import json

from django.contrib.auth.decorators import login_required
from django.db.models import Max, Q
from django.http import JsonResponse
from django.shortcuts import redirect, render

from apps.applets.utils import applet_context, apply_applet_toggle
from apps.dashboard.forms import LineForm
from apps.dashboard.models import Post
from apps.drama.models import GameEvent, Note, ScrollPosition
from apps.epic.models import Room
from apps.epic.utils import rooms_for_user


def _recent_posts(user, limit=3):
    return (
        Post
            .objects
            .filter(Q(owner=user) | Q(shared_with=user))
            .annotate(last_line=Max('lines__id'))
            .order_by('-last_line')
            .distinct()[:limit]
    )


@login_required(login_url="/")
def billboard(request):
    my_rooms = rooms_for_user(request.user).order_by("-created_at")

    recent_room = (
        Room.objects.filter(
            Q(owner=request.user) | Q(gate_slots__gamer=request.user)
        )
        .annotate(last_event=Max("events__timestamp"))
        .filter(last_event__isnull=False)
        .order_by("-last_event")
        .distinct()
        .first()
    )
    recent_events = (
        list(
            recent_room.events
            .select_related("actor")
            .exclude(verb=GameEvent.SIG_UNREADY)
            .exclude(verb=GameEvent.SIG_READY, data__retracted=True)
            .order_by("-timestamp")[:36]
        )[::-1]
        if recent_room else []
    )

    return render(request, "apps/billboard/billboard.html", {
        "my_rooms": my_rooms,
        "recent_room": recent_room,
        "recent_events": recent_events,
        "viewer": request.user,
        "applets": applet_context(request.user, "billboard"),
        "form": LineForm(),
        "recent_posts": _recent_posts(request.user),
        "page_class": "page-billboard",
    })


@login_required(login_url="/")
def toggle_billboard_applets(request):
    checked = request.POST.getlist("applets")
    apply_applet_toggle(request.user, "billboard", checked)
    if request.headers.get("HX-Request"):
        return render(request, "apps/billboard/_partials/_applets.html", {
            "applets": applet_context(request.user, "billboard"),
            "form": LineForm(),
            "recent_posts": _recent_posts(request.user),
        })
    return redirect("billboard:billboard")


@login_required(login_url="/")
def room_scroll(request, room_id):
    room = Room.objects.get(id=room_id)
    events = room.events.select_related("actor").all()
    sp = ScrollPosition.objects.filter(user=request.user, room=room).first()
    return render(request, "apps/billboard/room_scroll.html", {
        "room": room,
        "events": events,
        "viewer": request.user,
        "scroll_position": sp.position if sp else 0,
        "page_class": "page-billscroll",
    })


_NOTE_META = {
    "stargazer": {
        "title":           "Stargazer",
        "description":     "You saved your first personal sky chart.",
        "palette_options": ["palette-bardo", "palette-sheol"],
    },
    "schizo": {
        "title":           "Schizo",
        "description":     "The socius recognizes the line of flight.",
        "palette_options": [],
    },
    "nomad": {
        "title":           "Nomad",
        "description":     "The socius recognizes the smooth space.",
        "palette_options": [],
    },
}


@login_required(login_url="/")
def note_set_palette(request, slug):
    from django.http import Http404
    from apps.dashboard.views import _unlocked_palettes_for_user
    try:
        note = Note.objects.get(user=request.user, slug=slug)
    except Note.DoesNotExist:
        raise Http404
    if request.method == "POST":
        body = json.loads(request.body)
        palette = body.get("palette", "")
        note.palette = palette
        note.save(update_fields=["palette"])
        # Commit as the user's active sitewide palette now that the Note unlocks it.
        if palette in _unlocked_palettes_for_user(request.user):
            request.user.palette = palette
            request.user.save(update_fields=["palette"])
    return JsonResponse({"ok": True})


@login_required(login_url="/")
def my_notes(request):
    qs = Note.objects.filter(user=request.user)
    note_items = [
        {
            "obj":             n,
            "title":           _NOTE_META.get(n.slug, {}).get("title", n.slug),
            "description":     _NOTE_META.get(n.slug, {}).get("description", ""),
            "palette_options": _NOTE_META.get(n.slug, {}).get("palette_options", []),
        }
        for n in qs
    ]
    return render(request, "apps/billboard/my_notes.html", {
        "notes": qs,
        "note_items": note_items,
        "page_class": "page-notes",
    })


@login_required(login_url="/")
def save_scroll_position(request, room_id):
    if request.method != "POST":
        from django.http import HttpResponseNotAllowed
        return HttpResponseNotAllowed(["POST"])
    room = Room.objects.get(id=room_id)
    position = int(request.POST.get("position", 0))
    ScrollPosition.objects.update_or_create(
        user=request.user, room=room,
        defaults={"position": position},
    )
    from django.http import HttpResponse
    return HttpResponse(status=204)