from django.contrib.admin.models import LogEntry
from django.contrib.auth import get_user_model
from django.contrib.contenttypes.models import ContentType
from rest_framework import viewsets
from rest_framework.permissions import IsAuthenticated
from django.shortcuts import render, get_object_or_404
from .models import Risk, Control, ResidualRisk, AuditLog, Incident
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
        instance.save()

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

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
        instance.save()

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

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
        instance.save()

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

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
        instance.save()

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

# ---------------------------------------------------------------------------
# Web
# ---------------------------------------------------------------------------

def dashboard(request):
    return render(request, "risks/dashboard.html")

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

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,
    })

def show_risk(request, id):
    risk = get_object_or_404(Risk, 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})

def list_controls(request):
    qs = Control.objects.all().select_related("risk", "responsible")

    # Filter
    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(risk_id=risk_id)
    if status:
        qs = qs.filter(status=status)
    if responsible_id:
        qs = qs.filter(responsible_id=responsible_id)

    controls = qs.order_by("title")

    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,
    })

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})

def list_incidents(request):
    return render(request, "risks/list_incidents.html")

def show_incident(request, id):
    incident = Incident.objects.get(pk=id)
    return render(request, "risks/item_incident.html", {"incident": incident })