# Copyright (c) 2017 Mycroft AI, Inc.
#
# This file is part of Mycroft Core.
#
# Mycroft Core is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Mycroft Core is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Mycroft Core.  If not, see <http://www.gnu.org/licenses/>.
import json


def load_commented_json(filename):
    """ Loads an JSON file, ignoring comments

    Supports a trivial extension to the JSON file format.  Allow comments
    to be embedded within the JSON, requiring that a comment be on an
    independent line starting with '//' or '#'.

    NOTE: A file created with these style comments will break strict JSON
          parsers.  This is similar to but lighter-weight than "human json"
          proposed at https://hjson.org

    Args:
        filename (str):  path to the commented JSON file

    Returns:
        obj: decoded Python object
    """
    with open(filename) as f:
        contents = f.read()

    return json.loads(uncomment_json(contents))


def uncomment_json(commented_json_str):
    """ Removes comments from a JSON string.

    Supporting a trivial extension to the JSON format.  Allow comments
    to be embedded within the JSON, requiring that a comment be on an
    independent line starting with '//' or '#'.

    Example...
       {
         // comment
         'name' : 'value'
       }

    Args:
        commented_json_str (str):  a JSON string

    Returns:
        str: uncommented, legal JSON
    """
    lines = commented_json_str.splitlines()
    # remove all comment lines, starting with // or #
    nocomment = []
    for line in lines:
        stripped = line.lstrip()
        if stripped.startswith("//") or stripped.startswith("#"):
            continue
        nocomment.append(line)

    return " ".join(nocomment)