import json

from django.contrib import messages
from django.contrib.auth.mixins import LoginRequiredMixin, UserPassesTestMixin
from django.db.models import Count, Q
from django.shortcuts import redirect
from django.urls import reverse
from django.utils import timezone
from django.views.generic import TemplateView, ListView, DetailView, CreateView, UpdateView
from django.views import View
from django.shortcuts import get_object_or_404, render

from apps.batches.models import ProcessingBatch
from apps.core.tiles import browser_tile_url
from apps.qc.models import QCResult
from apps.shipments.models import Shipment
from apps.capa.models import CAPARecord
from apps.documents.downloads import file_response
from apps.documents.models import Document, CertificateOfAnalysis
from apps.esg.models import ESGFieldReport
from apps.notifications.models import Notification
from apps.compliance.models import (
    CollectorGroup,
    DueDiligenceCase,
    DueDiligenceStatementReference,
    EUDREvidence,
    Facility,
    HarvestIntake,
    IntakeBatchLineage,
    MitigationAction,
    OriginZone,
    ProductSpecification,
)
from apps.compliance import services
from apps.guides.views import GuideDetailView as BaseGuideDetailView
from apps.guides.views import GuideIndexView as BaseGuideIndexView
from .forms import (
    BatchForm,
    BatchLineageFormSet,
    CollectorGroupForm,
    EUDREvidenceForm,
    FacilityForm,
    HarvestIntakeForm,
    MitigationActionForm,
    OriginZoneForm,
    ShipmentForm,
    SpecificationForm,
    SpecParameterFormSet,
    StatementReferenceForm,
)


def suggested_intake_reference(today=None):
    """Next intake reference, continuing this year's sequence.

    Suggested rather than imposed: the reference may have to match a weighbridge
    ticket, so the field stays editable.
    """
    year = (today or timezone.localdate()).year
    prefix = f"IXG-INTAKE-{year}-"
    highest = 0
    for ref in HarvestIntake.objects.filter(
        intake_reference__startswith=prefix
    ).values_list("intake_reference", flat=True):
        tail = ref[len(prefix):]
        if tail.isdigit():
            highest = max(highest, int(tail))
    return f"{prefix}{highest + 1:04d}"


def suggested_batch_reference(today=None):
    """Next batch reference, continuing this year's sequence. Same reasoning.

    Three digits, because that is the shape the existing references have
    (``IXG-BATCH-2026-014``); it widens by itself past 999.
    """
    year = (today or timezone.localdate()).year
    prefix = f"IXG-BATCH-{year}-"
    highest = 0
    for ref in ProcessingBatch.objects.filter(
        batch_reference__startswith=prefix
    ).values_list("batch_reference", flat=True):
        tail = ref[len(prefix):]
        if tail.isdigit():
            highest = max(highest, int(tail))
    return f"{prefix}{highest + 1:03d}"


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)
        lineage = batch.intake_lineage.select_related(
            'harvest_intake',
            'harvest_intake__origin_zone',
            'harvest_intake__collector_group',
        ).order_by('harvest_intake__intake_reference')
        ctx['lineage'] = lineage
        ctx['lineage_allocated'] = sum((row.weight_allocated_kg or 0) for row in lineage)
        if batch.weight_kg is not None:
            ctx['lineage_difference'] = batch.weight_kg - ctx['lineage_allocated']
        return ctx


class BatchCreateView(OpsRequiredMixin, CreateView):
    model = ProcessingBatch
    form_class = BatchForm
    template_name = 'ops/batch_form.html'

    def get_initial(self):
        initial = super().get_initial()
        initial['batch_reference'] = suggested_batch_reference()
        initial['harvest_date'] = timezone.localdate()
        initial['status'] = ProcessingBatch.Status.HARVESTED
        return initial

