#!/usr/bin/env python3
#
# Copyright (C) 2022 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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/>.

from sys import argv,exit

from vyos.base import Warning
from vyos.configtree import ConfigTree
from vyos.utils.file import read_file

def bandwidth_percent_to_val(interface, percent) -> int:
    speed = read_file(f'/sys/class/net/{interface}/speed')
    if not speed.isnumeric():
        Warning('Interface speed cannot be determined (assuming 10 Mbit/s)')
        speed = 10
    speed = int(speed) *1000000 # convert to MBit/s
    return speed * int(percent) // 100 # integer division

if (len(argv) < 1):
    print("Must specify file name!")
    exit(1)

file_name = argv[1]

with open(file_name, 'r') as f:
    config_file = f.read()

base = ['traffic-policy']
config = ConfigTree(config_file)

if not config.exists(base):
    # Nothing to do
    exit(0)

iface_config = {}

if config.exists(['interfaces']):
    def get_qos(config, interface, interface_base):
        if config.exists(interface_base):
            tmp = { interface : {} }
            if config.exists(interface_base + ['in']):
                tmp[interface]['ingress'] = config.return_value(interface_base + ['in'])
            if config.exists(interface_base + ['out']):
                tmp[interface]['egress'] = config.return_value(interface_base + ['out'])
            config.delete(interface_base)
            return tmp
        return None

    # Migrate "interface ethernet eth0 traffic-policy in|out" to "qos interface eth0 ingress|egress"
    for type in config.list_nodes(['interfaces']):
        for interface in config.list_nodes(['interfaces', type]):
            interface_base = ['interfaces', type, interface, 'traffic-policy']
            tmp = get_qos(config, interface, interface_base)
            if tmp: iface_config.update(tmp)

            vif_path = ['interfaces', type, interface, 'vif']
            if config.exists(vif_path):
                for vif in config.list_nodes(vif_path):
                    vif_interface_base = vif_path + [vif, 'traffic-policy']
                    ifname = f'{interface}.{vif}'
                    tmp = get_qos(config, ifname, vif_interface_base)
                    if tmp: iface_config.update(tmp)

            vif_s_path = ['interfaces', type, interface, 'vif-s']
            if config.exists(vif_s_path):
                for vif_s in config.list_nodes(vif_s_path):
                    vif_s_interface_base = vif_s_path + [vif_s, 'traffic-policy']
                    ifname = f'{interface}.{vif_s}'
                    tmp = get_qos(config, ifname, vif_s_interface_base)
                    if tmp: iface_config.update(tmp)

                    # vif-c interfaces MUST be migrated before their parent vif-s
                    # interface as the migrate_*() functions delete the path!
                    vif_c_path = ['interfaces', type, interface, 'vif-s', vif_s, 'vif-c']
                    if config.exists(vif_c_path):
                        for vif_c in config.list_nodes(vif_c_path):
                            vif_c_interface_base = vif_c_path + [vif_c, 'traffic-policy']
                            ifname = f'{interface}.{vif_s}.{vif_c}'
                            tmp = get_qos(config, ifname, vif_s_interface_base)
                            if tmp: iface_config.update(tmp)


# Now we have the information which interface uses which QoS policy.
# Interface binding will be moved to the qos CLi tree
config.set(['qos'])
config.copy(base, ['qos', 'policy'])
config.delete(base)

# Now map the interface policy binding to the new CLI syntax
if len(iface_config):
    config.set(['qos', 'interface'])
    config.set_tag(['qos', 'interface'])

for interface, interface_config in iface_config.items():
    config.set(['qos', 'interface', interface])
    config.set_tag(['qos', 'interface', interface])
    if 'ingress' in interface_config:
        config.set(['qos', 'interface', interface, 'ingress'], value=interface_config['ingress'])
    if 'egress' in interface_config:
        config.set(['qos', 'interface', interface, 'egress'], value=interface_config['egress'])

# Remove "burst" CLI node from network emulator
netem_base = ['qos', 'policy', 'network-emulator']
if config.exists(netem_base):
    for policy_name in config.list_nodes(netem_base):
        if config.exists(netem_base + [policy_name, 'burst']):
            config.delete(netem_base + [policy_name, 'burst'])

# Change bandwidth unit MBit -> mbit as tc only supports mbit
base = ['qos', 'policy']
if config.exists(base):
    for policy_type in config.list_nodes(base):
        for policy in config.list_nodes(base + [policy_type]):
            policy_base = base + [policy_type, policy]
            if config.exists(policy_base + ['bandwidth']):
                tmp = config.return_value(policy_base + ['bandwidth'])
                config.set(policy_base + ['bandwidth'], value=tmp.lower())

            if config.exists(policy_base + ['class']):
                for cls in config.list_nodes(policy_base + ['class']):
                    cls_base = policy_base + ['class', cls]
                    if config.exists(cls_base + ['bandwidth']):
                        tmp = config.return_value(cls_base + ['bandwidth'])
                        config.set(cls_base + ['bandwidth'], value=tmp.lower())

            if config.exists(policy_base + ['default', 'bandwidth']):
                if config.exists(policy_base + ['default', 'bandwidth']):
                    tmp = config.return_value(policy_base + ['default', 'bandwidth'])
                    config.set(policy_base + ['default', 'bandwidth'], value=tmp.lower())

try:
    with open(file_name, 'w') as f:
        f.write(config.to_string())
except OSError as e:
    print("Failed to save the modified config: {}".format(e))
    exit(1)