import uuid
from datetime import datetime, timedelta
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.defaultfilters import floatformat
from django.template.loader import render_to_string
from django.utils import timezone
from django.utils.functional import cached_property
from django.utils.html import format_html
from django.utils.safestring import SafeString
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 import GroupConcat
from django_sendfile import sendfile
from django_tables2 import A, SingleTableMixin
from django_tables2.export.views import ExportMixin
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


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 DurationColumn(tables.Column):
    def render(self, value: timedelta):
        if value is None:
            return None
        return floatformat(value.total_seconds() / 60 / 60, -2)

    def value(self, value: timedelta):
        if value is None:
            return None
        return value.total_seconds() / 60 / 60


class EventTable(tables.Table):
    title = tables.TemplateColumn(
        template_code=(
            '<a title="MembershipWorks" href="https://membershipworks.com/admin/#!event/admin/{{ record.url }}">{{ value }}</a> '
            '<a title="Admin" href="{% url "admin:membershipworks_eventext_change" record.pk %}"><i class="bi bi-pencil-square"></i></a> '
            '<a title="Details" href="{% url "membershipworks:event-detail" record.pk %}"><i class="bi bi-receipt"></i></a> '
        ),
        accessor="unescaped_title",
    )
    occurred = tables.BooleanColumn(visible=False)
    start = tables.DateColumn("N d, Y")
    duration = DurationColumn()
    person_hours = DurationColumn()
    meetings = tables.Column()
    gross_revenue = tables.Column()
    total_due_to_instructor = tables.Column()
    net_revenue = tables.Column()
    invoice__date_submitted = tables.DateColumn(verbose_name="Invoice Submitted")
    invoice__date_paid = tables.DateColumn(verbose_name="Invoice Paid")

    class Meta:
        model = EventExt
        fields = (
            "title",
            "occurred",
            "start",
            "instructor",
            "category",
            "count",
            "cap",
            "meetings",
            "duration",
            "person_hours",
            "gross_revenue",
            "total_due_to_instructor",
            "net_revenue",
        )
        row_attrs = {
            "class": lambda record: (
                "" if record.occurred else "text-decoration-line-through table-danger"
            )
        }


class EventSummaryTable(tables.Table):
    event_count = tables.Column("Events")
    canceled_event_count = tables.Column("Canceled Events")
    count__sum = tables.Column("Tickets")
    instructor__count = tables.Column("Unique Instructors")
    meetings__sum = tables.Column("Meetings")
    duration__sum = DurationColumn("Class Hours")
    person_hours__sum = DurationColumn("Person Hours")
    gross_revenue__sum = tables.Column("Gross Revenue")
    total_due_to_instructor__sum = tables.Column("Total Due to Instructor")
    net_revenue__sum = tables.Column("Net Revenue")


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 UserEventTable(EventTable):
    title = tables.Column(linkify=True, accessor="unescaped_title")
    instructor = None
    person_hours = None
    gross_revenue = None
    net_revenue = None


class UserEventView(SingleTableMixin, ListView):
    model = 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 InvoiceMoneyColumn(tables.columns.Column):
    def render(self, value):
        return f"${super().render(value):.2f}"


class InvoiceMoneyFooterColumn(InvoiceMoneyColumn):
    def render_footer(self, bound_column, table):
        value = getattr(table.event, bound_column.accessor)
        if value is not None:
            return f"${value:.2f}"
        else:
            return bound_column.default


class InvoiceTable(tables.Table):
    def __init__(self, *args, **kwargs):
        self.event = kwargs.pop("event")
        super().__init__(*args, **kwargs)

    @staticmethod
    def _math_header(name: str, formula: str) -> SafeString:
        return format_html(
            '{} <div class="text-nowrap font-monospace fw-light">[{}]</div>',
            name,
            formula,
        )

    label = tables.Column("Ticket Type", footer="Subtotals")
    list_price = InvoiceMoneyColumn("Ticket Price")
    actual_price = InvoiceMoneyColumn(_math_header("Actual Price", "P"))
    quantity = tables.Column(
        _math_header("Quantity", "Q"),
        footer=lambda table: table.event.quantity,
    )
    amount = InvoiceMoneyFooterColumn(_math_header("Amount", "A=P*Q"))
    materials = InvoiceMoneyFooterColumn(
        _math_header("CMS Collected Materials Fee", "M=m*Q")
    )
    amount_without_materials = InvoiceMoneyFooterColumn(
        _math_header("Event Revenue Base", "B=A-M")
    )
    instructor_revenue = InvoiceMoneyFooterColumn(
        _math_header("Instructor Percentage Revenue", "R=B*I")
    )
    instructor_amount = InvoiceMoneyFooterColumn(
        _math_header("Amount Due to Instructor", "R+M")
    )

    class Meta:
        attrs = {
            "class": "table table-sm mx-auto w-auto",
            "tbody": {"class": "table-group-divider"},
            "tfoot": {"class": "table-group-divider"},
        }
        orderable = False


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,
            # NOTE: this needs to be resolved before the object is
            # saved, so cannot use the Now() db function
            date_submitted=timezone.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 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 HttpResponse(invoice.pdf.path)
            return sendfile(request, invoice.pdf.path, mimetype="application/pdf")

        else:
            return self.handle_no_permission()


class EventAttendeeTable(tables.Table):
    class Meta:
        model = EventAttendee
        fields = ("name", "email")


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 MissingPaperworkTable(tables.Table):
    policy_agreement = tables.BooleanColumn()
    authorize_charge = tables.BooleanColumn()

    class Meta:
        model = Member
        fields = [
            "first_name",
            "last_name",
            "membership",
            "billing_method",
            "join_date",
            "membership_agreement_signed_and_on_file_date",
            "waiver_form_signed_and_on_file_date",
            "policy_agreement",
            "authorize_charge",
        ]


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"))
                ),
            )
        )