import uuid
from datetime import datetime
from typing import Any

from django.conf import settings
from django.contrib import messages
from django.contrib.auth.decorators import permission_required
from django.contrib.auth.mixins import (
    AccessMixin,
    PermissionRequiredMixin,
)
from django.core import mail
from django.core.files.base import ContentFile
from django.db.models import OuterRef, Q, Subquery
from django.db.models.functions import TruncMonth, TruncYear
from django.http import HttpRequest, HttpResponse
from django.shortcuts import render
from django.template.loader import render_to_string
from django.utils import timezone
from django.utils.functional import cached_property
from django.views.generic import DetailView, ListView
from django.views.generic.dates import (
    ArchiveIndexView,
    MonthArchiveView,
    YearArchiveView,
)
from django.views.generic.detail import BaseDetailView
from django.views.generic.edit import FormMixin, ProcessFormView

import django_filters
import django_tables2 as tables
import weasyprint
from dal import autocomplete
from django_filters.views import BaseFilterView
from django_mysql.models.aggregates import GroupConcat
from django_sendfile import sendfile
from django_tables2 import A, SingleTableMixin
from django_tables2.export.views import ExportMixin
from django_weasyprint import WeasyTemplateResponseMixin
from django_weasyprint.utils import django_url_fetcher

from membershipworks.membershipworks_api import MembershipWorks

from .forms import EventInvoiceForm
from .invoice_email import make_invoice_emails
from .models import EventAttendee, EventExt, EventInvoice, Member
from .tables import (
    EventAttendeeTable,
    EventSummaryTable,
    EventTable,
    InvoiceTable,
    MissingPaperworkTable,
    UserEventTable,
)


class MemberAutocomplete(autocomplete.Select2QuerySetView):
    model = Member
    search_fields = ["account_name"]

    def get_queryset(self):
        if not self.request.user.has_perm("membershipworks.view_member"):
            return Member.objects.none()
        else:
            return super().get_queryset()


@permission_required("membershipworks.view_eventext")
def upcoming_events(request):
    now = datetime.now()

    membershipworks = MembershipWorks()
    membershipworks.login(
        settings.MEMBERSHIPWORKS_USERNAME, settings.MEMBERSHIPWORKS_PASSWORD
    )

    events = membershipworks.get_events_list(now)
    if "error" in events:
        messages.add_message(
            request,
            messages.ERROR,
            f"MembershipWorks Error: {events['error']}",
        )
        # TODO: this should probably be an HTTP 500 response
        return render(request, "base.dj.html")

    ongoing_events = []
    full_events = []
    upcoming_events = []
    for event in events["evt"]:
        try:
            # ignore hidden events
            if event["cal"] == 0:
                continue
            event_details = membershipworks.get_event_by_eid(event["eid"])

            # Convert timestamps to datetime objects
            event_details["sdp_dt"] = datetime.fromtimestamp(event_details["sdp"])
            event_details["edp_dt"] = datetime.fromtimestamp(event_details["edp"])

            # registration has already ended
            if (
                "erd" in event_details
                and datetime.fromtimestamp(event_details["erd"]) < now
            ):
                ongoing_events.append(event_details)
            # class is full
            elif event_details["cnt"] >= event_details["cap"]:
                full_events.append(event_details)
            else:
                upcoming_events.append(event_details)

        except KeyError as e:
            messages.add_message(
                request,
                messages.ERROR,
                f"Event '{event.get('ttl')}' missing required property: '{e.args[0]}'",
            )
            # TODO: this should probably be an HTTP 500 response
            return render(request, "base.dj.html")

    context = {
        "event_sections": [
            {
                "title": "Upcoming Events",
                "blurb": "Events that are currently open for registration.",
                "events": upcoming_events,
                "truncate": False,
            },
            {
                "title": "Just Missed",
                "blurb": "These classes are currently full at time of writing. If you are interested, please check the event's page; spots occasionally open up. Keep an eye on this newsletter to see when these classes are offered again.",
                "events": full_events,
                "truncate": True,
            },
            {
                "title": "Ongoing Events",
                "blurb": "These events are ongoing. Registration is currently closed, but these events may be offered again in the future.",
                "events": ongoing_events,
                "truncate": True,
            },
        ]
    }
    return render(request, "membershipworks/upcoming_events.dj.html", context)


