import os
import logging
from dynCommons import DynCommons

__author__ = "BBVA-NEXT"
__version__ = "1.0.0"

logger = logging.getLogger()


def get_key_even_if_not_exist(key, dictionary, substitute_element=None):
    """
    Gets a value from a key even if doesn't exist in the dictionary.
    :param key: String that contains the field to get.
    :param dictionary: Dictionary object
    :param substitute_element: Any type of variable to substitute the field if doesn't exist
    :return:
    Returns the value or the substitute element.
    """
    try:
        logger.info('LAMBDA HANDLER|GET KEY EVEN IF NOT EXIST|INIT')
        result = (dictionary[key] if dictionary[key] else substitute_element) if dictionary.get(
            key) else substitute_element
        logger.info('LAMBDA HANDLER|GET KEY EVEN IF NOT EXIST|FINISH|OK')

        return result
    except Exception as e:

        logger.error('|'.join(['LAMBDA HANDLER|GET KEY EVEN IF NOT EXIST|FINISH|KO', str(e)]))
        raise Exception(str(e))


def refactor_to_dynamo_object(item):
    """
    Changes the format of the dictionary to another dictionary to save it in DynamoDB.
    :param item: JSON object with the next format:
        {
            'ENDPOINT_FIELD': environment variable that contains a string with the end point
            'AUTH_FIELD': environment variable that contains a string with the auth
            'PDH_FIELD': environment variable that contains a string with the end p256dh
            'EMAIL_FIELD': environment variable that contains a string with the email
        }
    :return:
    Returns a new JSON with a DynamoDB format.
    """
    try:
        dynamo_object = {}

        dynamo_object[os.environ['ENDPOINT_FIELD']] = {'S': item[os.environ['ENDPOINT_FIELD']]}
        dynamo_object[os.environ['AUTH_FIELD']] = {'S': item[os.environ['AUTH_FIELD']]}
        dynamo_object[os.environ['PDH_FIELD']] = {'S': item[os.environ['PDH_FIELD']]}
        dynamo_object[os.environ['EMAIL_FIELD']] = {
            'S': get_key_even_if_not_exist(key=os.environ['EMAIL_FIELD'], dictionary=item, substitute_element=" ")}

        return dynamo_object
    except Exception as e:
        logger.error('|'.join(['LAMBDA HANDLER|REFACTOR TO DYNAMO OBJECT|FINISH|KO', str(e)]))
        return None


def lambda_handler(event, context):
    """
    Lambda to save the FCM credentials in dynamoDB.
    :params event :
    :return: boolean goal.
    """
    try:
        logger.info('LAMBDA HANDLER|SAVE CREDENTIALS FCM|INIT')

        dyncommons_object = DynCommons()
        dyncommons_object.create_resource()
        result = dyncommons_object.put_item(os.environ['CREDENTIALS_TABLE'], refactor_to_dynamo_object(event))

        logger.info('LAMBDA HANDLER|SAVE CREDENTIALS FCM|FIN')
        return result
    except Exception as e:
        logger.error('|'.join(['LAMBDA HANDLER|SAVE CREDENTIALS FCM|FINISH|KO', str(e)]))
        return False