#!/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/>.
#

ANSIBLE_METADATA = {'metadata_version': '1.0',
                    'status': ['preview'],
                    'supported_by': 'community'}


DOCUMENTATION = """
---
module: eos_banner
version_added: "2.3"
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.
extends_documentation_fragment: eos
options:
  banner:
    description:
      - The C(banner) argument specifies the banner that should be
        configured on the remote device.  Current this module supports
        configuration of either C(login) or C(motd) banners.
    required: true
    default: null
  text:
    description:
      - The C(text) argument specifics the banner text that should be
        present in the remote device running configuration.  This argument
        accepts a multiline string.
    required: false
    default: null
  state:
    description:
      - The C(state) argument specifies whether or not the configuration is
        present in the current devices active running configuration.  When
        this value is set to C(present), the configuration stanzas should be
        in the current device configuration.  When this value is set to
        C(absent), the configuration should not be in the current running
        configuration.
    required: false
    default: present
    choices: ['present', 'absent']
"""

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

- name: remove the motd 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: always
  type: str
  sample: ansible_1479315771
"""
from ansible.module_utils.basic import AnsibleModule
from ansible.module_utils.eos import load_config, run_commands
from ansible.module_utils.eos import eos_argument_spec, check_args

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

    if state == 'absent' and have['text']:
        commands.append('no banner %s' % module.params['banner'])

    elif state == 'present':
        if want['text'] and (want['text'] != have.get('text')):
            if module.params['transport'] == 'cli':
                commands.append('banner %s' % module.params['banner'])
                commands.extend(want['text'].strip().split('\n'))
                commands.append('EOF')
            else:
                # 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 module.params['transport'] == 'cli':
            obj['text'] = output[0]
        else:
            # On EAPI we need to extract the banner text from dict key
            # 'loginBanner'
            obj['text'] = output[0]['loginBanner'].strip('\n')
        obj['state'] = 'present'
    return obj

def map_params_to_obj(module):
    text = module.params['text']
    if text:
        text = 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=['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()
    check_args(module, warnings)

    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()