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New processing batch'
        ctx['submit_label'] = 'Create batch'
        # The template cannot ask the instance whether it is new — ProcessingBatch's
        # primary key is a UUID with a default, so an unsaved batch already has one,
        # and `_state` is unreachable from a template. The view knows, so it says.
        ctx['creating'] = True
        return ctx

    def form_valid(self, form):
        form.instance.created_by = self.request.user
        response = super().form_valid(form)
        messages.success(
            self.request,
            f"Batch {self.object.batch_reference} created. "
            "Allocate its harvest intakes next — a batch with no lineage fails "
            "the due-diligence lineage check.",
        )
        return response

    def get_success_url(self):
        # Straight to the lineage, because a batch with no intake behind it is
        # not traceable and the check will say so.
        return reverse('ops:batch_lineage', kwargs={'pk': self.object.pk})


class BatchUpdateView(OpsRequiredMixin, UpdateView):
    model = ProcessingBatch
    form_class = BatchForm
    template_name = 'ops/batch_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = f"Edit batch {self.object.batch_reference}"
        ctx['submit_label'] = 'Save changes'
        ctx['creating'] = False
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(
            self.request, f"Batch {self.object.batch_reference} updated."
        )
        return response

    def get_success_url(self):
        return reverse('ops:batch_detail', kwargs={'pk': self.object.pk})


class BatchLineageView(OpsRequiredMixin, View):
    """Allocate harvest intakes to a batch, and correct what is already there.

    This is the screen that closes the lineage gap in walkthrough steps 3 and 4:
    the link between an intake and a batch, with the weight that went into it, is
    created here rather than in the administration area. The formset refuses an
    allocation the intake cannot support — see
    ``apps/ops/forms.py::BaseBatchLineageFormSet``.
    """

    template_name = 'ops/batch_lineage.html'

    def get_batch(self):
        return get_object_or_404(ProcessingBatch, pk=self.kwargs['pk'])

    def get_formset(self, batch, data=None):
        queryset = IntakeBatchLineage.objects.filter(batch=batch).select_related(
            'harvest_intake'
        ).order_by('harvest_intake__intake_reference')
        return BatchLineageFormSet(
            data,
            queryset=queryset,
            prefix='lineage',
            batch=batch,
            form_kwargs={'batch': batch},
        )

    def get_context_data(self, batch, formset):
        rows = list(batch.intake_lineage.select_related(
            'harvest_intake', 'harvest_intake__origin_zone',
            'harvest_intake__collector_group',
        ).order_by('harvest_intake__intake_reference'))
        allocated = sum((row.weight_allocated_kg or 0) for row in rows)
        return {
            'batch': batch,
            'formset': formset,
            'lineage_rows': rows,
            'total_allocated': allocated,
            'difference': (batch.weight_kg - allocated)
            if batch.weight_kg is not None else None,
        }

    def get(self, request, *args, **kwargs):
        batch = self.get_batch()
        formset = self.get_formset(batch)
        return render(
            request, self.template_name, self.get_context_data(batch, formset)
        )

    def post(self, request, *args, **kwargs):
        batch = self.get_batch()
        formset = self.get_formset(batch, data=request.POST)
        if formset.is_valid():
            # A plain ModelFormSet does not know the batch, so the new rows get it
            # here; the deleted ones are removed explicitly.
            for obj in formset.save(commit=False):
                obj.batch = batch
                obj.save()
            for obj in formset.deleted_objects:
                obj.delete()
            messages.success(
                request,
                f"Intake lineage for {batch.batch_reference} updated.",
            )
            return redirect('ops:batch_detail', pk=batch.pk)
        return render(
            request, self.template_name, self.get_context_data(batch, formset)
        )


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 ShipmentFormContextMixin:
    """Shared context for the shipment create and edit forms.

    The batch's own status is shown on the form through the batch dropdown's
    label, and the other shipments on the batch are listed here so an operator
    can see a possible duplicate before saving — the form does not block one,
    because a split consignment is legitimate.
    """

    template_name = 'ops/shipment_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        shipment = getattr(self, 'object', None)
        if shipment is not None and shipment.pk:
            ctx['other_shipments'] = shipment.batch.shipments.exclude(pk=shipment.pk)
        else:
            ctx['other_shipments'] = Shipment.objects.none()
        return ctx


class ShipmentCreateView(ShipmentFormContextMixin, OpsRequiredMixin, CreateView):
    model = Shipment
    form_class = ShipmentForm

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New shipment'
        ctx['submit_label'] = 'Create shipment'
        return ctx

    def form_valid(self, form):
        batch = form.instance.batch
        existing = Shipment.objects.filter(batch=batch).count()
        response = super().form_valid(form)
        messages.success(
            self.request, f"Shipment for {batch.batch_reference} created."
        )
        if existing:
            messages.warning(
                self.request,
                f"{batch.batch_reference} already had {existing} shipment(s). This "
                "was saved as a further consignment — check it is not a duplicate.",
            )
        return response

    def get_success_url(self):
        return reverse('ops:shipment_detail', kwargs={'pk': self.object.pk})


class ShipmentUpdateView(ShipmentFormContextMixin, OpsRequiredMixin, UpdateView):
    model = Shipment
    form_class = ShipmentForm

