import os
from io import BytesIO
from zipfile import ZipFile

from django.core.mail import send_mail

from corres2math.lists import get_sympa_client
from django.contrib.auth.mixins import LoginRequiredMixin
from django.core.exceptions import PermissionDenied
from django.db import transaction
from django.http import HttpResponse
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.edit import FormMixin, ProcessFormView
from magic import Magic
from registration.models import AdminRegistration

from .forms import JoinTeamForm, ParticipationForm, RequestValidationForm, TeamForm, UploadVideoForm,\
    ValidateParticipationForm
from .models import Participation, Team, Video


class CreateTeamView(LoginRequiredMixin, CreateView):
    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):
        ret = super().form_valid(form)
        user = self.request.user
        registration = user.registration
        registration.team = form.instance
        registration.save()
        get_sympa_client().subscribe(user.email, f"equipe-{form.instance.trigram.lower()}", False,
                                     f"{user.first_name} {user.last_name}")
        return ret

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


class JoinTeamView(LoginRequiredMixin, FormView):
    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):
        self.object = form.instance
        ret = super().form_valid(form)
        user = self.request.user
        registration = user.registration
        registration.team = form.instance
        registration.save()
        get_sympa_client().subscribe(user.email, f"equipe-{form.instance.trigram.lower()}", False,
                                     f"{user.first_name} {user.last_name}")
        return ret

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


class MyTeamDetailView(LoginRequiredMixin, RedirectView):
    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):
    model = Team

    def get(self, request, *args, **kwargs):
        user = request.user
        self.object = self.get_object()
        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)
        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,
                          [f"equipe-{self.object.trigram.lower()}@{os.getenv('SYMPA_HOST', 'localhost')}"],
                          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,
                          [f"equipe-{self.object.trigram.lower()}@{os.getenv('SYMPA_HOST', 'localhost')}"],
                          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):
    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):
    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 MyParticipationDetailView(LoginRequiredMixin, RedirectView):
    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):
    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


class UploadVideoView(LoginRequiredMixin, UpdateView):
    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,))