from ares_util.ares import validate_czech_company_id
from ares_util.exceptions import InvalidCompanyIDError
from crispy_forms import helper
from crispy_forms import layout
from django import forms
from django.core.exceptions import ValidationError
from django.forms import fields
from django.utils.translation import gettext_lazy as _

from . import models


class CreateSubjectForm(forms.Form):
    error_messages = {
        'invalid_cin': _('Your provided CIN is not correct.'),
        'already_existing': _('Subject with provided CIN already exists.'),
    }
    cin = fields.CharField(
        label=_('CIN'),
        max_length=8,
        help_text=_('Enter the subject CIN, rest will be generated automatically'),
    )

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.helper = helper.FormHelper()
        self.helper.form_action = 'subjects:create'
        self.helper.form_method = 'post'
        self.helper.add_input(layout.Submit('submit', _('Add')))

    def clean_cin(self):
        cin = self.cleaned_data.get('cin')
        try:
            validate_czech_company_id(cin)
        except InvalidCompanyIDError:
            raise ValidationError(self.error_messages['invalid_cin'])

        try:
            models.Subject.objects.get(id=cin)
        except models.Subject.DoesNotExist:
            return cin

        raise ValidationError(self.error_messages['already_existing'])