#!/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_ntp
version_added: "2.2"
short_description: Manages core NTP configuration.
description:
    - Manages core NTP configuration.
extends_documentation_fragment: nxos
author:
    - Jason Edelman (@jedelman8)
options:
    server:
        description:
            - Network address of NTP server.
        required: false
        default: null
    peer:
        description:
            - Network address of NTP peer.
        required: false
        default: null
    key_id:
        description:
            - Authentication key identifier to use with
              given NTP server or peer.
        required: false
        default: null
    prefer:
        description:
            - Makes given NTP server or peer the preferred
              NTP server or peer for the device.
        required: false
        default: null
        choices: ['enabled', 'disabled']
    vrf_name:
        description:
            - Makes the device communicate with the given
              NTP server or peer over a specific VRF.
        required: false
        default: null
    source_addr:
        description:
            - Local source address from which NTP messages are sent.
        required: false
        default: null
    source_int:
        description:
            - Local source interface from which NTP messages are sent.
              Must be fully qualified interface name.
        required: false
        default: null
    state:
        description:
            - Manage the state of the resource.
        required: false
        default: present
        choices: ['present','absent']
'''

EXAMPLES = '''
# Set NTP Server with parameters
- nxos_ntp:
    server: 1.2.3.4
    key_id: 32
    prefer: enabled
    host: {{ inventory_hostname }}
    username: {{ un }}
    password: {{ pwd }}
'''

RETURN = '''
proposed:
    description: k/v pairs of parameters passed into module
    returned: always
    type: dict
    sample: {"address": "2.2.2.2", "key_id": "48",
            "peer_type": "server", "prefer": "enabled",
            "source": "3.3.3.3", "source_type": "source"}
existing:
    description:
        - k/v pairs of existing ntp server/peer
    type: dict
    sample: {"address": "2.2.2.2", "key_id": "32",
            "peer_type": "server", "prefer": "enabled",
            "source": "ethernet2/1", "source_type": "source-interface"}
end_state:
    description: k/v pairs of ntp info after module execution
    returned: always
    type: dict
    sample: {"address": "2.2.2.2", "key_id": "48",
            "peer_type": "server", "prefer": "enabled",
            "source": "3.3.3.3", "source_type": "source"}
updates:
    description: command sent to the device
    returned: always
    type: list
    sample: ["ntp server 2.2.2.2 prefer key 48",
             "no ntp source-interface ethernet2/1", "ntp source 3.3.3.3"]
changed:
    description: check to see if a change was made on the device
    returned: always
    type: boolean
    sample: true
'''

import json

# 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, NetworkError


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)
    except AttributeError:
        try:
            module.config.load_config(commands)
        except NetworkError:
            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. Instead, the output will be a raw string
    when issuing commands containing 'show run'.
    """
    if 'xml' in response[0] or response[0] == '\n':
        body = []
    elif 'show run' in command:
        body = response
    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, raw=True)
                response = module.cli.run_commands()
        except NetworkError:
            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':
        if 'show run' not in command:
            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 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_ntp_source(module):
    source_type = None
    source = None
    command = 'show run | inc ntp.source'
    output = execute_show_command(command, module, command_type='cli_show_ascii')

    if output:
        try:
            if 'interface' in output[0]:
                source_type = 'source-interface'
            else:
                source_type = 'source'
            source = output[0].split()[2].lower()
        except AttributeError:
            source_type = None
            source = None

    return source_type, source


def get_ntp_peer(module):
    command = 'show run | inc ntp.(server|peer)'
    ntp_peer_list = []
    ntp = execute_show_command(
                command, module, command_type='cli_show_ascii')[0]

    ntp_regex = (
                ".*ntp\s(server\s(?P<address>\S+)|peer\s(?P<peer_address>\S+))"
                "\s*((?P<prefer>prefer)\s*)?(use-vrf\s(?P<vrf_name>\S+)\s*)?"
                "(key\s(?P<key_id>\d+))?.*"
                )

    split_ntp = ntp.splitlines()
    for peer_line in split_ntp:
        ntp_peer = {}
        try:
            peer_address = None
            vrf_name = None
            prefer = None
            key_id = None
            match_ntp = re.match(ntp_regex, peer_line, re.DOTALL)
            group_ntp = match_ntp.groupdict()

            address = group_ntp["address"]
            peer_address = group_ntp['peer_address']
            prefer = group_ntp['prefer']
            vrf_name = group_ntp['vrf_name']
            key_id = group_ntp['key_id']

            if prefer is not None:
                prefer = 'enabled'
            else:
                prefer = 'disabled'

            if address is not None:
                peer_type = 'server'
            elif peer_address is not None:
                peer_type = 'peer'
                address = peer_address

            args = dict(peer_type=peer_type, address=address, prefer=prefer,
                        vrf_name=vrf_name, key_id=key_id)

            ntp_peer = dict((k, v) for k, v in args.items())
            ntp_peer_list.append(ntp_peer)
        except AttributeError:
            ntp_peer_list = []

    return ntp_peer_list


def get_ntp_existing(address, peer_type, module):
    peer_dict = {}
    peer_server_list = []

