# 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/>.

# migrate from pmacct to ipt-NETFLOW:
# Remove 'timeout' subtree, 'buffer-size', 'disable-imt', 'packet-length' and
# 'syslog-facility' from 'system flow-accounting'
#
# Move "system flow-accounting interface" to "system flow-accounting netflow interface"
#
# Remove "system flow-accounting source" and add it to each server
#   under "system flow-accounting netflow server SERVER source-address"


from vyos.configtree import ConfigTree

base = ['system', 'flow-accounting']
remove_keys = [
    ['buffer-size'],
    ['disable-imt'],
    ['netflow', 'timeout'],
    ['packet-length'],
    ['syslog-facility'],
]

def migrate(config: ConfigTree) -> None:
    if not config.exists(base):
        # Nothing to do
        return

    # Remove not needed pmacct fields
    for k in remove_keys:
        p = base + k
        if config.exists(p):
            config.delete(p)

    # Move "system flow-accounting interface" -> "system flow-accounting netflow interface"
    if config.exists(base + ['interface']):
        config.copy(base + ['interface'], base + ['netflow', 'interface'])
        config.delete(base + ['interface'])

    # Remove old "source-address", add it to each server as "source-address"
    source_prev_path = base + ['netflow', 'source-address']
    if config.exists(source_prev_path):
        source_value = config.return_value(source_prev_path)
        config.delete(source_prev_path)

        # So we loose 'source-address' value if there are no servers
        # configured, but it is not valid configuration if there
        # is no server, so it shouldn't be a problem
        if config.exists(base + ['netflow', 'server']):
            path = base + ['netflow', 'server']
            for server in config.list_nodes(path):
                config.set(path + [server, 'source-address'], source_value)