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.utils.translation import ugettext_lazy as _
from django.conf import settings
import markdown


def markdown_to_html(txt):
    md = markdown.Markdown(
        extensions=[
            'markdown.extensions.fenced_code',
            'markdown.extensions.codehilite(css_class=highlight,linenums=False)',
            'markdown.extensions.attr_list',
            'footnotes',
            'extra'
        ],
        output_format='html5',
        safe_mode=False
    )
    return md.convert(txt)


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 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': 50, 'cols': 100}),
        }