#!/usr/bin/python
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.
#
from __future__ import absolute_import, division, print_function


__metaclass__ = type

DOCUMENTATION = """
module: ios_system
author: Peter Sprygada (@privateip)
short_description: Module to manage the system attributes.
description:
  - This module provides declarative management of node system attributes on Cisco IOS
    devices.  It provides an option to configure host system parameters or remove those
    parameters from the device active configuration.
version_added: 1.0.0
extends_documentation_fragment:
  - cisco.ios.ios
notes:
  - Tested against Cisco IOSXE Version 17.3 on CML.
  - This module works with connection C(network_cli).
    See U(https://docs.ansible.com/ansible/latest/network/user_guide/platform_ios.html)
options:
  hostname:
    description:
      - Configure the device hostname parameter. This option takes an ASCII string value.
    type: str
  domain_name:
    description:
      - Configure the IP domain name on the remote device to the provided value. Value
        should be in the dotted name form and will be appended to the C(hostname) to
        create a fully-qualified domain name.
    type: list
    elements: raw
  domain_search:
    description:
      - Provides the list of domain suffixes to append to the hostname for the purpose
        of doing name resolution. This argument accepts a list of names and will be
        reconciled with the current active configuration on the running node.
    type: list
    elements: raw
  lookup_source:
    description:
      - Provides one or more source interfaces to use for performing DNS lookups.  The
        interface provided in C(lookup_source) must be a valid interface configured
        on the device.
    type: str
  lookup_enabled:
    description:
      - Administrative control for enabling or disabling DNS lookups.  When this argument
        is set to True, lookups are performed and when it is set to False, lookups are
        not performed.
    type: bool
  name_servers:
    description:
      - List of DNS name servers by IP address to use to perform name resolution lookups.  This
        argument accepts either a list of DNS servers See examples.
    type: list
    elements: raw
  state:
    description:
      - State of the configuration values in the device's current active configuration.  When
        set to I(present), the values should be configured in the device active configuration
        and when set to I(absent) the values should not be in the device active configuration
    default: present
    choices:
      - present
      - absent
    type: str
"""

EXAMPLES = """
- name: Configure hostname and domain name
  cisco.ios.ios_system:
    hostname: ios01
    domain_name: test.example.com
    domain_search:
      - ansible.com
      - redhat.com
      - cisco.com

- name: Remove configuration
  cisco.ios.ios_system:
    state: absent

- name: Configure DNS lookup sources
  cisco.ios.ios_system:
    lookup_source: MgmtEth0/0/CPU0/0
    lookup_enabled: true

- name: Configure name servers
  cisco.ios.ios_system:
    name_servers:
      - 8.8.8.8
      - 8.8.4.4
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - hostname ios01
    - ip domain name test.example.com
"""
import re

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    ComplexList,
)

from ansible_collections.cisco.ios.plugins.module_utils.network.ios.ios import (
    get_config,
    load_config,
)


_CONFIGURED_VRFS = None


def has_vrf(module, vrf):
    global _CONFIGURED_VRFS
    if _CONFIGURED_VRFS is not None:
        return vrf in _CONFIGURED_VRFS
    config = get_config(module)
    _CONFIGURED_VRFS = re.findall("vrf definition (\\S+)", config)
    return vrf in _CONFIGURED_VRFS


def requires_vrf(module, vrf):
    if not has_vrf(module, vrf):
        module.fail_json(msg="vrf %s is not configured" % vrf)


def diff_list(want, have):
    adds = [w for w in want if w not in have]
    removes = [h for h in have if h not in want]
    return adds, removes


def map_obj_to_commands(want, have, module):
    commands = list()
    state = module.params["state"]

    def needs_update(x):
        return want.get(x) is not None and want.get(x) != have.get(x)

