import csv
import json
from types import SimpleNamespace

from django import http
from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.core.serializers.json import DjangoJSONEncoder
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse, reverse_lazy
from django.utils import timezone
from django.views import generic
from django_weasyprint import WeasyTemplateResponseMixin
from icalendar import Calendar, Event, vCalAddress, vText

from ..forms import GroupedOrderForm, Item, JoinGroupedOrderForm
from ..models import GroupedOrder, OrderAuthor
from .mixins import UserIsOrgaMixin


class IndexView(LoginRequiredMixin, generic.ListView):
    """View showing all the grouped orders managed by the authenticated user"""

    template_name = "order/index.html"
    context_object_name = "grouped_order_list"

    def get_queryset(self):
        grouped_orders = GroupedOrder.objects.filter(orga=self.request.user)

        now = timezone.now()
        today = now.date()

        # Get the 5 most recent old grouped orders
        old = grouped_orders.filter(delivery_date__lt=today).order_by("-delivery_date")[
            :5
        ]

        # Get grouped orders that have crossed their ordering deadline
        # but the delivery date is still to come.
        crossed_deadline = (
            grouped_orders.filter(delivery_date__gte=today)
            .filter(deadline__lt=now)
            .order_by("-delivery_date")
        )

        # Get all incoming grouped orders.
        incoming = grouped_orders.filter(deadline__gte=now).order_by("deadline")
        return {
            "old_grouped_orders": old,
            "crossed_deadline_grouped_orders": crossed_deadline,
            "incoming_grouped_orders": incoming,
        }


class JoinGroupedOrderView(generic.FormView, generic.RedirectView, LoginRequiredMixin):
    form_class = JoinGroupedOrderForm
    template_name = "dashboard.html"

    def form_valid(self, form):
        return redirect(
            reverse_lazy(
                "order:grouped_order_detail", kwargs={"code": form.cleaned_data["code"]}
            )
        )


class GroupedOrderEventView(generic.DetailView):
    model = GroupedOrder
    slug_field = "code"
    slug_url_kwarg = "code"
    content_type = "text/calendar"
    response_class = http.HttpResponse

    def get_content(self):
        event = Event()
        event.add("summary", self.object.name)
        event.add("dtstart", self.object.delivery_date)
        event.add("dtend", self.object.delivery_date)
        event.add("date", self.object.delivery_date)
        event.add("location", vText(self.object.place))

        description = ""
        if self.object.delivery_slot:
            description += "Heure de livraison : " + self.object.delivery_slot + "\n"
        if self.object.description:
            description += (
                "Note de l'organisateur.ice : " + "\n" + self.object.description
            )
        event.add("description", vText(description))

        organizer = vCalAddress("MAILTO:" + self.object.orga.email)
        organizer.params["cn"] = vText(
            self.object.orga.first_name + " " + self.object.orga.last_name
        )
        event.add("organizer", organizer)
        cal = Calendar()
        cal.add_component(event)
        return cal.to_ical()

    def render_to_response(self, context, **response_kwargs):
        response_kwargs.setdefault("content_type", self.content_type)

        response = self.response_class(content=self.get_content(), **response_kwargs)
        response["Content-Disposition"] = f"attachment; filename={self.object.name}.ics"
        return response


class GroupedOrderDetailView(generic.DetailView):
    model = GroupedOrder
    template_name = "order/grouped_order_detail.html"
    context_object_name = "grouped_order"

    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

    def get_context_data(self, **kwargs):
        items = self.get_object().item_set.all()

        remaining_qty = {item.id: item.get_remaining_nb() for item in items}
        prices_dict = {item.id: item.price for item in items}

        if self.request.user.is_authenticated:
            order_author = SimpleNamespace(
                first_name=self.request.user.first_name,
                last_name=self.request.user.last_name,
                email=self.request.user.username,
            )
        else:
            order_author = None

        context = super().get_context_data(**kwargs)
        context.update(
            {
                # Used for the js display of total price of an order
                "prices_dict": json.dumps(prices_dict, cls=DjangoJSONEncoder),
                "remaining_qty": remaining_qty,
                "order_author": order_author,
            }
        )
        return context


class GroupedOrderOverview(UserIsOrgaMixin, generic.DetailView):
    model = GroupedOrder
    template_name = "order/grouped_order_overview.html"
    context_object_name = "grouped_order"

