import csv
import io
from rest_framework.views import APIView
from rest_framework.response import Response
from rest_framework.permissions import IsAuthenticated
from .models import Player, User
from tournaments.models import Tournament, Registration
from .serializers import PlayerSerializer, PlayerImportDataSerializer

class PlayerListView(APIView):
    """Listet alle Spieler auf."""
    
    def get(self, request):
        players = Player.objects.all()
        serializer = PlayerSerializer(players, many=True)
        return Response(serializer.data)

class PlayerImportView(APIView):
    """
    Importiert Spieler aus Moodle-CSV.
    Erwartet ein POST mit JSON: { "csv_data": "...", "tournament_id": 1 }
    """
    
    def post(self, request):
        serializer = PlayerImportDataSerializer(data=request.data)
        if not serializer.is_valid():
            return Response(serializer.errors, status=400)

        csv_string = serializer.validated_data['csv_data']
        tournament_id = serializer.validated_data['tournament_id']
        
        # Ziel-Turnier finden
        try:
            tournament = Tournament.objects.get(id=tournament_id)
        except Tournament.DoesNotExist:
            return Response({"error": "Turnier nicht gefunden"}, status=404)

        created_count = 0
        existing_count = 0
        
        # CSV parsen (Moodle nutzt Semikolon als Separator)
        csv_file = io.StringIO(csv_string)
        reader = csv.reader(csv_file, delimiter=';')
        
        next(reader, None) # Überspringe Header-Zeile

        for row in reader:
            if len(row) < 5: 
                continue
            
            last_name = row[0].strip()
            first_name = row[1].strip()
            email = row[2].strip()
            # city = row[3] (optional)
            club = row[4].strip() # Die Moodle-Gruppe/Klasse als "Verein"

            if not first_name or not last_name:
                continue

            # 1. Spieler anlegen oder aktualisieren
            player, created = Player.objects.update_or_create(
                defaults={'club': club},
                first_name=first_name,
                last_name=last_name
            )
            
            if created:
                created_count += 1
            else:
                existing_count += 1

            # 2. Spieler ins Turnier registrieren (Registration anlegen)
            Registration.objects.get_or_create(
                tournament=tournament,
                player=player
            )
            
            # Optional: Falls ein Login-Wunsch besteht und keine User existiert:
            if email and not User.objects.filter(username=email).exists():
                User.objects.create_user(
                    username=email, 
                    email=email, 
                    password='schach1234' # Default-Passwort für Moodle-Imports
                )

        return Response({
            "message": "Import abgeschlossen",
            "created_players": created_count,
            "updated_players": existing_count
        }, status=201)