from django.contrib.admin.models import LogEntry
from django.contrib.auth import get_user_model
from django.contrib.auth.decorators import login_required
from django.contrib.contenttypes.models import ContentType
from django.db.models import Count, Q
from rest_framework import viewsets
from rest_framework.permissions import IsAuthenticated
from django.shortcuts import render, get_object_or_404
from collections import Counter
from .models import Risk, Control, ResidualRisk, AuditLog, Incident, Notification
from .serializers import ControlSerializer, RiskSerializer, ResidualRiskSerializer, UserSerializer, AuditSerializer, IncidentSerializer

User = get_user_model()

# ---------------------------------------------------------------------------
# API
# ---------------------------------------------------------------------------
class RiskViewSet(viewsets.ModelViewSet):
    """
    API endpoint for managing Risks.
    Provides CRUD operations.
    """
    queryset = Risk.objects.all()
    serializer_class = RiskSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

    def perform_update(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

class ControlViewSet(viewsets.ModelViewSet):
    """
    API endpoint for managing Controls.
    Provides CRUD operations.
    """
    queryset = Control.objects.all()
    serializer_class = ControlSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

    def perform_update(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

class ResidualRiskViewSet(viewsets.ModelViewSet):
    queryset = ResidualRisk.objects.all()
    serializer_class = ResidualRiskSerializer
    permission_classes = [IsAuthenticated]

class UserViewSet(viewsets.ReadOnlyModelViewSet):
    """
    API endpoint for listing users and their responsibilities.
    """
    queryset = User.objects.all()
    serializer_class = UserSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

    def perform_update(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

class AuditViewSet(viewsets.ReadOnlyModelViewSet):
    """
    API endpoint for view audit logging.
    """
    queryset = AuditLog.objects.all()
    serializer_class = AuditSerializer
    permission_classes = [IsAuthenticated]

class IncidentViewSet(viewsets.ModelViewSet):
    """
    API endpoint for listing incidents and its related risks.
    """
    queryset = Incident.objects.all()
    serializer_class = IncidentSerializer
    permission_classes = [IsAuthenticated]

    def perform_create(self, serializer):
        instance = serializer.save(reported_by=self.request.user)
        instance._changed_by = self.request.user

    def perform_update(self, serializer):
        instance = serializer.save()
        instance._changed_by = self.request.user

# ---------------------------------------------------------------------------
# Web => Risks, Controls, Incidents
# ---------------------------------------------------------------------------

@login_required
def stats(request):
    return render(request, "risks/statistics.html")

@login_required
def list_risks(request):
    qs = Risk.objects.all().select_related("owner")

    # GET-Parameter lesen
    risk_id = request.GET.get("risk")
    control_id = request.GET.get("control")
    owner_id = request.GET.get("owner")

    if risk_id:
        qs = qs.filter(id=risk_id)
    if control_id:
        qs = qs.filter(controls__id=control_id)
    if owner_id:
        qs = qs.filter(owner_id=owner_id)

    risks = qs.order_by("title").distinct()

    controls = Control.objects.all().order_by("title")
    owners = User.objects.filter(owned_risks__isnull=False).distinct().order_by("username")

    return render(request, "risks/list_risks.html", {
        "risks": risks,
        "controls": controls,
        "owners": owners,
    })

@login_required
def show_risk(request, id):
    risk = get_object_or_404(
        Risk.objects.select_related("residual_risk", "owner").prefetch_related("controls"),
        pk=id,
    )
    ct = ContentType.objects.get_for_model(Risk)
    logs = LogEntry.objects.filter(content_type=ct, object_id=risk.pk).order_by("-action_time")
    
    return render(request, "risks/item_risk.html", {"risk": risk, "logs": logs})

