#!/usr/bin/env python3
# -*- coding: utf-8 -*-
import json
import sys
from pathlib import Path


class Config:
    def __init__(self):
        # global config path
        conf_path = '/etc/ejabberd-metrics.conf'
        self.file = Path(conf_path)

        self.content = None

    def _read(self):
        with open(self.file, 'r', encoding='utf-8') as f:
            try:
                self.content = json.load(f)

            # catch json decoding errors
            except json.JSONDecodeError as err:
                print(err, file=sys.stderr)
                exit(1)

    def _check(self):
        try:
            # if file is present try to read it's contents
            if self.file.exists():
                self._read()

            # if not create a blank file
            else:
                Path.touch(self.file)

        # catch permission exceptions as this tries to write to /etc/
        except PermissionError as err:
            print(err, file=sys.stderr)
            sys.exit(err.errno)

    def get(self, key: str = None) -> (dict, None):
        self._check()

        # if a special key is request, return just that
        if key is not None:

            # safety measure
            if key in self.content:
                return self.content[key]

            # if the key isn't part if self.content return None
            else:
                return None

        # else return everything
        return self.content