#
# Copyright 2016,2017
# - Skia <skia@libskia.so>
# - Sli <antoine@bartuccio.fr>
#
# Ce fichier fait partie du site de l'Association des Étudiants de l'UTBM,
# http://ae.utbm.fr.
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License a published by the Free Software
# Foundation; either version 3 of the License, or (at your option) any later
# version.
#
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Sofware Foundation, Inc., 59 Temple
# Place - Suite 330, Boston, MA 02111-1307, USA.
#
#
import itertools
from datetime import timedelta

# This file contains all the views that concern the user model
from operator import itemgetter
from smtplib import SMTPException

from django.contrib.auth import login, views
from django.contrib.auth.decorators import login_required
from django.contrib.auth.forms import PasswordChangeForm, SetPasswordForm
from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.core.exceptions import PermissionDenied
from django.db.models import DateField, F, QuerySet, Sum
from django.db.models.functions import Trunc
from django.forms.models import modelform_factory
from django.http import Http404
from django.shortcuts import get_object_or_404, redirect
from django.template.loader import render_to_string
from django.urls import reverse, reverse_lazy
from django.utils.decorators import method_decorator
from django.utils.safestring import SafeString
from django.utils.translation import gettext as _
from django.views.decorators.http import require_POST
from django.views.generic import (
    CreateView,
    DeleteView,
    DetailView,
    ListView,
    RedirectView,
    TemplateView,
)
from django.views.generic.dates import MonthMixin, YearMixin
from django.views.generic.edit import FormView, UpdateView
from honeypot.decorators import check_honeypot

from core.auth.mixins import CanEditMixin, CanEditPropMixin, CanViewMixin
from core.models import Gift, Preferences, User
from core.views.forms import (
    GiftForm,
    LoginForm,
    RegisteringForm,
    UserGodfathersForm,
    UserGroupsForm,
    UserProfileForm,
)
from core.views.mixins import TabedViewMixin, UseFragmentsMixin
from counter.models import Refilling, Selling
from eboutic.models import Invoice
from trombi.views import UserTrombiForm


class SithLoginView(views.LoginView):
    """The login View."""

    template_name = "core/login.jinja"
    authentication_form = LoginForm
    form_class = PasswordChangeForm
    redirect_authenticated_user = True


class SithPasswordChangeView(views.PasswordChangeView):
    """Allows a user to change its password."""

    template_name = "core/password_change.jinja"
    success_url = reverse_lazy("core:password_change_done")


class SithPasswordChangeDoneView(views.PasswordChangeDoneView):
    """Allows a user to change its password."""

    template_name = "core/password_change_done.jinja"


def logout(request):
    """The logout view."""
    return views.logout_then_login(request)


class PasswordRootChangeView(UserPassesTestMixin, FormView):
    """Allows a root user to change someone's password."""

    template_name = "core/password_change.jinja"
    form_class = SetPasswordForm
    success_url = reverse_lazy("core:password_change_done")

    def test_func(self):
        return self.request.user.is_root

    def get_form_kwargs(self):
        user = get_object_or_404(User, id=self.kwargs["user_id"])
        return super().get_form_kwargs() | {"user": user}

    def form_valid(self, form: SetPasswordForm):
        form.save()
        return super().form_valid(form)


@method_decorator(check_honeypot, name="post")
class SithPasswordResetView(views.PasswordResetView):
    """Allows someone to enter an email address for resetting password."""

    template_name = "core/password_reset.jinja"
    email_template_name = "core/password_reset_email.jinja"
    success_url = reverse_lazy("core:password_reset_done")


class SithPasswordResetDoneView(views.PasswordResetDoneView):
    """Confirm that the reset email has been sent."""

    template_name = "core/password_reset_done.jinja"


class SithPasswordResetConfirmView(views.PasswordResetConfirmView):
    """Provide a reset password form."""

