from django.http import HttpResponseForbidden, HttpResponseRedirect, JsonResponse
from django.urls import reverse
from django.shortcuts import get_object_or_404
from django.db.models import Func, CharField

from urllib.parse import urlencode
import time
import functools
import unicodedata

from common.models import Thematic, UserConfig, UserThematics


def check_thematic_access(thematic_code, edit_permission_required=False):
    """Decorator to verify user access to a specific thematic (passed as a parameter)."""
    
    def decorator(view_func):
        @functools.wraps(view_func)
        def _wrapped_view(request, *args, **kwargs):
            user_config = UserConfig.objects.filter(user=request.user).first()  # Get user access configuration
            thematic = get_object_or_404(Thematic, code=thematic_code)  # Get thematic from the given parameter

            # Check if the user has a configuration
            if not user_config:
                return HttpResponseForbidden("Access denied: You do not have access to this thematic.")

            # Check if the user has access to the thematic
            if edit_permission_required:
                if not UserThematics.objects.filter(
                    user_config=user_config,
                    thematic=thematic,
                    can_edit_assets=True
                ).exists():
                    return HttpResponseForbidden("Access denied: You do not have edit permissions for this thematic.")
            else:
                # Si l'utilisateur a un rôle 'admin' ou 'operator', il peut voir tous les assets
                if (
                    (not user_config.roles.filter(name__in=['admin','operator']).exists())
                    and 
                    (not UserThematics.objects.filter(
                        user_config=user_config,
                        thematic=thematic,
                        can_view_assets=True
                    ).exists())
                    ):
                    return HttpResponseForbidden("Access denied: You do not have view permissions for this thematic.")

            # Execute the view if everything is OK
            return view_func(request, *args, **kwargs)

        return _wrapped_view

    return decorator


def redirect_with_variant(viewname, variant=None, url_kwargs=None, extra_query_params=None):
    """
    Redirige vers une vue avec des paramètres d'URL et le paramètre ?v=... si fourni.
    
    :param viewname: nom de la vue (ex: 'controls:controls_detail')
    :param variant: 'mobile' ou 'desktop' (ajouté comme ?v=mobile dans l'URL)
    :param url_kwargs: dictionnaire des arguments de reverse (ex: {'control_id': 3})
    :param extra_query_params: dictionnaire de paramètres supplémentaires à ajouter dans la query string
    """
    if url_kwargs is None:
        url_kwargs = {}
    if extra_query_params is None:
        extra_query_params = {}
    
    if variant:
        extra_query_params['v'] = variant

    base_url = reverse(viewname, kwargs=url_kwargs)
    
    if extra_query_params:
        query_string = urlencode(extra_query_params)
        full_url = f"{base_url}?{query_string}"
    else:
        full_url = base_url
    
    return HttpResponseRedirect(full_url)



def measure_time(func):
    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        start = time.time()
        response = func(*args, **kwargs)
        elapsed = time.time() - start
        print(f"{func.__name__} exécutée en {elapsed:.4f} secondes")
        return response
    return wrapper



# Appelle la fonction PostgreSQL unaccent(...)
class Unaccent(Func):
    function = 'public.unaccent_immutable'
    output_field = CharField()

def strip_accents_lower(s: str) -> str:
    if not s:
        return ''
    s = ''.join(c for c in unicodedata.normalize('NFD', s) if unicodedata.category(c) != 'Mn')
    return s.lower()



def get_short_name(user):
    """
    Retourne 'Prénom N.' à partir d'un objet User.
    """
    if not user:
        return ""
    first = getattr(user, "first_name", "") or ""
    last = getattr(user, "last_name", "") or ""
    initial = (last[0].upper() + ".") if last else ""
    return f"{first} {initial}".strip()