class EventIndexReport(
    ExportMixin, SingleTableMixin, PermissionRequiredMixin, ArchiveIndexView
):
    permission_required = "membershipworks.view_eventext"
    queryset = EventExt.objects.all()
    date_field = "start"
    template_name = "membershipworks/event_index_report.dj.html"
    make_object_list = True
    table_class = EventSummaryTable
    export_formats = ("csv", "xlsx", "ods")
    export_name = "mw_events_index"

    def get_table_data(self):
        return (
            super()
            .get_table_data()
            .with_financials()
            .values(year=TruncYear("start"))
            .summarize()
            .order_by("year")
        )

    def get_table_kwargs(self):
        year_column = tables.DateColumn(
            "Y",
            linkify=(
                "membershipworks:event-year-report",
                [A("year__year")],
            ),
        )
        return {
            "sequence": ("year", "..."),
            "extra_columns": (("year", year_column),),
        }


class EventYearReport(
    ExportMixin, SingleTableMixin, PermissionRequiredMixin, YearArchiveView
):
    permission_required = "membershipworks.view_eventext"
    queryset = EventExt.objects.all()
    date_field = "start"
    template_name = "membershipworks/event_year_report.dj.html"
    make_object_list = True
    table_class = EventSummaryTable
    export_formats = ("csv", "xlsx", "ods")

    def get_table_data(self):
        return (
            super()
            .get_table_data()
            .with_financials()
            .values(month=TruncMonth("start"))
            .summarize()
            .order_by("month")
        )

    def get_export_filename(self, export_format):
        return f"mw_events_{self.get_year()}.{export_format}"

    def get_table_kwargs(self):
        month_column = tables.DateColumn(
            "F Y",
            linkify=(
                "membershipworks:event-month-report",
                [A("month__year"), A("month__month")],
            ),
        )
        return {
            "sequence": ("month", "..."),
            "extra_columns": (("month", month_column),),
        }


class EventMonthReport(
    ExportMixin, SingleTableMixin, PermissionRequiredMixin, MonthArchiveView
):
    permission_required = "membershipworks.view_eventext"
    queryset = EventExt.objects.all()
    date_field = "start"
    template_name = "membershipworks/event_month_report.dj.html"
    table_class = EventTable
    export_formats = ("csv", "xlsx", "ods")

    def get_table_data(self):
        return (
            super()
            .get_table_data()
            .select_related("category", "instructor", "invoice")
            .with_financials()
        )

    def get_export_filename(self, export_format):
        return f"mw_events_{self.get_year()}-{self.get_month():02}.{export_format}"


class UserEventView(SingleTableMixin, ListView):
    model: type[EventExt] = EventExt
    table_class = UserEventTable
    export_formats = ("csv", "xlsx", "ods")
    template_name = "membershipworks/user_event_list.dj.html"

    @cached_property
    def member(self) -> Member | None:
        return Member.from_user(self.request.user)

    def get_queryset(self):
        if self.member is None:
            return self.model.objects.none()
        else:
            return super().get_queryset().filter(instructor__member=self.member)

    def get_table_data(self):
        return (
            super()
            .get_table_data()
            .select_related("category", "instructor", "invoice")
            .with_financials()
        )

    def get_export_filename(self, export_format):
        return f"my_events_{self.member.uid if self.member is not None else 'no-uid'}.{export_format}"


class EventDetailView(
    SingleTableMixin, FormMixin, AccessMixin, DetailView, ProcessFormView
):
    permission_required = "membershipworks.view_eventext"
    queryset = EventExt.objects.with_financials().all()
    pk_url_kwarg = "eid"
    context_object_name = "event"
    template_name = "membershipworks/event_detail.dj.html"
    table_pagination = False
    table_class = InvoiceTable
    form_class = EventInvoiceForm

    def render_to_response(
        self, context: dict[str, Any], **response_kwargs: Any
    ) -> HttpResponse:
        if self.request.user.has_perm(
            self.permission_required
        ) or self.object.user_is_instructor(self.request.user):
            return super().render_to_response(context, **response_kwargs)
        else:
            return self.handle_no_permission()

    def display_instructor_version(self):
        return (
            self.request.method == "POST"  # generating a PDF
            or not self.request.user.has_perm(self.permission_required)
            or self.request.GET.get("instructor_view")
        )

    def get_table_data(self):
        if self.display_instructor_version():
            return self.object.ticket_types.group_by_ticket_type()
        else:
            return self.object.ticket_types.all()

    def get_table_kwargs(self):
        kwargs = super().get_table_kwargs()

        kwargs["event"] = self.object
        if self.display_instructor_version():
            kwargs["exclude"] = [
                "list_price",
            ]

        return kwargs

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

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context["user_is_instructor"] = self.object.user_is_instructor(
            self.request.user
        )
        return context

