import json

from django.contrib.admin.views.decorators import staff_member_required
from django.db.models import Count, Max, Min
from django.http import JsonResponse
from django.shortcuts import render, HttpResponse, redirect
from django.utils import timezone
from django.views.decorators.csrf import csrf_exempt
from django.views.decorators.http import require_POST

from datetime import timedelta

from .models import UsageEvent
from .utils import parse_user_agent

# Create your views here.
def index(request):
    return render(request, "app/base.html")

def install(request):
    return render(request, "app/install.html")

def home(request):
    return redirect("/app/v263")

def login(request):
    return render(request, "app/login.html")

def v1321(request):
    return redirect("/app/v263")

def v1322(request):
    return redirect("/app/v263")

def v133(request):
    return redirect("/app/v263")

def v1332(request):
    return redirect("/app/v263")

def v1333(request):
    return redirect("/app/v263")

def v1334(request):
    return redirect("/app/v263")

def v1335(request):
    return redirect("/app/v263")

def v1340(request):
    return redirect("/app/v263")

def v260(request):
    return redirect("/app/v263")

def v261(request):
    return redirect("/app/v263")

def v262(request):
    return redirect("/app/v263")

def v263(request):
    return render(request, "app/home.html")


# ---------------------------------------------------------------------------
# Anonyme Nutzungsstatistik fürs Admin-Dashboard
# ---------------------------------------------------------------------------

@csrf_exempt
@require_POST
def track_usage(request):
    """Nimmt ein anonymes Nutzungssignal entgegen (ein Aufruf pro Gerät und Tag,
    siehe home01.js: pingUsageIfNeeded()). Kein CSRF-Schutz nötig, da rein additiv
    und ohne jeden Personenbezug - device_id kommt aus dem localStorage des Geräts."""
    try:
        data = json.loads(request.body or "{}")
    except json.JSONDecodeError:
        data = {}

    device_id = str(data.get("device_id", "")).strip()[:64]
    if not device_id:
        return JsonResponse({"ok": False, "error": "device_id fehlt"}, status=400)

    user_agent = request.META.get("HTTP_USER_AGENT", "")
    platform, browser = parse_user_agent(user_agent)

    UsageEvent.objects.create(
        device_id=device_id,
        app_version=str(data.get("app_version", ""))[:20],
        user_agent=user_agent[:1000],
        platform=platform,
        browser=browser,
        is_standalone=bool(data.get("standalone", False)),
    )
    return JsonResponse({"ok": True})


@staff_member_required
def usage_dashboard(request):
    """Nutzungs-Dashboard für Admins - nur für angemeldete Staff-Nutzer (Django-Admin-Login)."""
    now = timezone.now()
    today_start = now.replace(hour=0, minute=0, second=0, microsecond=0)

    events = UsageEvent.objects.all()

    # "Nutzer" = Gerät hat PioMint mindestens einmal als installierte PWA
    # (Standalone) geöffnet - nur das ist echte Nutzung. Ein Gerät, das die
    # Seite nur im Browser-Tab geöffnet hat, ist ein "Aufrufer", kein Nutzer.
    user_device_ids = events.filter(is_standalone=True).values_list("device_id", flat=True).distinct()
    users = events.filter(device_id__in=user_device_ids)
    visitors_total = events.exclude(device_id__in=user_device_ids).values("device_id").distinct().count()

    context = {
        "total_connections": events.count(),
        "visitors_total": visitors_total,
        "users_total": user_device_ids.count(),
        "users_today": users.filter(created_at__gte=today_start).values("device_id").distinct().count(),
        "users_7d": users.filter(created_at__gte=now - timedelta(days=7)).values("device_id").distinct().count(),
        "users_30d": users.filter(created_at__gte=now - timedelta(days=30)).values("device_id").distinct().count(),
        "by_platform": users.values("platform").annotate(count=Count("device_id", distinct=True)).order_by("-count"),
        "by_browser": users.values("browser").annotate(count=Count("device_id", distinct=True)).order_by("-count"),
        "device_summary": (
            events.values("device_id")
            .annotate(
                ping_count=Count("id"),
                first_seen=Min("created_at"),
                last_seen=Max("created_at"),
                standalone_any=Max("is_standalone"),
            )
            .order_by("-last_seen")
        ),
        "recent_events": events[:30],
    }
    return render(request, "app/dashboard.html", context)