#!/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_switchport
version_added: "2.1"
short_description: Manages Layer 2 switchport interfaces.
extends_documentation_fragment: nxos
description:
    - Manages Layer 2 interfaces
author: Jason Edelman (@jedelman8)
notes:
    - When C(state=absent), VLANs can be added/removed from trunk links and
      the existing access VLAN can be 'unconfigured' to just having VLAN 1
      on that interface.
    - When working with trunks VLANs the keywords add/remove are always sent
      in the `switchport trunk allowed vlan` command. Use verbose mode to see
      commands sent.
    - When C(state=unconfigured), the interface will result with having a default
      Layer 2 interface, i.e. vlan 1 in access mode.
options:
    interface:
        description:
            - Full name of the interface, i.e. Ethernet1/1.
        required: true
        default: null
    mode:
        description:
            - Mode for the Layer 2 port.
        required: false
        default: null
        choices: ['access','trunk']
    access_vlan:
        description:
            - If C(mode=access), used as the access VLAN ID.
        required: false
        default: null
    native_vlan:
        description:
            - If C(mode=trunk), used as the trunk native VLAN ID.
        required: false
        default: null
    trunk_vlans:
        description:
            - If C(mode=trunk), used as the VLAN range to ADD or REMOVE
              from the trunk.
        aliases:
          - trunk_add_vlans
        required: false
        default: null
    state:
        description:
            - Manage the state of the resource.
        required: false
        default:  present
        choices: ['present','absent', 'unconfigured']
    trunk_allowed_vlans:
        description:
            - if C(mode=trunk), these are the only VLANs that will be
              configured on the trunk, i.e. "2-10,15".
        required: false
        version_added: 2.2
        default: null
'''
EXAMPLES = '''
# ENSURE Eth1/5 is in its default switchport state
- nxos_switchport: interface=eth1/5 state=unconfigured host={{ inventory_hostname }}
# ENSURE Eth1/5 is configured for access vlan 20
- nxos_switchport: interface=eth1/5 mode=access access_vlan=20 host={{ inventory_hostname }}
# ENSURE Eth1/5 only has vlans 5-10 as trunk vlans
- nxos_switchport: interface=eth1/5 mode=trunk native_vlan=10 trunk_vlans=5-10 host={{ inventory_hostname }}
# Ensure eth1/5 is a trunk port and ensure 2-50 are being tagged (doesn't mean others aren't also being tagged)
- nxos_switchport: interface=eth1/5 mode=trunk native_vlan=10 trunk_vlans=2-50 host={{ inventory_hostname }}
# Ensure these VLANs are not being tagged on the trunk
- nxos_switchport: interface=eth1/5 mode=trunk trunk_vlans=51-4094 host={{ inventory_hostname }} state=absent
'''

RETURN = '''
proposed:
    description: k/v pairs of parameters passed into module
    returned: always
    type: dict
    sample: {"access_vlan": "10", "interface": "eth1/5", "mode": "access"}
existing:
    description: k/v pairs of existing switchport
    type: dict
    sample:  {"access_vlan": "10", "access_vlan_name": "VLAN0010",
              "interface": "Ethernet1/5", "mode": "access",
              "native_vlan": "1", "native_vlan_name": "default",
              "switchport": "Enabled", "trunk_vlans": "1-4094"}
end_state:
    description: k/v pairs of switchport after module execution
    returned: always
    type: dict or null
    sample:  {"access_vlan": "10", "access_vlan_name": "VLAN0010",
              "interface": "Ethernet1/5", "mode": "access",
              "native_vlan": "1", "native_vlan_name": "default",
              "switchport": "Enabled", "trunk_vlans": "1-4094"}
updates:
    description: command string sent to the device
    returned: always
    type: list
    sample: ["interface eth1/5", "switchport access vlan 20"]
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 get_interface_type(interface):
    """Gets the type of interface
    Args:
        interface (str): full name of interface, i.e. Ethernet1/1, loopback10,
            port-channel20, vlan20
    Returns:
        type of interface: ethernet, svi, loopback, management, portchannel,
         or unknown
    """
    if interface.upper().startswith('ET'):
        return 'ethernet'
    elif interface.upper().startswith('VL'):
        return 'svi'
    elif interface.upper().startswith('LO'):
        return 'loopback'
    elif interface.upper().startswith('MG'):
        return 'management'
    elif interface.upper().startswith('MA'):
        return 'management'
    elif interface.upper().startswith('PO'):
        return 'portchannel'
    else:
        return 'unknown'


def get_interface_mode(interface, module):
    """Gets current mode of interface: layer2 or layer3
    Args:
        device (Device): This is the device object of an NX-API enabled device
            using the Device class within device.py
        interface (string): full name of interface, i.e. Ethernet1/1,
            loopback10, port-channel20, vlan20
    Returns:
        str: 'layer2' or 'layer3'
    """
    command = 'show interface ' + interface
    intf_type = get_interface_type(interface)
    body = execute_show_command(command, module)
    mode = 'unknown'
    interface_table = {}

    try:
        interface_table = body[0]['TABLE_interface']['ROW_interface']
    except (KeyError, AttributeError, IndexError):
        return mode