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Edit shipment for {self.object.batch.batch_reference}"
        )
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        batch = form.instance.batch
        previous_batch_id = (
            Shipment.objects.filter(pk=self.object.pk)
            .values_list('batch_id', flat=True)
            .first()
        )
        others = Shipment.objects.filter(batch=batch).exclude(pk=self.object.pk).count()
        response = super().form_valid(form)
        messages.success(
            self.request, f"Shipment for {batch.batch_reference} updated."
        )
        if others and previous_batch_id != batch.pk:
            messages.warning(
                self.request,
                f"{batch.batch_reference} already had {others} shipment(s). This "
                "was saved as a further consignment — check it is not a duplicate.",
            )
        return response

    def get_success_url(self):
        return reverse('ops:shipment_detail', kwargs={'pk': self.object.pk})


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 DocumentDownloadView(OpsRequiredMixin, View):
    """Serve the stored file behind a document row to operations staff.

    Operations may fetch any document the ops document list shows it. Note the
    list itself has always shown every row regardless of visibility, so this
    matches the list rather than being stricter than it; the buyer-side view is
    where visibility does the gatekeeping.
    """

    def get(self, request, pk):
        doc = get_object_or_404(Document, pk=pk)
        return file_response(doc.file_url, doc.file_name)


class CoADownloadView(OpsRequiredMixin, View):
    """Serve a certificate of analysis to operations staff, at any status.

    Unlike the buyer's view, a certificate still awaiting release is exactly what
    a reviewer needs to open, so the status is not part of the gate here.
    """

    def get(self, request, pk):
        coa = get_object_or_404(CertificateOfAnalysis, pk=pk)
        return file_response(coa.file_url, coa.file_name)


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()


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

    def get_queryset(self):
        qs = QCResult.objects.select_related('batch', 'entered_by').filter(
            verification_status=QCResult.VerificationStatus.DRAFT
        )
        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 QCVerifyDetailView(OpsRequiredMixin, DetailView):
    model = QCResult
    template_name = 'ops/qc_verify_detail.html'
    context_object_name = 'result'

    def post(self, request, *args, **kwargs):
        from django.contrib import messages
        from apps.compliance.services import create_coa_for_qc

        qc = self.get_object()
        user = request.user
        if qc.entered_by is not None and qc.entered_by_id == user.id:
            messages.error(request, 'The submitter cannot approve their own QC result (four-eyes control).')
            return redirect(self.request.path)

        approved = request.POST.get('approved') == '1'
        if approved:
            if not qc.overall_pass:
                messages.error(request, 'A failed QC result cannot be approved; it remains quarantined with an open CAPA.')
                return redirect(self.request.path)
            qc.verification_status = QCResult.VerificationStatus.APPROVED
            qc.verified_by = user
            qc.approved_at = timezone.now()
            qc.save()
            coa = create_coa_for_qc(qc, approved_by=user)
            messages.success(request, f'QC result approved. CoA created (status: {coa.status}).')
            return redirect('ops:coa_review_detail', pk=coa.pk)
        else:
            qc.verification_status = QCResult.VerificationStatus.REJECTED
            qc.verified_by = user
            qc.approved_at = timezone.now()
            qc.save()
            messages.warning(request, 'QC result rejected.')
            return redirect('ops:qc_verify_list')


class COAReviewListView(OpsRequiredMixin, ListView):
    model = CertificateOfAnalysis
    template_name = 'ops/coa_review_list.html'
    context_object_name = 'coas'
    paginate_by = 25

    def get_queryset(self):
        qs = CertificateOfAnalysis.objects.select_related('batch', 'qc_result', 'quality_approved_by').all()
        status = self.request.GET.get('status')
        if status:
            qs = qs.filter(status=status)
        else:
            qs = qs.filter(status=CertificateOfAnalysis.Status.PENDING_APPROVAL)
        return qs

