#!/usr/bin/python3
# Copyright (c) 2017-2019 David Steele <dsteele@gmail.com>
#
# SPDX-License-Identifier: GPL-2.0-or-later
# License-Filename: LICENSE

#
# Copyright 2016-2017 David Steele <steele@debian.org>
# This file is part of comitup
# Available under the terms of the GNU General Public License version 2
# or later
#

import argparse
import dbus
from functools import wraps
import getpass
import logging
import NetworkManager as nm
import pprint
import sys
import uuid

if __name__ == '__main__':
    import os
    fullpath = os.path.abspath(__file__)
    parentdir = '/'.join(fullpath.split('/')[:-2])
    sys.path.insert(0, parentdir)

from comitup import iwscan  # noqa

device_list = None
settings_cache = {}

pp = pprint.PrettyPrinter(indent=4)

log = logging.getLogger('comitup')

this_module = sys.modules[__name__]
for key in nm.__dict__:
    if key.startswith("NM_"):
        setattr(this_module, key, nm.__dict__[key])


def initialize():
    nm.Settings.ReloadConnections()


def nm_state():

    log.debug("Calling nm.NetworkManager.State()")
    return nm.NetworkManager.State


def none_on_exception(*exceptions):
    def _none_on_exception(fp):
        @wraps(fp)
        def wrapper(*args, **kwargs):
            try:
                return fp(*args, **kwargs)
            except exceptions:
                log.debug("Got an exception, returning None, %s", fp.__name__,
                          exc_info=True)
                return None

        return wrapper

    return _none_on_exception


def get_devices():
    global device_list

    if not device_list:
        try:
            log.debug("Calling nm.GetDevices()")
            device_list = nm.NetworkManager.GetDevices()
        except TypeError:
            # NetworkManager is gone for some reason. Bail big time.
            sys.exit(1)

    return device_list


def device_name(device):
    return device.Interface


def get_wifi_devices():
    return [x for x in get_devices() if x.DeviceType == 2]


def get_phys_dev_names():
    return [device_name(x) for x in get_devices() if x.DeviceType in (1, 2)]


@none_on_exception(IndexError)
def get_wifi_device(index=0):
    return get_wifi_devices()[index]


def get_device_path(device):
    log.debug("Getting specific device for path")
    return device.SpecificDevice().object_path


def disconnect(device):
    try:
        log.debug("Calling disconnect")
        device.Disconnect()
    except:   # noqa
        log.debug("Error received in disconnect")


def get_connection_settings(connection):
    global settings_cache

    if connection.uuid not in settings_cache:
        log.debug("Not in cache")
        settings_cache[connection.uuid] = connection.GetSettings()

    return settings_cache[connection.uuid]


def get_device_settings(device):
    try:
        connection = device.ActiveConnection
    except nm.ObjectVanished:
        sys.exit(1)

    log.debug("Getting Connection settings")
    return get_connection_settings(connection.Connection)


@none_on_exception(AttributeError)
def get_active_ssid(device):
    return get_device_settings(device)['802-11-wireless']['ssid']


@none_on_exception(AttributeError, IndexError)
def get_active_ip(device):
    return device.Ip4Config.Addresses[0][0]


def get_all_connections():
    log.debug("Calling nm.ListConnections()")
    return [x for x in nm.Settings.ListConnections()]


@none_on_exception(AttributeError, KeyError)
def get_ssid_from_connection(connection):
    log.debug("Calling GetSettings")
    settings = get_connection_settings(connection)

    return settings['802-11-wireless']['ssid']


def get_connection_by_ssid(name):
    for connection in get_all_connections():
        ssid = get_ssid_from_connection(connection)
        if name == ssid:
            return connection

    return None


def del_connection_by_ssid(name):
    for connection in get_all_connections():
        ssid = get_ssid_from_connection(connection)
        if name == ssid:
            connection.Delete()


def activate_connection_by_ssid(ssid, device, path='/'):
    connection = get_connection_by_ssid(ssid)

    log.debug("Calling nm.ActivateConnection()")
    nm.NetworkManager.ActivateConnection(connection, device, path)


def deactivate_connection(device):
    connection = device.ActiveConnection
    if connection:
        log.debug("Calling nm.DeactivateConnection()")
        nm.NetworkManager.DeactivateConnection(connection)


@none_on_exception(AttributeError)
def get_access_points(device):
    log.debug("Calling GetAllAccessPoints()")
    return device.SpecificDevice().GetAllAccessPoints()


def get_points_ext(device):
    try:
        inlist = sorted(get_access_points(device), key=lambda x: -x.Strength)
    except (TypeError, dbus.exceptions.DBusException):
        log.debug("Error getting access points")
        inlist = []

    outlist = []
    for point in inlist:

        try:
            if point.Flags or point.WpaFlags or point.RsnFlags:
                encstr = "encrypted"
            else:
                encstr = "unencrypted"

            outpoint = {
                'ssid': point.Ssid,
                'strength': str(point.Strength),
                'security': encstr,
                'nmpath': point.object_path,
            }

            outlist.append(outpoint)
        except dbus.exceptions.DBusException:
            log.debug("Error getting point info")

    return outlist


def get_candidate_connections(device):
    candidates = []

    for conn in get_all_connections():
        log.debug("Getting settings 2")
        settings = get_connection_settings(conn)
        ssid = get_ssid_from_connection(conn)

        try:
            if ssid \
               and settings['connection']['type'] == '802-11-wireless' \
               and settings['802-11-wireless']['mode'] == 'infrastructure':

                candidates.append(ssid)
        except KeyError:
            log.debug("Unexpected connection format for %s" % ssid)

