# combo - content management system
# Copyright (C) 2015-2018  Entr'ouvert
#
# This program is free software: you can redistribute it and/or modify it
# under the terms of the GNU Affero General Public License as published
# by the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import re

from django.conf import settings
from django.utils.encoding import force_text
from django.template import Context, Template, TemplateSyntaxError, VariableDoesNotExist
from django.utils.http import quote


class TemplateError(Exception):
    def __init__(self, msg, params=()):
        self.msg = msg
        self.params = params

    def __str__(self):
        return self.msg % self.params


def get_templated_url(url, context=None):
    if '{{' not in url and '{%' not in url and '[' not in url:
        return url
    template_vars = Context(use_l10n=False)
    if context:
        if hasattr(context, 'flatten'):
            # it's a django Context, dictionarize it:
            context = context.flatten()
        template_vars.update(context)
        template_vars['user_email'] = ''
        template_vars['user_nameid'] = ''
        user = getattr(context.get('request'), 'user', None)
        if user and user.is_authenticated:
            template_vars['user_email'] = quote(user.email)
            user_nameid = user.get_name_id()
            if user_nameid:
                template_vars['user_nameid'] = quote(user_nameid)
    template_vars.update(settings.TEMPLATE_VARS)
    if '{{' in url or '{%' in url:  # Django template
        try:
            return Template(url).render(template_vars)
        except VariableDoesNotExist as e:
            raise TemplateError(e.msg, e.params)
        except TemplateSyntaxError:
            raise TemplateError('syntax error')
    # ezt-like template
    def repl(matchobj):
        varname = matchobj.group(0)[1:-1]
        if varname == '[':
            return '['
        if varname not in template_vars:
            raise TemplateError('unknown variable %s', varname)
        return force_text(template_vars[varname])
    return re.sub(r'(\[.+?\])', repl, url)