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

from apps.dashboard.forms import ExistingListItemForm, ItemForm
from apps.dashboard.models import Applet, Item, List, UserApplet
from apps.lyric.models import User


APPLET_ORDER = ["new-list", "my-lists", "username", "palette"]
UNLOCKED_PALETTES = frozenset(["palette-default"])
PALETTES = [
    {"name": "palette-default", "label": "Earthman", "locked": False},
    {"name": "palette-nirvana", "label": "Nirvana", "locked": True},
    {"name": "palette-sheol", "label": "Sheol", "locked": True},
]


def _recent_lists(user, limit=3):
    return (
        List
            .objects
            .filter(Q(owner=user) | Q(shared_with=user))
            .annotate(last_item=Max('item__id'))
            .order_by('-last_item')
            .distinct()[:limit]
    )

def _applet_context(user):
    ua_map = {ua.applet_id: ua.visible for ua in user.user_applets.all()}
    applets = {a.slug: a for a in Applet.objects.all()}
    return [
        {"applet": applets[slug], "visible": ua_map.get(applets[slug].pk, applets[slug].default_visible)}
        for slug in APPLET_ORDER
        if slug in applets
    ]


def home_page(request):
    context = {
        "form": ItemForm(),
        "palettes": PALETTES,
        "page_class": "page-dashboard",
    }
    if request.user.is_authenticated:
        context["applets"] = _applet_context(request.user)
        context["recent_lists"] = _recent_lists(request.user)
    return render(request, "apps/dashboard/home.html", context)

def new_list(request):
    form = ItemForm(data=request.POST)
    if form.is_valid():
        nulist = List.objects.create()
        if request.user.is_authenticated:
            nulist.owner = request.user
            nulist.save()
        form.save(for_list=nulist)
        return redirect(nulist)
    else:
        context = {
            "form": form,
            "palettes": PALETTES,
            "page_class": "page-dashboard",
        }
        if request.user.is_authenticated:
            context["applets"] = _applet_context(request.user)
            context["recent_lists"] = _recent_lists(request.user)
        return render(request, "apps/dashboard/home.html", context)

def view_list(request, list_id):
    our_list = List.objects.get(id=list_id)

    if our_list.owner:
        if not request.user.is_authenticated:
            return redirect("/")
        if request.user != our_list.owner and request.user not in our_list.shared_with.all():
            return HttpResponseForbidden()

    form = ExistingListItemForm(for_list=our_list)

    if request.method == "POST":
        form = ExistingListItemForm(for_list=our_list, data=request.POST)
        if form.is_valid():
            form.save()
            return redirect(our_list)
    return render(request, "apps/dashboard/list.html", {"list": our_list, "form": form})
       
def my_lists(request, user_id):
    owner = User.objects.get(id=user_id)
    if not request.user.is_authenticated:
        return redirect("/")
    if request.user.id != owner.id:
        return HttpResponseForbidden()
    return render(request, "apps/dashboard/my_lists.html", {"owner": owner})

def share_list(request, list_id):
    our_list = List.objects.get(id=list_id)
    try:
        recipient = User.objects.get(email=request.POST["recipient"])
        if recipient == request.user:
            return redirect(our_list)
        our_list.shared_with.add(recipient)
    except User.DoesNotExist:
        pass
    messages.success(request, "An invite has been sent if that address is registered.")
    return redirect(our_list)

@login_required(login_url="/")
def set_palette(request):
    if request.method == "POST":
        palette = request.POST.get("palette", "")
        if palette in UNLOCKED_PALETTES:
            request.user.palette = palette
            request.user.save(update_fields=["palette"])
    return redirect("home")

@login_required(login_url="/")
def set_profile(request):
    if request.method == "POST":
        username = request.POST.get("username", "")
        request.user.username = username
        request.user.save(update_fields=["username"])
    return redirect("/")

@login_required(login_url="/")
def toggle_applets(request):
    checked = request.POST.getlist("applets")
    for applet in Applet.objects.all():
        UserApplet.objects.update_or_create(
            user=request.user,
            applet=applet,
            defaults={"visible": applet.slug in checked},
        )
    if request.headers.get("HX-Request"):
        return render(request, "apps/dashboard/_partials/_applets.html", {
            "applets": _applet_context(request.user),
            "palettes": PALETTES,
            "form": ItemForm(),
            "recent_lists": _recent_lists(request.user),
        })
    return redirect("home")