# Copyright VyOS maintainers and contributors <maintainers@vyos.io>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library.  If not, see <http://www.gnu.org/licenses/>.

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


def delete_orphaned_interface_policy(config, iftype, ifname, vif=None, vifs=None, vifc=None):
    """Delete unexpected traffic-policy on interfaces in cases when
       policy does not exist but inreface has a policy configuration
       Example T5941:
         set interfaces bonding bond0 vif 995 traffic-policy
    """
    if_path = ['interfaces', iftype, ifname]

    if vif:
        if_path += ['vif', vif]
    elif vifs:
        if_path += ['vif-s', vifs]
        if vifc:
            if_path += ['vif-c', vifc]

    if not config.exists(if_path + ['traffic-policy']):
        return

    config.delete(if_path + ['traffic-policy'])


def migrate(config: ConfigTree) -> None:
    base = ['traffic-policy']

    if not config.exists(base):
        # Delete orphaned nodes on interfaces T5941
        for iftype in config.list_nodes(['interfaces']):
            for ifname in config.list_nodes(['interfaces', iftype]):
                delete_orphaned_interface_policy(config, iftype, ifname)

                if config.exists(['interfaces', iftype, ifname, 'vif']):
                    for vif in config.list_nodes(['interfaces', iftype, ifname, 'vif']):
                        delete_orphaned_interface_policy(config, iftype, ifname, vif=vif)

                if config.exists(['interfaces', iftype, ifname, 'vif-s']):
                    for vifs in config.list_nodes(['interfaces', iftype, ifname, 'vif-s']):
                        delete_orphaned_interface_policy(config, iftype, ifname, vifs=vifs)

                        if config.exists(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                            for vifc in config.list_nodes(['interfaces', iftype, ifname, 'vif-s', vifs, 'vif-c']):
                                delete_orphaned_interface_policy(config, iftype, ifname, vifs=vifs, vifc=vifc)

        # Nothing to do
        return

    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())