    template_name = "core/password_reset_confirm.jinja"
    success_url = reverse_lazy("core:password_reset_complete")


class SithPasswordResetCompleteView(views.PasswordResetCompleteView):
    """Confirm the password has successfully been reset."""

    template_name = "core/password_reset_complete.jinja"


@method_decorator(check_honeypot, name="post")
class UserCreationView(FormView):
    success_url = reverse_lazy("core:index")
    form_class = RegisteringForm
    template_name = "core/register.jinja"

    def form_valid(self, form):
        # Just knowing that the user gave sound data isn't enough,
        # we must also know if the given email actually exists.
        # This step must happen after the whole validation has been made,
        # but before saving the user, while being tightly coupled
        # to the request/response cycle.
        # Thus this is here.
        user: User = form.save(commit=False)
        username = user.generate_username()
        try:
            user.email_user(
                "Création de votre compte AE",
                render_to_string(
                    "core/register_confirm_mail.jinja", context={"username": username}
                ),
            )
        except SMTPException:
            # if the email couldn't be sent, it's likely to be
            # that the given email doesn't exist (which means it's either a typo or a bot).
            # It may also be a genuine bug, but that's less likely to happen
            # and wouldn't be critical as the favoured way to create an account
            # is to contact an AE board member
            form.add_error(
                "email", _("We couldn't verify that this email actually exists")
            )
            return super().form_invalid(form)
        user = form.save()
        login(self.request, user)
        return super().form_valid(form)


class UserMeRedirect(LoginRequiredMixin, RedirectView):
    def get_redirect_url(self, *args, **kwargs):
        if remaining := kwargs.get("remaining_path"):
            return f"/user/{self.request.user.id}/{remaining}/"
        return f"/user/{self.request.user.id}/"


class UserTabsMixin(TabedViewMixin):
    def get_tabs_title(self):
        return self.object.get_display_name()

    def get_list_of_tabs(self):
        user: User = self.object
        tab_list = [
            {
                "url": reverse("core:user_profile", kwargs={"user_id": user.id}),
                "slug": "infos",
                "name": _("Infos"),
            },
            {
                "url": reverse("core:user_godfathers", kwargs={"user_id": user.id}),
                "slug": "godfathers",
                "name": _("Family"),
            },
            {
                "url": reverse("sas:user_pictures", kwargs={"user_id": user.id}),
                "slug": "pictures",
                "name": _("Pictures"),
            },
        ]
        if self.request.user == user:
            tab_list.append(
                {"url": reverse("core:user_tools"), "slug": "tools", "name": _("Tools")}
            )
        if self.request.user.can_edit(user):
            tab_list.append(
                {
                    "url": reverse("core:user_edit", kwargs={"user_id": user.id}),
                    "slug": "edit",
                    "name": _("Edit"),
                }
            )
            tab_list.append(
                {
                    "url": reverse("core:user_prefs", kwargs={"user_id": user.id}),
                    "slug": "prefs",
                    "name": _("Preferences"),
                }
            )
        if self.request.user.can_view(user):
            tab_list.append(
                {
                    "url": reverse("core:user_clubs", kwargs={"user_id": user.id}),
                    "slug": "clubs",
                    "name": _("Clubs"),
                }
            )
        if self.request.user.is_owner(user):
            tab_list.append(
                {
                    "url": reverse("core:user_groups", kwargs={"user_id": user.id}),
                    "slug": "groups",
                    "name": _("Groups"),
                }
            )
        if (
            hasattr(user, "customer")
            and user.customer
            and (
                user == self.request.user
                or self.request.user.has_perm("counter.view_customer")
            )
        ):
            tab_list.append(
                {
                    "url": reverse("core:user_stats", kwargs={"user_id": user.id}),
                    "slug": "stats",
                    "name": _("Stats"),
                }
            )
            tab_list.append(
                {
                    "url": reverse("core:user_account", kwargs={"user_id": user.id}),
                    "slug": "account",
                    "name": _("Account") + " (%s €)" % user.customer.amount,
                }
            )
        return tab_list


class UserView(UserTabsMixin, CanViewMixin, DetailView):
    """Display a user's profile."""

