#!/usr/bin/env python3

# Copyright (C) 2021 The naxalnet 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/>.

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

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

NETWORKD_CONFIGS = "/usr/share/naxalnet/networkd"
NETWORKD_VOLATILE_DIR = "/run/systemd/network"
ADHOC_SSID = "HelloWorld"
AP_SSID = "NaxalNet"
AP_PASSWD = "naxalnet256"
# Copy networkd configs to volatile dir.
# The D-Bus API does not support creating new interfaces
# or linking to bridges. So we use config files.
# See man:systemd.network(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 error:
    print(error)
    sys.exit("Make sure you are root")

# 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 that support ad-hoc
    adhoc_devices = []
    # devices that support ap
    ap_devices = []
    for path, obj in objects.items():
        if "net.connman.iwd.Device" in obj:
            # add all devices to the list
            name = obj["net.connman.iwd.Device"]["Name"]
            print("Found device", name)
            adapter_path = obj["net.connman.iwd.Device"]["Adapter"].get_string()
            adapter = objects[adapter_path]["net.connman.iwd.Adapter"]
            if "ad-hoc" in adapter["SupportedModes"]:
                print(name, "supports ad-hoc")
                adhoc_devices.append(path)
            if "ap" in adapter["SupportedModes"]:
                print(name, "supports ap")
                ap_devices.append(path)

    if len(adhoc_devices) != 0:
        # Start ad-hoc on first device supporting ad-hoc
        dev1path = adhoc_devices.pop()
        # The same device is likely to have ap support too.
        # But we can't start ad-hoc and ap on the same interface.
        # Remove dev1 from ap_devices if it exists there
        if dev1path in ap_devices:
            ap_devices.remove(dev1path)
        print("Working on ad-hoc")
        dev1 = bus.get_proxy("net.connman.iwd", dev1path)
        print("Starting ad-hoc on", dev1.Name)
        if not dev1.Powered:
            print("Device is off. Turning on")
            dev1.Powered = True
        if dev1.Mode != "ad-hoc":
            print("Device is in", dev1.Mode)
            print("Switching to ad-hoc")
            dev1.Mode = "ad-hoc"
            # Changing Mode needs connecting to the proxy again
            dev1 = bus.get_proxy("net.connman.iwd", dev1path)
        # If already connected to ad-hoc, stop it
        if dev1.Started is True:
            print("Already connected to ad-hoc. Stopping")
            dev1.Stop()
            # Reconnect to proxy or StartOpen won't work
            dev1 = bus.get_proxy("net.connman.iwd", dev1path)
        print("Starting ad-hoc network")
        dev1.StartOpen(ADHOC_SSID)

        # Start Access point if ap_device is not empty,
        # ie, we have more devices
        if len(ap_devices) != 0:
            print("Working on AP")
            dev2path = ap_devices.pop()
            dev2 = bus.get_proxy("net.connman.iwd", dev2path)
            if not dev1.Powered:
                print("Device is off. Turning on")
                dev1.Powered = True
            if dev2.Mode != "ap":
                print(dev2.Name, "is in", dev2.Mode)
                print("Switching to ap")
                dev2.Mode = "ap"
                dev2 = bus.get_proxy("net.connman.iwd", dev2path)
            if dev2.Started is True:
                print("An AP is already started on", dev2.Name)
                print("Stopping")
                dev2.Stop()
                dev2 = bus.get_proxy("net.connman.iwd", dev2path)
            print("Starting AP on", dev2.Name)
            dev2.Start(AP_SSID, AP_PASSWD)
except DBusError:
    sys.exit("An error occured while communicating with iwd")

print("Bye")