#!/usr/bin/env python3
# This file is placed in the Public Domain.
# pylint: disable=C0411,C0413,W0212,W0718,E0401


"main"


import getpass
import os
import pwd
import sys


from rssbot.cfg   import Config
from rssbot.defer import errors, later
from rssbot.disk  import Persist, pidfile, skel
from rssbot.main  import enable, init
from rssbot.utils import forever


from rssbot import modules
from rssbot import user


Cfg         = Config()
Cfg.dis     = ""
Cfg.mod     = "irc,rss"
Cfg.opts    = ""
Cfg.name    = "rssbot"
Cfg.user    = getpass.getuser()
Cfg.wdr     = os.path.expanduser(f"~/.{Cfg.name}")
Cfg.pidfile = os.path.join(Cfg.wdr, f"{Cfg.name}.pid")


Persist.workdir = Cfg.wdr


def daemon(verbose=False):
    "switch to background."
    pid = os.fork()
    if pid != 0:
        os._exit(0)
    os.setsid()
    pid2 = os.fork()
    if pid2 != 0:
        os._exit(0)
    if not verbose:
        with open('/dev/null', 'r', encoding="utf-8") as sis:
            os.dup2(sis.fileno(), sys.stdin.fileno())
        with open('/dev/null', 'a+', encoding="utf-8") as sos:
            os.dup2(sos.fileno(), sys.stdout.fileno())
        with open('/dev/null', 'a+', encoding="utf-8") as ses:
            os.dup2(ses.fileno(), sys.stderr.fileno())
    os.umask(0)
    os.chdir("/")


def privileges(username):
    "drop privileges."
    pwnam = pwd.getpwnam(username)
    os.setgid(pwnam.pw_gid)
    os.setuid(pwnam.pw_uid)


def wrap(func):
    "catch exceptions"
    try:
        func()
    except (KeyboardInterrupt, EOFError):
        print("")
    except Exception as ex:
        later(ex)
    errors()


def main():
    "main"
    daemon("-v" in sys.argv)
    skel()
    pidfile(Cfg.pidfile)
    privileges(Cfg.user)
    if "-v" in sys.argv:
        enable(print)
    init(Cfg.mod, modules, user)
    forever()


if __name__ == "__main__":
    wrap(main)
