import django.contrib.auth
import django.core.exceptions
from django import forms
from django.utils.translation import ugettext_lazy as _


class RequiresPasswordMixin(forms.Form):
    error_messages = {
        'password_incorrect': _("Your old password was entered incorrectly. Please enter it again."),
    }

    password = forms.CharField(
        label=_("Password"),
        strip=False,
        widget=forms.PasswordInput,
        required=True
    )

    def __init__(self, *args, **kwargs):
        self.username = kwargs.pop('username')
        super().__init__(*args, **kwargs)

    def clean_password(self):
        self.user_cache = django.contrib.auth.authenticate(username=self.username, password=self.cleaned_data['password'])
        if self.user_cache is None:
            raise forms.ValidationError(
                self.error_messages['password_incorrect'],
                code='password_incorrect',
            )