#!/usr/bin/python3

# Copyright 2019 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/>.

import sys
import os
import subprocess
import tempfile
import vyos.defaults
import vyos.remote
import vyos.migrator
from vyos.config import Config
from vyos.configtree import ConfigTree


if (len(sys.argv) < 2):
    print("Need config file name to merge.")
    print("Usage: merge <config file> [config path]")
    sys.exit(0)

file_name = sys.argv[1]

configdir = vyos.defaults.directories['config']

protocols = ['scp', 'sftp', 'http', 'https', 'ftp', 'tftp']

if any(x in file_name for x in protocols):
    config_file = vyos.remote.get_remote_config(file_name)
    if not config_file:
        sys.exit("No config file by that name.")
else:
    canonical_path = "{0}/{1}".format(configdir, file_name)
    first_err = None
    try:
        with open(canonical_path, 'r') as f:
            config_file = f.read()
    except Exception as err:
        first_err = err
        try:
            with open(file_name, 'r') as f:
                config_file = f.read()
        except Exception as err:
            print(first_err)
            print(err)
            sys.exit(1)

path = None
if (len(sys.argv) > 2):
    path = " ".join(sys.argv[2:])

with tempfile.NamedTemporaryFile() as file_to_migrate:
    with open(file_to_migrate.name, 'w') as fd:
        fd.write(config_file)

    migration = vyos.migrator.Migrator(file_to_migrate.name)
    migration.run()
    if migration.config_changed():
        with open(file_to_migrate.name, 'r') as fd:
            config_file = fd.read()

merge_config_tree = ConfigTree(config_file)

effective_config = Config()

output_effective_config = effective_config.show_config()
# showConfig (called by config.show_config() does not escape
# backslashes, which configtree expects; cf. T1001.
output_effective_config = output_effective_config.replace("\\", "\\\\")

effective_config_tree = ConfigTree(output_effective_config)

effective_cmds = effective_config_tree.to_commands()
merge_cmds = merge_config_tree.to_commands()

effective_cmd_list = effective_cmds.splitlines()
merge_cmd_list =  merge_cmds.splitlines()

effective_cmd_set = set(effective_cmd_list)
add_cmds = [ cmd for cmd in merge_cmd_list if cmd not in effective_cmd_set ]

if path:
    if not effective_config.exists(path):
        print("path {} does not exist in running config; will use "
              "root.".format(path))
    else:
        add_cmds = [ cmd for cmd in add_cmds if path in cmd ]

for cmd in add_cmds:
    cmd = "/opt/vyatta/sbin/my_" + cmd

    try:
        subprocess.check_call(cmd, shell=True)
    except subprocess.CalledProcessError as err:
        print("Called process error: {}.".format(err))

if effective_config.session_changed():
    print("Merge complete. Use 'commit' to make changes effective.")
else:
    print("No configuration changes to commit.")