"""Revenue cache model.

Revenue cache models are stored in AWS ElastiCache Redis
(For reducing RedShift load)
"""

import json
import time

from ows_accounting import response
from ows_accounting.connectors import redis
from ows_accounting.constants import error


def _get_key(account_type, account_id, period_id):
    """Get generated key for cache.

    Args:
        account_type (str): Account type from grass
        account_id (int): Account Id
        period_id (int): Accounting period Id

    Returns:
        string: Key for cache record identifier

    """
    return 'revenue:{account_type}:{account_id}:{period_id}'.format(
        account_type=account_type,
        account_id=str(account_id),
        period_id=str(period_id)
    )


def _get_created_time():
    """Get cache record creation time in specified format.

    Returns:
        string: Formatted current time

    """
    return time.strftime("%Y%m%d%H%M%S", time.localtime())


def save(
        account_type, account_id, period_id, revenue, num_transactions,
        gross_revenue=None):
    """Save revenue information to cache.

    Args:
        account_type (str): Account type from grass
        account_id (int): Account Id
        period_id (int): Accounting period Id
        revenue (float): Account net revenue
        num_transactions (int): Account number of transactions
        gross_revenue (float): Account gross revenue

    Returns:
        response.Response: Saved data or error response
    """
    data = {
        'revenue': revenue,
        'num_transactions': num_transactions,
        'created': _get_created_time()
    }
    if gross_revenue:
        data['gross_revenue'] = gross_revenue
    result = redis.client.set(
        _get_key(account_type, account_id, period_id),
        json.dumps(data))
    if result:
        return response.Response(data)

    return response.create_error_response(
        code=error.ERROR_CODE_ELASTICACHE_ERROR,
        message=error.ERROR_MESSAGE_ELASTICACHE_RECORD
    )


def get(account_type, account_id, period_id):
    """Get revenue information.

    Args:
        account_type (str): Account type from grass
        account_id (int): Account Id
        period_id (int): Accounting period Id
    Returns:
        response.Response: Account revenue data or error response
    """
    result = redis.client.get(_get_key(account_type, account_id, period_id))
    if result:
        return response.Response(message=json.loads(result.decode('utf8')))
    return response.create_not_found_response()