import threading

from django.http import FileResponse, HttpResponse
from django.urls import path


def hello(request):
    name = request.GET.get('name') or 'World'
    return HttpResponse('Hello %s!' % name)


def hello_meta(request):
    return HttpResponse(
        'From %s' % request.META.get('HTTP_REFERER') or '',
        content_type=request.META.get('CONTENT_TYPE'),
    )


def sync_waiter(request):
    with sync_waiter.lock:
        sync_waiter.active_threads.add(threading.current_thread())
    sync_waiter.barrier.wait(timeout=0.5)
    return hello(request)


sync_waiter.active_threads = set()
sync_waiter.lock = threading.Lock()
sync_waiter.barrier = threading.Barrier(2)


test_filename = __file__


urlpatterns = [
    path('', hello),
    path('file/', lambda x: FileResponse(open(test_filename, 'rb'))),
    path('meta/', hello_meta),
    path('wait/', sync_waiter),
]