    model = User
    pk_url_kwarg = "user_id"
    context_object_name = "profile"
    template_name = "core/user_detail.jinja"
    current_tab = "infos"

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["gift_form"] = GiftForm(
            user_id=self.object.id, initial={"user": self.object}
        )
        return kwargs


@require_POST
@login_required
def delete_user_godfather(request, user_id, godfather_id, is_father):
    user_is_admin = request.user.is_root or request.user.is_board_member
    if user_id != request.user.id and not user_is_admin:
        raise PermissionDenied
    user = get_object_or_404(User, id=user_id)
    to_remove = get_object_or_404(User, id=godfather_id)
    if is_father:
        user.godfathers.remove(to_remove)
    else:
        user.godchildren.remove(to_remove)
    return redirect("core:user_godfathers", user_id=user_id)


class UserGodfathersView(UserTabsMixin, CanViewMixin, DetailView, FormView):
    """Display a user's godfathers."""

    model = User
    pk_url_kwarg = "user_id"
    context_object_name = "profile"
    template_name = "core/user_godfathers.jinja"
    current_tab = "godfathers"
    form_class = UserGodfathersForm

    def get_form_kwargs(self):
        return super().get_form_kwargs() | {"user": self.object}

    def form_valid(self, form):
        if form.cleaned_data["type"] == "godfather":
            self.object.godfathers.add(form.cleaned_data["user"])
        else:
            self.object.godchildren.add(form.cleaned_data["user"])
        return redirect("core:user_godfathers", user_id=self.object.id)

    def get_context_data(self, **kwargs):
        return super().get_context_data(**kwargs) | {
            "godfathers": list(self.object.godfathers.select_related("profile_pict")),
            "godchildren": list(self.object.godchildren.select_related("profile_pict")),
        }


class UserGodfathersTreeView(UserTabsMixin, CanViewMixin, DetailView):
    """Display a user's family tree."""

    model = User
    pk_url_kwarg = "user_id"
    context_object_name = "profile"
    template_name = "core/user_godfathers_tree.jinja"
    current_tab = "godfathers"

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["api_url"] = reverse(
            "api:family_graph", kwargs={"user_id": self.object.id}
        )
        return kwargs


class UserStatsView(UserTabsMixin, CanViewMixin, DetailView):
    """Display a user's stats."""

    model = User
    pk_url_kwarg = "user_id"
    context_object_name = "profile"
    template_name = "core/user_stats.jinja"
    current_tab = "stats"
    queryset = User.objects.exclude(customer=None).select_related("customer")

    def dispatch(self, request, *arg, **kwargs):
        profile = self.get_object()
        if not (
            profile == request.user or request.user.has_perm("counter.view_customer")
        ):
            raise PermissionDenied
        return super().dispatch(request, *arg, **kwargs)

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

        kwargs["perm_time"] = list(
            self.object.permanencies.filter(end__isnull=False, counter__type="BAR")
            .values("counter", "counter__name")
            .annotate(total=Sum(F("end") - F("start"), default=timedelta(seconds=0)))
            .order_by("-total")
        )
        kwargs["total_perm_time"] = sum(
            [perm["total"] for perm in kwargs["perm_time"]], start=timedelta(seconds=0)
        )
        kwargs["purchase_sums"] = list(
            self.object.customer.buyings.filter(counter__type="BAR")
            .values("counter", "counter__name")
            .annotate(total=Sum(F("unit_price") * F("quantity")))
            .order_by("-total")
        )
        kwargs["total_purchases"] = sum(s["total"] for s in kwargs["purchase_sums"])
        kwargs["top_product"] = (
            self.object.customer.buyings.values("product__name")
            .annotate(product_sum=Sum("quantity"))
            .order_by("-product_sum")
            .all()[:15]
        )
        return kwargs


class UserMiniView(CanViewMixin, DetailView):
    """Display a user's profile."""