#     # kicknm
#     get_access_points(device)
#     iwscan.candidates()

    log.debug("candidates: %s" % candidates)

    return candidates


def make_hotspot(name='comitup', device=None, password="", hash="0000"):
    comitup_uuid = str(uuid.uuid4())
    settings = {
        'connection':
        {
            'type': '802-11-wireless',
            'uuid': comitup_uuid,
            'id': "{0}-{1}".format(name, hash),
            'autoconnect': False,
        },
        '802-11-wireless':
        {
            'mode': 'ap',
            'ssid': name,
            'band': "bg",
        },
        'ipv4':
        {
            'method': 'manual',
            'address-data': [
                {
                    'address': '10.41.0.1',
                    'prefix': 24,
                }
            ]
        },
        'ipv6':
        {
            'method': 'ignore',
        },
    }

    if device:
        settings['connection']['interface-name'] = device_name(device)

    if password and len(password) >= 8:
        settings['802-11-wireless-security'] = {}
        settings['802-11-wireless-security']['key-mgmt'] = "wpa-psk"
        settings['802-11-wireless-security']['psk'] = password

    log.debug("Calling nm.AddConnection()")
    nm.Settings.AddConnection(settings)


def make_connection_for(ssid, password=None, interface=None):

    settings = dbus.Dictionary({
        'connection': dbus.Dictionary(
            {
                'id': ssid,
                'type': '802-11-wireless',
                'uuid': str(uuid.uuid4()),
            }),
        '802-11-wireless': dbus.Dictionary(
            {
                'ssid': dbus.ByteArray(ssid.encode()),
                'mode': 'infrastructure',
            }),
        'ipv4': dbus.Dictionary(
            {
                # assume DHCP
                'method': 'auto',
            }),
        'ipv6': dbus.Dictionary(
            {
                'method': 'auto',
            }),
    })

    if interface:
        settings['connection']['interface-name'] = interface

    # assume privacy = WPA(2) psk
    if password:
        settings['802-11-wireless']['security'] = '802-11-wireless-security'
        settings['802-11-wireless-security'] = dbus.Dictionary({
            'auth-alg': 'open',
            'key-mgmt': 'wpa-psk',
            'psk': password,
        })

    log.debug("Calling nm.AddConnection()")
    nm.Settings.AddConnection(settings)


#
# CLI Interface
#


def do_listaccess(arg):
    """List all accessible access points"""
    rows = []
    for point in get_access_points(get_wifi_device()):
        row = (
            point.Ssid, point.HwAddress,
            point.Flags, point.WpaFlags,
            point.RsnFlags, point.Strength,
            point.Frequency
        )
        rows.append(row)

    bypwr = sorted(rows, key=lambda x: -x[5])

    hdrs = ('SSID', 'MAC', 'Private', 'WPA', 'RSN', 'Power', 'Frequency')

    try:
        import tabulate
        print(tabulate.tabulate(bypwr, headers=hdrs))
    except:    # noqa
        for entry in bypwr:
            print(entry)


def do_listconnections(arg):
    """List all defined connections"""
    for connection in get_all_connections():
        ssid = get_ssid_from_connection(connection)

        if ssid:
            print(ssid)


def do_setconnection(ssid):
    """Connect to a connection"""
    activate_connection_by_ssid(ssid, get_wifi_device())


def do_getconnection(dummy):
    """Print the active connection ssid"""
    print(get_active_ssid(get_wifi_device()))


def do_getip(dummy):
    """Print the current IP address"""
    print(get_active_ip(get_wifi_device()))


def do_detailconnection(ssid):
    """Print details about a connection"""

    connection = get_connection_by_ssid(ssid)

    pp.pprint(connection.GetSettings())
    pp.pprint(connection.GetSecrets())


def do_delconnection(ssid):
    """Delete a connection id'd by ssid"""

    del_connection_by_ssid(ssid)


def do_makehotspot(dummy):
    """Create a hotspot connection for future use"""

    make_hotspot()


def do_listcandidates(dummy):
    """List available connections for current access points"""

    for candidate in get_candidate_connections(get_wifi_device()):
        print(candidate)


def do_makeconnection(ssid):
    """Create a connection for an access point, for future use"""

    password = getpass.getpass('password: ')

    make_connection_for(ssid, password)


def get_command(cmd):
    cmd_name = "do_" + cmd

    try:
        return(globals()[cmd_name])
    except KeyError:
        return None


def parse_args():
    prog = 'comitup'
    epilog = "Commands:\n"
    for x in sorted([x for x in globals().keys() if x[0:3] == "do_"]):
        epilog += "  %s - %s\n" % (x[3:], globals()[x].__doc__)

    parser = argparse.ArgumentParser(
        formatter_class=argparse.RawDescriptionHelpFormatter,
        prog=prog,
        description="Manage NetworkManager Wifi connections",
        epilog=epilog,
    )

    parser.add_argument(
        'command',
        help="command",
    )

    parser.add_argument(
        'arg',
        nargs='?',
        help="command argument",
    )

    args = parser.parse_args()

    if get_command(args.command) is None:
        parser.error("Invalid command")

    return args


def main():
    try:
        initialize()
    except dbus.exceptions.DBusException:
        print("Must run as root")
        sys.exit(1)

    args = parse_args()
    fn = get_command(args.command)
    fn(args.arg)


if __name__ == '__main__':
    main()