from datetime import timedelta

from django.conf import settings
from django.shortcuts import redirect
from django.urls import reverse_lazy
from django.utils.datetime_safe import datetime
from django.views.generic import ListView, DetailView

from AKModel.models import AKSlot, Room, AKTrack
from AKModel.views import FilterByEventSlugMixin


class PlanIndexView(FilterByEventSlugMixin, ListView):
    model = AKSlot
    template_name = "AKPlan/plan_index.html"
    context_object_name = "akslots"
    ordering = "start"

    def get_queryset(self):
        # Ignore slots not scheduled yet
        return super().get_queryset().filter(start__isnull=False)

    def get_context_data(self, *, object_list=None, **kwargs):
        context = super().get_context_data(object_list=object_list, **kwargs)

        context["event"] = self.event

        current_timestamp = datetime.now().astimezone(self.event.timezone)

        context["akslots_now"] = []
        context["akslots_next"] = []
        rooms = set()
        buildings = set()

        # Get list of current and next slots
        for akslot in context["akslots"]:
            # Construct a list of all rooms used by these slots on the fly
            if akslot.room is not None:
                rooms.add(akslot.room)
                # Store buildings for hierarchical view
                if akslot.room.building != '':
                    buildings.add(akslot.room.building)

            # Recent AKs: Started but not ended yet
            if akslot.start <= current_timestamp <= akslot.end:
                context["akslots_now"].append(akslot)
            # Next AKs: Not started yet, list will be filled in order until threshold is reached
            elif akslot.start > current_timestamp:
                if len(context["akslots_next"]) < settings.PLAN_MAX_NEXT_AKS:
                    context["akslots_next"].append(akslot)

        # Sort list of rooms by title
        context["rooms"] = sorted(rooms, key=lambda x: x.title)
        if settings.PLAN_SHOW_HIERARCHY:
            context["buildings"] = sorted(buildings)

        return context


class PlanScreenView(PlanIndexView):
    template_name = "AKPlan/plan_wall.html"

    def get(self, request, *args, **kwargs):
        s = super().get(request, *args, **kwargs)
        # Don't show wall when event is not active -> redirect to normal schedule
        if not self.event.active:
            return redirect(reverse_lazy("plan:plan_overview", kwargs={"event_slug": self.event.slug}))
        return s

    def get_queryset(self):
        # Determine interesting range (some hours ago until some hours in the future as specified in the settings)
        now = datetime.now().astimezone(self.event.timezone)
        if self.event.start < now < self.event.end:
            self.start = now - timedelta(hours=settings.PLAN_WALL_HOURS_RETROSPECT)
        else:
            self.start = self.event.start
        self.end = self.event.end

        # Restrict AK slots to relevant ones
        # This will automatically filter all rooms not needed for the selected range in the orginal get_context method
        return super().get_queryset().filter(start__gt=self.start, start__lt=self.end)

    def get_context_data(self, *, object_list=None, **kwargs):
        context = super().get_context_data(object_list=object_list, **kwargs)
        context["start"] = self.start
        context["end"] = self.end
        return context


class PlanRoomView(FilterByEventSlugMixin, DetailView):
    template_name = "AKPlan/plan_room.html"
    model = Room
    context_object_name = "room"


class PlanTrackView(FilterByEventSlugMixin, DetailView):
    template_name = "AKPlan/plan_track.html"
    model = AKTrack
    context_object_name = "track"

    def get_context_data(self, *, object_list=None, **kwargs):
        context = super().get_context_data(object_list=object_list, **kwargs)

        context["slots"] = []
        for ak in context["track"].ak_set.all():
            context["slots"].extend(ak.akslot_set.all())

        return context