#!/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/>.
#

DOCUMENTATION = '''
---
module: nxos_feature
version_added: "2.1"
short_description: Manage features in NX-OS switches.
description:
    - Offers ability to enable and disable features in NX-OS.
extends_documentation_fragment: nxos
author:
    - Jason Edelman (@jedelman8)
    - Gabriele Gerbino (@GGabriele)
options:
    feature:
        description:
            - Name of feature.
        required: true
    state:
        description:
            - Desired state of the feature.
        required: false
        default: 'enabled'
        choices: ['enabled','disabled']
'''

EXAMPLES = '''
# Ensure lacp is enabled
- nxos_feature: feature=lacp state=enabled host={{ inventory_hostname }}
# Ensure ospf is disabled
- nxos_feature: feature=ospf state=disabled host={{ inventory_hostname }}
# Ensure vpc is enabled
- nxos_feature: feature=vpc state=enabled host={{ inventory_hostname }}
'''

RETURN = '''
proposed:
    description: proposed feature state
    returned: always
    type: dict
    sample: {"state": "disabled"}
existing:
    description: existing state of feature
    returned: always
    type: dict
    sample: {"state": "enabled"}
end_state:
    description: feature state after executing module
    returned: always
    type: dict
    sample: {"state": "disabled"}
updates:
    description: commands sent to the device
    returned: always
    type: list
    sample: ["no feature eigrp"]
changed:
    description: check to see if a change was made on the device
    returned: always
    type: boolean
    sample: true
feature:
    description: the feature that has been examined
    returned: always
    type: string
    sample: "vpc"
'''

import json
import collections

# COMMON CODE FOR MIGRATION
import re

from ansible.module_utils.basic import get_exception
from ansible.module_utils.netcfg import NetworkConfig, ConfigLine
from ansible.module_utils.shell import ShellError

try:
    from ansible.module_utils.nxos import get_module
except ImportError:
    from ansible.module_utils.nxos import NetworkModule


def to_list(val):
     if isinstance(val, (list, tuple)):
         return list(val)
     elif val is not None:
         return [val]
     else:
         return list()


class CustomNetworkConfig(NetworkConfig):

    def expand_section(self, configobj, S=None):
        if S is None:
            S = list()
        S.append(configobj)
        for child in configobj.children:
            if child in S:
                continue
            self.expand_section(child, S)
        return S

    def get_object(self, path):
        for item in self.items:
            if item.text == path[-1]:
                parents = [p.text for p in item.parents]
                if parents == path[:-1]:
                    return item

    def to_block(self, section):
        return '\n'.join([item.raw for item in section])

    def get_section(self, path):
        try:
            section = self.get_section_objects(path)
            return self.to_block(section)
        except ValueError:
            return list()

    def get_section_objects(self, path):
        if not isinstance(path, list):
            path = [path]
        obj = self.get_object(path)
        if not obj:
            raise ValueError('path does not exist in config')
        return self.expand_section(obj)


    def add(self, lines, parents=None):
        """Adds one or lines of configuration
        """

        ancestors = list()
        offset = 0
        obj = None

        ## global config command
        if not parents:
            for line in to_list(lines):
                item = ConfigLine(line)
                item.raw = line
                if item not in self.items:
                    self.items.append(item)

        else:
            for index, p in enumerate(parents):
                try:
                    i = index + 1
                    obj = self.get_section_objects(parents[:i])[0]
                    ancestors.append(obj)

                except ValueError:
                    # add parent to config
                    offset = index * self.indent
                    obj = ConfigLine(p)
                    obj.raw = p.rjust(len(p) + offset)
                    if ancestors:
                        obj.parents = list(ancestors)
                        ancestors[-1].children.append(obj)
                    self.items.append(obj)
                    ancestors.append(obj)

            # add child objects
            for line in to_list(lines):
                # check if child already exists
                for child in ancestors[-1].children:
                    if child.text == line:
                        break
                else:
                    offset = len(parents) * self.indent
                    item = ConfigLine(line)
                    item.raw = line.rjust(len(line) + offset)
                    item.parents = ancestors
                    ancestors[-1].children.append(item)
                    self.items.append(item)


def get_network_module(**kwargs):
    try:
        return get_module(**kwargs)
    except NameError:
        return NetworkModule(**kwargs)

def get_config(module, include_defaults=False):
    config = module.params['config']
    if not config:
        try:
            config = module.get_config()
        except AttributeError:
            defaults = module.params['include_defaults']
            config = module.config.get_config(include_defaults=defaults)
    return CustomNetworkConfig(indent=2, contents=config)

def load_config(module, candidate):
    config = get_config(module)

    commands = candidate.difference(config)
    commands = [str(c).strip() for c in commands]

    save_config = module.params['save']

    result = dict(changed=False)

    if commands:
        if not module.check_mode:
            try:
                module.configure(commands)
            except AttributeError:
                module.config(commands)

            if save_config:
                try:
                    module.config.save_config()
                except AttributeError:
                    module.execute(['copy running-config startup-config'])

        result['changed'] = True
        result['updates'] = commands

    return result
# END OF COMMON CODE


def execute_config_command(commands, module):
    try:
        module.configure(commands)
    except ShellError:
        clie = get_exception()
        module.fail_json(msg='Error sending CLI commands',
                         error=str(clie), commands=commands)