    peer_list = get_ntp_peer(module)
    for peer in peer_list:
        if peer['address'] == address:
            peer_dict.update(peer)
        else:
            peer_server_list.append(peer)

    source_type, source = get_ntp_source(module)

    if (source_type is not None and source is not None):
        peer_dict['source_type'] = source_type
        peer_dict['source'] = source

    return (peer_dict, peer_server_list)


def set_ntp_server_peer(peer_type, address, prefer, key_id, vrf_name):
    command_strings = []

    if prefer:
        command_strings.append(' prefer')
    if key_id:
        command_strings.append(' key {0}'.format(key_id))
    if vrf_name:
        command_strings.append(' use-vrf {0}'.format(vrf_name))

    command_strings.insert(0, 'ntp {0} {1}'.format(peer_type, address))

    command = ''.join(command_strings)

    return command


def config_ntp(delta, existing):
    address = delta.get('address', existing.get('address'))
    peer_type = delta.get('peer_type', existing.get('peer_type'))
    vrf_name = delta.get('vrf_name', existing.get('vrf_name'))
    key_id = delta.get('key_id', existing.get('key_id'))
    prefer = delta.get('prefer', existing.get('prefer'))

    source_type = delta.get('source_type')
    source = delta.get('source')

    if prefer:
        if prefer == 'enabled':
            prefer = True
        elif prefer == 'disabled':
            prefer = False

    if source:
        source_type = delta.get('source_type', existing.get('source_type'))

    ntp_cmds = []
    if peer_type:
        ntp_cmds.append(set_ntp_server_peer(
            peer_type, address, prefer, key_id, vrf_name))
    if source:
        existing_source_type = existing.get('source_type')
        existing_source = existing.get('source')
        if existing_source_type and source_type != existing_source_type:
            ntp_cmds.append('no ntp {0} {1}'.format(existing_source_type, existing_source))
        ntp_cmds.append('ntp {0} {1}'.format(source_type, source))

    return ntp_cmds


def main():
    argument_spec = dict(
            server=dict(type='str'),
            peer=dict(type='str'),
            key_id=dict(type='str'),
            prefer=dict(type='str', choices=['enabled', 'disabled']),
            vrf_name=dict(type='str'),
            source_addr=dict(type='str'),
            source_int=dict(type='str'),
            state=dict(choices=['absent', 'present'], default='present'),
    )
    module = get_network_module(argument_spec=argument_spec,
                                mutually_exclusive=[
                                    ['server','peer'],
                                    ['source_addr','source_int']],
                                supports_check_mode=True)

    server = module.params['server'] or None
    peer = module.params['peer'] or None
    key_id = module.params['key_id']
    prefer = module.params['prefer']
    vrf_name = module.params['vrf_name']
    source_addr = module.params['source_addr']
    source_int = module.params['source_int']
    state = module.params['state']
    if source_int is not None:
        source_int = source_int.lower()

    if server:
        peer_type = 'server'
        address = server
    elif peer:
        peer_type = 'peer'
        address = peer
    else:
        peer_type = None
        address = None

    source_type = None
    source = None
    if source_addr:
        source_type = 'source'
        source = source_addr
    elif source_int:
        source_type = 'source-interface'
        source = source_int

    if key_id or vrf_name or prefer:
        if not server and not peer:
            module.fail_json(
                msg='Please supply the server or peer parameter')

    args = dict(peer_type=peer_type, address=address, key_id=key_id,
                prefer=prefer, vrf_name=vrf_name, source_type=source_type,
                source=source)

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

    existing, peer_server_list = get_ntp_existing(address, peer_type, module)

    end_state = existing
    changed = False
    commands = []

    if state == 'present':
        delta = dict(set(proposed.items()).difference(existing.items()))
        if delta:
            command = config_ntp(delta, existing)
            if command:
                commands.append(command)

    elif state == 'absent':
        if existing.get('peer_type') and existing.get('address'):
            command = 'no ntp {0} {1}'.format(
                existing['peer_type'], existing['address'])
            if command:
                commands.append([command])

        existing_source_type = existing.get('source_type')
        existing_source = existing.get('source')
        proposed_source_type = proposed.get('source_type')
        proposed_source = proposed.get('source')

        if proposed_source_type:
            if proposed_source_type == existing_source_type:
                if proposed_source == existing_source:
                    command = 'no ntp {0} {1}'.format(
                                existing_source_type, existing_source)
                    if command:
                        commands.append([command])

    cmds = flatten_list(commands)
    if cmds:
        if module.check_mode:
            module.exit_json(changed=True, commands=cmds)
        else:
            changed = True
            execute_config_command(cmds, module)
            end_state = get_ntp_existing(address, peer_type, module)[0]

    results = {}
    results['proposed'] = proposed
    results['existing'] = existing
    results['updates'] = cmds
    results['changed'] = changed
    results['end_state'] = end_state
    results['peer_server_list'] = peer_server_list

    module.exit_json(**results)


from ansible.module_utils.basic import *
if __name__ == '__main__':
    main()