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


class COAReviewDetailView(OpsRequiredMixin, DetailView):
    model = CertificateOfAnalysis
    template_name = 'ops/coa_review_detail.html'
    context_object_name = 'coa'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['lab_documents'] = Document.objects.filter(batch=self.object.batch, doc_type=Document.DocType.LAB_REPORT)
        return ctx

    def post(self, request, *args, **kwargs):
        from django.contrib import messages
        from apps.compliance.services import publish_coa

        coa = self.get_object()
        if request.POST.get('action') == 'approve':
            try:
                publish_coa(coa, released_by=request.user)
                messages.success(request, 'CoA published to buyers.')
            except ValueError as exc:
                messages.error(request, str(exc))
        return redirect(self.request.path)


class EUDRCaseListView(OpsRequiredMixin, ListView):
    model = DueDiligenceCase
    template_name = 'ops/eudr_list.html'
    context_object_name = 'cases'
    paginate_by = 25

    def get_queryset(self):
        qs = DueDiligenceCase.objects.select_related('batch', 'approved_by').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'] = DueDiligenceCase.Status.choices
        ctx['current_status'] = self.request.GET.get('status', '')
        return ctx


class EUDRCaseDetailView(OpsRequiredMixin, DetailView):
    model = DueDiligenceCase
    template_name = 'ops/eudr_detail.html'
    context_object_name = 'case'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        case = self.object
        ctx['lineage'] = list(case.batch.intake_lineage.select_related(
            'harvest_intake', 'harvest_intake__origin_zone', 'harvest_intake__collector_group'
        ))
        ctx['evidence'] = case.evidence.all()
        ctx['risk_assessments'] = case.risk_assessments.all()
        ctx['mitigation_actions'] = case.mitigation_actions.all()
        ctx['statement_references'] = case.statement_references.all()
        return ctx

    def post(self, request, *args, **kwargs):
        from apps.compliance import services

        case = self.get_object()
        action = request.POST.get('action')
        try:
            if action == 'check':
                services.run_completeness_check(case)
                messages.info(request, 'Completeness check completed.')
            elif action == 'assess_risk':
                services.evaluate_risk(case, user=request.user)
                messages.info(request, 'Risk assessment recorded.')
            elif action == 'approve':
                services.approve_case(case, request.user)
                messages.success(request, 'Case approved.')
            elif action == 'reject':
                services.reject_case(case, request.user, request.POST.get('reason', ''))
                messages.warning(request, 'Case rejected.')
            elif action == 'record_submission':
                ref = request.POST.get('dds_reference')
                if not ref:
                    messages.error(request, 'DDS reference required.')
                else:
                    services.record_submission(case, request.user, ref, request.POST.get('submission_date') or None)
                    messages.success(request, 'External submission recorded.')
        except ValueError as exc:
            messages.error(request, str(exc))
        return redirect(self.request.path)


class IntakeListView(OpsRequiredMixin, ListView):
    """Harvest intakes, the first record the business actually creates itself."""

    model = HarvestIntake
    template_name = 'ops/intake_list.html'
    context_object_name = 'intakes'
    paginate_by = 25

    def get_queryset(self):
        qs = HarvestIntake.objects.select_related(
            'collector_group', 'origin_zone'
        ).order_by('-intake_date', '-intake_reference')
        status = self.request.GET.get('status')
        q = self.request.GET.get('q')
        if status:
            qs = qs.filter(status=status)
        if q:
            qs = qs.filter(intake_reference__icontains=q)
        return qs

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


class IntakeFormContextMixin:
    """Shared context for the create and edit forms."""

    template_name = 'ops/intake_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        # Which zone each collector group draws from, so the form can fill the
        # zone in when a group is chosen. Kept in a data attribute rather than
        # injected into a script block.
        ctx['group_zones'] = json.dumps({
            str(group.pk): str(group.origin_zone_id)
            for group in CollectorGroup.objects.exclude(origin_zone__isnull=True)
        })
        return ctx


class IntakeCreateView(IntakeFormContextMixin, OpsRequiredMixin, CreateView):
    model = HarvestIntake
    form_class = HarvestIntakeForm

    def get_initial(self):
        initial = super().get_initial()
        initial['intake_reference'] = suggested_intake_reference()
        initial['intake_date'] = timezone.localdate()
        initial['status'] = HarvestIntake.Status.RECEIVED
        officer = self.request.user.full_name or self.request.user.email
        if officer:
            initial['receiving_officer'] = officer
        return initial

