#
###############################################################################
# Copyright (C) 2020 Simon Adlem, G7RZU <g7rzu@gb7fr.org.uk>
# Copyright (C) 2016-2019 Cortney T. Buffington, N0MJS <n0mjs@me.com>
#
#   This program 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.
#
#   This program 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 this program; if not, write to the Free Software Foundation,
#   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
###############################################################################

#Some utilty functions from dmr_utils3 have been modified. These live here.

# Also new FreeDMR specific functions.

import ssl
from time import time
from os.path import isfile, getmtime
from urllib.request import urlopen
from json import load as jload
import hashlib



#Use this try_download instead of that from dmr_utils3
def try_download(_path, _file, _url, _stale,):
    no_verify = ssl._create_unverified_context()
    now = time()
    file_exists = isfile(''.join([_path,_file])) == True
    if file_exists:
        file_old = (getmtime(''.join([_path,_file])) + _stale) < now
    if not file_exists or (file_exists and file_old):
        try:
            with urlopen(_url, context=no_verify) as response:
                data = response.read()
                #outfile.write(data)
                response.close()
            result = 'ID ALIAS MAPPER: \'{}\' successfully downloaded'.format(_file)
        except IOError:
            result = 'ID ALIAS MAPPER: \'{}\' could not be downloaded due to an IOError'.format(_file)
        else:
            if data and (data != b'{}'):
                try:
                    with open(''.join([_path,_file]), 'wb') as outfile:
                        outfile.write(data)
                        outfile.close()
                except IOError:
                    result = 'ID ALIAS mapper \'{}\' file could not be written due to an IOError'.format(_file)
            else:
                result = 'ID ALIAS mapper \'{}\' file not written because downloaded data is empty for some reason'.format(_file)

    else:
        result = 'ID ALIAS MAPPER: \'{}\' is current, not downloaded'.format(_file)

    return result

# SHORT VERSION - MAKES A SIMPLE {INTEGER ID: 'CALLSIGN'} DICTIONARY
def mk_id_dict(_path, _file):
    _dict = {}
    try:
        with open(_path+_file, 'r', encoding='latin1') as _handle:
            records = jload(_handle)
            if 'count' in [*records]:
                records.pop('count')
            records = records[[*records][0]]
            _handle.close
            for record in records:
                try:
                    _dict[int(record['id'])] = record['callsign']
                except:
                    pass
        return _dict
    except:
        raise

#Read JSON from file
def load_json(filename):
    try:
        with open(filename) as f:
            data = jload(f)
    except:
        raise
    else:
        return(data)


#Calculate blake2b checksum of file
def blake2bsum(filename):
    blake2b_hash = hashlib.blake2b()
    try:
        with open(filename,"rb") as f:
            for byte_block in iter(lambda: f.read(4096),b""):
                blake2b_hash.update(byte_block)
            return(blake2b_hash.hexdigest())
    except:
        raise