#!/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"
ADHOC_SSID = "HelloWorld"

# 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 PermissionError as e:
    print(e)
    sys.exit("Make sure you are root")


# 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 PermissionError as e:
    print(e)
    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)

    # Start ad-hoc on first device
    devpath = devices.pop()
    print("Working on first device", devpath)
    dev1 = bus.get_proxy("net.connman.iwd", devpath)
    if not dev1.Powered:
        print("Device is off. Turning on")
        dev1.Powered = True
    print("Device is in", dev1.Mode)
    dev1.Mode = "ad-hoc"
    print("Switched to", dev1.Mode)
    print("Starting ad-hoc network")
    dev1.StartOpen(ADHOC_SSID)
    # TODO: If there is a second device, start AP
    # in it
except:
    sys.exit("An error occured while communicating with iwd")

# Sleep my little baby-oh
# Sleep until you waken
# When you wake you'll see the world
# If I'm not mistaken...
#
# Kiss a lover
# Dance a measure,
# Find your name
# And buried treasure...
#
# Face your life
# Its pain,
# Its pleasure,
# Leave no path untaken.
#
# -- Neil Gaiman, The Graveyard Book
print("Bye")