from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.core.files.storage import default_storage
from django.db import IntegrityError
from django.http import HttpResponse, JsonResponse
from django.shortcuts import get_object_or_404, redirect, render
from django.views.decorators.http import require_POST
from django.views.generic import ListView
from .forms import NoteUploadForm, SeatsForm
from .models import Workshop
from .services import SoldOut, cancel, reserve

class WorkshopListView(ListView):
    template_name = "workshops/list.html"
    context_object_name = "workshops"
    paginate_by = 2
    def get_queryset(self):
        return Workshop.objects.public().select_related("venue")

def detail(request, slug):
    workshop = get_object_or_404(Workshop.objects.public().select_related("venue"), slug=slug)
    return render(request, "workshops/detail.html", {"workshop": workshop, "form": SeatsForm()})

@login_required
@require_POST
def book(request, slug):
    workshop = get_object_or_404(Workshop.objects.public(), slug=slug)
    form = SeatsForm(request.POST)
    if not form.is_valid():
        return render(request, "workshops/detail.html", {"workshop": workshop, "form": form}, status=400)
    try:
        reserve(workshop_id=workshop.pk, user=request.user, seats=form.cleaned_data["seats"])
    except (SoldOut, IntegrityError):
        form.add_error(None, "No reservation made. Check available seats or an existing reservation.")
        workshop.refresh_from_db()
        return render(request, "workshops/detail.html", {"workshop": workshop, "form": form}, status=409)
    messages.success(request, "Reservation saved in this local lab.")
    return redirect(workshop)

@login_required
@require_POST
def cancel_booking(request, pk):
    if not cancel(reservation_id=pk, user=request.user):
        return HttpResponse("Reservation not found", status=404)
    return redirect("workshops:list")

def api_list(request):
    rows = list(Workshop.objects.public().values("slug", "title", "remaining"))
    return JsonResponse({"workshops": rows})

async def health(request):
    return JsonResponse({"status": "local lab"})

@login_required
def upload_note(request):
    form = NoteUploadForm(request.POST or None, request.FILES or None)
    if request.method == "POST" and form.is_valid():
        name = default_storage.save("notes/access.txt", form.cleaned_data["note"])
        return HttpResponse("Stored privately: " + name, content_type="text/plain")
    return render(request, "workshops/upload.html", {"form": form}, status=400 if request.method == "POST" else 200)

def not_found(request, exception):
    return render(request, "404.html", status=404)