#!/usr/bin/python
# -*- coding: utf-8 -*-
#
# (C) 2017 Red Hat Inc.
# Copyright (C) 2017 Lenovo.
#
# GNU General Public License v3.0+
#
# This program 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.
#
# (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)
#
# Module to configure Lenovo Switches.
# Lenovo Networking
#
from __future__ import absolute_import, division, print_function
__metaclass__ = type


DOCUMENTATION = '''
---
module: cnos_config
author: "Anil Kumar Muraleedharan (@amuraleedhar)"
short_description: Manage Lenovo CNOS configuration sections
description:
  - Lenovo CNOS configurations use a simple block indent file syntax
    for segmenting configuration into sections.  This module provides
    an implementation for working with CNOS configuration sections in
    a deterministic way.
notes:
  - Tested against CNOS 10.9.1
options:
  lines:
    description:
      - The ordered set of commands that should be configured in the
        section.  The commands must be the exact same commands as found
        in the device running-config.  Be sure to note the configuration
        command syntax as some commands are automatically modified by the
        device config parser.
    aliases: ['commands']
  parents:
    description:
      - The ordered set of parents that uniquely identify the section
        the commands should be checked against.  If the parents argument
        is omitted, the commands are checked against the set of top
        level or global commands.
  src:
    description:
      - Specifies the source path to the file that contains the configuration
        or configuration template to load.  The path to the source file can
        either be the full path on the Ansible control host or a relative
        path from the playbook or role root directory.  This argument is
        mutually exclusive with I(lines), I(parents).
  before:
    description:
      - The ordered set of commands to push on to the command stack if
        a change needs to be made.  This allows the playbook designer
        the opportunity to perform configuration commands prior to pushing
        any changes without affecting how the set of commands are matched
        against the system.
  after:
    description:
      - The ordered set of commands to append to the end of the command
        stack if a change needs to be made.  Just like with I(before) this
        allows the playbook designer to append a set of commands to be
        executed after the command set.
  match:
    description:
      - Instructs the module on the way to perform the matching of
        the set of commands against the current device config.  If
        match is set to I(line), commands are matched line by line.  If
        match is set to I(strict), command lines are matched with respect
        to position.  If match is set to I(exact), command lines
        must be an equal match.  Finally, if match is set to I(none), the
        module will not attempt to compare the source configuration with
        the running configuration on the remote device.
    default: line
    choices: ['line', 'strict', 'exact', 'none']
  replace:
    description:
      - Instructs the module on the way to perform the configuration
        on the device.  If the replace argument is set to I(line) then
        the modified lines are pushed to the device in configuration
        mode.  If the replace argument is set to I(block) then the entire
        command block is pushed to the device in configuration mode if any
        line is not correct.
    default: line
    choices: ['line', 'block', 'config']
  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 in a playbook.  The I(config) argument allows the
        implementer to pass in the configuration to use as the base
        config for comparison.
  backup:
    description:
      - This argument will cause the module to create a full backup of
        the current C(running-config) from the remote device before any
        changes are made. If the C(backup_options) value is not given,
        the backup file is written to the C(backup) folder in the playbook
        root directory. If the directory does not exist, it is created.
    type: bool
    default: 'no'
  comment:
    description:
      - Allows a commit description to be specified to be included
        when the configuration is committed.  If the configuration is
        not changed or committed, this argument is ignored.
    default: 'configured by cnos_config'
  admin:
    description:
      - Enters into administration configuration mode for making config
        changes to the device.
    type: bool
    default: 'no'
  backup_options:
    description:
      - This is a dict object containing configurable options related to backup file path.
        The value of this option is read only when C(backup) is set to I(yes), if C(backup) is set
        to I(no) this option will be silently ignored.
    suboptions:
      filename:
        description:
          - The filename to be used to store the backup configuration. If the filename
            is not given it will be generated based on the hostname, current time and date
            in format defined by <hostname>_config.<current-date>@<current-time>
      dir_path:
        description:
          - This option provides the path ending with directory name in which the backup
            configuration file will be stored. If the directory does not exist it will be first
            created and the filename is either the value of C(filename) or default filename
            as described in C(filename) options description. If the path value is not given
            in that case a I(backup) directory will be created in the current working directory
            and backup configuration will be copied in C(filename) within I(backup) directory.
        type: path
    type: dict
'''

