import os
import sched
import time
import sys
from termcolor import colored, cprint
import getpass
import json
import datetime
import uuid
import logging
import logging.handlers
import multiprocessing

syslog = True
debug = False
config_path = '/etc/python-backup.json'
Config = None


###############
#   Helpers   #
###############


def log(message):
    if debug:
        cprint('[DEBUG]: %s' % message, 'yellow')


def error(message):
    cprint('[ERROR]: %s' % message, 'white', 'on_red')


def printHelp():
    cprint(
        'Please run backup.py like so:\n~$ python3 ./backup.py\t\t\tRun with default configuration file (/etc/python-backup.json)\n\
    or\n~$ python3 ./backup.py {parameter}\n\
        -h (--help)\t\t\tShow help\n\
        -v (--version)\t\t\tShow script version\n\
        -d (--debug)\t\t\tShow debug messages\n\
        -c (--config) [PATH]\t\tConfiguration file path\n\
        --single\t\t\tRun single backup - otherwise run in daemon mode\n', 'cyan')


def printVersion():
    cprint('Python-backup version 1.0\nBy Dominik Dancs | email> do@dancs.sk | web> https://do.dancs.sk', 'cyan')
    exit(0)


def loadConfig():
    global config_path, Config, syslog
    try:
        Config = json.load(open(config_path))
        try:
            Config['syslog']
            if isinstance(Config['syslog'], bool) and not Config['syslog']:
                syslog = False
            Config['unit-name']
            Config['to-backup']
            if not isinstance(Config['to-backup'], list):
                raise Exception('Paths to backup must be a list!')
            for location in Config['to-backup']:
                location['path']
                location['name']
            Config['compression-level']
            if not isinstance(Config['compression-level'], int) or Config['compression-level'] < 0 or Config['compression-level'] > 9:
                raise Exception(
                    'Compression level must be a number between 0 - 9!')
            Config['cpu-threads']
            if not isinstance(Config['cpu-threads'], int):
                raise Exception('Number of CPU threads must be a number!')
            if Config['cpu-threads'] < 1 or Config['cpu-threads'] > multiprocessing.cpu_count():
                raise Exception('Invalid number of CPU threads!')
            Config['backup-locations']
            if not isinstance(Config['backup-locations'], list):
                raise Exception('Backup locations must be a priority list!')
            for location in Config['backup-locations']:
                location['path']
                location['priority']
                if not isinstance(location['priority'], int) or location['priority'] < 0 or location['priority'] > 999:
                    raise Exception(
                        'Location priority must be a number from 0 - 999')
        except Exception as e:
            if e == 'syslog':
                error('Please specify unit name!')
            if e == 'unit-name':
                error('Please specify unit name!')
            elif e == 'to-backup':
                error('Please specify paths to backup!')
            elif e == 'compression-level':
                error('Please specify compression level (0-9)!')
            elif e == 'cpu-threads':
                error('Please specify number of available CPU threads!')
            elif e == 'backup-locations':
                error('Please specify backup locations!')
            else:
                error('Config file does not follow standards!')
                log(e)
            exit(1)
    except Exception as e:
        error('Unable to read config file!')
        exit(1)


########################
#   Argument parsing   #
########################


# not enough parameters supplied - show help
if len(sys.argv) > 0:
    i = 1
    while i < len(sys.argv):
        arg = sys.argv[i]
        i += 1
        if arg == '-h' or arg == '--help':
            printHelp()
            exit(0)
        if arg == '-v' or arg == '--version':
            printVersion()
            exit(0)
        if arg == '-d' or arg == '--debug':
            debug = True
        elif arg == '-c' or arg == '--config':
            try:
                config_path = sys.argv[i]
                i += 1
            except:
                error('No config file provided!')
                printHelp()
                exit(1)
        else:
            error('Unrecognized argument')
            printHelp()
            exit(1)

loadConfig()


########################
#     Setup syslog     #
########################


if syslog:
    logger = logging.getLogger('python-backup')
    handler = logging.handlers.SysLogHandler(address='/dev/log')
    handler.setFormatter(logging.Formatter(
        '%(name)s: [%(levelname)s] %(message)s'
    ))
    logger.addHandler(handler)