    if interface_table:
        # HACK FOR NOW
        if intf_type in ['ethernet', 'portchannel']:
            mode = str(interface_table.get('eth_mode', 'layer3'))
            if mode in ['access', 'trunk']:
                mode = 'layer2'
            if mode == 'routed':
                mode = 'layer3'
        elif intf_type == 'loopback' or intf_type == 'svi':
            mode = 'layer3'
    return mode


def interface_is_portchannel(interface, module):
    """Checks to see if an interface is part of portchannel bundle
    Args:
        interface (str): full name of interface, i.e. Ethernet1/1
    Returns:
        True/False based on if interface is a member of a portchannel bundle
    """
    intf_type = get_interface_type(interface)
    if intf_type == 'ethernet':
        command = 'show interface ' + interface
        body = execute_show_command(command, module)
        try:
            interface_table = body[0]['TABLE_interface']['ROW_interface']
        except (KeyError, AttributeError, IndexError):
            interface_table = None

        if interface_table:
            state = interface_table.get('eth_bundle')
            if state:
                return True
            else:
                return False

    return False


def get_switchport(port, module):
    """Gets current config of L2 switchport
    Args:
        device (Device): This is the device object of an NX-API enabled device
            using the Device class within device.py
        port (str): full name of interface, i.e. Ethernet1/1
    Returns:
        dictionary with k/v pairs for L2 vlan config
    """

    command = 'show interface {0} switchport'.format(port)

    body = execute_show_command(command, module)

    try:
        body = execute_show_command(command, module)[0]
    except IndexError:
        body = []

    if body:
        key_map = {
            "interface": "interface",
            "oper_mode": "mode",
            "switchport": "switchport",
            "access_vlan": "access_vlan",
            "access_vlan_name": "access_vlan_name",
            "native_vlan": "native_vlan",
            "native_vlan_name": "native_vlan_name",
            "trunk_vlans": "trunk_vlans"
        }

        sp_table = body['TABLE_interface']['ROW_interface']

        sp = apply_key_map(key_map, sp_table)

        return sp
    else:
        return {}


def remove_switchport_config_commands(interface, existing, proposed, module):
    mode = proposed.get('mode')
    commands = []
    command = None
    if mode == 'access':
        av_check = existing.get('access_vlan') == proposed.get('access_vlan')
        if av_check:
            command = 'no switchport access vlan {0}'.format(
                existing.get('access_vlan'))
            commands.append(command)
    elif mode == 'trunk':
        tv_check = existing.get('trunk_vlans_list') == proposed.get('trunk_vlans_list')
        if not tv_check:
            existing_vlans = existing.get('trunk_vlans_list')
            proposed_vlans = proposed.get('trunk_vlans_list')
            vlans_to_remove = set(proposed_vlans).intersection(existing_vlans)
            if vlans_to_remove:
                command = 'switchport trunk allowed vlan remove {0}'.format(
                    proposed.get('trunk_vlans', proposed.get('trunk_allowed_vlans')))
                commands.append(command)
        native_check = existing.get(
            'native_vlan') == proposed.get('native_vlan')
        if native_check and proposed.get('native_vlan'):
            command = 'no switchport trunk native vlan {0}'.format(
                existing.get('native_vlan'))
            commands.append(command)
    if commands:
        commands.insert(0, 'interface ' + interface)
    return commands


def get_switchport_config_commands(interface, existing, proposed, module):
    """Gets commands required to config a given switchport interface
    """

    proposed_mode = proposed.get('mode')
    existing_mode = existing.get('mode')

    commands = []
    command = None
    if proposed_mode != existing_mode:
        if proposed_mode == 'trunk':
            command = 'switchport mode trunk'
        elif proposed_mode == 'access':
            command = 'switchport mode access'
    if command:
        commands.append(command)

    if proposed_mode == 'access':
        av_check = existing.get('access_vlan') == proposed.get('access_vlan')
        if not av_check:
            command = 'switchport access vlan {0}'.format(
                proposed.get('access_vlan'))
            commands.append(command)
    elif proposed_mode == 'trunk':
        tv_check = existing.get('trunk_vlans_list') == proposed.get('trunk_vlans_list')
        if not tv_check:
            if proposed.get('allowed'):
                command = 'switchport trunk allowed vlan {0}'.format(proposed.get('trunk_allowed_vlans'))
                commands.append(command)
            else:
                existing_vlans = existing.get('trunk_vlans_list')
                proposed_vlans = proposed.get('trunk_vlans_list')
                vlans_to_add = set(proposed_vlans).difference(existing_vlans)
                if vlans_to_add:
                    command = 'switchport trunk allowed vlan add {0}'.format(proposed.get('trunk_vlans'))
                    commands.append(command)

        native_check = existing.get(
            'native_vlan') == proposed.get('native_vlan')
        if not native_check and proposed.get('native_vlan'):
            command = 'switchport trunk native vlan {0}'.format(
                proposed.get('native_vlan'))
            commands.append(command)
    if commands:
        commands.insert(0, 'interface ' + interface)
    return commands


