import random

from django.db.models import Prefetch
from django.http import JsonResponse
from django.shortcuts import render
from django.views import View
from django.views.generic import DetailView, ListView, TemplateView

from apps.products.models import MainProduct, SubProduct
from apps.projects.models import ProjectBrief

from .forms import ContactForm
from .models import (
    AboutSection,
    ContactSubmission,
    ContactSubmissionAttachment,
    CustomPage,
    FAQEntry,
    HeroSection,
    HomepageSection,
    PageVideo,
)


def _homepage_products_catalog_queryset():
    return (
        MainProduct.objects.filter(is_active=True)
        .prefetch_related(
            Prefetch(
                "sub_products",
                queryset=SubProduct.objects.filter(is_active=True).order_by("order", "name"),
            )
        )
        .order_by("order", "name")
    )


class HomeView(TemplateView):
    template_name = "pages/home.html"

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["hero"] = HeroSection.objects.first()
        ctx["homepage_sections"] = (
            HomepageSection.objects.filter(is_active=True)
            .prefetch_related("items")
            .order_by("order")
        )
        ctx["homepage_products"] = (
            MainProduct.objects.filter(is_active=True, show_on_homepage=True)
            .order_by("homepage_order", "order")
        )
        ctx["homepage_products_catalog"] = _homepage_products_catalog_queryset()
        ctx["website_project_briefs"] = (
            ProjectBrief.objects.filter(show_on_website=True)
            .order_by("-submitted_at")
        )
        return ctx


class AboutView(TemplateView):
    template_name = "pages/about.html"

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["about_sections"] = (
            AboutSection.objects.filter(is_active=True)
            .prefetch_related("items")
            .order_by("order")
        )
        return ctx


class FAQView(ListView):
    model = FAQEntry
    template_name = "pages/faq.html"
    context_object_name = "faq_entries"
    queryset = FAQEntry.objects.filter(is_active=True)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["faq_videos"] = PageVideo.objects.filter(
            page=PageVideo.PAGE_FAQ,
            is_active=True,
        ).order_by("order")
        return ctx


class ContactView(View):
    template_name = "pages/contact.html"

    def _new_captcha(self, request):
        a, b = random.randint(1, 9), random.randint(1, 9)
        request.session["captcha_answer"] = a + b
        return f"{a} + {b}"

    def get(self, request, *args, **kwargs):
        return render(
            request,
            self.template_name,
            {
                "form": ContactForm(),
                "captcha_question": self._new_captcha(request),
                "contact_videos": PageVideo.objects.filter(
                    page=PageVideo.PAGE_CONTACT,
                    is_active=True,
                ).order_by("order"),
            },
        )

    def post(self, request, *args, **kwargs):
        form = ContactForm(
            request.POST,
            file_list=request.FILES.getlist("attachments"),
        )
        expected = request.session.get("captcha_answer")
        captcha_question = self._new_captcha(request)

        captcha_ok = False
        try:
            captcha_ok = int(request.POST.get("captcha_answer", "")) == expected
        except (ValueError, TypeError):
            pass

        if form.is_valid() and captcha_ok:
            submission = form.save()
            for uploaded_file, original_name in form.cleaned_data.get(
                "attachments", []
            ):
                attachment = ContactSubmissionAttachment(
                    submission=submission,
                    original_filename=original_name,
                )
                attachment.file.save(original_name, uploaded_file, save=True)
            return JsonResponse({"success": True})

        errors: dict = {}
        if not captcha_ok:
            errors["captcha"] = ["Incorrect answer — please try again."]
        errors.update(
            {field: [str(e) for e in errs] for field, errs in form.errors.items()}
        )
        return JsonResponse(
            {"success": False, "errors": errors, "captcha_question": captcha_question},
            status=400,
        )


class CustomPageView(DetailView):
    model = CustomPage
    template_name = "pages/custom_page.html"
    context_object_name = "custom_page"
    slug_url_kwarg = "slug"

    def get_queryset(self):
        return CustomPage.objects.filter(is_published=True)

    def get_context_data(self, **kwargs):
        ctx = super().get_context_data(**kwargs)
        ctx["page_sections"] = (
            self.object.sections.filter(is_active=True)
            .prefetch_related("items")
            .order_by("order")
        )
        ctx["homepage_products"] = (
            MainProduct.objects.filter(is_active=True, show_on_homepage=True)
            .order_by("homepage_order", "order")
        )
        ctx["homepage_products_catalog"] = _homepage_products_catalog_queryset()
        return ctx