form.html"

    def get_success_url(self):
        return reverse_lazy("participation:participation_detail", args=(self.object.pk,))


class UploadVideoView(LoginRequiredMixin, UpdateView):
    """
    Upload a solution video for a team.
    """
    model = Video
    form_class = UploadVideoForm
    template_name = "participation/upload_video.html"

    def dispatch(self, request, *args, **kwargs):
        user = request.user
        if user.registration.is_admin or user.registration.participates \
                and user.registration.team.participation.pk == self.get_object().participation.pk:
            return super().dispatch(request, *args, **kwargs)
        raise PermissionDenied

    def get_success_url(self):
        return reverse_lazy("participation:participation_detail", args=(self.object.participation.pk,))


class CalendarView(SingleTableView):
    """
    Display the calendar of the action.
    """
    table_class = CalendarTable
    model = Phase


class PhaseUpdateView(AdminMixin, UpdateView):
    """
    Update a phase of the calendar, if we have sufficient rights.
    """
    model = Phase
    form_class = PhaseForm

    def get_success_url(self):
        return reverse_lazy("participation:calendar")