import os
from django import forms
from django.contrib import admin
from django.contrib.admin.widgets import AdminFileWidget
from django.utils.safestring import mark_safe
from django.forms import widgets
from django.urls import reverse
from django.utils.translation import ugettext_lazy as _
from django.template.loader import render_to_string
from django.template import Context
from django.forms.widgets import SelectMultiple
from django.conf import settings

import markdown

from bs4 import BeautifulSoup
from django.utils.module_loading import import_string


class CustomSelectMultiple(SelectMultiple):
    def render_options(self, choices, selected_choices):
        if not selected_choices:
            # there is CreatView and we have no selected choices - render all selected
            render_option = self.render_option
        else:
            # there is UpdateView and we have selected choices - render as default
            render_option = super(CustomSelectMultiple, self).render_option

        selected_choices = set(force_text(v) for v in selected_choices)
        output = []
        for option_value, option_label in chain(self.choices, choices):
            if isinstance(option_label, (list, tuple)):
                output.append(format_html('<optgroup label="{0}">', force_text(option_value)))
                for option in option_label:
                    output.append(render_option(selected_choices, *option))
                output.append('</optgroup>')
            else:

                output.append(render_option(selected_choices, option_value, option_label))
        return '\n'.join(output)

    def render_option(self, selected_choices, option_value, option_label):
        option_value = force_text(option_value)
        selected_html = mark_safe(' selected="selected"')

        return format_html('<option value="{0}"{1}>{2}</option>',
                           option_value,
                           selected_html,
                           force_text(option_label))


class TagListFilter(admin.SimpleListFilter):
    # Human-readable title which will be displayed in the
    # right admin sidebar just above the filter options.
    title = _('tag')

    # Parameter for the filter that will be used in the URL query.
    parameter_name = 'tag'

    def lookups(self, request, model_admin):
        """
        Returns a list of tuples. The first element in each
        tuple is the coded value for the option that will
        appear in the URL query. The second element is the
        human-readable name for the option that will appear
        in the right sidebar.
        """
        tl = []
        self.model_to_use = model_admin.model
        for t in self.model_to_use.tags.all().order_by('name'):
            tl += (t.name, t.name),
        return tl

    def queryset(self, request, queryset):
        """
        Returns the filtered queryset based on the value
        provided in the query string and retrievable via
        `self.value()`.
        """
        qs = self.model_to_use.objects.all()
        try:
            request.GET['tag']
            return qs.filter(tags__name=self.value())
        except:
            return qs


def thumbnail(image_path):
    absolute_url = os.path.join(settings.IMAGES_URL, image_path[7:])
    print(absolute_url)
    return '<img style="max-width: 400px" src="%s" alt="%s" />' % (absolute_url, image_path)


class ImageRadioSelect(forms.RadioSelect):
    template_name = 'horizontal_select.html'


class AdminImageWidget(AdminFileWidget):
    """
    A FileField Widget that displays an image instead of a file path
    if the current file is an image.
    """
    def render(self, name, value, attrs=None):
        output = []
        file_name = str(value)
        help_text = ''
        if file_name:
            file_path = '%s' % (file_name)
            if attrs['id'] == 'id_thumbnail':
                help_text = '160 wide'
            if attrs['id'] == 'id_image':
                help_text = '205px high'
            output.append('<span>%s</span><a target="_blank" href="%s">%s</a>' % (help_text, file_path, thumbnail(file_name)))

        output.append(super(AdminFileWidget, self).render(name, value, attrs))
        return mark_safe(''.join(output))


class LGEntryForm(forms.ModelForm):
    class Meta:
        widgets = {
            'body_markdown': forms.Textarea(attrs={'rows': 40, 'cols': 100}),
            'featured_image': ImageRadioSelect,
        }


class LGEntryFormSmall(forms.ModelForm):
    class Meta:
        widgets = {
            'body_markdown': forms.Textarea(attrs={'rows': 12, 'cols': 100}),
        }


class RelatedFieldWidgetCanAdd(widgets.Select):
    """
    Modifies standard django Select widget to add link after to add new instance
    of related model (doesn't check permissions, that's for the form instance)
    """
    def __init__(self, related_model, related_url=None, *args, **kw):
        super(RelatedFieldWidgetCanAdd, self).__init__(*args, **kw)
        if not related_url:
            rel_to = related_model
            info = (rel_to._meta.app_label, rel_to._meta.object_name.lower())
            related_url = 'admin:%s_%s_add' % info
        self.related_url = related_url

    def render(self, name, value, *args, **kwargs):
        self.related_url = reverse(self.related_url)
        output = [super(RelatedFieldWidgetCanAdd, self).render(name, value, *args, **kwargs)]
        output.append('<a class="circle plus small-circle modal-open" href="%s" id="add_id_%s" data-modal-hed-class="%s" data-modal-hed="Add a New %s">New</a>' % (self.related_url, name, name, name.capitalize()))
        return mark_safe(u''.join(output))