#!/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: nxos_aaa_server
extends_documentation_fragment:
- cisco.nxos.nxos
short_description: Manages AAA server global configuration.
description:
- Manages AAA server global configuration
version_added: 1.0.0
author:
- Jason Edelman (@jedelman8)
notes:
- Tested against NXOSv 7.3.(0)D1(1) on VIRL
- The server_type parameter is always required.
- If encrypt_type is not supplied, the global AAA server key will be stored as encrypted
  (type 7).
- Changes to the global AAA server key with encrypt_type=0 are not idempotent.
- state=default will set the supplied parameters to their default values. The parameters
  that you want to default must also be set to default. If global_key=default, the
  global key will be removed.
options:
  server_type:
    description:
    - The server type is either radius or tacacs.
    required: true
    choices:
    - radius
    - tacacs
  global_key:
    description:
    - Global AAA shared secret or keyword 'default'.
  encrypt_type:
    description:
    - The state of encryption applied to the entered global key. O clear text, 7 encrypted.
      Type-6 encryption is not supported.
    choices:
    - '0'
    - '7'
  deadtime:
    description:
    - Duration for which a non-reachable AAA server is skipped, in minutes or keyword
      'default. Range is 1-1440. Device default is 0.
  server_timeout:
    description:
    - Global AAA server timeout period, in seconds or keyword 'default. Range is 1-60.
      Device default is 5.
  directed_request:
    description:
    - Enables direct authentication requests to AAA server or keyword 'default' Device
      default is disabled.
    choices:
    - enabled
    - disabled
  state:
    description:
    - Manage the state of the resource.
    default: present
    choices:
    - present
    - default
"""

EXAMPLES = """
# Radius Server Basic settings
- name: Radius Server Basic settings
  cisco.nxos.nxos_aaa_server:
    server_type: radius
    server_timeout: 9
    deadtime: 20
    directed_request: enabled

# Tacacs Server Basic settings
- name: Tacacs Server Basic settings
  cisco.nxos.nxos_aaa_server:
    server_type: tacacs
    server_timeout: 8
    deadtime: 19
    directed_request: disabled

# Setting Global Key
- name: AAA Server Global Key
  cisco.nxos.nxos_aaa_server:
    server_type: radius
    global_key: test_key
"""

RETURN = """
commands:
    description: command sent to the device
    returned: always
    type: list
    sample: ["radius-server deadtime 22", "radius-server timeout 11",
             "radius-server directed-request"]
"""
import re

from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    load_config,
    run_commands,
)
from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    nxos_argument_spec,
)
from ansible.module_utils.basic import AnsibleModule


PARAM_TO_DEFAULT_KEYMAP = {
    "server_timeout": "5",
    "deadtime": "0",
    "directed_request": "disabled",
}


def execute_show_command(command, module):
    command = {"command": command, "output": "text"}

    return run_commands(module, command)


def flatten_list(command_lists):
    flat_command_list = []
    for command in command_lists:
        if isinstance(command, list):
            flat_command_list.extend(command)
        else:
            flat_command_list.append(command)
    return flat_command_list


def get_aaa_server_info(server_type, module):
    aaa_server_info = {}
    server_command = "show {0}-server".format(server_type)
    request_command = "show {0}-server directed-request".format(server_type)
    global_key_command = "show run | sec {0}".format(server_type)
    aaa_regex = r".*{0}-server\skey\s\d\s+(?P<key>\S+).*".format(server_type)

    server_body = execute_show_command(server_command, module)[0]

    split_server = server_body.splitlines()

    for line in split_server:
        if line.startswith("timeout"):
            aaa_server_info["server_timeout"] = line.split(":")[1]

        elif line.startswith("deadtime"):
            aaa_server_info["deadtime"] = line.split(":")[1]

    request_body = execute_show_command(request_command, module)[0]

    if bool(request_body):
        aaa_server_info["directed_request"] = request_body.replace("\n", "")
    else:
        aaa_server_info["directed_request"] = "disabled"

    key_body = execute_show_command(global_key_command, module)[0]

    try:
        match_global_key = re.match(aaa_regex, key_body, re.DOTALL)
        group_key = match_global_key.groupdict()
        aaa_server_info["global_key"] = group_key["key"].replace('"', "")
    except (AttributeError, TypeError):
        aaa_server_info["global_key"] = None

    return aaa_server_info


def config_aaa_server(params, server_type):
    cmds = []

