#!/usr/bin/python
#
# (c) 2015 Peter Sprygada, <psprygada@ansible.com>
#
# Copyright (c) 2016 Dell Inc.
#
# 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/>.
#
DOCUMENTATION = """
---
module: dellos9_template
version_added: "2.2"
author: "Dhivya P (@dhivyap)"
short_description: Manage Dell OS9 device configurations over SSH.
description:
  - Manages Dell OS9 network device configurations over SSH.  This module
    allows implementors to work with the device running-config.  It
    provides a way to push a set of commands onto a network device
    by evaluating the current running-config and only pushing configuration
    commands that are not already configured.  The config source can
    be a set of commands or a template.
extends_documentation_fragment: dellos9
options:
  src:
    description:
      - The path to the config source.  The source can be either a
        file with config or a template that will be merged during
        runtime.  By default the task will first search for the source
        file in role or playbook root folder in templates unless a full
        path to the file is given.
    required: true
  force:
    description:
      - The force argument instructs the module not to consider the
        current device running-config.  When set to true, this will
        cause the module to push the contents of I(src) into the device
        without first checking if already configured. This argument is
        mutually exclusive with I(config).
    required: false
    default: false
    choices: [ "true", "false" ]
  backup:
    description:
      - When this argument is configured true, the module will backup
        the running-config from the node prior to making any changes.
        The backup file will be written to backup_{{ hostname }} in
        the root of the playbook directory. This argument is
        mutually exclusive with I(config).

    required: false
    default: false
    choices: [ "true", "false" ]
  config:
    description:
      - The module, by default, will connect to the remote device and
        retrieve the current running-config to use as a base for comparing
        against the contents of source.  There are times when it is not
        desirable to have the task get the current running-config for
        every task.  The I(config) argument allows the implementer to
        pass in the configuration to use as the base config for
        comparison. This argument is mutually exclusive with
        I(force) and I(backup).

    required: false
    default: null
"""

EXAMPLES = """
- name: push a configuration onto the device
  dellos9_template:
    host: hostname
    username: foo
    src: config.j2

- name: forceable push a configuration onto the device
  dellos9_template:
    host: hostname
    username: foo
    src: config.j2
    force: yes

- name: provide the base configuration for comparison
  dellos9_template:
    host: hostname
    username: foo
    src: candidate_config.txt
    config: current_config.txt
"""

RETURN = """
updates:
  description: The set of commands that will be pushed to the remote device
  returned: always
  type: list
  sample: ['...', '...']

_backup:
  description: The current running config of the remote device.
  returned: when running config is present in the remote device.
  type: list
  sample: ['...', '...']

responses:
  description: The set of responses from issuing the commands on the device
  returned: when not check_mode
  type: list
  sample: ['...', '...']
"""
from ansible.module_utils.netcfg import NetworkConfig, dumps
from ansible.module_utils.network import NetworkModule
import ansible.module_utils.dellos9


def get_config(module):
    config = module.params['config'] or dict()
    if not config and not module.params['force']:
        config = module.config.get_config()
    return config


def main():
    """ main entry point for module execution
    """

    argument_spec = dict(
        src=dict(),
        force=dict(default=False, type='bool'),
        backup=dict(default=False, type='bool'),
        config=dict(),
    )

    mutually_exclusive = [('config', 'backup'), ('config', 'force')]

    module = NetworkModule(argument_spec=argument_spec,
                           mutually_exclusive=mutually_exclusive,
                           supports_check_mode=True)

    result = dict(changed=False)

    candidate = NetworkConfig(contents=module.params['src'], indent=1)

    contents = get_config(module)

    if contents:
        config = NetworkConfig(contents=contents[0], indent=1)
        result['_backup'] = contents[0]

    commands = list()
    if not module.params['force']:
        commands = dumps(candidate.difference(config), 'commands')
    else:
        commands = str(candidate)

    if commands:
        commands = commands.split('\n')
        if not module.check_mode:
            response = module.config(commands)
            result['responses'] = response
        result['changed'] = True

    result['updates'] = commands
    module.exit_json(**result)


if __name__ == '__main__':
    main()