import random
import sys
from operator import attrgetter
from functools import partial
from ujson import dumps as uj_dumps

from django.http import HttpResponse
from django.shortcuts import render

from world.models import World, Fortune


if sys.version_info[0] == 3:
  xrange = range

def _get_queries(request):
  try:
    queries = int(request.GET.get('queries', 1))
  except Exception:
    queries = 1
  if queries < 1:
    queries = 1
  if queries > 500:
    queries = 500
  return queries

def plaintext(request):
  return HttpResponse("Hello, World!", content_type="text/plain")

def json(request):
  response = {
    "message": "Hello, World!"
  }
  return HttpResponse(uj_dumps(response), content_type="application/json")

def db(request):
  r = random.randint(1, 10000)
  world = uj_dumps({'id' : r, 'randomNumber' : World.objects.get(id=r).randomnumber})
  return HttpResponse(world, content_type="application/json")

def dbs(request):
  queries = _get_queries(request)

  # fun fact:  every dot-notation lookup calls some python magic under the hood.  Like every other code,
  # one can eliminate dereferences by storing the end dereferenced thing in an identifier
  g = World.objects.get

  # but wait!  there's more!  if we're calling a function over and over with the same parameters,
  # we can use even more function magic.
  #r = random.randint
  rp = partial(random.randint, 1, 10000)

  # now we're ready to write our awesome query iterator thingy
  # first of all, we know the id's correspond to the random number we're picking, so we can create
  # dictionaries on the fly instead of serializing later
  # by creating dicts, we don't need to user the model serializer, which is probably slow and only appropriate
  # for complicated serializations of joins and crazy query sets etc
  # test xrange vs range if the query number is gigantic
  worlds = uj_dumps([{'id' : r, 'randomNumber' : g(id=r).randomnumber} for r in [rp() for q in xrange(queries)]])
  return HttpResponse(worlds, content_type="application/json")

def fortunes(request):
  fortunes = list(Fortune.objects.all())
  fortunes.append(Fortune(id=0, message="Additional fortune added at request time."))

  fortunes = sorted(fortunes, key=attrgetter('message'))

  context = {'fortunes': fortunes}
  return render(request, 'fortunes.html', context)

def update(request):
  queries = _get_queries(request)
  g = World.objects.get
  rp = partial(random.randint, 1, 10000)

  worlds = []
  for r in [rp() for q in xrange(queries)]:
    w = g(id=r)
    w.randomnumber=rp()
    w.save()
    worlds.append({'id' : r, 'randomNumber' : w.randomnumber})

  return HttpResponse(uj_dumps(worlds), content_type="application/json")