#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2017, Ansible by Red Hat, inc
#
# This file is part of Ansible by Red Hat
#
# 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/>.
#


DOCUMENTATION = """
module: vyos_banner
author: Trishna Guha (@trishnaguha)
short_description: Manage multiline banners on VyOS devices
description:
- This will configure both pre-login and post-login banners on remote devices running
  VyOS. It allows playbooks to add or remote banner text from the active running configuration.
version_added: 1.0.0
notes:
- Tested against VyOS 1.1.8 (helium).
- This module works with connection C(network_cli). See L(the VyOS OS Platform Options,../network/user_guide/platform_vyos.html).
options:
  banner:
    description:
    - Specifies which banner that should be configured on the remote device.
    required: true
    choices:
    - pre-login
    - post-login
  text:
    description:
    - The banner text that should be present in the remote device running configuration.
      This argument accepts a multiline string, with no empty lines. Requires I(state=present).
  state:
    description:
    - Specifies whether or not the configuration is present in the current devices
      active running configuration.
    default: present
    choices:
    - present
    - absent
extends_documentation_fragment:
- vyos.vyos.vyos
"""

EXAMPLES = """
- name: configure the pre-login banner
  vyos.vyos.vyos_banner:
    banner: pre-login
    text: |
      this is my pre-login banner
      that contains a multiline
      string
    state: present
- name: remove the post-login banner
  vyos.vyos.vyos_banner:
    banner: post-login
    state: absent
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - banner pre-login
    - this is my pre-login banner
    - that contains a multiline
    - string
"""

import re

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.vyos.vyos.plugins.module_utils.network.vyos.vyos import (
    get_config,
    load_config,
)
from ansible_collections.vyos.vyos.plugins.module_utils.network.vyos.vyos import (
    vyos_argument_spec,
)


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

    if state == "absent":
        if have.get("state") != "absent" or (
            have.get("state") != "absent"
            and "text" in have.keys()
            and have["text"]
        ):
            commands.append(
                "delete system login banner %s" % module.params["banner"]
            )

    elif state == "present":
        if want["text"] and want["text"].encode().decode(
            "unicode_escape"
        ) != have.get("text"):
            banner_cmd = (
                "set system login banner %s " % module.params["banner"]
            )
            banner_cmd += want["text"].strip()
            commands.append(banner_cmd)

    return commands


def config_to_dict(module):
    data = get_config(module)
    output = None
    obj = {"banner": module.params["banner"], "state": "absent"}

    for line in data.split("\n"):
        if line.startswith("set system login banner %s" % obj["banner"]):
            match = re.findall(r"%s (.*)" % obj["banner"], line, re.M)
            output = match
    if output:
        obj["text"] = output[0].encode().decode("unicode_escape")
        obj["state"] = "present"

    return obj


def map_params_to_obj(module):
    text = module.params["text"]
    if text:
        text = "%r" % (str(text).strip())

    return {
        "banner": module.params["banner"],
        "text": text,
        "state": module.params["state"],
    }


def main():
    """ main entry point for module execution
    """
    argument_spec = dict(
        banner=dict(required=True, choices=["pre-login", "post-login"]),
        text=dict(),
        state=dict(default="present", choices=["present", "absent"]),
    )

    argument_spec.update(vyos_argument_spec)

    required_if = [("state", "present", ("text",))]

    module = AnsibleModule(
        argument_spec=argument_spec,
        required_if=required_if,
        supports_check_mode=True,
    )

    warnings = list()

    result = {"changed": False}
    if warnings:
        result["warnings"] = warnings

    want = map_params_to_obj(module)
    have = config_to_dict(module)

    commands = spec_to_commands((want, have), module)
    result["commands"] = commands

    if commands:
        commit = not module.check_mode
        load_config(module, commands, commit=commit)
        result["changed"] = True

    module.exit_json(**result)


if __name__ == "__main__":
    main()