from datetime import timedelta

from django.contrib.auth.decorators import login_required
from django.http import HttpResponse
from django.shortcuts import redirect, render
from django.utils import timezone

from apps.epic.models import GateSlot, Room, RoomInvite, debit_token, select_token


RESERVE_TIMEOUT = timedelta(seconds=60)


def _expire_reserved_slots(room):
    cutoff = timezone.now() - RESERVE_TIMEOUT
    room.gate_slots.filter(
        status=GateSlot.RESERVED,
        reserved_at__lt=cutoff,
    ).update(status=GateSlot.EMPTY, gamer=None, reserved_at=None)


def _gate_context(room, user):
    _expire_reserved_slots(room)
    slots = room.gate_slots.order_by("slot_number")
    pending_slot = slots.filter(status=GateSlot.RESERVED).first()
    user_reserved_slot = None
    user_filled_slot = None
    if user.is_authenticated:
        user_reserved_slot = slots.filter(gamer=user, status=GateSlot.RESERVED).first()
        user_filled_slot = slots.filter(gamer=user, status=GateSlot.FILLED).first()
    eligible = (
        user.is_authenticated
        and pending_slot is None
        and user_reserved_slot is None
        and user_filled_slot is None
    )
    token_depleted = eligible and select_token(user) is None
    can_drop = eligible and not token_depleted
    is_last_slot = (
        user_reserved_slot is not None
        and slots.filter(status=GateSlot.EMPTY).count() == 0
    )
    user_can_reject = user_reserved_slot is not None or user_filled_slot is not None
    return {
        "slots": slots,
        "pending_slot": pending_slot,
        "user_reserved_slot": user_reserved_slot,
        "user_filled_slot": user_filled_slot,
        "can_drop": can_drop,
        "token_depleted": token_depleted,
        "is_last_slot": is_last_slot,
        "user_can_reject": user_can_reject,
    }


@login_required
def create_room(request):
    if request.method == "POST":
        name = request.POST.get("name", "").strip()
        if name:
            room = Room.objects.create(name=name, owner=request.user)
            return redirect("epic:gatekeeper", room_id=room.id)
    return redirect("/gameboard/")


def gatekeeper(request, room_id):
    room = Room.objects.get(id=room_id)
    ctx = _gate_context(room, request.user)
    ctx["room"] = room
    return render(request, "apps/gameboard/room.html", ctx)


@login_required
def drop_token(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        if room.gate_slots.filter(status=GateSlot.RESERVED).exists():
            return redirect("epic:gatekeeper", room_id=room_id)
        if room.gate_slots.filter(gamer=request.user, status=GateSlot.FILLED).exists():
            return redirect("epic:gatekeeper", room_id=room_id)
        if select_token(request.user) is None:
            return HttpResponse(status=402)
        slot = room.gate_slots.filter(
            status=GateSlot.EMPTY
        ).order_by("slot_number").first()
        if slot:
            slot.gamer = request.user
            slot.status = GateSlot.RESERVED
            slot.reserved_at = timezone.now()
            slot.save()
    return redirect("epic:gatekeeper", room_id=room_id)


@login_required
def confirm_token(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        slot = room.gate_slots.filter(
            gamer=request.user, status=GateSlot.RESERVED
        ).first()
        if slot:
            token = select_token(request.user)
            if token:
                debit_token(request.user, slot, token)
    return redirect("epic:gatekeeper", room_id=room_id)


@login_required
def reject_token(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        slot = room.gate_slots.filter(
            gamer=request.user,
            status__in=[GateSlot.RESERVED, GateSlot.FILLED],
        ).first()
        if slot:
            slot.gamer = None
            slot.status = GateSlot.EMPTY
            slot.reserved_at = None
            slot.filled_at = None
            slot.save()
    return redirect("epic:gatekeeper", room_id=room_id)


@login_required
def invite_gamer(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        email = request.POST.get("invitee_email", "").strip()
        if email:
            RoomInvite.objects.get_or_create(
                room=room,
                inviter=request.user,
                invitee_email=email,
                defaults={"status": RoomInvite.PENDING}
            )
    return redirect("epic:gatekeeper", room_id=room_id)


@login_required
def delete_room(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        if request.user == room.owner:
            room.delete()
    return redirect("/gameboard/")


@login_required
def abandon_room(request, room_id):
    if request.method == "POST":
        room = Room.objects.get(id=room_id)
        room.gate_slots.filter(gamer=request.user).update(
            gamer=None, status="EMPTY", filled_at=None
        )
        room.invites.filter(
            invitee_email=request.user.email,
            status=RoomInvite.PENDING
        ).delete()
    return redirect("/gameboard/")


def gate_status(request, room_id):
    room = Room.objects.get(id=room_id)
    if room.gate_status == Room.OPEN:
        return HttpResponse("")
    ctx = _gate_context(room, request.user)
    ctx["room"] = room
    return render(request, "apps/gameboard/_partials/_gatekeeper.html", ctx)