    if state == "absent":
        if have["hostname"] != "Router":
            commands.append("no hostname")
        if have["lookup_source"]:
            commands.append("no ip domain lookup source-interface %s" % have["lookup_source"])
        if have["lookup_enabled"] is False:
            commands.append("ip domain lookup")
        vrfs = set()
        for item in have["domain_name"]:
            if item["vrf"] and item["vrf"] not in vrfs:
                vrfs.add(item["vrf"])
                commands.append("no ip domain name vrf %s" % item["vrf"])
            elif None not in vrfs:
                vrfs.add(None)
                commands.append("no ip domain name")
        vrfs = set()
        for item in have["domain_search"]:
            if item["vrf"] and item["vrf"] not in vrfs:
                vrfs.add(item["vrf"])
                commands.append("no ip domain list vrf %s" % item["vrf"])
            elif None not in vrfs:
                vrfs.add(None)
                commands.append("no ip domain list")
        vrfs = set()
        for item in have["name_servers"]:
            if item["vrf"] and item["vrf"] not in vrfs:
                vrfs.add(item["vrf"])
                commands.append("no ip name-server vrf %s" % item["vrf"])
            elif None not in vrfs:
                vrfs.add(None)
                commands.append("no ip name-server")
    elif state == "present":
        if needs_update("hostname"):
            commands.append("hostname %s" % want["hostname"])
        if needs_update("lookup_source"):
            commands.append("ip domain lookup source-interface %s" % want["lookup_source"])
        if needs_update("lookup_enabled"):
            cmd = "ip domain lookup"
            if want["lookup_enabled"] is False:
                cmd = "no %s" % cmd
            commands.append(cmd)
        if want["domain_name"]:
            adds, removes = diff_list(want["domain_name"], have["domain_name"])
            for item in removes:
                if item["vrf"]:
                    commands.append("no ip domain name vrf %s %s" % (item["vrf"], item["name"]))
                else:
                    commands.append("no ip domain name %s" % item["name"])
            for item in adds:
                if item["vrf"]:
                    requires_vrf(module, item["vrf"])
                    commands.append("ip domain name vrf %s %s" % (item["vrf"], item["name"]))
                else:
                    commands.append("ip domain name %s" % item["name"])
        if want["domain_search"]:
            adds, removes = diff_list(want["domain_search"], have["domain_search"])
            for item in removes:
                if item["vrf"]:
                    commands.append("no ip domain list vrf %s %s" % (item["vrf"], item["name"]))
                else:
                    commands.append("no ip domain list %s" % item["name"])
            for item in adds:
                if item["vrf"]:
                    requires_vrf(module, item["vrf"])
                    commands.append("ip domain list vrf %s %s" % (item["vrf"], item["name"]))
                else:
                    commands.append("ip domain list %s" % item["name"])
        if want["name_servers"]:
            adds, removes = diff_list(want["name_servers"], have["name_servers"])
            for item in removes:
                if item["vrf"]:
                    commands.append("no ip name-server vrf %s %s" % (item["vrf"], item["server"]))
                else:
                    commands.append("no ip name-server %s" % item["server"])
            for item in adds:
                if item["vrf"]:
                    requires_vrf(module, item["vrf"])
                    commands.append("ip name-server vrf %s %s" % (item["vrf"], item["server"]))
                else:
                    commands.append("ip name-server %s" % item["server"])
    return commands


def parse_hostname(config):
    match = re.search("^hostname (\\S+)", config, re.M)
    return match.group(1)


def parse_domain_name(config):
    match = re.findall("^ip domain[- ]name (?:vrf (\\S+) )*(\\S+)", config, re.M)
    matches = list()
    for vrf, name in match:
        if not vrf:
            vrf = None
        matches.append({"name": name, "vrf": vrf})
    return matches


def parse_domain_search(config):
    match = re.findall("^ip domain[- ]list (?:vrf (\\S+) )*(\\S+)", config, re.M)
    matches = list()
    for vrf, name in match:
        if not vrf:
            vrf = None
        matches.append({"name": name, "vrf": vrf})
    return matches


def parse_name_servers(config):
    match = re.findall("^ip name-server (?:vrf (\\S+) )*(.*)", config, re.M)
    matches = list()
    for vrf, servers in match:
        if not vrf:
            vrf = None
        for server in servers.split():
            matches.append({"server": server, "vrf": vrf})
    return matches


def parse_lookup_source(config):
    match = re.search("ip domain[- ]lookup source-interface (\\S+)", config, re.M)
    if match:
        return match.group(1)


def map_config_to_obj(module):
    config = get_config(module)
    return {
        "hostname": parse_hostname(config),
        "domain_name": parse_domain_name(config),
        "domain_search": parse_domain_search(config),
        "lookup_source": parse_lookup_source(config),
        "lookup_enabled": "no ip domain lookup" not in config
        and "no ip domain-lookup" not in config,
        "name_servers": parse_name_servers(config),
    }


def map_params_to_obj(module):
    obj = {
        "hostname": module.params["hostname"],
        "lookup_source": module.params["lookup_source"],
        "lookup_enabled": module.params["lookup_enabled"],
    }
    domain_name = ComplexList(dict(name=dict(key=True), vrf=dict()), module)
    domain_search = ComplexList(dict(name=dict(key=True), vrf=dict()), module)
    name_servers = ComplexList(dict(server=dict(key=True), vrf=dict()), module)
    for arg, cast in [
        ("domain_name", domain_name),
        ("domain_search", domain_search),
        ("name_servers", name_servers),
    ]:
        if module.params[arg]:
            obj[arg] = cast(module.params[arg])
        else:
            obj[arg] = None
    return obj


def main():
    """Main entry point for Ansible module execution"""
    argument_spec = dict(
        hostname=dict(),
        domain_name=dict(type="list", elements="raw"),
        domain_search=dict(type="list", elements="raw"),
        name_servers=dict(type="list", elements="raw"),
        lookup_source=dict(),
        lookup_enabled=dict(type="bool"),
        state=dict(choices=["present", "absent"], default="present"),
    )
    module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
    result = {"changed": False}
    warnings = list()
    result["warnings"] = warnings
    want = map_params_to_obj(module)
    have = map_config_to_obj(module)
    commands = map_obj_to_commands(want, have, module)
    result["commands"] = commands
    if commands:
        if not module.check_mode:
            load_config(module, commands)
        result["changed"] = True
    module.exit_json(**result)


if __name__ == "__main__":
    main()