#!/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_portchannel
version_added: "2.2"
short_description: Manages port-channel interfaces.
description:
    - Manages port-channel specific configuration parameters.
extends_documentation_fragment: nxos
author:
    - Jason Edelman (@jedelman8)
    - Gabriele Gerbino (@GGabriele)
notes:
    - C(state=absent) removes the portchannel config and interface if it
      already exists. If members to be removed are not explicitly
      passed, all existing members (if any), are removed.
    - Members must be a list.
    - LACP needs to be enabled first if active/passive modes are used.
options:
    group:
        description:
            - Channel-group number for the port-channel.
        required: true
    mode:
        description:
            - Mode for the port-channel, i.e. on, active, passive.
        required: false
        default: on
        choices: ['active','passive','on']
    min_links:
        description:
            - Min links required to keep portchannel up.
        required: false
        default: null
    members:
        description:
            - List of interfaces that will be managed in a given portchannel.
        required: false
        default: null
    force:
        description:
            - When true it forces port-channel members to match what is
              declared in the members param. This can be used to remove
              members.
        required: false
        choices: ['true', 'false']
        default: false
    state:
        description:
            - Manage the state of the resource.
        required: false
        default: present
        choices: ['present','absent']
'''
EXAMPLES = '''
# Ensure port-channel99 is created, add two members, and set to mode on
- nxos_portchannel:
    group: 99
    members: ['Ethernet1/1','Ethernet1/2']
    mode: 'active'
    state: present
    username: "{{ un }}"
    password: "{{ pwd }}"
    host: "{{ inventory_hostname }}"
'''

RETURN = '''
proposed:
    description: k/v pairs of parameters passed into module
    returned: always
    type: dict
    sample: {"group": "12", "members": ["Ethernet2/5",
            "Ethernet2/6"], "mode": "on"}
existing:
    description:
        - k/v pairs of existing portchannel
    type: dict
    sample: {"group": "12", "members": ["Ethernet2/5",
            "Ethernet2/6"], "members_detail": {
            "Ethernet2/5": {"mode": "active", "status": "D"},
            "Ethernet2/6": {"mode": "active", "status": "D"}},
            "min_links": null, "mode": "active"}
end_state:
    description: k/v pairs of portchannel info after module execution
    returned: always
    type: dict
    sample: {"group": "12", "members": ["Ethernet2/5",
            "Ethernet2/6"], "members_detail": {
            "Ethernet2/5": {"mode": "on", "status": "D"},
            "Ethernet2/6": {"mode": "on", "status": "D"}},
            "min_links": null, "mode": "on"}
updates:
    description: command sent to the device
    returned: always
    type: list
    sample: ["interface Ethernet2/6", "no channel-group 12",
             "interface Ethernet2/5", "no channel-group 12",
             "interface Ethernet2/6", "channel-group 12 mode on",
             "interface Ethernet2/5", "channel-group 12 mode on"]
changed:
    description: check to see if a change was made on the device
    returned: always
    type: boolean
    sample: true
'''

import collections
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
WARNINGS = []
PARAM_TO_COMMAND_KEYMAP = {
    'min_links': 'lacp min-links'
}


def invoke(name, *args, **kwargs):
    func = globals().get(name)
    if func:
        return func(*args, **kwargs)


def get_value(arg, config, module):
    REGEX = re.compile(r'(?:{0}\s)(?P<value>.*)$'.format(PARAM_TO_COMMAND_KEYMAP[arg]), re.M)
    value = ''
    if PARAM_TO_COMMAND_KEYMAP[arg] in config:
        value = REGEX.search(config).group('value')
    return value


def check_interface(module, netcfg):
    config = str(netcfg)
    REGEX = re.compile(r'\s+interface port-channel{0}*$'.format(module.params['group']), re.M)
    value = False
    try:
        if REGEX.search(config):
            value = True
    except TypeError:
        value = False

    return value


def get_custom_value(arg, config, module):
    REGEX = re.compile(r'\s+member vni {0} associate-vrf\s*$'.format(
                                                module.params['vni']), re.M)
    value = False
    try:
        if REGEX.search(config):
            value = True
    except TypeError:
        value = False
    return value


