from django.utils.http import urlsafe_base64_encode, urlsafe_base64_decode
from django.shortcuts import redirect, render, get_object_or_404
from django.contrib.auth.tokens import default_token_generator
from django.contrib.sites.shortcuts import get_current_site
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import LoginRequiredMixin
from django.contrib.auth import logout
from django.contrib import messages
from django.template.loader import render_to_string
from django.utils.translation import gettext_lazy as _
from django.core.mail import EmailMultiAlternatives
from django.views.generic.edit import FormView
from django.utils.encoding import force_bytes
from django.http import HttpResponse, Http404
from django.conf import settings
from django.urls import reverse_lazy
from nsfw.views import is_nsfw_allowed
from .forms import RegistrationForm, ChangePasswordForm, DeleteAccountForm
from .models import NelUser


@login_required
def settings_default(request):
    next_page = reverse_lazy("set_nsfw")
    return redirect(next_page)


@login_required
def set_nsfw(request):
    ctx = {
        "nsfw_allowed": is_nsfw_allowed(request),
        "current_url": reverse_lazy("set_nsfw"),
        "tab": "preferences",
        "active_block": "nsfw_filter",
    }
    return render(request, "neluser/settings/preferences/nsfw.html", ctx)


class ChangePasswordView(LoginRequiredMixin, FormView):
    template_name = "neluser/settings/security/password.html"
    form_class = ChangePasswordForm
    success_url = reverse_lazy("password_change")

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["tab"] = "security"
        context["active_block"] = "password"
        return context

    def get_form_kwargs(self):
        kw = super().get_form_kwargs()
        kw["request"] = self.request
        return kw

    def form_valid(self, form):
        new_password = form.cleaned_data["new_password"]
        user = self.request.user
        user.set_password(new_password)
        user.save()
        return super().form_valid(form)


class DeleteAccountView(LoginRequiredMixin, FormView):
    template_name = "neluser/settings/security/delete_account.html"
    form_class = DeleteAccountForm
    success_url = reverse_lazy("delete_account")

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["tab"] = "security"
        context["active_block"] = "delete_account"
        return context

    def get_form_kwargs(self):
        kw = super().get_form_kwargs()
        kw["request"] = self.request
        return kw

    def form_valid(self, form):
        self.request.user.delete()
        logout(self.request)
        messages.info(self.request, _("Your account has been deleted."))
        return super().form_valid(form)


def send_activation_email(request, user):
    current_site = get_current_site(request)
    context = {
        "email": user.email,
        "domain": current_site.domain,
        "site_name": current_site.name,
        "uid": urlsafe_base64_encode(force_bytes(user.pk)),
        "user": user,
        "token": default_token_generator.make_token(user),
        "protocol": "https" if request.is_secure() else "http",
    }
    subject = render_to_string("neluser/activate_email_subject.txt", context)
    subject = "".join(subject.splitlines())
    email_message = EmailMultiAlternatives(
        subject,
        render_to_string("neluser/activate_email.txt", context),
        settings.DEFAULT_FROM_EMAIL,
        [user.email],
    )
    email_message.attach_alternative(
        render_to_string("neluser/activate_email.html", context), "text/html"
    )
    email_message.send()


def activate(request, uidb64, token):
    uid = urlsafe_base64_decode(uidb64).decode()
    user = get_object_or_404(NelUser, pk=uid)
    if default_token_generator.check_token(user, token):
        user.is_active = True
        user.save()
        return render(request, "neluser/activate_done.html")
    raise Http404("Unable to activate user %d with token %s." % (uid, token))


def register(request):
    if request.method == "GET":
        form = RegistrationForm()
    elif request.method == "POST":
        form = RegistrationForm(data=request.POST)
        if form.is_valid():
            user = form.save(commit=False)
            user.set_password(form.cleaned_data.get("password1"))
            user.is_active = not settings.REGISTER_REQUIRE_VALIDATION
            user.save()
            if settings.REGISTER_REQUIRE_VALIDATION:
                send_activation_email(request, user)
            return render(request, "neluser/register_done.html")
    return render(request, "neluser/register.html", {"form": form})