"""Components to handle access codes.
"""
import grok
from random import SystemRandom as random
from waeup.sirp.accesscodes.interfaces import IAccessCode, IAccessCodeBatch

class AccessCode(grok.Model):
    grok.implements(IAccessCode)

    def __init__(self, batch_serial, batch_prefix, batch_num, random_num,
                 cost, invalidation_date=None, student_id=None):
        self.batch_serial = batch_serial
        self.batch_prefix = batch_prefix.upper()
        self.batch_num = str(batch_num)
        self.random_num = random_num
        self.cost = cost
        self.invalidation_date = invalidation_date
        self.student_id = student_id

    @property
    def representation(self):
        return '%s-%s-%s' % (
            self.batch_prefix, self.batch_num, self.random_num)


class AccessCodeBatch(object):
    """A batch of access codes.
    """
    grok.implements(IAccessCodeBatch)

    def __init__(self, creation_date, creator, batch_num, batch_prefix, cost,
                 entry_num):
        self.creation_date = creation_date
        self.creator = creator
        self.batch_num = batch_num
        self.batch_prefix = batch_prefix
        self.cost = cost
        self.entry_num = entry_num
        self._used = []

    def __iter__(self):
        if len(self._used) >= self.entry_num:
            for num in range(self.entry_num):
                random_num = self._used[num]
                ac = AccessCode(len(self._used), self.batch_prefix,
                                self.batch_num, random_num, self.cost)
                yield ac
        else:
            while len(self._used) < self.entry_num:
                random_num = self.getNewRandomNum()
                ac = AccessCode(len(self._used), self.batch_prefix,
                                self.batch_num, random_num, self.cost)
                self._used.append(random_num)
                yield ac
        
    def getNewRandomNum(self):
        """Create a random number of 10 digits.

        The number is returned as string.
        """
        result = ''
        while result == '' or result in self._used:
            result = ''
            for x in range(10):
                result += str(random().randint(0, 9))
        return result