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


def get_cli_body_ssh(command, response, module):
    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 port-channel summary' 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 get_portchannel_members(pchannel):
    try:
        members = pchannel['TABLE_member']['ROW_member']
    except KeyError:
        members = []

    return members


def get_portchannel_mode(interface, protocol, module, netcfg):
    if protocol != 'LACP':
        mode = 'on'
    else:
        netcfg = get_config(module)
        parents = ['interface {0}'.format(interface.capitalize())]
        body = netcfg.get_section(parents)

        mode_list = body.split('\n')

        for line in mode_list:
            this_line = line.strip()
            if this_line.startswith('channel-group'):
                find = this_line
        if 'mode' in find:
            if 'passive' in find:
                mode = 'passive'
            elif 'active' in find:
                mode = 'active'

    return mode


def get_portchannel(module, netcfg=None):
    command = 'show port-channel summary'
    portchannel = {}
    portchannel_table = {}
    members = []

    body = execute_show_command(command, module)

    try:
        pc_table = body[0]['TABLE_channel']['ROW_channel']

        if isinstance(pc_table, dict):
            pc_table = [pc_table]

        for pc in pc_table:
            if pc['group'] == module.params['group']:
                portchannel_table = pc
    except (KeyError, AttributeError, TypeError, IndexError):
        return {}

    if portchannel_table:
        portchannel['group'] = portchannel_table['group']
        protocol = portchannel_table['prtcl']
        members_list = get_portchannel_members(portchannel_table)

        if isinstance(members_list, dict):
            members_list = [members_list]

        member_dictionary = {}
        for each_member in members_list:
            interface = each_member['port']
            members.append(interface)

            pc_member = {}
            pc_member['status'] = str(each_member['port-status'])
            pc_member['mode'] = get_portchannel_mode(interface,
                                                     protocol, module, netcfg)

            member_dictionary[interface] = pc_member
            portchannel['members'] = members
            portchannel['members_detail'] = member_dictionary

        # Ensure each member have the same mode.
        modes = set()
        for each, value in member_dictionary.items():
            modes.update([value['mode']])
        if len(modes) == 1:
            portchannel['mode'] = value['mode']
        else:
            portchannel['mode'] = 'unknown'
    return portchannel


def get_existing(module, args):
    existing = {}
    netcfg = get_config(module)

    interface_exist = check_interface(module, netcfg)
    if interface_exist:
        parents = ['interface port-channel{0}'.format(module.params['group'])]
        config = netcfg.get_section(parents)

        if config:
            existing['min_links'] = get_value('min_links', config, module)
            existing.update(get_portchannel(module, netcfg=netcfg))

    return existing, interface_exist


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] = value
            else:
                new_dict[new_key] = value
    return new_dict


def config_portchannel(proposed, mode, group):
    commands = []
    config_args = {
        'mode': 'channel-group {group} mode {mode}',
        'min_links': 'lacp min-links {min_links}',
    }

    for member in proposed.get('members', []):
        commands.append('interface {0}'.format(member))
        commands.append(config_args.get('mode').format(group=group, mode=mode))

    min_links = proposed.get('min_links', None)
    if min_links:
        command = 'interface port-channel {0}'.format(group)
        commands.append(command)
        commands.append(config_args.get('min_links').format(
                                                    min_links=min_links))

    return commands


def get_commands_to_add_members(proposed, existing, module):
    try:
        proposed_members = proposed['members']
    except KeyError:
        proposed_members = []

    try:
        existing_members = existing['members']
    except KeyError:
        existing_members = []

    members_to_add = list(set(proposed_members).difference(existing_members))

    commands = []
    if members_to_add:
        for member in members_to_add:
            commands.append('interface {0}'.format(member))
            commands.append('channel-group {0} mode {1}'.format(
                existing['group'], proposed['mode']))

    return commands


def get_commands_to_remove_members(proposed, existing, module):
    try:
        proposed_members = proposed['members']
    except KeyError:
        proposed_members = []

    try:
        existing_members = existing['members']
    except KeyError:
        existing_members = []

