from django.db.models import Count
from taggit.models import Tag
from math import floor
from operator import itemgetter
from django.conf import settings
import os
from random import choice

def randomheader(request):
    header_file = choice(filter(
            lambda x: os.path.isfile(
                    settings.HEADER_DIR + os.path.sep + x
                ),
            os.listdir(settings.HEADER_DIR)
        ))
    return {'header': header_file}

def tagcloud(request):
    tagcloud = []
    tagcloudlist = Tag.objects.annotate(
            ct = Count('taggit_taggeditem_items')
        ).order_by('-ct')

    if (len(tagcloudlist) > 0):
        tmax = tagcloudlist[0].ct
        tmin = 1

        if (tmax == tmin):
            tmax += 1

        for cloudelement in tagcloudlist:
            tagcount = cloudelement.ct

            if (tagcount >= tmin):
                size = int(floor((5.0 * (tagcount - tmin)) / (tmax - tmin)))
                tagcloud.append({
                        'name': cloudelement.name,
                        'slug': cloudelement.slug,
                        'size': size
                    })

        tagcloud.sort(key = itemgetter('name'))

    return {'tagcloud': tagcloud}

def viewname(request):
    if hasattr(request, 'view_name'):
        return {
            'view_name': request.view_name,
        }
    else:
        return {}