#!/usr/bin/env python3

import argparse
import json
import logging


_level = logging.INFO
_format = "%(asctime)-15s [%(levelname)-8s] %(lineno)d : %(funcName)s : %(message)s"
logging.basicConfig(format=_format, level=_level)
logger = logging.getLogger()


def parse_args():
    argp = argparse.ArgumentParser()

    argp.add_argument(
            '--debug',
            action='store_true',
            help="Run in debug mode"
    )

    argp.add_argument(
            'json_filename',
            help="JSON filename to flatten"
    )

    argp.add_argument(
            '--output-file', '-o',
            help="Output filename for results"
    )

    return argp.parse_args()


def flatten(data_object, key_name=None, variable_list=[]):
    """Will flatten a JSON file by listing the variables in
    a dot notation.

    Args:
        data_object: Data as dict, list, string, etc. to parse recursively
        key_name: String of the key name to pass into in the next call
        variable_list: List of the generated variables

    Returns:
        The list of the variables in dot notation.
    """

    if type(data_object) == list:
        for data_line in data_object:
            flatten(data_line, key_name=key_name, variable_list=variable_list)
    elif type(data_object) == dict:
        for k, v in data_object.items():
            key_name = f"{key_name}.{k}" if key_name else k
            flatten(v, key_name=key_name, variable_list=variable_list)

            key_name = ".".join(key_name.split('.')[:-1])
    else:
        variable_list.append(f"{key_name}: {data_object}" if key_name else None)

    return variable_list


def main():
    args = parse_args()

    if args.debug:
        logger.info("Running in debug mode")
        logger.setLevel(logging.DEBUG)

    with open(args.json_filename) as fp:
        json_file = json.load(fp)

    json_variables = flatten(json_file)

    if args.output_file:
        with open(args.output_file, 'w') as fp:
            for variable in json_variables:
                fp.write(f"{variable}\n")
    else:
        for variable in json_variables:
            print(f"{variable}")


if __name__ == "__main__":
    main()