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        return super().post(request, *args, **kwargs)

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

    def form_valid(self, form: EventInvoiceForm):
        self.object = self.get_object()
        event = self.object

        invoice_uuid = uuid.uuid4()

        pdf_context = self.get_context_data(object=event)
        pdf_context.update({"now": timezone.now(), "invoice_uuid": invoice_uuid})
        weasy_html = weasyprint.HTML(
            string=render_to_string(
                "membershipworks/event_invoice_pdf.dj.html",
                context=pdf_context,
                request=self.request,
            ),
            url_fetcher=django_url_fetcher,
            base_url="file://",
        )
        pdf = weasy_html.write_pdf()
        # the result will be None only if a target was provided
        assert pdf is not None

        # NOTE: this is only saved AFTER the emails are successfully sent
        invoice = EventInvoice(
            uuid=invoice_uuid,
            event=event,
            date_submitted=pdf_context["now"],
            amount=event.total_due_to_instructor,
        )
        # removed), currently used in event_invoice_admin.dj.html.

        emails = make_invoice_emails(
            invoice, pdf, self.request.build_absolute_uri(event.get_absolute_url())
        )
        with mail.get_connection() as conn:
            conn.send_messages(emails)

        # this also saves the invoice object
        invoice.pdf.save(f"{event.eid}.pdf", ContentFile(pdf))

        messages.success(
            self.request,
            "Created Invoice! You should receive a confirmation email shortly.",
        )

        return super().form_valid(form)


class EventInvoicePDFPreviewView(WeasyTemplateResponseMixin, EventDetailView):
    template_name = "membershipworks/event_invoice_pdf.dj.html"
    pdf_attachment = False

    def display_instructor_version(self):
        return True

    def get_pdf_filename(self):
        return f"event-invoice_{self.object.pk}.pdf"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context.update(
            {
                "now": timezone.now(),
                "invoice_uuid": "00000000-0000-0000-0000-000000000000",
                "preview": True,
            }
        )
        return context


class EventInvoicePDFView(AccessMixin, BaseDetailView):
    model = EventInvoice
    pk_url_kwarg = "uuid"

    def get(self, request: HttpRequest, *args: Any, **kwargs: Any) -> HttpResponse:
        invoice = self.get_object()
        if request.user.has_perm(
            "membershipworks.view_eventinvoice"
        ) or invoice.event.user_is_instructor(request.user):
            return sendfile(request, invoice.pdf.path, mimetype="application/pdf")

        else:
            return self.handle_no_permission()


class EventAttendeeFilters(django_filters.FilterSet):
    new_since = django_filters.DateFilter(
        field_name="event__start", method="filter_new_since"
    )

    def filter_new_since(self, queryset, name, value):
        return queryset.filter(**{f"{name}__gte": value}).exclude(
            email__in=Subquery(
                queryset.filter(**{f"{name}__lt": value}).values("email")
            )
        )


class EventAttendeeListView(
    BaseFilterView, ExportMixin, SingleTableMixin, PermissionRequiredMixin, ListView
):
    permission_required = "membershipworks.view_eventext"
    queryset = EventAttendee.objects.all()
    table_class = EventAttendeeTable
    template_name = "membershipworks/eventattendee_list.dj.html"
    export_formats = ("csv", "xlsx", "ods")
    filterset_class = EventAttendeeFilters

    def get_table_data(self):
        return super().get_table_data().values("name", "email").distinct()


class MissingPaperworkReport(
    ExportMixin,
    SingleTableMixin,
    PermissionRequiredMixin,
    ListView,
):
    model = Member
    permission_required = "membershipworks.view_member"
    template_name = "membershipworks/missing_paperwork_report.dj.html"
    table_class = MissingPaperworkTable
    export_formats = ("csv", "xlsx", "ods")

    def get_queryset(self):
        qs = super().get_queryset()
        return (
            qs.with_is_active()
            .filter(
                Q(membership_agreement_signed_and_on_file_date__isnull=True)
                | Q(waiver_form_signed_and_on_file_date__isnull=True),
                is_active=True,
            )
            .annotate(
                membership=Subquery(
                    qs.filter(
                        pk=OuterRef("pk"), flags__type__in=("level", "addon")
                    ).values(m=GroupConcat("flags__name"))
                ),
            )
        )