from django import template
from classytags.core import Tag, Options
from classytags.arguments import Argument, MultiValueArgument, KeywordArgument
from django.core.cache import cache
from django.core.urlresolvers import reverse, NoReverseMatch
from django.core.exceptions import ImproperlyConfigured
from ..models import Placeholder
from ..conf import settings as django_front_settings
from django.utils.html import strip_tags
import hashlib
import six
try:
    import simplejson as json
except ImportError:
    import json


register = template.Library()


class FrontEditTag(Tag):
    name = 'front_edit'
    options = Options(
        Argument('name', resolve=False, required=True),
        MultiValueArgument('extra_bits', required=False, resolve=True),
        blocks=[
            ('end_front_edit', 'nodelist'),
        ]
    )

    def render_tag(self, context, name, extra_bits, nodelist=None):
        hash_val = hashlib.new('sha1', six.text_type(name + ''.join([six.text_type(token) for token in extra_bits])).encode('utf8')).hexdigest()
        cache_key = "front-edit-%s" % hash_val

        val = cache.get(cache_key)
        if val is None:
            try:
                val = Placeholder.objects.get(key=hash_val).value
                cache.set(cache_key, val, 3600 * 24)
            except Placeholder.DoesNotExist:
                pass

        if val is None and nodelist:
            val = nodelist.render(context)

        classes = ['editable']

        user = context.get('request', None) and context.get('request').user
        if django_front_settings.DJANGO_FRONT_PERMISSION(user):
            render = six.text_type(val).strip()
            if not strip_tags(render).strip():
                classes.append('empty-editable')

            return '<div class="%s" id="%s">%s</div>' % (' '.join(classes), hash_val, render)
        return val or ''


class FrontEditJS(Tag):
    name = 'front_edit_scripts'
    options = Options(
        KeywordArgument('editor', resolve=False, required=False, defaultkey='editor')
    )

    def render_tag(self, context, editor=''):
        try:
            save_url = reverse('front-placeholder-save')
            history_url = reverse('front-placeholder-history', args=('0000', ))
        except NoReverseMatch:
            raise ImproperlyConfigured('You must add an urlconf entry for django-front to work, see: http://django-front.readthedocs.org/en/latest/installation.html')

        static_url = context.get('STATIC_URL', '/static/')
        user = context.get('request', None) and context.get('request').user
        token = six.text_type(context.get('csrf_token'))
        plugin = editor.get('editor').lower() if \
            editor.get('editor') and editor.get('editor').lower() \
            in django_front_settings.DJANGO_FRONT_ALLOWED_EDITORS else 'default'
        edit_mode = django_front_settings.DJANGO_FRONT_EDIT_MODE if \
            django_front_settings.DJANGO_FRONT_EDIT_MODE in ('lightbox', 'inline') else 'lightbox'

        if django_front_settings.DJANGO_FRONT_PERMISSION(user):
            return """
<link rel="stylesheet" href="%sfront/css/front-edit.css" />
<script>
    document._front_edit = {
        save_url: '%s',
        history_url_prefix: '%s',
        csrf_token: '%s',
        plugin: '%s',
        static_root: '%s',
        edit_mode: '%s',
        editor_options: %s
    };
</script>
<script src="%sfront/js/front-edit.%s.js"></script>
<script src="%sfront/js/front-edit.js"></script>""".strip() % (
                static_url,
                save_url,
                history_url.replace('0000/', ''),
                token,
                plugin,
                static_url,
                edit_mode,
                json.dumps(django_front_settings.DJANGO_FRONT_EDITOR_OPTIONS),
                static_url,
                plugin,
                static_url,
            )
        else:
            return ''


register.tag(FrontEditTag)
register.tag(FrontEditJS)