    model = User
    pk_url_kwarg = "user_id"
    context_object_name = "profile"
    template_name = "core/user_mini.jinja"


class UserListView(ListView, CanEditPropMixin):
    """Displays the user list."""

    model = User
    template_name = "core/user_list.jinja"


# FIXME: the edit_once fields aren't displayed to the user (as expected).
#  However, if the user re-add them manually in the form, they are saved.
class UserUpdateProfileView(UserTabsMixin, CanEditMixin, UpdateView):
    """Edit a user's profile."""

    model = User
    pk_url_kwarg = "user_id"
    template_name = "core/user_edit.jinja"
    form_class = UserProfileForm
    current_tab = "edit"
    edit_once = ["profile_pict", "date_of_birth", "first_name", "last_name"]

    def remove_restricted_fields(self, request):
        """Removes edit_once and board_only fields."""
        for i in self.edit_once:
            if getattr(self.form.instance, i) and not (
                request.user.is_board_member or request.user.is_root
            ):
                self.form.fields.pop(i, None)

    def get(self, request, *args, **kwargs):
        self.object = self.get_object()
        self.form = self.get_form()
        self.remove_restricted_fields(request)
        return self.render_to_response(self.get_context_data(form=self.form))

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        self.form = self.get_form()
        self.remove_restricted_fields(request)
        files = request.FILES.items()
        self.form.process(files)
        if (
            request.user.is_authenticated
            and request.user.can_edit(self.object)
            and self.form.is_valid()
        ):
            return super().form_valid(self.form)
        return self.form_invalid(self.form)

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["profile"] = self.form.instance
        kwargs["form"] = self.form
        return kwargs


class UserClubView(UserTabsMixin, CanViewMixin, DetailView):
    """Display the user's club(s)."""

    model = User
    context_object_name = "profile"
    pk_url_kwarg = "user_id"
    template_name = "core/user_clubs.jinja"
    current_tab = "clubs"


class UserPreferencesView(UserTabsMixin, UseFragmentsMixin, CanEditMixin, UpdateView):
    """Edit a user's preferences."""

    model = User
    pk_url_kwarg = "user_id"
    template_name = "core/user_preferences.jinja"
    form_class = modelform_factory(
        Preferences, fields=["receive_weekmail", "notify_on_click", "notify_on_refill"]
    )
    context_object_name = "profile"
    current_tab = "prefs"

    def get_form_kwargs(self):
        return super().get_form_kwargs() | {"instance": self.object.preferences}

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

    def get_fragment_context_data(self) -> dict[str, SafeString]:
        # Avoid cyclic import error
        from counter.views.student_card import StudentCardFormFragment

        res = super().get_fragment_context_data()
        if hasattr(self.object, "customer"):
            res["student_card_fragment"] = StudentCardFormFragment.as_fragment()(
                self.request, customer=self.object.customer
            )
        return res

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        if not hasattr(self.object, "trombi_user"):
            kwargs["trombi_form"] = UserTrombiForm()
        return kwargs


class UserUpdateGroupView(UserTabsMixin, CanEditPropMixin, UpdateView):
    """Edit a user's groups."""

    model = User
    pk_url_kwarg = "user_id"
    template_name = "core/user_group.jinja"
    form_class = UserGroupsForm
    context_object_name = "profile"
    current_tab = "groups"


class UserToolsView(LoginRequiredMixin, UserTabsMixin, TemplateView):
    """Displays the logged user's tools."""

    template_name = "core/user_tools.jinja"
    current_tab = "tools"

    def get_context_data(self, **kwargs):
        self.object = self.request.user

        kwargs = super().get_context_data(**kwargs)
        kwargs["profile"] = self.request.user
        kwargs["object"] = self.request.user
        return kwargs


class UserAccountBase(UserTabsMixin, DetailView):
    """Base class for UserAccount."""

