"""
Auction Views für Biet-System
"""

from django.shortcuts import render, get_object_or_404, redirect
from django.contrib.auth.decorators import login_required
from django.contrib import messages
from django.http import JsonResponse
from django.utils import timezone
from django.db.models import Q, Count, Max
from django.core.paginator import Paginator
from django.views.decorators.http import require_POST
from django.views.decorators.csrf import csrf_exempt
from .models import Auction, Bid, AuctionWatch, AuctionAnalytics
from .forms import AuctionForm, BidForm
import json


def auction_list(request):
    """Liste aller Auktionen"""
    # Filter
    status_filter = request.GET.get('status', '')
    fursuit_type_filter = request.GET.get('fursuit_type', '')
    search_query = request.GET.get('search', '')
    
    auctions = Auction.objects.select_related('created_by', 'winner').prefetch_related('bids')
    
    if status_filter:
        auctions = auctions.filter(status=status_filter)
    
    if fursuit_type_filter:
        auctions = auctions.filter(fursuit_type=fursuit_type_filter)
    
    if search_query:
        auctions = auctions.filter(
            Q(title__icontains=search_query) |
            Q(description__icontains=search_query) |
            Q(character_description__icontains=search_query)
        )
    
    # Nur aktive Auktionen anzeigen (außer für Admins)
    if not request.user.is_staff:
        auctions = auctions.filter(status='active')
    
    # Sortierung
    sort_by = request.GET.get('sort', '-created_at')
    auctions = auctions.order_by(sort_by)
    
    # Pagination
    paginator = Paginator(auctions, 12)
    page_number = request.GET.get('page')
    page_obj = paginator.get_page(page_number)
    
    # Statistiken
    total_auctions = auctions.count()
    active_auctions = auctions.filter(status='active').count()
    total_bids = sum(auction.total_bids for auction in page_obj)
    
    context = {
        'page_obj': page_obj,
        'status_filter': status_filter,
        'fursuit_type_filter': fursuit_type_filter,
        'search_query': search_query,
        'sort_by': sort_by,
        'total_auctions': total_auctions,
        'active_auctions': active_auctions,
        'total_bids': total_bids,
        'status_choices': Auction.AUCTION_STATUS_CHOICES,
        'fursuit_type_choices': Auction._meta.get_field('fursuit_type').choices,
    }
    
    return render(request, 'auction/auction_list.html', context)


def auction_detail(request, auction_id):
    """Auktion Detail-Ansicht"""
    auction = get_object_or_404(Auction, id=auction_id)
    
    # View Count erhöhen
    auction.view_count += 1
    auction.save()
    
    # Analytics aktualisieren
    analytics, created = AuctionAnalytics.objects.get_or_create(auction=auction)
    analytics.total_views += 1
    analytics.save()
    
    # Bid History
    bid_history = auction.bids.select_related('bidder').order_by('-created_at')[:10]
    
    # User's current bid
    user_bid = None
    if request.user.is_authenticated:
        user_bid = auction.bids.filter(bidder=request.user).order_by('-amount').first()
    
    # Watchlist Status
    is_watching = False
    if request.user.is_authenticated:
        is_watching = auction.watchers.filter(user=request.user).exists()
    
    # Similar Auctions
    similar_auctions = Auction.objects.filter(
        fursuit_type=auction.fursuit_type,
        status='active'
    ).exclude(id=auction.id)[:3]
    
    context = {
        'auction': auction,
        'bid_history': bid_history,
        'user_bid': user_bid,
        'is_watching': is_watching,
        'similar_auctions': similar_auctions,
        'bid_form': BidForm() if auction.is_active else None,
    }
    
    return render(request, 'auction/auction_detail.html', context)


@login_required
def auction_create(request):
    """Neue Auktion erstellen"""
    if request.method == 'POST':
        form = AuctionForm(request.POST, request.FILES)
        if form.is_valid():
            auction = form.save(commit=False)
            auction.created_by = request.user
            
            # Start- und Endzeit setzen
            if not auction.start_time:
                auction.start_time = timezone.now()
            if not auction.end_time:
                auction.end_time = auction.start_time + timezone.timedelta(days=auction.duration_days)
            
            auction.save()
            
            messages.success(request, 'Auktion erfolgreich erstellt!')
            return redirect('auction:auction_detail', auction_id=auction.id)
    else:
        form = AuctionForm()
    
    context = {
        'form': form,
        'title': 'Neue Auktion erstellen',
    }
    
    return render(request, 'auction/auction_form.html', context)


@login_required
def auction_edit(request, auction_id):
    """Auktion bearbeiten"""
    auction = get_object_or_404(Auction, id=auction_id, created_by=request.user)
    
    if request.method == 'POST':
        form = AuctionForm(request.POST, request.FILES, instance=auction)
        if form.is_valid():
            form.save()
            messages.success(request, 'Auktion erfolgreich aktualisiert!')
            return redirect('auction:auction_detail', auction_id=auction.id)
    else:
        form = AuctionForm(instance=auction)
    
    context = {
        'form': form,
        'auction': auction,
        'title': 'Auktion bearbeiten',
    }
    
    return render(request, 'auction/auction_form.html', context)


