from django.apps import apps
from django.contrib.auth.decorators import user_passes_test
from functools import wraps

from django.http import JsonResponse
from django.shortcuts import redirect
from django.core.exceptions import PermissionDenied

from application.accounts.models import AccountProfile
from application.pjt_mgnt.forms import ProjectLedgerForm, ProjectLedgerManagementForm


def is_in_group(user, group_name):
    return user.groups.filter(name=group_name).exists()


def group_required(group_name):
    return user_passes_test(lambda u: is_in_group(u, group_name))


def custom_permission_required(perm, raise_exception=False):
    def decorator(view_func):
        @wraps(view_func)
        def _wrapped_view(request, *args, **kwargs):
            if request.user.has_perm(perm):
                return view_func(request, *args, **kwargs)
            if raise_exception:
                raise PermissionDenied
            return redirect('error_page')
        return _wrapped_view
    return decorator


def permission_based_queryset(app_name, model_name, id_field, leader_field=None, department_field=None):
    def decorator(view_func):
        @wraps(view_func)
        def _wrapped_view(request, *args, **kwargs):
            current_user = request.user

            try:
                account_profile = AccountProfile.objects.get(user=current_user)
                employee = account_profile.employee_information
            except AccountProfile.DoesNotExist:
                return JsonResponse({'message': '您的账户未关联到员工信息，请联系管理员。'}, status=405)

            model = apps.get_model(app_name, model_name)

            if account_profile.role == 'all_permissions':
                query_set = model.objects.all().order_by(f'-{id_field}')
            elif account_profile.role == 'department_permissions':
                filter_kwargs = {department_field: employee.primary_department}
                query_set = model.objects.filter(**filter_kwargs).order_by(f'-{id_field}')
            elif department_field and not leader_field and account_profile.role in ['department_permissions', 'own_permissions']:
                filter_kwargs = {department_field: employee.primary_department}
                query_set = model.objects.filter(**filter_kwargs).order_by(f'-{id_field}')
            elif leader_field and account_profile.role == 'own_permissions':
                filter_kwargs = {leader_field: employee.name}
                query_set = model.objects.filter(**filter_kwargs).order_by(f'-{id_field}')
            else:
                query_set = model.objects.none()

            request.query_set = query_set

            return view_func(request, *args, **kwargs)

        return _wrapped_view

    return decorator


def dynamic_form_selection(view_func):
    @wraps(view_func)
    def _wrapped_view(request, *args, **kwargs):
        current_user = request.user

        try:
            account_profile = AccountProfile.objects.get(user=current_user)
            user_department = account_profile.employee_information.primary_department
        except AccountProfile.DoesNotExist:
            return JsonResponse({'message': '您的账户未关联到员工信息，请联系管理员。'}, status=405)

        if user_department == '中后台':
            request.form_class = ProjectLedgerManagementForm
        else:
            request.form_class = ProjectLedgerForm
        return view_func(request, *args, **kwargs)
    return _wrapped_view