Synnefo

from db.models import Debit, FlavorCost

import utils

def get_costs(vm, start_datetime, end_datetime, active):

    """Return a list with FlavorCost objects for the specified duration"""

    def between(enh_fc, a_date):

        """Checks if a date is between a FlavorCost duration"""

        if enh_fc.effective_from <= a_date and enh_fc.effective_to is None:

            return True

        return enh_fc.effective_from <= a_date and enh_fc.effective_to >= a_date

    # Get the related FlavorCost objects, sorted.

    price_list = FlavorCost.objects.filter(flavor=vm).order_by('effective_from')

    # add the extra field FlavorCost.effective_to

    for idx in range(0, len(price_list)):

        if idx + 1 == len(price_list):

            price_list[idx].effective_to = None

        else:

            price_list[idx].effective_to = price_list[idx + 1].effective_from

    price_result = []

    found_start = False

    # Find the affected FlavorCost, according to the

    # dates, and put them in price_result

    for p in price_list:

        if between(p, start_datetime):

            found_start = True

            p.effective_from = start_datetime

        if between(p, end_datetime):

            p.effective_to = end_datetime

            price_result.append(p)

            break

        if found_start:

            price_result.append(p)

    results = []

    # Create the list and the result tuples

    for p in price_result:

        if active:

            cost = p.cost_active

        else:

            cost = p.cost_inactive

        results.append( ( p.effective_from, utils.calculate_cost(p.effective_from, p.effective_to, cost)) )

    return results