#!/bin/python
#
import os
import sys

SERVICE_FILE = """
[Unit]
Description=Smarthome Ambient Information Service
After=network-online.target
Wants=network-online.target
[Service]
User=%(UID)d
Group=%(GID)d
ExecStart=%(MY_PATH)s/smart_brain.sh
Type=simple
[Install]
WantedBy=default.target
"""


def help():
    print("Usage: prog <UID> <GID> <TARGET_PATH>")

if __name__ == "__main__":
    if len(sys.argv) == 4:
        try:
            uid = int(sys.argv[1])
            gid = int(sys.argv[2])
        except ValueError:
            help()
        else:
            if os.path.isdir(sys.argv[3]):
                with open(os.path.join(sys.argv[3], 'smart_brain.service'), "w") as fh:
                    fh.write(SERVICE_FILE % {
                        "MY_PATH": os.path.dirname(os.path.abspath(__file__)),
                        "UID": uid,
                        "GID": gid})
            else:
                help()
    else:
        help()