from rest_framework import serializers
from .models import CustomUser

class UserSerializer(serializers.ModelSerializer):
    assigned_vehicle = serializers.SerializerMethodField()
    assigned_crane = serializers.SerializerMethodField()

    class Meta:
        model = CustomUser
        fields = ['id', 'email', 'first_name', 'last_name', 'is_serviser', 'is_kupac', 'is_team_member', 'telefon', 'oib', 'occupation', 'residence', 'work_position', 'client_profile', 'assigned_vehicle', 'assigned_crane']
        read_only_fields = ['id', 'email']
        extra_kwargs = {
            'first_name': {'required': True, 'allow_blank': False}
        }

    def _get_assigned_assets(self, obj):
        return obj.assigned_vehicles.all()

    def _serialize_asset(self, vehicle):
        if not vehicle:
            return None
        return {
            'id': vehicle.id,
            'asset_type': vehicle.asset_type,
            'registration_number': vehicle.registration_number,
            'make': vehicle.make,
            'model': vehicle.model,
            'current_mileage': vehicle.current_mileage,
            'service_interval_km': vehicle.service_interval_km,
        }

    def get_assigned_vehicle(self, obj):
        assigned = self._get_assigned_assets(obj)
        vehicle = assigned.filter(asset_type='vehicle').first() or assigned.first()
        return self._serialize_asset(vehicle)

    def get_assigned_crane(self, obj):
        assigned = self._get_assigned_assets(obj)
        crane = assigned.filter(asset_type='crane').first() or assigned.first()
        return self._serialize_asset(crane)
    
    def validate(self, data):
        """
        Provodi poslovnu logiku na razini serializer-a.
        """
        is_kupac = data.get('is_kupac')
        client_profile = data.get('client_profile')

        # Logika: Ako je kupac, mora imati profil
        if is_kupac and not client_profile:
            raise serializers.ValidationError({
                "client_profile": "Korisnik označen kao kupac mora imati dodijeljen klijentski profil."
            })

        # Logika: Ako ima profil, trebao bi biti kupac (opcionalno, ali preporučeno)
        if client_profile and not is_kupac:
            raise serializers.ValidationError({
                "is_kupac": "Korisnik s dodijeljenim klijentskim profilom mora biti označen kao kupac."
            })

        return data


class TeamMemberSerializer(serializers.ModelSerializer):
    full_name = serializers.SerializerMethodField()

    class Meta:
        model = CustomUser
        fields = ['id', 'email', 'full_name', 'is_team_member']
        read_only_fields = fields

    def get_full_name(self, obj):
        return obj.get_full_name() or obj.email