    members_to_remove = list(set(existing_members).difference(proposed_members))
    commands = []
    if members_to_remove:
        for member in members_to_remove:
            commands.append('interface {0}'.format(member))
            commands.append('no channel-group {0}'.format(existing['group']))

    return commands


def get_commands_if_mode_change(proposed, existing, group, mode, module):
    try:
        proposed_members = proposed['members']
    except KeyError:
        proposed_members = []

    try:
        existing_members = existing['members']
    except KeyError:
        existing_members = []

    try:
        members_dict = existing['members_detail']
    except KeyError:
        members_dict = {}

    members_to_remove = set(existing_members).difference(proposed_members)
    members_with_mode_change = []
    if members_dict:
        for interface, values in members_dict.items():
            if (interface in proposed_members and
                    (interface not in members_to_remove)):
                if values['mode'] != mode:
                    members_with_mode_change.append(interface)

    commands = []
    if members_with_mode_change:
        for member in members_with_mode_change:
            commands.append('interface {0}'.format(member))
            commands.append('no channel-group {0}'.format(group))

        for member in members_with_mode_change:
            commands.append('interface {0}'.format(member))
            commands.append('channel-group {0} mode {1}'.format(group, mode))

    return commands


def get_commands_min_links(existing, proposed, group, min_links, module):
    commands = []
    try:
        if (existing['min_links'] is None or
                (existing['min_links'] != proposed['min_links'])):
            commands.append('interface port-channel{0}'.format(group))
            commands.append('lacp min-link {0}'.format(min_links))
    except KeyError:
        commands.append('interface port-channel{0}'.format(group))
        commands.append('lacp min-link {0}'.format(min_links))
    return commands


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 main():
    argument_spec = dict(
            group=dict(required=True, type='str'),
            mode=dict(required=False, choices=['on', 'active', 'passive'],
                      default='on', type='str'),
            min_links=dict(required=False, default=None, type='str'),
            members=dict(required=False, default=None, type='list'),
            force=dict(required=False, default='false', type='str',
                       choices=['true', 'false']),
            state=dict(required=False, choices=['absent', 'present'],
                       default='present'),
            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)

    group = str(module.params['group'])
    mode = module.params['mode']
    min_links = module.params['min_links']
    members = module.params['members']
    state = module.params['state']

    if str(module.params['force']).lower() == 'true':
        force = True
    elif module.params['force'] == 'false':
        force = False

    if ((min_links or mode) and
            (not members and state == 'present')):
        module.fail_json(msg='"members" is required when state=present and '
                             '"min_links" or "mode" are provided')

    changed = False
    args =  [
            'group',
            'members',
            'min_links',
            'mode'
        ]

    existing, interface_exist = invoke('get_existing', module, args)
    end_state = existing
    proposed = dict((k, v) for k, v in module.params.items()
                    if v is not None and k in args)

    result = {}
    commands = []
    if state == 'absent':
        if existing:
            commands.append(['no interface port-channel{0}'.format(group)])
    elif state == 'present':
        if not interface_exist:
            command = config_portchannel(proposed, mode, group)
            commands.append(command)
            commands.insert(0, 'interface port-channel{0}'.format(group))
            WARNINGS.append("The proposed port-channel interface did not "
                            "exist. It's recommended to use nxos_interface to "
                            "create all logical interfaces.")

        elif existing and interface_exist:
            if force:
                command = get_commands_to_remove_members(proposed, existing, module)
                commands.append(command)

            command = get_commands_to_add_members(proposed, existing, module)
            commands.append(command)

            mode_command = get_commands_if_mode_change(proposed, existing,
                                                       group, mode, module)

            commands.insert(0, mode_command)

            if min_links:
                command = get_commands_min_links(existing, proposed,
                                                 group, min_links, module)
                commands.append(command)

    cmds = flatten_list(commands)
    if cmds:
        if module.check_mode:
            module.exit_json(changed=True, commands=cmds)
        else:
            output = execute_config_command(cmds, module)
            changed = True
            end_state, interface_exist = get_existing(module, args)

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

    if WARNINGS:
        results['warnings'] = WARNINGS

    module.exit_json(**results)


if __name__ == '__main__':
    main()