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New harvest intake'
        ctx['submit_label'] = 'Record intake'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(
            self.request, f"Intake {self.object.intake_reference} recorded."
        )
        return response

    def get_success_url(self):
        return reverse('ops:intake_list')


class IntakeUpdateView(IntakeFormContextMixin, OpsRequiredMixin, UpdateView):
    model = HarvestIntake
    form_class = HarvestIntakeForm

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = f"Correct intake {self.object.intake_reference}"
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(
            self.request, f"Intake {self.object.intake_reference} updated."
        )
        return response

    def get_success_url(self):
        return reverse('ops:intake_list')


class GuideIndexView(OpsRequiredMixin, BaseGuideIndexView):
    template_name = 'guides/index_ops.html'


class GuideDetailView(OpsRequiredMixin, BaseGuideDetailView):
    template_name = 'guides/detail_ops.html'


# ---------------------------------------------------------------------------
# Compliance registers
#
# Facility, origin zone and collector group used to be editable only in the
# Django administration area, which left the platform unable to register a new
# supply site, zone or group from the portal. These screens close that gap. The
# admin registrations stay: the portal and the admin are two write paths to the
# same records, and the forms here mirror the admin's fields.


class FacilityListView(OpsRequiredMixin, ListView):
    model = Facility
    template_name = 'ops/facility_list.html'
    context_object_name = 'facilities'
    paginate_by = 25

    def get_queryset(self):
        qs = Facility.objects.all().order_by('name')
        q = self.request.GET.get('q')
        active = self.request.GET.get('active')
        if q:
            qs = qs.filter(name__icontains=q)
        if active == '1':
            qs = qs.filter(is_active=True)
        elif active == '0':
            qs = qs.filter(is_active=False)
        return qs

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['current_q'] = self.request.GET.get('q', '')
        ctx['current_active'] = self.request.GET.get('active', '')
        return ctx


class FacilityFormContextMixin:
    model = Facility
    form_class = FacilityForm
    template_name = 'ops/register_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['cancel_url'] = reverse('ops:facility_list')
        return ctx


class FacilityCreateView(FacilityFormContextMixin, OpsRequiredMixin, CreateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New facility'
        ctx['submit_label'] = 'Create facility'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, f"Facility {self.object.name} created.")
        return response

    def get_success_url(self):
        return reverse('ops:facility_list')


class FacilityUpdateView(FacilityFormContextMixin, OpsRequiredMixin, UpdateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = f"Edit facility {self.object.name}"
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, f"Facility {self.object.name} updated.")
        return response

    def get_success_url(self):
        return reverse('ops:facility_list')


def apply_zone_verification(zone, user, previous_status=None):
    """Record who verified or rejected a zone, and when.

    A zone moved back to Unverified has its stamp cleared, so the record and the
    audit agree. An unchanged status keeps the original verifier and date — a
    later edit of an unrelated field must not silently re-attribute the check.
    """
    if zone.verification_status == OriginZone.VerificationStatus.UNVERIFIED:
        zone.verified_by = None
        zone.verified_at = None
    elif previous_status != zone.verification_status or zone.verified_at is None:
        zone.verified_by = user
        zone.verified_at = timezone.now()


class OriginZoneListView(OpsRequiredMixin, ListView):
    model = OriginZone
    template_name = 'ops/origin_zone_list.html'
    context_object_name = 'zones'
    paginate_by = 25

    def get_queryset(self):
        qs = OriginZone.objects.select_related('facility').order_by('zone_code')
        q = self.request.GET.get('q')
        status = self.request.GET.get('status')
        if q:
            qs = qs.filter(zone_code__icontains=q)
        if status:
            qs = qs.filter(verification_status=status)
        return qs

