import math
from django.db import models
from django.utils import timezone

from mydefs import MyGenericIPAddressField
from .fields import UnixDateTimeField


class StatElem(models.Model):
    cur_time = UnixDateTimeField(primary_key=True)
    ip = MyGenericIPAddressField()
    octets = models.PositiveIntegerField(default=0)
    packets = models.PositiveIntegerField(default=0)

    @staticmethod
    def percentile(N, percent, key=lambda x:x):
        """
        Find the percentile of a list of values.

        @parameter N - is a list of values. Note N MUST BE already sorted.
        @parameter percent - a float value from 0.0 to 1.0.
        @parameter key - optional key function to compute value from each element of N.

        @return - the percentile of the values
        """
        if not N:
            return None
        k = (len(N)-1) * percent
        f = math.floor(k)
        c = math.ceil(k)
        if f == c:
            return key(N[int(k)])
        d0 = key(N[int(f)]) * (c-k)
        d1 = key(N[int(c)]) * (k-f)
        return d0+d1

    class Meta:
        abstract = True


def getModel():

    class DynamicStatElem(StatElem):
        class Meta:
            db_table = 'flowstat_%s' % timezone.now().strftime("%d%m%Y")
            abstract = False
    return DynamicStatElem