# ⁻*- coding: utf-8 -*-
# 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 General Public License version 3 for
# more details.
#
# You should have received a copy of the GNU General Public License version 3
# along with this program; if not, write to the Free Software Foundation, Inc., 51
# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#
# (c) 2015 Valentin Samir
"""Some util function for the app"""
from .default_settings import settings

from django.core.urlresolvers import reverse
from django.http import HttpResponseRedirect, HttpResponse
from django.contrib import messages

import random
import string
import json
import BaseHTTPServer
from threading import Thread
from importlib import import_module

try:
    from urlparse import urlparse, urlunparse, parse_qsl
    from urllib import urlencode
except ImportError:
    from urllib.parse import urlparse, urlunparse, parse_qsl, urlencode


def context(params):
    params["settings"] = settings
    return params


def JsonResponse(request, data):
    data["messages"] = []
    for msg in messages.get_messages(request):
        data["messages"].append({'message': msg.message, 'level': msg.level_tag})
    return HttpResponse(json.dumps(data), content_type="application/json")


def import_attr(path):
    """transform a python module.attr path to the attr"""
    if not isinstance(path, str):
        return path
    if "." not in path:
        ValueError("%r should be of the form `module.attr` and we just got `attr`" % path)
    module, attr = path.rsplit('.', 1)
    try:
        return getattr(import_module(module), attr)
    except ImportError:
        raise ImportError("Module %r not found" % module)
    except AttributeError:
        raise AttributeError("Module %r has not attribut %r" % (module, attr))


def redirect_params(url_name, params=None):
    """Redirect to `url_name` with `params` as querystring"""
    url = reverse(url_name)
    params = urlencode(params if params else {})
    return HttpResponseRedirect(url + "?%s" % params)


def reverse_params(url_name, params=None, **kwargs):
    url = reverse(url_name, **kwargs)
    params = urlencode(params if params else {})
    return url + "?%s" % params


def update_url(url, params):
    """update params in the `url` query string"""
    if not isinstance(url, bytes):
        url = url.encode('utf-8')
    for key, value in list(params.items()):
        if not isinstance(key, bytes):
            del params[key]
            key = key.encode('utf-8')
        if not isinstance(value, bytes):
            value = value.encode('utf-8')
        params[key] = value
    url_parts = list(urlparse(url))
    query = dict(parse_qsl(url_parts[4]))
    query.update(params)
    url_parts[4] = urlencode(query)
    for i in range(len(url_parts)):
        if not isinstance(url_parts[i], bytes):
            url_parts[i] = url_parts[i].encode('utf-8')
    return urlunparse(url_parts).decode('utf-8')


def unpack_nested_exception(error):
    """If exception are stacked, return the first one"""
    i = 0
    while True:
        if error.args[i:]:
            if isinstance(error.args[i], Exception):
                error = error.args[i]
                i = 0
            else:
                i += 1
        else:
            break
    return error


def _gen_ticket(prefix, lg=settings.CAS_TICKET_LEN):
    """Generate a ticket with prefix `prefix`"""
    return '%s-%s' % (
        prefix,
        ''.join(
            random.choice(
                string.ascii_letters + string.digits
            ) for _ in range(lg - len(prefix) - 1)
        )
    )


def gen_lt():
    """Generate a Service Ticket"""
    return _gen_ticket(settings.CAS_LOGIN_TICKET_PREFIX, settings.CAS_LT_LEN)


def gen_st():
    """Generate a Service Ticket"""
    return _gen_ticket(settings.CAS_SERVICE_TICKET_PREFIX, settings.CAS_ST_LEN)


def gen_pt():
    """Generate a Proxy Ticket"""
    return _gen_ticket(settings.CAS_PROXY_TICKET_PREFIX, settings.CAS_PT_LEN)


def gen_pgt():
    """Generate a Proxy Granting Ticket"""
    return _gen_ticket(settings.CAS_PROXY_GRANTING_TICKET_PREFIX, settings.CAS_PGT_LEN)


def gen_pgtiou():
    """Generate a Proxy Granting Ticket IOU"""
    return _gen_ticket(settings.CAS_PROXY_GRANTING_TICKET_IOU_PREFIX, settings.CAS_PGTIOU_LEN)


def gen_saml_id():
    """Generate an saml id"""
    return _gen_ticket('_')


class PGTUrlHandler(BaseHTTPServer.BaseHTTPRequestHandler):
    PARAMS = {}

    def do_GET(s):
        s.send_response(200)
        s.send_header("Content-type", "text/plain")
        s.end_headers()
        s.wfile.write("ok")
        url = urlparse(s.path)
        params = dict(parse_qsl(url.query))
        PGTUrlHandler.PARAMS.update(params)
        s.wfile.write("%s" % params)

    def log_message(self, format, *args):
        return

    @staticmethod
    def run():
        server_class = BaseHTTPServer.HTTPServer
        httpd = server_class(("127.0.0.1", 0), PGTUrlHandler)
        (host, port) = httpd.socket.getsockname()

        def lauch():
            httpd.handle_request()
            httpd.server_close()

        httpd_thread = Thread(target=lauch)
        httpd_thread.daemon = True
        httpd_thread.start()
        return (httpd_thread, host, port)