    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

    def test_func(self):
        # Staff can see but not edit grouped orders
        return super().test_func() or self.request.user.is_staff

    def get(self, request, *args, **kwargs):
        # Compute grouped order total price before display
        self.get_object().compute_total_price()
        self.get_object().compute_items_ordered_nb()
        return super().get(self, request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        context = super(GroupedOrderOverview, self).get_context_data(**kwargs)
        # Add share link to context
        context["share_link"] = self.request.build_absolute_uri(
            reverse("order:grouped_order_detail", args=(self.get_object().code,))
        )
        participants = OrderAuthor.objects.filter(
            order__in=self.get_object().order_set.all()
        )
        context["emails_list"] = set(participant.email for participant in participants)
        context["total_ordered_items"] = self.get_object().get_total_ordered_items()
        return context


class GroupedOrderCreateView(LoginRequiredMixin, generic.CreateView):
    model = GroupedOrder
    form_class = GroupedOrderForm
    template_name = "order/grouped_order_create.html"

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

    def form_valid(self, form):
        """If the form is valid, generate a unique code and save"""
        self.object = form.save()
        self.object.create_code_from_pk()
        return super().form_valid(form)


class GroupedOrderUpdateView(UserIsOrgaMixin, generic.UpdateView):
    model = GroupedOrder
    template_name = "order/grouped_order_update.html"
    context_object_name = "grouped_order"
    form_class = GroupedOrderForm

    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

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


class GroupedOrderDuplicateView(UserIsOrgaMixin, generic.RedirectView):
    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

    def get(self, request, *args, **kwargs):
        # overwrite the ``get`` function to copy the initial grouped order before
        # redirecting to the update view of the new grouped order
        initial_grouped_order = get_object_or_404(
            GroupedOrder, code=self.kwargs.get("code")
        )
        new_grouped_order = GroupedOrder.objects.create(
            name=f"{initial_grouped_order.name} - copie",
            orga=self.request.user,
            delivery_date=initial_grouped_order.delivery_date,
            deadline=initial_grouped_order.deadline,
            place=initial_grouped_order.place,
            description=initial_grouped_order.description,
        )

        # create a unique code for the new grouped order
        new_grouped_order.create_code_from_pk()
        new_grouped_order.save()

        # duplicate each item and add it to new_grouped_order
        for item in initial_grouped_order.item_set.all():
            item.pk = None
            item.ordered_nb = 0
            item.save()
            new_grouped_order.item_set.add(item)

        self.kwargs["new_go_code"] = new_grouped_order.code

        return super().get(request, *args, **kwargs)

    def get_redirect_url(self, *args, **kwargs):
        return reverse_lazy(
            "order:update_grouped_order", kwargs={"code": self.kwargs["new_go_code"]}
        )


class GroupedOrderDeleteView(UserIsOrgaMixin, generic.DeleteView):
    model = GroupedOrder
    template_name = "order/grouped_order_confirm_delete.html"
    context_object_name = "grouped_order"

    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

    def get_success_url(self):
        return reverse_lazy("order:index")

    def form_valid(self, form):
        # Delete related OrderAuthors
        grouped_order = self.get_object()
        for order in grouped_order.order_set.all():
            order.author.delete()
        return super().form_valid(form)


class GroupedOrderAddItemsView(UserPassesTestMixin, generic.ListView):
    model = Item
    template_name = "order/grouped_order_add_items.html"
    queryset = Item.objects.all()

    def get_queryset(self):
        items = super().get_queryset()
        items = items.filter(grouped_order__code=self.kwargs.get("code"))
        return items

    def get_context_data(self, **kwargs):
        context = super(GroupedOrderAddItemsView, self).get_context_data(**kwargs)
        context["grouped_order"] = GroupedOrder.objects.get(
            code=self.kwargs.get("code")
        )
        return context

    def test_func(self):
        # Restrict access to the manager
        grouped_order = get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))
        return grouped_order.orga == self.request.user


class GroupedOrderExportView(UserIsOrgaMixin, generic.DetailView):
    model = GroupedOrder
    template_name = "order/grouped_order_sheet.html"
    context_object_name = "grouped_order"

    def test_func(self):
        # Grouped order orga, superuser and staff can get this view
        return super().test_func() or self.request.user.is_staff

    def get_object(self, queryset=None):
        return get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))

