from __future__ import unicode_literals

import os

from django import forms
from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.db import models
from django.utils.module_loading import import_string
from django.utils.translation import ugettext_lazy as _

from .classes import Package
from .models import UserLocaleProfile
from .utils import resolve_attribute
from .widgets import DisableableSelectWidget, PlainWidget, TextAreaDiv


class ChoiceForm(forms.Form):
    """
    Form to be used in side by side templates used to add or remove
    items from a many to many field
    """
    def __init__(self, *args, **kwargs):
        choices = kwargs.pop('choices', [])
        label = kwargs.pop('label', _('Selection'))
        help_text = kwargs.pop('help_text', None)
        disabled_choices = kwargs.pop('disabled_choices', ())
        super(ChoiceForm, self).__init__(*args, **kwargs)
        self.fields['selection'].choices = choices
        self.fields['selection'].label = label
        self.fields['selection'].help_text = help_text
        self.fields['selection'].widget.disabled_choices = disabled_choices
        self.fields['selection'].widget.attrs.update(
            {
                'class': 'full-height', 'data-height-difference': '450'
            }
        )

    selection = forms.MultipleChoiceField(widget=DisableableSelectWidget())


class DetailForm(forms.ModelForm):
    def __init__(self, *args, **kwargs):
        self.extra_fields = kwargs.pop('extra_fields', ())
        super(DetailForm, self).__init__(*args, **kwargs)

        for extra_field in self.extra_fields:
            result = resolve_attribute(obj=self.instance, attribute=extra_field['field'])
            label = 'label' in extra_field and extra_field['label'] or None
            # TODO: Add others result types <=> Field types
            if isinstance(result, models.query.QuerySet):
                self.fields[extra_field['field']] = \
                    forms.ModelMultipleChoiceField(
                        queryset=result, label=label)
            else:
                self.fields[extra_field['field']] = forms.CharField(
                    label=extra_field['label'],
                    initial=resolve_attribute(
                        obj=self.instance,
                        attribute=extra_field['field']
                    ),
                    widget=extra_field.get('widget', PlainWidget)
                )

        for field_name, field in self.fields.items():
            self.fields[field_name].widget.attrs.update(
                {'readonly': 'readonly'}
            )


class DynamicFormMixin(object):
    def __init__(self, *args, **kwargs):
        self.schema = kwargs.pop('schema')
        super(DynamicFormMixin, self).__init__(*args, **kwargs)

        widgets = self.schema.get('widgets', {})
        field_order = self.schema.get(
            'field_order', self.schema['fields'].keys()
        )

        for field_name in field_order:
            field_data = self.schema['fields'][field_name]
            field_class = import_string(field_data['class'])
            kwargs = {
                'label': field_data['label'],
                'required': field_data.get('required', True),
                'initial': field_data.get('default', None),
                'help_text': field_data.get('help_text'),
            }
            if widgets and field_name in widgets:
                widget = widgets[field_name]
                kwargs['widget'] = import_string(
                    widget['class']
                )(**widget.get('kwargs', {}))

            kwargs.update(field_data.get('kwargs', {}))
            self.fields[field_name] = field_class(**kwargs)


class DynamicForm(DynamicFormMixin, forms.Form):
    pass


class DynamicModelForm(DynamicFormMixin, forms.ModelForm):
    pass


class FileDisplayForm(forms.Form):
    DIRECTORY = None
    FILENAME = None

    text = forms.CharField(
        label='',
        widget=TextAreaDiv(
            attrs={
                'class': 'full-height scrollable',
                'data-height-difference': 270
            }
        )
    )

    def __init__(self, *args, **kwargs):
        super(FileDisplayForm, self).__init__(*args, **kwargs)
        if self.DIRECTORY or self.FILENAME:
            file_path = os.path.join(
                settings.BASE_DIR, os.sep.join(self.DIRECTORY), self.FILENAME
            )
            with open(file_path) as file_object:
                self.fields['text'].initial = file_object.read()


class FilteredSelectionForm(forms.Form):
    """
    Form to select the from a list of choice filtered by access. Can be
    configure to allow single or multiple selection.
    """
    def __init__(self, *args, **kwargs):
        field_name = kwargs.pop('field_name', None)
        label = kwargs.pop('label', None)
        help_text = kwargs.pop('help_text', None)
        permission = kwargs.pop('permission', None)
        queryset = kwargs.pop('queryset', None)

        if queryset is None:
            model = kwargs.pop('model', None)
            if not model:
                raise ImproperlyConfigured(
                    'Must provide a queryset or a model.'
                )

            queryset = model.objects.all()

        user = kwargs.pop('user', None)
        widget_class = kwargs.pop('widget_class', None)
        widget_attributes = kwargs.pop('widget_attributes', {'size': '10'})

        if not widget_class:
            if kwargs.pop('allow_multiple', False):
                extra_kwargs = {}
                field_class = forms.ModelMultipleChoiceField
                widget_class = forms.widgets.SelectMultiple
            else:
                extra_kwargs = {'empty_label': None}
                field_class = forms.ModelChoiceField
                widget_class = forms.widgets.Select

        super(FilteredSelectionForm, self).__init__(*args, **kwargs)

        if permission:
            queryset = AccessControlList.objects.filter_by_access(
                permission=permission, queryset=queryset, user=user
            )

        self.fields[field_name] = field_class(
            help_text=help_text, label=label,
            queryset=queryset, required=True,
            widget=widget_class(attrs=widget_attributes), **extra_kwargs
        )


class LicenseForm(FileDisplayForm):
    DIRECTORY = ()
    FILENAME = 'LICENSE'


class LocaleProfileForm(forms.ModelForm):
    class Meta:
        fields = ('language', 'timezone')
        model = UserLocaleProfile
        widgets = {
            'language': forms.Select(
                attrs={
                    'class': 'select2'
                }
            ),
            'timezone': forms.Select(
                attrs={
                    'class': 'select2'
                }
            )
        }


class LocaleProfileForm_view(DetailForm):
    class Meta:
        fields = ('language', 'timezone')
        model = UserLocaleProfile


class PackagesLicensesForm(FileDisplayForm):
    def __init__(self, *args, **kwargs):
        super(PackagesLicensesForm, self).__init__(*args, **kwargs)
        self.fields['text'].initial = '\n\n'.join(
            ['{}\n{}'.format(package.label, package.license_text) for package in Package.get_all()]
        )