#!/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: eos_banner
author: Peter Sprygada (@privateip)
short_description: Manage multiline banners on Arista EOS devices
description:
- This will configure both login and motd banners on remote devices running Arista
  EOS.  It allows playbooks to add or remote banner text from the active running configuration.
version_added: 1.0.0
extends_documentation_fragment:
- arista.eos.eos
notes:
- Tested against EOS 4.15
options:
  banner:
    description:
    - Specifies which banner that should be configured on the remote device.
    required: true
    choices:
    - login
    - motd
  text:
    description:
    - The banner text that should be present in the remote device running configuration.  This
      argument accepts a multiline string. 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
"""

EXAMPLES = """
- name: configure the login banner
  arista.eos.eos_banner:
    banner: login
    text: |
      this is my login banner
      that contains a multiline
      string
    state: present

- name: remove the motd banner
  arista.eos.eos_banner:
    banner: motd
    state: absent
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - banner login
    - this is my login banner
    - that contains a multiline
    - string
    - EOF
session_name:
  description: The EOS config session name used to load the configuration
  returned: if changes
  type: str
  sample: ansible_1479315771
"""
from ansible.module_utils.basic import AnsibleModule
from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    load_config,
    run_commands,
)
from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    eos_argument_spec,
    is_local_eapi,
)
from ansible.module_utils.six import string_types
from ansible.module_utils._text import to_text


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

    if state == "absent" and have.get("text"):
        if isinstance(have["text"], string_types):
            commands.append("no banner %s" % module.params["banner"])
        elif have["text"].get("loginBanner") or have["text"].get("motd"):
            commands.append({"cmd": "no banner %s" % module.params["banner"]})

    elif state == "present":
        if isinstance(have["text"], string_types):
            if want["text"] != have["text"]:
                commands.append("banner %s" % module.params["banner"])
                commands.extend(want["text"].strip().split("\n"))
                commands.append("EOF")
        else:
            have_text = have["text"].get("loginBanner") or have["text"].get(
                "motd"
            )
            if have_text:
                have_text = have_text.strip()

            if to_text(want["text"]) != have_text or not have_text:
                # For EAPI we need to construct a dict with cmd/input
                # key/values for the banner
                commands.append(
                    {
                        "cmd": "banner %s" % module.params["banner"],
                        "input": want["text"].strip("\n"),
                    }
                )

    return commands


def map_config_to_obj(module):
    output = run_commands(module, ["show banner %s" % module.params["banner"]])
    obj = {"banner": module.params["banner"], "state": "absent"}
    if output:
        if is_local_eapi(module):
            # On EAPI we need to extract the banner text from dict key
            # 'loginBanner'
            if module.params["banner"] == "login":
                banner_response_key = "loginBanner"
            else:
                banner_response_key = "motd"
            if (
                isinstance(output[0], dict)
                and banner_response_key in output[0].keys()
            ):
                obj["text"] = output[0]
        else:
            obj["text"] = output[0]
        obj["state"] = "present"
    return obj


def map_params_to_obj(module):
    text = module.params["text"]
    if text:
        text = to_text(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=["login", "motd"]),
        text=dict(),
        state=dict(default="present", choices=["present", "absent"]),
    )

    argument_spec.update(eos_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 = map_config_to_obj(module)

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

    if commands:
        commit = not module.check_mode
        response = load_config(module, commands, commit=commit)
        if response.get("diff") and module._diff:
            result["diff"] = {"prepared": response.get("diff")}
        result["session_name"] = response.get("session")
        result["changed"] = True

    module.exit_json(**result)


if __name__ == "__main__":
    main()
