#!/usr/bin/env python3

"""
Setup a working BATMAN Advanced network
with systemd-networkd and iwd
"""

# Copyright (C) 2021  The Authors

# 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, see <http://www.gnu.org/licenses/>.


import sys
from pathlib import Path
from shutil import copy
from dasbus.connection import SystemMessageBus

NETWORKD_CONFIGS = "/usr/share/naxalnet/networkd"
NETWORKD_VOLATILE_DIR = "/run/systemd/network"
RESOLVED_STUB_RESOLVE = "/run/systemd/resolve/stub-resolv.conf"
RESOLV_CONF = "/etc/resolv.conf"


# Copy networkd configs to volatile dir.
# See man:systemd.networkm(5)
try:
    print("Copying network config files")
    dest = Path(NETWORKD_VOLATILE_DIR)
    src = Path(NETWORKD_CONFIGS)

    # Create the volatile directory if it doesn't exist
    dest.mkdir(parents=True, exist_ok=True)

    # Copy all files in src to dest
    for i in src.iterdir():
        copy(i, dest)
except:
    sys.exit("An error occured while copying network files")


# Symlink resolvd.conf to systemd's stub-resolvd.conf
# This is needed for DNS resolution to work.
# see https://wiki.archlinux.org/title/Systemd-resolved#DNS
try:
    print("Checking resolv.conf")
    r = Path(RESOLV_CONF)
    if r.exists():
        print(r, "already exists. Removing it")
        r.unlink()
        print("Linking resolv.conf")
    r.symlink_to(RESOLVED_STUB_RESOLVE)
except:
    sys.exit("An error occured while linking resolv.conf")


# Now, the iwd part
try:
    # connect to the System bus
    bus = SystemMessageBus()
    # iwd proxy
    iwd = bus.get_proxy("net.connman.iwd", "/")
    # Get list of all devices
    print("Finding connected devices")
    objects = iwd.GetManagedObjects()
    devices = []
    for name, obj in objects.items():
        if "net.connman.iwd.Device" in obj:
            # add all devices to the list
            print("Found device:", obj["net.connman.iwd.Device"]["Name"])
            devices.append(name)
    # TODO: On first devices, start ad-hoc
    # If there is a second device, start AP
    # in it
except:
    sys.exit("An error occured while communicating with iwd")


print("Bye")