#!/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.error import DBusError
from naxalnet.iwd import IWD, Device, Adapter

NETWORKD_CONFIGS = "/usr/share/naxalnet/networkd"
NETWORKD_VOLATILE_DIR = "/run/systemd/network"
ADHOC_SSID = "HelloWorld"
AP_SSID = "NaxalNet"
AP_PASSWD = "naxalnet256"


def copy_files():
    """
    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)
    """

    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)


def here_be_dragons():
    """
    This function is run every time you
    execute naxalnet from commandline
    """
    try:
        copy_files()
    except PermissionError as error:
        print(error)
        sys.exit("Make sure you are root")

    # Now, the iwd part
    try:
        iwd = IWD()
        devices = iwd.get_devices()
        adhoc_devices = []
        ap_devices = []

        for i in devices:
            device = Device(i)
            adapter = Adapter(device.adapter)
            if adapter.supports_mode("ad-hoc"):
                adhoc_devices.append(i)
            if adapter.supports_mode("ap"):
                ap_devices.append(i)

        if len(adhoc_devices) != 0:
            # Start ad-hoc on first device supporting ad-hoc
            adhoc_device = Device(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 adhoc_device from ap_devices if it exists there
            if adhoc_device.name in ap_devices:
                ap_devices.remove(adhoc_device.name)
            print("Working on ad-hoc")
            # Turn on adapter if it is off
            # See issue #9
            adhoc_adapter = Adapter(adhoc_device.adapter)
            if not adhoc_adapter.is_powered_on():
                adhoc_adapter.power_on()
                adhoc_device.reload()
            adhoc_device.start_adhoc_open(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")
                ap_device = Device(ap_devices.pop())
                # Turn on adapter if it is off
                # See issue #9
                ap_adapter = Adapter(ap_device.adapter)
                if not ap_adapter.is_powered_on():
                    ap_adapter.power_on()
                    ap_adapter.reload()
                ap_device.start_ap(AP_SSID, AP_PASSWD)
    except DBusError as error:
        print(error)
        sys.exit("An error occured while communicating with iwd")

    # naxalnet will print Bye if no errors occured
    print("Bye")