from __future__ import annotations

import json
from typing import Any, Dict

from django.http import HttpRequest, HttpResponse
from django.shortcuts import redirect
from django.views import View
from django.views.generic.detail import SingleObjectMixin
from inertia import render

from labs.models import CertificateIssuance
from labs.tasks.certificate import generate_certificate_issuance_pdf_task

from .base import PermissionRequiredAdminMixin


class CertificateIssuanceDetailView(
    PermissionRequiredAdminMixin, SingleObjectMixin, View
):
    model = CertificateIssuance
    permission_required = "labs.view_certificateissuance"
    component = "certificate-issuances/Detail"

    def get_queryset(self):
        return self.model._default_manager.select_related(
            "cert_type", "recipient", "recipient__user"
        )

    def serialize_issuance(self, issuance: CertificateIssuance) -> Dict[str, Any]:
        has_file = bool(issuance.file_object_key)
        return {
            "id": issuance.id,
            "cert_number": issuance.cert_number,
            "issued_at": issuance.issued_at.isoformat(),
            "source": {
                "value": issuance.source,
                "label": CertificateIssuance.Source(issuance.source).name,
            },
            "tlms_course_id": issuance.tlms_course_id,
            "cert_type": {
                "id": issuance.cert_type_id,
                "name": issuance.cert_type.name,
                "short_name": issuance.cert_type.short_name,
            },
            "cert_type_has_template": bool(issuance.cert_type.template),
            "recipient": {
                "id": issuance.recipient_id,
                "first_name": issuance.recipient.first_name,
                "last_name": issuance.recipient.last_name,
                "email": issuance.recipient.email,
                "email_verified": issuance.recipient.email_verified,
                "country": issuance.recipient.country,
                "company_name": issuance.recipient.company_name,
                "user_id": issuance.recipient.user_id,
                "external_user_info": issuance.recipient.external_user_info or {},
            },
            "file": {
                "storage_provider": issuance.file_storage_provider,
                "bucket": issuance.file_bucket,
                "object_key": issuance.file_object_key,
                "content_type": issuance.file_content_type,
                "status": "ready" if has_file else "pending",
                "public_url": issuance.get_file_public_url() if has_file else None,
            },
            "cert_snapshot": issuance.cert_snapshot or {},
            "cert_snapshot_pretty": json.dumps(
                issuance.cert_snapshot or {}, ensure_ascii=False, indent=2, sort_keys=True
            ),
        }

    def get(self, request: HttpRequest, pk: int) -> HttpResponse:
        self.object = self.get_object()
        return render(
            request,
            self.component,
            {
                "issuance": self.serialize_issuance(self.object),
            },
        )


class CertificateIssuanceRegeneratePdfView(PermissionRequiredAdminMixin, View):
    permission_required = "labs.change_certificateissuance"

    def post(self, request: HttpRequest, pk: int) -> HttpResponse:
        issuance = (
            CertificateIssuance.objects.select_related("cert_type", "recipient")
            .filter(id=pk)
            .first()
        )
        if not issuance:
            request.session["flash_error"] = "Certificate issuance not found."
            return redirect("/admin/certificates/")

        if not issuance.cert_type.template:
            request.session["flash_error"] = (
                "Cannot regenerate PDF: certificate type template is empty."
            )
            return redirect(f"/admin/certificate-issuances/{pk}/")

        if issuance.source == CertificateIssuance.Source.TLMS:
            request.session["flash_error"] = (
                "Cannot regenerate PDF for TLMS-synced issuances."
            )
            return redirect(f"/admin/certificate-issuances/{pk}/")

        generate_certificate_issuance_pdf_task.apply_async(args=[issuance.id])
        request.session["flash_success"] = "PDF regeneration task queued."

        next_url = request.POST.get("next", "")
        if next_url.startswith("/admin/"):
            return redirect(next_url)
        return redirect(f"/admin/certificate-issuances/{pk}/")