from ares_util.ares import validate_czech_company_id
from ares_util.exceptions import InvalidCompanyIDError
from crispy_forms import helper, 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"]
        )