from django import shortcuts
from django.conf import settings
from django.contrib.auth.models import User
from django.db.models import Q
from django.http import Http404
from ldap3 import Connection

from gestioncof.decorators import buro_required
from gestioncof.models import CofProfile


class Clipper(object):
    def __init__(self, clipper, fullname):
        if fullname is None:
            fullname = ""
        assert isinstance(clipper, str)
        assert isinstance(fullname, str)
        self.clipper = clipper
        self.fullname = fullname

    def __str__(self):
        return "{} ({})".format(self.clipper, self.fullname)

    def __eq__(self, other):
        return self.clipper == other.clipper and self.fullname == other.fullname


@buro_required
def autocomplete(request):
    if "q" not in request.GET:
        raise Http404
    q = request.GET["q"]
    data = {"q": q}

    queries = {}
    bits = q.split()

    # Fetching data from User and CofProfile tables
    queries["members"] = CofProfile.objects.filter(is_cof=True)
    queries["users"] = User.objects.filter(profile__is_cof=False)
    for bit in bits:
        queries["members"] = queries["members"].filter(
            Q(user__first_name__icontains=bit)
            | Q(user__last_name__icontains=bit)
            | Q(user__username__icontains=bit)
            | Q(login_clipper__icontains=bit)
        )
        queries["users"] = queries["users"].filter(
            Q(first_name__icontains=bit)
            | Q(last_name__icontains=bit)
            | Q(username__icontains=bit)
        )
    queries["members"] = queries["members"].distinct()
    queries["users"] = queries["users"].distinct()

    # Clearing redundancies
    usernames = set(queries["members"].values_list("login_clipper", flat="True")) | set(
        queries["users"].values_list("profile__login_clipper", flat="True")
    )

    # Fetching data from the SPI
    if getattr(settings, "LDAP_SERVER_URL", None):
        # Fetching
        ldap_query = "(&{:s})".format(
            "".join(
                "(|(cn=*{bit:s}*)(uid=*{bit:s}*))".format(bit=bit)
                for bit in bits
                if bit.isalnum()
            )
        )
        if ldap_query != "(&)":
            # If none of the bits were legal, we do not perform the query
            entries = None
            with Connection(settings.LDAP_SERVER_URL) as conn:
                conn.search("dc=spi,dc=ens,dc=fr", ldap_query, attributes=["uid", "cn"])
                entries = conn.entries
            # Clearing redundancies
            queries["clippers"] = [
                Clipper(entry.uid.value, entry.cn.value)
                for entry in entries
                if entry.uid.value and entry.uid.value not in usernames
            ]

    # Resulting data
    data.update(queries)
    data["options"] = sum(len(query) for query in queries)

    return shortcuts.render(request, "autocomplete_user.html", data)