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

        items = grouped_order.item_set.filter(ordered_nb__gt=0).order_by("name")
        orders = grouped_order.order_set.all().order_by(
            "author__last_name", "author__first_name"
        )
        orders_dict = {}

        for order in orders:
            ordered_values = []
            for item in items:
                match = order.ordered_items.filter(item=item).first()
                value = match.nb if match else 0
                ordered_values.append(value)
            orders_dict[order] = ordered_values

        context["items"] = items
        context["orders_dict"] = orders_dict

        return context


class DownloadGroupedOrderSheetView(WeasyTemplateResponseMixin, GroupedOrderExportView):
    def get_pdf_filename(self):
        # This is the name of the file that will be generated to download.
        return f"{self.get_object().delivery_date} - {self.get_object().name}"


class ExportGroupOrderEmailAdressesToDownloadView(UserPassesTestMixin, generic.View):
    def test_func(self):
        # Restrict access to the manager, superuser and staff
        origin = get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))
        return origin.orga == self.request.user or self.request.user.is_staff

    def get(self, request, *args, **kwargs):
        grouped_order = get_object_or_404(GroupedOrder, code=self.kwargs.get("code"))
        participants = OrderAuthor.objects.filter(
            order__in=grouped_order.order_set.all()
        )
        email_list = set(participant.email for participant in participants)

        format = self.request.GET.get("format", "json")
        if format == "csv":
            response = http.HttpResponse(content_type="text/csv")
            filename = f"commande _{grouped_order.name.replace(' ', '_')}"
            response["Content-Disposition"] = f'attachment; filename="{filename}.csv"'
            writer = csv.writer(response)
            for email in email_list:
                writer.writerow([email])
            return response
        else:
            email_list = ";\n".join(email_list)
            return http.HttpResponse(f"{email_list}")


class ExportGroupedOrderToCSVView(GroupedOrderExportView):
    def get(self, request, *args, **kwargs):
        super(ExportGroupedOrderToCSVView, self).get(self, request, *args, **kwargs)
        context = self.get_context_data()

        response = http.HttpResponse(
            content_type="text/csv",
            headers={
                "Content-Disposition": f'attachment; filename="{ context["object"].name }-commandes"'
            },
        )
        writer = csv.writer(response)

        # write headers rows
        row = ["", ""]
        for item in context["items"]:
            row.append(item.name)
        row.append("Prix de la commande")
        row.append("Mail")
        row.append("Téléphone")
        row.append("Note")
        row.append("Date")
        row.append("Heure")
        writer.writerow(row)

        row = ["", "Prix unitaire TTC (€)"]
        for item in context["items"]:
            row.append(str(item.price).replace(".", ","))
        writer.writerow(row)

        row = ["Nom", "Prénom"]
        writer.writerow(row)

        # write ordered values rows
        for order, ordered_items in context["orders_dict"].items():
            row = [order.author.last_name]
            row.append(order.author.first_name)
            for ordered_nb in ordered_items:
                row.append(ordered_nb)
            row.append(str(order.price).replace(".", ","))
            row.append(order.author.email)
            row.append(f"'{order.author.phone}")
            row.append(order.note)
            row.append(order.created_date.strftime("%d/%m/%Y"))
            row.append(order.created_date.strftime("%H:%M"))
            writer.writerow(row)

        # write total row
        row = ["", "TOTAL"]
        for item in context["items"]:
            row.append(item.ordered_nb)
        row.append(str(context["object"].total_price).replace(".", ","))
        writer.writerow(row)

        return response