EXAMPLES = """
Tasks: The following are examples of using the module cnos_config.
---
- name: Configure top level configuration
  cnos_config:
    "lines: hostname {{ inventory_hostname }}"

- name: Configure interface settings
  cnos_config:
    lines:
      - enable
      - ip ospf enable
    parents: interface ip 13

- name: Load a config from disk and replace the current config
  cnos_config:
    src: config.cfg
    backup: yes

- name: Configurable backup path
  cnos_config:
    src: config.cfg
    backup: yes
    backup_options:
      filename: backup.cfg
      dir_path: /home/user
"""

RETURN = """
updates:
  description: The set of commands that will be pushed to the remote device
  returned: Only when lines is specified.
  type: list
  sample: ['...', '...']
backup_path:
  description: The full path to the backup file
  returned: when backup is yes
  type: str
  sample: /playbooks/ansible/backup/cnos01.2016-07-16@22:28:34
"""
from ansible.module_utils.basic import AnsibleModule
from ansible_collections.community.network.plugins.module_utils.network.cnos.cnos import load_config, get_config
from ansible_collections.community.network.plugins.module_utils.network.cnos.cnos import check_args
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.config import NetworkConfig, dumps


DEFAULT_COMMIT_COMMENT = 'configured by cnos_config'


def get_running_config(module):
    contents = module.params['config']
    if not contents:
        contents = get_config(module)
    return NetworkConfig(indent=1, contents=contents)


def get_candidate(module):
    candidate = NetworkConfig(indent=1)
    if module.params['src']:
        candidate.load(module.params['src'])
    elif module.params['lines']:
        parents = module.params['parents'] or list()
        candidate.add(module.params['lines'], parents=parents)
    return candidate


def run(module, result):
    match = module.params['match']
    replace = module.params['replace']
    replace_config = replace == 'config'
    path = module.params['parents']
    comment = module.params['comment']
    admin = module.params['admin']
    check_mode = module.check_mode

    candidate = get_candidate(module)

    if match != 'none' and replace != 'config':
        contents = get_running_config(module)
        configobj = NetworkConfig(contents=contents, indent=1)
        commands = candidate.difference(configobj, path=path, match=match,
                                        replace=replace)
    else:
        commands = candidate.items

    if commands:
        commands = dumps(commands, 'commands').split('\n')

        if any((module.params['lines'], module.params['src'])):
            if module.params['before']:
                commands[:0] = module.params['before']

            if module.params['after']:
                commands.extend(module.params['after'])

            result['commands'] = commands

        diff = load_config(module, commands)
        if diff:
            result['diff'] = dict(prepared=diff)
            result['changed'] = True


def main():
    """main entry point for module execution
    """
    backup_spec = dict(
        filename=dict(),
        dir_path=dict(type='path')
    )
    argument_spec = dict(
        src=dict(type='path'),

        lines=dict(aliases=['commands'], type='list'),
        parents=dict(type='list'),

        before=dict(type='list'),
        after=dict(type='list'),

        match=dict(default='line', choices=['line', 'strict',
                                            'exact', 'none']),
        replace=dict(default='line', choices=['line', 'block', 'config']),

        config=dict(),
        backup=dict(type='bool', default=False),
        backup_options=dict(type='dict', options=backup_spec),
        comment=dict(default=DEFAULT_COMMIT_COMMENT),
        admin=dict(type='bool', default=False)
    )

    mutually_exclusive = [('lines', 'src'),
                          ('parents', 'src')]

    required_if = [('match', 'strict', ['lines']),
                   ('match', 'exact', ['lines']),
                   ('replace', 'block', ['lines']),
                   ('replace', 'config', ['src'])]

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

    warnings = list()
    check_args(module, warnings)

    result = dict(changed=False, warnings=warnings)

    if module.params['backup']:
        result['__backup__'] = get_config(module)

    run(module, result)

    module.exit_json(**result)


if __name__ == '__main__':
    main()
