ck

import decimal


# Price for each flavor. These are equivalent to hashmap field mappings.
flavors_id_price = {
    '251f07b7-e40c-4d7c-b025-20cc3036be7a': decimal.Decimal(0.65),
    '8af61796-e4be-4b97-9ded-37a047b35e7c': decimal.Decimal(0.35),
    'a6ec9bb0-4be8-4651-84ff-df745aa9525e': decimal.Decimal(1.67),
    'c565b92c-cceb-49d9-971c-9ec4d53c7ec4': decimal.Decimal(1.1),
    'dbe2de22-305d-4831-92fe-95d801aa5f89': decimal.Decimal(1.2),
    'f3f987e2-044c-47bb-a20a-c9712e3ecb9e': decimal.Decimal(1.3)
}

# Price per MB / GB for images and volumes. These are equivalent to
# hashmap service mappings.
image_mb_price = decimal.Decimal(0.002)
volume_gb_price = decimal.Decimal(0.35)

# These functions return the price of a service usage on a collect period.
# The price is always equivalent to the price per unit multiplied by
# the quantity.


def get_compute_price(item):
    if not item['desc']['flavor_id'] in flavors_id_price:
        return 0
    elif item['desc']['cpu'] > 0:
        return (decimal.Decimal(flavors_id_price[item['desc']['flavor_id']]))


"""
def get_image_price(item):
    if not item['vol']['qty']:
        return 0
    else:
        return decimal.Decimal(item['vol']['qty']) * image_mb_price

"""


def get_volume_price(item):
    if not item['desc']['disk.root.size']:
        return 0
    else:
        return (decimal.Decimal(item['desc']['disk.root.size']) * volume_gb_price)


# Mapping each service to its price calculation function
services = {
    'compute': get_compute_price,
    'volume': get_volume_price
    # 'image': get_image_price
}


def process(data):
    # The 'data' parameter is a list of dictionaries containing a
    # "usage" and a "period" field
    for d in data:
        usage = d['usage']
        for service_name, service_data in usage.items():
            # Do not calculate the price if the service has no
            # price calculation function
            if service_name in services.keys():
                # A service can have several items. For example,
                # each running instance is an item of the compute service
                for item in service_data:
                    item['rating'] = {'price': services[service_name](item)}
    return data


# 'data' is passed as a global variable. The script is supposed to set the
# 'rating' element of each item in each service
data = process(data)