from typing import List

from django import forms
from django.conf import settings

from .value import LocalizedValue
from .widgets import LocalizedFieldWidget



class LocalizedFieldForm(forms.MultiValueField):
    """Form for a localized field, allows editing
    the field in multiple languages."""

    widget = LocalizedFieldWidget
    value_class = LocalizedValue

    def __init__(self, *args, **kwargs):
        """Initializes a new instance of :see:LocalizedFieldForm."""

        fields = []

        for lang_code, _ in settings.LANGUAGES:
            field_options = {'required': False}

            if lang_code == settings.LANGUAGE_CODE:
                field_options['required'] = kwargs.get('required', True)

            field_options['label'] = lang_code
            fields.append(forms.fields.CharField(**field_options))

        super(LocalizedFieldForm, self).__init__(
            fields,
            require_all_fields=False,
            *args, **kwargs
        )
        # set 'required' attribute for each widget separately
        for f, w in zip(self.fields, self.widget.widgets):
            w.is_required = f.required

    def compress(self, value: List[str]) -> value_class:
        """Compresses the values from individual fields
        into a single :see:LocalizedValue instance.

        Arguments:
            value:
                The values from all the widgets.

        Returns:
            A :see:LocalizedValue containing all
            the value in several languages.
        """

        localized_value = self.value_class()

        for (lang_code, _), value in zip(settings.LANGUAGES, value):
            localized_value.set(lang_code, value)

        return localized_value