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


class OriginZoneFormContextMixin:
    model = OriginZone
    form_class = OriginZoneForm
    template_name = 'ops/register_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['cancel_url'] = reverse('ops:origin_zone_list')
        ctx['show_zone_map'] = True
        ctx['tile_url'] = browser_tile_url()
        zone = getattr(self, 'object', None)
        geometry = getattr(zone, 'geometry', None) if zone is not None else None
        ctx['zone_has_geometry'] = bool(geometry and geometry.get('coordinates'))
        ctx['zone_geometry_json'] = json.dumps(geometry) if ctx['zone_has_geometry'] else ''
        return ctx

    def form_valid(self, form):
        apply_zone_verification(
            form.instance,
            self.request.user,
            previous_status=form.initial.get('verification_status'),
        )
        return super().form_valid(form)


class OriginZoneCreateView(OriginZoneFormContextMixin, OpsRequiredMixin, CreateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New origin zone'
        ctx['submit_label'] = 'Create zone'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(
            self.request,
            f"Origin zone {self.object.zone_code} created. "
            "The map below is a view of the stored polygon, not a check of it.",
        )
        return response

    def get_success_url(self):
        return reverse('ops:origin_zone_update', kwargs={'pk': self.object.pk})


class OriginZoneUpdateView(OriginZoneFormContextMixin, OpsRequiredMixin, UpdateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = f"Edit origin zone {self.object.zone_code}"
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(
            self.request, f"Origin zone {self.object.zone_code} updated."
        )
        return response

    def get_success_url(self):
        return reverse('ops:origin_zone_update', kwargs={'pk': self.object.pk})


class CollectorGroupListView(OpsRequiredMixin, ListView):
    model = CollectorGroup
    template_name = 'ops/collector_group_list.html'
    context_object_name = 'groups'
    paginate_by = 25

    def get_queryset(self):
        qs = CollectorGroup.objects.select_related('origin_zone').order_by('name')
        q = self.request.GET.get('q')
        if q:
            qs = qs.filter(name__icontains=q)
        return qs

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


class CollectorGroupFormContextMixin:
    model = CollectorGroup
    form_class = CollectorGroupForm
    template_name = 'ops/register_form.html'

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['cancel_url'] = reverse('ops:collector_group_list')
        return ctx


class CollectorGroupCreateView(CollectorGroupFormContextMixin, OpsRequiredMixin, CreateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New collector group'
        ctx['submit_label'] = 'Create group'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, f"Collector group {self.object.name} created.")
        return response

    def get_success_url(self):
        return reverse('ops:collector_group_list')


class CollectorGroupUpdateView(CollectorGroupFormContextMixin, OpsRequiredMixin, UpdateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = f"Edit collector group {self.object.name}"
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, f"Collector group {self.object.name} updated.")
        return response

    def get_success_url(self):
        return reverse('ops:collector_group_list')


# ---------------------------------------------------------------------------
# Records that belong to a due-diligence case
#
# Mitigation actions, EUDR evidence and external-submission references used to
# be creatable/editable only in admin (or, for evidence, not at all from the
# portal). These screens are reached from the case detail and return to it.


class CaseChildMixin(OpsRequiredMixin):
    template_name = 'ops/register_form.html'

    def get_case(self):
        return get_object_or_404(DueDiligenceCase, pk=self.kwargs['case_pk'])

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['case'] = self.get_case()
        ctx['cancel_url'] = reverse(
            'ops:eudr_detail', kwargs={'pk': self.kwargs['case_pk']}
        )
        return ctx

    def get_success_url(self):
        return reverse('ops:eudr_detail', kwargs={'pk': self.kwargs['case_pk']})


class EUDREvidenceCreateView(CaseChildMixin, CreateView):
    model = EUDREvidence
    form_class = EUDREvidenceForm

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Attach evidence — {self.get_case().batch.batch_reference}"
        )
        ctx['submit_label'] = 'Attach evidence'
        return ctx

    def form_valid(self, form):
        form.instance.case = self.get_case()
        response = super().form_valid(form)
        # Adding evidence changes the evidence completeness result, so re-run it
        # exactly as the API does.
        services.run_completeness_check(self.object.case)
        messages.success(
            self.request,
            "Evidence attached. The case's completeness check has been re-run.",
        )
        return response


class EUDREvidenceUpdateView(CaseChildMixin, UpdateView):
    model = EUDREvidence
    form_class = EUDREvidenceForm

    def get_queryset(self):
        return EUDREvidence.objects.filter(case_id=self.kwargs['case_pk'])

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Edit evidence — {self.get_case().batch.batch_reference}"
        )
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        services.run_completeness_check(self.object.case)
        messages.success(self.request, 'Evidence updated.')
        return response


class MitigationActionCreateView(CaseChildMixin, CreateView):
    model = MitigationAction
    form_class = MitigationActionForm