    deadtime = params.get("deadtime")
    server_timeout = params.get("server_timeout")
    directed_request = params.get("directed_request")
    encrypt_type = params.get("encrypt_type", "7")
    global_key = params.get("global_key")

    if deadtime is not None:
        cmds.append("{0}-server deadtime {1}".format(server_type, deadtime))

    if server_timeout is not None:
        cmds.append(
            "{0}-server timeout {1}".format(server_type, server_timeout)
        )

    if directed_request is not None:
        if directed_request == "enabled":
            cmds.append("{0}-server directed-request".format(server_type))
        elif directed_request == "disabled":
            cmds.append("no {0}-server directed-request".format(server_type))

    if global_key is not None:
        cmds.append(
            "{0}-server key {1} {2}".format(
                server_type, encrypt_type, global_key
            )
        )

    return cmds


def default_aaa_server(existing, params, server_type):
    cmds = []

    deadtime = params.get("deadtime")
    server_timeout = params.get("server_timeout")
    directed_request = params.get("directed_request")
    global_key = params.get("global_key")
    existing_key = existing.get("global_key")

    if (
        deadtime is not None
        and existing.get("deadtime") != PARAM_TO_DEFAULT_KEYMAP["deadtime"]
    ):
        cmds.append("no {0}-server deadtime 1".format(server_type))

    if (
        server_timeout is not None
        and existing.get("server_timeout")
        != PARAM_TO_DEFAULT_KEYMAP["server_timeout"]
    ):
        cmds.append("no {0}-server timeout 1".format(server_type))

    if (
        directed_request is not None
        and existing.get("directed_request")
        != PARAM_TO_DEFAULT_KEYMAP["directed_request"]
    ):
        cmds.append("no {0}-server directed-request".format(server_type))

    if global_key is not None and existing_key is not None:
        cmds.append(
            "no {0}-server key 7 {1}".format(server_type, existing_key)
        )

    return cmds


def main():
    argument_spec = dict(
        server_type=dict(
            type="str", choices=["radius", "tacacs"], required=True
        ),
        global_key=dict(type="str"),
        encrypt_type=dict(type="str", choices=["0", "7"]),
        deadtime=dict(type="str"),
        server_timeout=dict(type="str"),
        directed_request=dict(
            type="str", choices=["enabled", "disabled", "default"]
        ),
        state=dict(choices=["default", "present"], default="present"),
    )

    argument_spec.update(nxos_argument_spec)

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

    warnings = list()
    results = {"changed": False, "commands": [], "warnings": warnings}

    server_type = module.params["server_type"]
    global_key = module.params["global_key"]
    encrypt_type = module.params["encrypt_type"]
    deadtime = module.params["deadtime"]
    server_timeout = module.params["server_timeout"]
    directed_request = module.params["directed_request"]
    state = module.params["state"]

    if encrypt_type and not global_key:
        module.fail_json(msg="encrypt_type must be used with global_key.")

    args = dict(
        server_type=server_type,
        global_key=global_key,
        encrypt_type=encrypt_type,
        deadtime=deadtime,
        server_timeout=server_timeout,
        directed_request=directed_request,
    )

    proposed = dict((k, v) for k, v in args.items() if v is not None)

    existing = get_aaa_server_info(server_type, module)

    commands = []
    if state == "present":
        if deadtime:
            try:
                if int(deadtime) < 0 or int(deadtime) > 1440:
                    raise ValueError
            except ValueError:
                module.fail_json(
                    msg="deadtime must be an integer between 0 and 1440"
                )

        if server_timeout:
            try:
                if int(server_timeout) < 1 or int(server_timeout) > 60:
                    raise ValueError
            except ValueError:
                module.fail_json(
                    msg="server_timeout must be an integer between 1 and 60"
                )

        delta = dict(set(proposed.items()).difference(existing.items()))
        if delta:
            command = config_aaa_server(delta, server_type)
            if command:
                commands.append(command)

    elif state == "default":
        for key, value in proposed.items():
            if key != "server_type" and value != "default":
                module.fail_json(
                    msg='Parameters must be set to "default"'
                    "when state=default"
                )
        command = default_aaa_server(existing, proposed, server_type)
        if command:
            commands.append(command)

    cmds = flatten_list(commands)
    if cmds:
        results["changed"] = True
        if not module.check_mode:
            load_config(module, cmds)
        if "configure" in cmds:
            cmds.pop(0)
        results["commands"] = cmds

    module.exit_json(**results)


if __name__ == "__main__":
    main()
