#! /usr/bin/env python3

import os
import sys

from string import Template
from subprocess import check_call
from subprocess import check_output

EXEC       = 'ground-control.py'
SERVICE    = 'ground-control.service'
SYSTEM_DIR = '~/.config/systemd/user'

CURRENT_DIR      = os.path.dirname(os.path.realpath(__file__))
SERVICE_TEMPLATE = os.path.join(CURRENT_DIR, SERVICE)
SERVICE_FILE     = os.path.join(os.path.expanduser(SYSTEM_DIR), SERVICE)
PYTHON           = sys.executable
EXEC_START       = f'{PYTHON} {EXEC}'
USER             = check_output(['logname']).decode('utf-8').strip()
LINGER           = check_output(['loginctl', 'show-user',  USER,  '--property=Linger']).decode('utf-8').strip()

with open(SERVICE_TEMPLATE) as f:
    serviceTemplate = Template(f.read())

serviceFile = serviceTemplate.substitute(
    workingDirectory=CURRENT_DIR,
    execStart=EXEC_START
)

os.makedirs(os.path.dirname(SERVICE_FILE), exist_ok=True)

with open(SERVICE_FILE, 'w') as f:
    f.write(serviceFile)

check_call(['systemctl', '--user', 'daemon-reload'])
check_call(['systemctl', '--user', 'enable', '--no-pager', SERVICE])
check_call(['systemctl', '--user', 'restart', '--no-pager', SERVICE])
check_call(['systemctl', '--user', 'status', '--no-pager', SERVICE])

if LINGER != 'Linger=yes':
    print(f'\n>>> Please run `sudo loginctl enable-linger {USER}` to allow this service to run without being logged in.')