@login_required
@require_POST
def place_bid(request, auction_id):
    """Gebot platzieren"""
    auction = get_object_or_404(Auction, id=auction_id)
    
    if not auction.is_active:
        return JsonResponse({'error': 'Auktion ist nicht aktiv'}, status=400)
    
    form = BidForm(request.POST)
    if form.is_valid():
        amount = form.cleaned_data['amount']
        
        try:
            bid = auction.place_bid(request.user, amount)
            
            return JsonResponse({
                'success': True,
                'bid_id': str(bid.id),
                'amount': float(bid.amount),
                'current_bid': float(auction.current_bid),
                'total_bids': auction.total_bids,
                'message': 'Gebot erfolgreich platziert!'
            })
        except ValueError as e:
            return JsonResponse({'error': str(e)}, status=400)
    else:
        return JsonResponse({'error': 'Ungültige Eingabe'}, status=400)


@login_required
@require_POST
def toggle_watch(request, auction_id):
    """Auktion zur Watchlist hinzufügen/entfernen"""
    auction = get_object_or_404(Auction, id=auction_id)
    
    watch, created = AuctionWatch.objects.get_or_create(
        user=request.user,
        auction=auction
    )
    
    if not created:
        watch.delete()
        is_watching = False
        message = 'Von Watchlist entfernt'
    else:
        is_watching = True
        message = 'Zur Watchlist hinzugefügt'
    
    return JsonResponse({
        'success': True,
        'is_watching': is_watching,
        'message': message
    })


@login_required
def my_auctions(request):
    """Eigene Auktionen"""
    auctions = Auction.objects.filter(created_by=request.user).order_by('-created_at')
    
    # Filter
    status_filter = request.GET.get('status', '')
    if status_filter:
        auctions = auctions.filter(status=status_filter)
    
    context = {
        'auctions': auctions,
        'status_choices': Auction.AUCTION_STATUS_CHOICES,
        'status_filter': status_filter,
    }
    
    return render(request, 'auction/my_auctions.html', context)


@login_required
def my_bids(request):
    """Eigene Gebote"""
    bids = Bid.objects.filter(bidder=request.user).select_related('auction').order_by('-created_at')
    
    context = {
        'bids': bids,
    }
    
    return render(request, 'auction/my_bids.html', context)


@login_required
def watchlist(request):
    """Watchlist"""
    watched_auctions = Auction.objects.filter(
        watchers__user=request.user
    ).order_by('-created_at')
    
    context = {
        'watched_auctions': watched_auctions,
    }
    
    return render(request, 'auction/watchlist.html', context)


# API Views für AJAX
@csrf_exempt
def auction_api(request, auction_id):
    """API für Auktion-Details"""
    auction = get_object_or_404(Auction, id=auction_id)
    
    data = {
        'id': str(auction.id),
        'title': auction.title,
        'description': auction.description,
        'current_bid': float(auction.current_bid) if auction.current_bid else None,
        'starting_bid': float(auction.starting_bid),
        'reserve_price': float(auction.reserve_price) if auction.reserve_price else None,
        'status': auction.status,
        'is_active': auction.is_active,
        'time_remaining': auction.time_remaining_formatted,
        'total_bids': auction.total_bids,
        'total_bidders': auction.total_bidders,
        'winner': auction.winner.username if auction.winner else None,
        'created_at': auction.created_at.isoformat(),
        'end_time': auction.end_time.isoformat(),
    }
    
    return JsonResponse(data)


@csrf_exempt
def bid_history_api(request, auction_id):
    """API für Bid-History"""
    auction = get_object_or_404(Auction, id=auction_id)
    bids = auction.bids.select_related('bidder').order_by('-created_at')[:20]
    
    bid_list = []
    for bid in bids:
        bid_list.append({
            'id': str(bid.id),
            'bidder': bid.bidder.username,
            'amount': float(bid.amount),
            'created_at': bid.created_at.isoformat(),
        })
    
    return JsonResponse({'bids': bid_list})


@csrf_exempt
def place_bid_api(request, auction_id):
    """API für Gebot platzieren"""
    if request.method != 'POST':
        return JsonResponse({'error': 'Nur POST erlaubt'}, status=405)
    
    if not request.user.is_authenticated:
        return JsonResponse({'error': 'Nicht eingeloggt'}, status=401)
    
    try:
        data = json.loads(request.body)
        amount = float(data.get('amount', 0))
        
        auction = get_object_or_404(Auction, id=auction_id)
        
        if not auction.is_active:
            return JsonResponse({'error': 'Auktion ist nicht aktiv'}, status=400)
        
        bid = auction.place_bid(request.user, amount)
        
        return JsonResponse({
            'success': True,
            'bid_id': str(bid.id),
            'amount': float(bid.amount),
            'current_bid': float(auction.current_bid),
            'total_bids': auction.total_bids,
        })
        
    except (json.JSONDecodeError, ValueError) as e:
        return JsonResponse({'error': str(e)}, status=400)


def auction_analytics(request, auction_id):
    """Auktion Analytics"""
    auction = get_object_or_404(Auction, id=auction_id)
    analytics = get_object_or_404(AuctionAnalytics, auction=auction)
    
    # Bid Distribution
    bid_distribution = auction.bids.extra(
        select={'hour': "EXTRACT(hour FROM created_at)"}
    ).values('hour').annotate(count=Count('id')).order_by('hour')
    
    # Top Bidders
    top_bidders = auction.bids.values('bidder__username').annotate(
        total_bids=Count('id'),
        max_bid=Max('amount')
    ).order_by('-max_bid')[:5]
    
    context = {
        'auction': auction,
        'analytics': analytics,
        'bid_distribution': bid_distribution,
        'top_bidders': top_bidders,
    }
    
    return render(request, 'auction/analytics.html', context)