from django import forms
from django.core.exceptions import ValidationError
from django.utils.translation import gettext_lazy as _

from .models import User

def validate_login(value):
    if len(User.objects.filter(login=value)) == 0:
        raise ValidationError(
            _("Ce login n'existe pas"),
            params={'value': value},
        )
        
class UserForm(forms.Form):
    login = forms.CharField(label="Login", max_length=10, validators=[validate_login])
    diff = forms.DecimalField(initial=10,label="Nombre d'atomes", min_value=10, max_value=100, decimal_places=0)