from django.contrib import messages
from django.contrib.contenttypes.models import ContentType
from django.shortcuts import get_object_or_404, redirect, render
from django.utils.translation import gettext_lazy as _

from netbox.views import generic
from utilities.views import register_model_view

from .engine.resolver import Resolver
from .filtersets import ServiceFilterSet, ServiceTemplateFilterSet
from .forms import (
    ResolveForm,
    ServiceBulkEditForm,
    ServiceFilterSetForm,
    ServiceForm,
    ServiceTemplateBulkEditForm,
    ServiceTemplateFilterSetForm,
    ServiceTemplateForm,
    ServiceTemplateImportForm,
)
from .models import Service, ServiceTemplate
from .tables import ServiceTable, ServiceTemplateTable


def _build_preview(result):
    """Transform result.planned_objects into a list of dicts with pre-computed action."""
    preview = []
    for node_name, obj in result.planned_objects:
        ct = ContentType.objects.get_for_model(obj.__class__)
        key = (ct.id, obj.pk)
        action = "add" if key in result.to_add else "keep"
        preview.append({"node": node_name, "object": obj, "action": action})
    return preview


# ════════════════════════════════════════════════════════════════════
#  Service Template
# ════════════════════════════════════════════════════════════════════

@register_model_view(ServiceTemplate, "list", path="", detail=False)
class ServiceTemplateListView(generic.ObjectListView):
    queryset = ServiceTemplate.objects.all()
    table = ServiceTemplateTable
    filterset = ServiceTemplateFilterSet
    filterset_form = ServiceTemplateFilterSetForm


@register_model_view(ServiceTemplate, "add", path="add", detail=False)
@register_model_view(ServiceTemplate, "edit")
class ServiceTemplateEditView(generic.ObjectEditView):
    queryset = ServiceTemplate.objects.all()
    form = ServiceTemplateForm


@register_model_view(ServiceTemplate, "delete")
class ServiceTemplateDeleteView(generic.ObjectDeleteView):
    queryset = ServiceTemplate.objects.all()


@register_model_view(ServiceTemplate, "bulk_edit", path="edit", detail=False)
class ServiceTemplateBulkEditView(generic.BulkEditView):
    queryset = ServiceTemplate.objects.all()
    table = ServiceTemplateTable
    form = ServiceTemplateBulkEditForm


@register_model_view(ServiceTemplate, "bulk_delete", path="delete", detail=False)
class ServiceTemplateBulkDeleteView(generic.BulkDeleteView):
    queryset = ServiceTemplate.objects.all()
    table = ServiceTemplateTable


@register_model_view(ServiceTemplate, "bulk_import", path="import", detail=False)
class ServiceTemplateBulkImportView(generic.BulkImportView):
    queryset = ServiceTemplate.objects.all()
    model_form = ServiceTemplateImportForm
    table = ServiceTemplateTable


@register_model_view(ServiceTemplate)
class ServiceTemplateView(generic.ObjectView):
    queryset = ServiceTemplate.objects.all()

    def get_extra_context(self, request, instance):
        context = super().get_extra_context(request, instance)
        context["is_locked"] = instance.is_locked
        return context


# ════════════════════════════════════════════════════════════════════
#  Service
# ════════════════════════════════════════════════════════════════════

@register_model_view(Service, "list", path="", detail=False)
class ServiceListView(generic.ObjectListView):
    queryset = Service.objects.all()
    table = ServiceTable
    filterset = ServiceFilterSet
    filterset_form = ServiceFilterSetForm


@register_model_view(Service, "add", path="add", detail=False)
@register_model_view(Service, "edit")
class ServiceEditView(generic.ObjectEditView):
    queryset = Service.objects.all()
    form = ServiceForm


@register_model_view(Service, "delete")
class ServiceDeleteView(generic.ObjectDeleteView):
    queryset = Service.objects.all()


@register_model_view(Service, "bulk_edit", path="edit", detail=False)
class ServiceBulkEditView(generic.BulkEditView):
    queryset = Service.objects.all()
    table = ServiceTable
    form = ServiceBulkEditForm


@register_model_view(Service, "bulk_delete", path="delete", detail=False)
class ServiceBulkDeleteView(generic.BulkDeleteView):
    queryset = Service.objects.all()
    table = ServiceTable


@register_model_view(Service)
class ServiceView(generic.ObjectView):
    queryset = Service.objects.all()

    def get_extra_context(self, request, instance):
        context = super().get_extra_context(request, instance)
        context["bindings"] = instance.bindings.select_related(
            "content_type",
        ).all()
        return context


@register_model_view(Service, "resolve", path="resolve")
class ServiceResolveView(generic.ObjectView):
    """Dry-run preview (GET) and commit (POST) for service resolution."""

    queryset = Service.objects.all()

    def get(self, request, pk):
        service = get_object_or_404(self.queryset, pk=pk)
        resolver = Resolver()
        try:
            result = resolver.resolve(service, mode="dry_run", user=request.user)
        except Exception as exc:
            messages.error(request, f"Resolution failed: {exc}")
            return redirect("plugins:netbox_services:service", pk=service.pk)

        return render(request, "netbox_services/service_resolve.html", {
            "object": service,
            "service": service,
            "result": result,
            "planned_preview": _build_preview(result),
            "form": ResolveForm(initial={"mode": "commit"}),
            "active_tab": "resolve",
        })

    def post(self, request, pk):
        service = get_object_or_404(self.queryset, pk=pk)
        form = ResolveForm(request.POST)
        mode = form.cleaned_data.get("mode", "dry_run") if form.is_valid() else "dry_run"

        resolver = Resolver()
        try:
            result = resolver.resolve(service, mode=mode, user=request.user)
        except Exception as exc:
            messages.error(request, f"Resolution failed: {exc}")
            return redirect("plugins:netbox_services:service", pk=service.pk)

        if mode == "commit":
            messages.success(
                request,
                _("Resolution committed: {added} added, {removed} removed, {kept} unchanged.").format(
                    added=len(result.to_add),
                    removed=len(result.to_remove),
                    kept=result.total_planned - len(result.to_add),
                ),
            )
            return redirect("plugins:netbox_services:service", pk=service.pk)

        return render(request, "netbox_services/service_resolve.html", {
            "object": service,
            "service": service,
            "result": result,
            "planned_preview": _build_preview(result),
            "form": ResolveForm(initial={"mode": "commit"}),
            "active_tab": "resolve",
        })