from django.shortcuts import render, get_object_or_404, redirect
from django.http import HttpResponse, HttpResponseBadRequest
from django.template.loader import render_to_string
from .models import Dinosaur, BackgroundImage
from .forms import DinosaurForm
from .forms import BackgroundImageForm


def is_htmx(request):
    return request.headers.get('HX-Request') == 'true'


def card_list(request):
    cards = Dinosaur.objects.all()
    background = BackgroundImage.get_active() if BackgroundImage.objects.exists() else None
    if is_htmx(request):
        return render(request, 'cards/_cards_list.html', {'cards': cards, 'background': background})
    return render(request, 'cards/list.html', {'cards': cards, 'background': background})


def card_create(request):
    background = BackgroundImage.get_active() if BackgroundImage.objects.exists() else None
    backgrounds = BackgroundImage.objects.all()

    if request.method == 'POST':
        form = DinosaurForm(request.POST, request.FILES)
        if form.is_valid():
            card = form.save()
            if is_htmx(request):
                card_html = render_to_string('cards/_card_item.html', {'card': card, 'background': background}, request=request)
                # Also return an out-of-band fragment to replace/clear the form container
                form_html = render_to_string('cards/_form.html', {'form': DinosaurForm(), 'background': background, 'backgrounds': backgrounds}, request=request)
                oob = f'<div id="htmx-form" hx-swap-oob="true">{form_html}</div>'
                return HttpResponse(card_html + oob)
            return redirect('cards:list')
        else:
            if is_htmx(request):
                # Return the form as an out-of-band fragment so it updates the form container
                form_html = render_to_string('cards/_form.html', {'form': form, 'background': background, 'backgrounds': backgrounds}, request=request)
                oob = f'<div id="htmx-form" hx-swap-oob="true">{form_html}</div>'
                return HttpResponse(oob)
    else:
        form = DinosaurForm()

    return render(request, 'cards/_form.html', {'form': form, 'background': background, 'backgrounds': backgrounds})


def card_edit(request, pk):
    card = get_object_or_404(Dinosaur, pk=pk)
    background = BackgroundImage.get_active() if BackgroundImage.objects.exists() else None
    backgrounds = BackgroundImage.objects.all()
    if request.method == 'POST':
        form = DinosaurForm(request.POST, request.FILES, instance=card)
        if form.is_valid():
            card = form.save()
            if is_htmx(request):
                card_html = render_to_string('cards/_card_item.html', {'card': card, 'background': background}, request=request)
                # Clear the form container via OOB so the edit form disappears after successful save
                oob = '<div id="htmx-form" hx-swap-oob="true"></div>'
                return HttpResponse(card_html + oob)
            return redirect('cards:list')
        else:
            if is_htmx(request):
                form_html = render_to_string('cards/_form.html', {'form': form, 'card': card, 'background': background, 'backgrounds': backgrounds}, request=request)
                oob = f'<div id="htmx-form" hx-swap-oob="true">{form_html}</div>'
                return HttpResponse(oob)
    else:
        form = DinosaurForm(instance=card)

    return render(request, 'cards/_form.html', {'form': form, 'card': card, 'background': background, 'backgrounds': backgrounds})


def card_delete(request, pk):
    card = get_object_or_404(Dinosaur, pk=pk)
    if request.method == 'POST':
        card.delete()
        if is_htmx(request):
            return HttpResponse(status=204)
        return redirect('cards:list')
    return HttpResponseBadRequest('Only POST allowed')


def background_list(request):
    """Show existing backgrounds and provide a form to upload a new one."""
    backgrounds = BackgroundImage.objects.all()
    form = BackgroundImageForm()
    if is_htmx(request):
        return render(request, 'cards/_backgrounds_list.html', {'backgrounds': backgrounds, 'form': form})
    return render(request, 'cards/backgrounds_list.html', {'backgrounds': backgrounds, 'form': form})


def background_create(request):
    if request.method != 'POST':
        return HttpResponseBadRequest('Only POST allowed')

    form = BackgroundImageForm(request.POST, request.FILES)
    if form.is_valid():
        bg = form.save()
        # If marked active, unset others
        if bg.is_active:
            BackgroundImage.objects.exclude(pk=bg.pk).update(is_active=False)
        if is_htmx(request):
            # return the updated list fragment and clear the form OOB
            list_html = render_to_string('cards/_backgrounds_list.html', {'backgrounds': BackgroundImage.objects.all(), 'form': BackgroundImageForm()}, request=request)
            oob = f'<div id="htmx-background-form" hx-swap-oob="true">{render_to_string("cards/_background_form.html", {"form": BackgroundImageForm()}, request=request)}</div>'
            return HttpResponse(list_html + oob)
        return redirect('cards:backgrounds')
    else:
        if is_htmx(request):
            form_html = render_to_string('cards/_background_form.html', {'form': form}, request=request)
            oob = f'<div id="htmx-background-form" hx-swap-oob="true">{form_html}</div>'
            return HttpResponse(oob)
        return render(request, 'cards/backgrounds_list.html', {'backgrounds': BackgroundImage.objects.all(), 'form': form})


def background_activate(request, pk):
    if request.method != 'POST':
        return HttpResponseBadRequest('Only POST allowed')
    bg = get_object_or_404(BackgroundImage, pk=pk)
    BackgroundImage.objects.update(is_active=False)
    bg.is_active = True
    bg.save()
    if is_htmx(request):
        list_html = render_to_string('cards/_backgrounds_list.html', {'backgrounds': BackgroundImage.objects.all(), 'form': BackgroundImageForm()}, request=request)
        return HttpResponse(list_html)
    return redirect('cards:backgrounds')


def background_delete(request, pk):
    if request.method != 'POST':
        return HttpResponseBadRequest('Only POST allowed')
    bg = get_object_or_404(BackgroundImage, pk=pk)
    bg.delete()
    if is_htmx(request):
        return HttpResponse(status=204)
    return redirect('cards:backgrounds')


def preview_card(request, pk):
    """Render a full preview of a card. HTMX loads the modal fragment into #modal-root."""
    card = get_object_or_404(Dinosaur, pk=pk)
    background = BackgroundImage.get_active() if BackgroundImage.objects.exists() else None
    if is_htmx(request):
        return render(request, 'cards/_card_preview.html', {'card': card, 'background': background})
    return render(request, 'cards/preview.html', {'card': card, 'background': background})