from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.db.models import Count, Q
from django.utils import timezone
from django.views.generic import TemplateView, ListView, DetailView
from django.shortcuts import get_object_or_404

from apps.batches.models import ProcessingBatch
from apps.qc.models import QCResult
from apps.shipments.models import Shipment
from apps.capa.models import CAPARecord
from apps.documents.models import Document
from apps.esg.models import ESGFieldReport
from apps.notifications.models import Notification


class OpsRequiredMixin(UserPassesTestMixin):
    def test_func(self):
        user = self.request.user
        return user.is_authenticated and (user.role in ('ops', 'admin') or user.is_superuser)


class DashboardView(OpsRequiredMixin, TemplateView):
    template_name = 'ops/dashboard.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['total_batches'] = ProcessingBatch.objects.count()
        ctx['batches_by_status'] = {
            s: ProcessingBatch.objects.filter(status=s).count()
            for s, _ in ProcessingBatch.Status.choices
        }
        ctx['recent_qc'] = QCResult.objects.select_related('batch').order_by('-tested_at')[:10]
        ctx['qc_summary'] = QCResult.objects.aggregate(
            passed=Count('id', filter=Q(overall_pass=True)),
            failed=Count('id', filter=Q(overall_pass=False)),
        )
        ctx['active_shipments'] = Shipment.objects.exclude(status='delivered').count()
        ctx['open_capas'] = CAPARecord.objects.filter(status__in=('open', 'in_progress')).count()
        ctx['recent_notifications'] = Notification.objects.filter(
            user=self.request.user, is_read=False
        )[:5]
        ctx['recent_batches'] = ProcessingBatch.objects.order_by('-created_at')[:5]
        return ctx


class BatchListView(OpsRequiredMixin, ListView):
    model = ProcessingBatch
    template_name = 'ops/batch_list.html'
    context_object_name = 'batches'
    paginate_by = 25

    def get_queryset(self):
        qs = ProcessingBatch.objects.all()
        status = self.request.GET.get('status')
        grade = self.request.GET.get('grade')
        search = self.request.GET.get('q')
        if status:
            qs = qs.filter(status=status)
        if grade:
            qs = qs.filter(grade=grade)
        if search:
            qs = qs.filter(batch_reference__icontains=search)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['status_choices'] = ProcessingBatch.Status.choices
        ctx['grade_choices'] = ProcessingBatch.Grade.choices
        ctx['current_status'] = self.request.GET.get('status', '')
        ctx['current_grade'] = self.request.GET.get('grade', '')
        ctx['current_q'] = self.request.GET.get('q', '')
        return ctx


class BatchDetailView(OpsRequiredMixin, DetailView):
    model = ProcessingBatch
    template_name = 'ops/batch_detail.html'
    context_object_name = 'batch'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        batch = self.object
        ctx['qc_results'] = QCResult.objects.filter(batch=batch)
        ctx['shipments'] = Shipment.objects.filter(batch=batch)
        ctx['capa_records'] = CAPARecord.objects.filter(batch=batch)
        ctx['documents'] = Document.objects.filter(batch=batch)
        ctx['esg_reports'] = ESGFieldReport.objects.filter(batch=batch)
        return ctx


class QCListView(OpsRequiredMixin, ListView):
    model = QCResult
    template_name = 'ops/qc_list.html'
    context_object_name = 'results'
    paginate_by = 25

    def get_queryset(self):
        qs = QCResult.objects.select_related('batch').all()
        passed = self.request.GET.get('passed')
        if passed == '1':
            qs = qs.filter(overall_pass=True)
        elif passed == '0':
            qs = qs.filter(overall_pass=False)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['current_passed'] = self.request.GET.get('passed', '')
        return ctx


class QCDetailView(OpsRequiredMixin, DetailView):
    model = QCResult
    template_name = 'ops/qc_detail.html'
    context_object_name = 'result'


class ShipmentListView(OpsRequiredMixin, ListView):
    model = Shipment
    template_name = 'ops/shipment_list.html'
    context_object_name = 'shipments'
    paginate_by = 25

    def get_queryset(self):
        qs = Shipment.objects.select_related('batch').all()
        status = self.request.GET.get('status')
        if status:
            qs = qs.filter(status=status)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['status_choices'] = Shipment.Status.choices
        ctx['current_status'] = self.request.GET.get('status', '')
        return ctx


class ShipmentDetailView(OpsRequiredMixin, DetailView):
    model = Shipment
    template_name = 'ops/shipment_detail.html'
    context_object_name = 'shipment'


class CAPAListView(OpsRequiredMixin, ListView):
    model = CAPARecord
    template_name = 'ops/capa_list.html'
    context_object_name = 'records'
    paginate_by = 25

    def get_queryset(self):
        qs = CAPARecord.objects.select_related('batch').all()
        status = self.request.GET.get('status')
        if status:
            qs = qs.filter(status=status)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['status_choices'] = CAPARecord.Status.choices
        ctx['current_status'] = self.request.GET.get('status', '')
        return ctx


class CAPADetailView(OpsRequiredMixin, DetailView):
    model = CAPARecord
    template_name = 'ops/capa_detail.html'
    context_object_name = 'record'


class DocumentListView(OpsRequiredMixin, ListView):
    model = Document
    template_name = 'ops/document_list.html'
    context_object_name = 'documents'
    paginate_by = 25

    def get_queryset(self):
        qs = Document.objects.select_related('batch', 'uploaded_by').all()
        doc_type = self.request.GET.get('doc_type')
        if doc_type:
            qs = qs.filter(doc_type=doc_type)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['doc_type_choices'] = Document.DocType.choices
        ctx['current_doc_type'] = self.request.GET.get('doc_type', '')
        return ctx


class ESGListView(OpsRequiredMixin, ListView):
    model = ESGFieldReport
    template_name = 'ops/esg_list.html'
    context_object_name = 'reports'
    paginate_by = 25

    def get_queryset(self):
        return ESGFieldReport.objects.select_related('batch').all()