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Add mitigation action — {self.get_case().batch.batch_reference}"
        )
        ctx['submit_label'] = 'Add action'
        return ctx

    def form_valid(self, form):
        form.instance.case = self.get_case()
        response = super().form_valid(form)
        messages.success(self.request, 'Mitigation action added.')
        return response


class MitigationActionUpdateView(CaseChildMixin, UpdateView):
    model = MitigationAction
    form_class = MitigationActionForm

    def get_queryset(self):
        return MitigationAction.objects.filter(case_id=self.kwargs['case_pk'])

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Edit mitigation action — {self.get_case().batch.batch_reference}"
        )
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, 'Mitigation action updated.')
        return response


class StatementReferenceUpdateView(CaseChildMixin, UpdateView):
    model = DueDiligenceStatementReference
    form_class = StatementReferenceForm

    def get_queryset(self):
        return DueDiligenceStatementReference.objects.filter(
            case_id=self.kwargs['case_pk']
        )

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Edit submission reference — {self.get_case().batch.batch_reference}"
        )
        ctx['submit_label'] = 'Save changes'
        return ctx

    def form_valid(self, form):
        response = super().form_valid(form)
        messages.success(self.request, 'Submission reference updated.')
        return response


# ---------------------------------------------------------------------------
# Product specifications
#
# A specification is the set of limits every QC result is judged against. The
# portal can create and edit a specification and its parameters together, but
# the **approval half is held**: status, is_current, approved_by and approved_at
# are not on the form, so a portal-created specification is a draft and cannot
# be approved here. See apps/ops/forms.py for the reasoning.


class SpecificationListView(OpsRequiredMixin, ListView):
    model = ProductSpecification
    template_name = 'ops/specification_list.html'
    context_object_name = 'specs'
    paginate_by = 25

    def get_queryset(self):
        qs = ProductSpecification.objects.prefetch_related('parameters').order_by(
            'product', '-version'
        )
        product = self.request.GET.get('product')
        status = self.request.GET.get('status')
        if product:
            qs = qs.filter(product__icontains=product)
        if status:
            qs = qs.filter(status=status)
        return qs

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


class SpecificationFormContextMixin:
    model = ProductSpecification
    form_class = SpecificationForm
    template_name = 'ops/specification_form.html'

    def get_formset(self, data=None):
        instance = self.object if self.object is not None else ProductSpecification()
        return SpecParameterFormSet(data, instance=instance, prefix='params')

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        if 'formset' not in ctx:
            ctx['formset'] = self.get_formset()
        ctx['cancel_url'] = reverse('ops:specification_list')
        spec = getattr(self, 'object', None)
        ctx['editing_approved'] = bool(
            spec is not None
            and spec.pk
            and spec.status != ProductSpecification.Status.DRAFT
        )
        return ctx

    def forms_valid(self, form, formset):
        self.object = form.save(commit=False)
        if self.object._state.adding:
            # The approval fields are not on the form; a portal-created spec is
            # always a draft, never current.
            self.object.status = ProductSpecification.Status.DRAFT
            self.object.is_current = False
        self.object.save()
        formset.instance = self.object
        formset.save()
        messages.success(
            self.request,
            f"Specification {self.object.product} v{self.object.version} saved.",
        )
        return redirect(reverse('ops:specification_list'))

    def forms_invalid(self, form, formset):
        return self.render_to_response(
            self.get_context_data(form=form, formset=formset)
        )


class SpecificationCreateView(SpecificationFormContextMixin, OpsRequiredMixin, CreateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = 'New product specification'
        ctx['submit_label'] = 'Create specification'
        return ctx

    def post(self, request, *args, **kwargs):
        self.object = None
        form = self.get_form()
        formset = self.get_formset(request.POST)
        if form.is_valid() and formset.is_valid():
            return self.forms_valid(form, formset)
        return self.forms_invalid(form, formset)


class SpecificationUpdateView(SpecificationFormContextMixin, OpsRequiredMixin, UpdateView):
    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx['page_title'] = (
            f"Edit specification {self.object.product} v{self.object.version}"
        )
        ctx['submit_label'] = 'Save changes'
        return ctx

    def post(self, request, *args, **kwargs):
        self.object = self.get_object()
        form = self.get_form()
        formset = self.get_formset(request.POST)
        if form.is_valid() and formset.is_valid():
            return self.forms_valid(form, formset)
        return self.forms_invalid(form, formset)