@login_required
def list_controls(request):
    qs = Control.objects.all().select_related("responsible")

    control_id = request.GET.get("control")
    risk_id = request.GET.get("risk")
    status = request.GET.get("status")
    responsible_id = request.GET.get("responsible")

    if control_id:
        qs = qs.filter(id=control_id)
    if risk_id:
        qs = qs.filter(risks__id=risk_id)  # FIX
    if status:
        qs = qs.filter(status=status)
    if responsible_id:
        qs = qs.filter(responsible_id=responsible_id)

    controls = qs.order_by("title").distinct()

    risks = Risk.objects.all().order_by("title")
    users = User.objects.filter(responsible_controls__isnull=False).distinct().order_by("username")

    return render(request, "risks/list_controls.html", {
        "controls": controls,
        "risks": risks,
        "users": users,
        "status_choices": Control.STATUS_CHOICES,
    })

@login_required
def show_control(request, id):
    control = get_object_or_404(Control, pk=id)
    ct = ContentType.objects.get_for_model(Control)
    logs = LogEntry.objects.filter(
        content_type=ct,
        object_id=control.pk
    ).order_by("-action_time")

    return render(request, "risks/item_control.html", {"control": control, "logs": logs})

@login_required
def list_incidents(request):
    qs = Incident.objects.all().select_related("reported_by").prefetch_related("related_risks")

    risk_id = request.GET.get("risk")
    status = request.GET.get("status")
    reported_by = request.GET.get("reported_by")

    if risk_id:
        qs = qs.filter(related_risks__id=risk_id)  # FIX
    if status:
        qs = qs.filter(status=status)
    if reported_by:
        qs = qs.filter(reported_by=reported_by)

    incidents = qs.order_by("title").distinct()

    risks = Risk.objects.all().order_by("title")
    users = User.objects.filter(incidents__isnull=False).distinct().order_by("username")  # sinnvoller

    return render(request, "risks/list_incidents.html", {
        "incidents": incidents,
        "risks": risks,
        "users": users,
        "status_choices": Incident.STATUS_CHOICES,
    })

@login_required
def show_incident(request, id):
    incident = get_object_or_404(Incident, pk=id)
    ct = ContentType.objects.get_for_model(Incident)
    logs = LogEntry.objects.filter(
        content_type=ct,
        object_id=incident.pk
    ).order_by("-action_time")

    return render(request, "risks/item_incident.html", {"incident": incident, "logs": logs})

# ---------------------------------------------------------------------------
# Web => Dashboard
# ---------------------------------------------------------------------------

@login_required
def dashboard(request):
    # Risikoübersicht
    risks_total = Risk.objects.count()
    risks_by_level = Risk.objects.values('level').annotate(count=Count('id'))

    # CIA-Zähler für MultiSelectField
    risks_cia = Risk.objects.values_list('cia', flat=True)
    cia_counter = Counter()
    for cia_list in risks_cia:
        if isinstance(cia_list, list):  # MultiSelectField gibt Liste zurück
            for c in cia_list:
                cia_counter[c] += 1
        elif cia_list:  # Falls irgendwie noch ein String drin ist
            cia_counter[cia_list] += 1

    # Residualrisiken
    residual_review_required = ResidualRisk.objects.filter(review_required=True).count()

    # Kontrollen
    controls_by_status = Control.objects.values('status').annotate(count=Count('id'))

    # Incidents
    incidents_status = Incident.objects.values('status').annotate(count=Count('id'))

    # Benachrichtigungen
    notifications_unread = Notification.objects.filter(user=request.user, read=False).count()

    print(type(cia_counter), cia_counter)

    # Context für Template
    context = {
        'risks_total': risks_total,
        'risks_by_level': risks_by_level,
        'risks_by_cia': dict(cia_counter),  # <-- hier Counter in dict umwandeln
        'residual_review_required': residual_review_required,
        'controls_by_status': controls_by_status,
        'incidents_status': incidents_status,
        'notifications_unread': notifications_unread,
    }
    return render(request, 'risks/dashboard.html', context)