def get_cli_body_ssh(command, response, module):
    """Get response for when transport=cli.  This is kind of a hack and mainly
    needed because these modules were originally written for NX-API.  And
    not every command supports "| json" when using cli/ssh.  As such, we assume
    if | json returns an XML string, it is a valid command, but that the
    resource doesn't exist yet.
    """
    if 'xml' in response[0]:
        body = []
    else:
        try:
            body = [json.loads(response[0])]
        except ValueError:
            module.fail_json(msg='Command does not support JSON output',
                             command=command)
    return body


def execute_show(cmds, module, command_type=None):
    command_type_map = {
        'cli_show': 'json',
        'cli_show_ascii': 'text'
    }

    try:
        if command_type:
            response = module.execute(cmds, command_type=command_type)
        else:
            response = module.execute(cmds)
    except ShellError:
        clie = get_exception()
        module.fail_json(msg='Error sending {0}'.format(cmds),
                         error=str(clie))
    except AttributeError:
        try:
            if command_type:
                command_type = command_type_map.get(command_type)
                module.cli.add_commands(cmds, output=command_type)
                response = module.cli.run_commands()
            else:
                module.cli.add_commands(cmds, output=command_type)
                response = module.cli.run_commands()
        except ShellError:
            clie = get_exception()
            module.fail_json(msg='Error sending {0}'.format(cmds),
                             error=str(clie))
    return response


def execute_show_command(command, module, command_type='cli_show'):
    if module.params['transport'] == 'cli':
        command += ' | json'
        cmds = [command]
        response = execute_show(cmds, module)
        body = get_cli_body_ssh(command, response, module)
    elif module.params['transport'] == 'nxapi':
        cmds = [command]
        body = execute_show(cmds, module, command_type=command_type)

    return body


def apply_key_map(key_map, table):
    new_dict = {}
    for key, value in table.items():
        new_key = key_map.get(key)
        if new_key:
            value = table.get(key)
            if value:
                new_dict[new_key] = str(value)
            else:
                new_dict[new_key] = value
    return new_dict


def get_available_features(feature, module):
    available_features = {}
    feature_regex = '(?P<feature>\S+)\s+\d+\s+(?P<state>.*)'
    command = 'show feature'

    body = execute_show_command(command, module, command_type='cli_show_ascii')
    split_body = body[0].splitlines()

    for line in split_body:
        try:
            match_feature = re.match(feature_regex, line, re.DOTALL)
            feature_group = match_feature.groupdict()
            feature = feature_group['feature']
            state = feature_group['state']
        except AttributeError:
            feature = ''
            state = ''

        if feature and state:
            if 'enabled' in state:
                state = 'enabled'

            if feature not in available_features.keys():
                available_features[feature] = state
            else:
                if (available_features[feature] == 'disabled' and
                    state == 'enabled'):
                    available_features[feature] = state

    return available_features



def get_commands(proposed, existing, state, module):
    feature = validate_feature(module, mode='config')
    commands = []
    feature_check = proposed == existing
    if not feature_check:
        if state == 'enabled':
            command = 'feature {0}'.format(feature)
            commands.append(command)
        elif state == 'disabled':
            command = "no feature {0}".format(feature)
            commands.append(command)
    return commands


def validate_feature(module, mode='show'):
    '''Some features may need to be mapped due to inconsistency
    between how they appear from "show feature" output and
    how they are configured'''

    feature = module.params['feature']

    feature_to_be_mapped = {
        'show': {
                'nv overlay': 'nve',
                'vn-segment-vlan-based': 'vnseg_vlan'},
        'config':
                {
                'nve': 'nv overlay',
                'vnseg_vlan': 'vn-segment-vlan-based'}
        }

    if feature in feature_to_be_mapped[mode]:
        feature = feature_to_be_mapped[mode][feature]

    return feature


def main():
    argument_spec = dict(
            feature=dict(type='str', required=True),
            state=dict(choices=['enabled', 'disabled'], default='enabled',
                       required=False),
            include_defaults=dict(default=False),
            config=dict(),
            save=dict(type='bool', default=False)
    )
    module = get_network_module(argument_spec=argument_spec,
                                supports_check_mode=True)

    feature = validate_feature(module)
    state = module.params['state'].lower()

    available_features = get_available_features(feature, module)
    if feature not in available_features.keys():
        module.fail_json(
            msg='Invalid feature name.',
            features_currently_supported=available_features,
            invalid_feature=feature)
    else:
        existstate = available_features[feature]

        existing = dict(state=existstate)
        proposed = dict(state=state)
        changed = False
        end_state = existing

        cmds = get_commands(proposed, existing, state, module)

        if cmds:
            if module.check_mode:
                module.exit_json(changed=True, commands=cmds)
            else:
                execute_config_command(cmds, module)
                changed = True
                updated_features = get_available_features(feature, module)
                existstate = updated_features[feature]
                end_state = dict(state=existstate)

    results = {}
    results['proposed'] = proposed
    results['existing'] = existing
    results['end_state'] = end_state
    results['updates'] = cmds
    results['changed'] = changed
    results['feature'] = module.params['feature']

    module.exit_json(**results)


if __name__ == '__main__':
    main()