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

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

    def __init__(self, batch_serial, random_num, cost,
                 invalidation_date=None, student_id=None):
        self.batch_serial = batch_serial
        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)

    @property
    def batch(self):
        return getattr(self, '__parent__', None)

    @property
    def batch_prefix(self):
        if self.batch is None:
            return ''
        return self.batch.prefix

    @property
    def batch_num(self):
        if self.batch is None:
            return ''
        return self.batch.num

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

    def __init__(self, creation_date, creator, batch_prefix, cost,
                 entry_num, num=None):
        super(AccessCodeBatch, self).__init__()
        self.creation_date = creation_date
        self.creator = creator
        self.prefix = batch_prefix
        self.cost = cost
        self.entry_num = entry_num
        self.num = num

    def createEntries(self):
        """Create the entries for this batch.
        """
        self._used = []
        for num in range(self.entry_num):
            random_num = self.getNewRandomNum()
            ac = AccessCode(num, random_num, self.cost)
            self[str(num)] = ac
        del self._used

    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

class AccessCodeBatchContainer(grok.Container):
    grok.implements(IAccessCodeBatchContainer)

    def addBatch(self, batch):
        """Add a batch.
        """
        batch.num = self.getNum(batch.prefix)
        key = "%s-%s" % (batch.prefix, batch.num)
        self[key] = batch
        batch.createEntries()
        self._p_changed = True
        self.curr_num += 1

    def getNum(self, prefix):
        """Get next unused num for given prefix.
        """
        num = 1
        prefix = prefix.upper()
        while self.get('%s-%s' % (prefix, num), None):
            num += 1
        return num
        
class AccessCodePlugin(grok.GlobalUtility):
    grok.name('accesscodes')
    grok.implements(IWAeUPSIRPPluggable)

    def setup(self, site, name, logger):
        site['accesscodes'] = AccessCodeBatchContainer()
        logger.info('Installed container for access code batches.')
        return

    def update(self, site, name, logger):
        pass