    model = User
    pk_url_kwarg = "user_id"
    current_tab = "account"
    queryset = User.objects.select_related("customer")

    def dispatch(self, request, *arg, **kwargs):
        if kwargs.get("user_id") == request.user.id or request.user.has_perm(
            "counter.view_customer"
        ):
            return super().dispatch(request, *arg, **kwargs)
        raise PermissionDenied

    def get_object(self, queryset=None):
        obj = super().get_object(queryset)
        if not hasattr(obj, "customer"):
            raise Http404(_("User has no account"))
        return obj


class UserAccountView(UserAccountBase):
    """Display a user's account."""

    template_name = "core/user_account.jinja"

    @staticmethod
    def expense_by_month[T](qs: QuerySet[T]) -> QuerySet[T]:
        month_trunc = Trunc("date", "month", output_field=DateField())
        return (
            qs.annotate(grouped_date=month_trunc)
            .values("grouped_date")
            .annotate_total()
            .exclude(total=0)
            .order_by("-grouped_date")
        )

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["profile"] = self.object
        kwargs["customer"] = self.object.customer
        kwargs["buyings_month"] = self.expense_by_month(
            Selling.objects.filter(customer=self.object.customer)
        )
        kwargs["refilling_month"] = self.expense_by_month(
            Refilling.objects.filter(customer=self.object.customer)
        )
        kwargs["invoices_month"] = [
            # the django ORM removes the `group by` clause in this query,
            # so a little of post-processing is needed
            {"grouped_date": key, "total": sum(i["total"] for i in group)}
            for key, group in itertools.groupby(
                self.expense_by_month(Invoice.objects.filter(user=self.object)),
                key=itemgetter("grouped_date"),
            )
        ]
        kwargs["etickets"] = self.object.customer.buyings.exclude(product__eticket=None)
        return kwargs


class UserAccountDetailView(UserAccountBase, YearMixin, MonthMixin):
    """Display a user's account for month."""

    template_name = "core/user_account_detail.jinja"

    def get_context_data(self, **kwargs):
        kwargs = super().get_context_data(**kwargs)
        kwargs["profile"] = self.object
        kwargs["customer"] = self.object.customer
        year, month = self.get_year(), self.get_month()
        filters = {
            "customer": self.object.customer,
            "date__year": year,
            "date__month": month,
        }
        kwargs["purchases"] = list(
            Selling.objects.filter(**filters)
            .select_related("counter", "counter__club", "seller")
            .order_by("-date")
        )
        kwargs["refills"] = list(
            Refilling.objects.filter(**filters)
            .select_related("counter", "counter__club", "operator")
            .order_by("-date")
        )
        kwargs["invoices"] = list(
            Invoice.objects.filter(user=self.object, date__year=year, date__month=month)
            .annotate_total()
            .prefetch_related("items")
            .order_by("-date")
        )
        return kwargs


class GiftCreateView(CreateView):
    form_class = GiftForm
    template_name = "core/create.jinja"

    def dispatch(self, request, *args, **kwargs):
        if not (request.user.is_board_member or request.user.is_root):
            raise PermissionDenied
        self.user = get_object_or_404(User, pk=kwargs["user_id"])
        return super().dispatch(request, *args, **kwargs)

    def get_initial(self):
        return {"user": self.user}

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        kwargs["user_id"] = self.user.id
        return kwargs

    def get_success_url(self):
        return reverse_lazy("core:user_profile", kwargs={"user_id": self.user.id})


class GiftDeleteView(CanEditPropMixin, DeleteView):
    model = Gift
    pk_url_kwarg = "gift_id"
    template_name = "core/delete_confirm.jinja"

    def dispatch(self, request, *args, **kwargs):
        self.user = get_object_or_404(User, pk=kwargs["user_id"])
        return super().dispatch(request, *args, **kwargs)

    def get_success_url(self):
        return reverse_lazy("core:user_profile", kwargs={"user_id": self.user.id})