def is_switchport_default(existing):
    """Determines if switchport has a default config based on mode
    Args:
        existing (dict): existing switchport configuration from Ansible mod
    Returns:
        boolean: True if switchport has OOB Layer 2 config, i.e.
           vlan 1 and trunk all and mode is access
    """

    c1 = existing['access_vlan'] == '1'
    c2 = existing['native_vlan'] == '1'
    c3 = existing['trunk_vlans'] == '1-4094'
    c4 = existing['mode'] == 'access'

    default = c1 and c2 and c3 and c4

    return default


def default_switchport_config(interface):
    commands = []
    commands.append('interface ' + interface)
    commands.append('switchport mode access')
    commands.append('switch access vlan 1')
    commands.append('switchport trunk native vlan 1')
    commands.append('switchport trunk allowed vlan all')
    return commands


def vlan_range_to_list(vlans):
    result = []
    if vlans:
        for part in vlans.split(','):
            if part == 'none':
                break
            if '-' in part:
                a, b = part.split('-')
                a, b = int(a), int(b)
                result.extend(range(a, b + 1))
            else:
                a = int(part)
                result.append(a)
        return numerical_sort(result)
    return result


def get_list_of_vlans(module):

    command = 'show vlan'
    body = execute_show_command(command, module)
    vlan_list = []
    vlan_table = body[0].get('TABLE_vlanbrief')['ROW_vlanbrief']

    if isinstance(vlan_table, list):
        for vlan in vlan_table:
            vlan_list.append(str(vlan['vlanshowbr-vlanid-utf']))
    else:
        vlan_list.append('1')

    return vlan_list


def numerical_sort(string_int_list):
    """Sorts list of strings/integers that are digits in numerical order.
    """

    as_int_list = []
    as_str_list = []
    for vlan in string_int_list:
        as_int_list.append(int(vlan))
    as_int_list.sort()
    for vlan in as_int_list:
        as_str_list.append(str(vlan))
    return as_str_list


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


def apply_value_map(value_map, resource):
    for key, value in value_map.items():
        resource[key] = value[resource.get(key)]
    return resource


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 'status' 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 'status' 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 main():

    argument_spec = dict(
        interface=dict(required=True, type='str'),
        mode=dict(choices=['access', 'trunk'], required=False),
        access_vlan=dict(type='str', required=False),
        native_vlan=dict(type='str', required=False),
        trunk_vlans=dict(type='str', aliases=['trunk_add_vlans'], required=False),
        trunk_allowed_vlans=dict(type='str', required=False),
        state=dict(choices=['absent', 'present', 'unconfigured'],
                   default='present')
    )
    module = get_network_module(argument_spec=argument_spec,
                                mutually_exclusive=[['access_vlan', 'trunk_vlans'],
                                                    ['access_vlan', 'native_vlan'],
                                                    ['access_vlan', 'trunk_allowed_vlans']],
                                supports_check_mode=True)

    interface = module.params['interface']
    mode = module.params['mode']
    access_vlan = module.params['access_vlan']
    state = module.params['state']
    trunk_vlans = module.params['trunk_vlans']
    native_vlan = module.params['native_vlan']
    trunk_allowed_vlans = module.params['trunk_allowed_vlans']

    args = dict(interface=interface, mode=mode, access_vlan=access_vlan,
                native_vlan=native_vlan, trunk_vlans=trunk_vlans,
                trunk_allowed_vlans=trunk_allowed_vlans)

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

    interface = interface.lower()

    if mode == 'access' and state == 'present' and not access_vlan:
        module.fail_json(msg='access_vlan param is required when '
                         'mode=access && state=present')

    if mode == 'trunk' and access_vlan:
        module.fail_json(msg='access_vlan param not supported when '
                         'using mode=trunk')

    current_mode = get_interface_mode(interface, module)

    # Current mode will return layer3, layer2, or unknown
    if current_mode == 'unknown' or current_mode == 'layer3':
        module.fail_json(msg='Ensure interface is configured to be a L2'
                         '\nport first before using this module. You can use'
                         '\nthe nxos_interface module for this.')

    if interface_is_portchannel(interface, module):
        module.fail_json(msg='Cannot change L2 config on physical '
                         '\nport because it is in a portchannel. '
                         '\nYou should update the portchannel config.')

    # existing will never be null for Eth intfs as there is always a default
    existing = get_switchport(interface, module)

    # Safeguard check
    # If there isn't an existing, something is wrong per previous comment
    if not existing:
        module.fail_json(msg='Make sure you are using the FULL interface name')

    current_vlans = get_list_of_vlans(module)

    if state == 'present':
        if access_vlan and access_vlan not in current_vlans:
            module.fail_json(msg='You are trying to configure a VLAN'
                             ' on an interface that\ndoes not exist on the '
                             ' switch yet!', vlan=access_vlan)
        elif native_vlan and native_vlan not in current_vlans:
            module.fail_json(msg='You are trying to configure a VLAN'
                             ' on an interface that\ndoes not exist on the '
                             ' switch yet!', vlan=native_vlan)

    if trunk_vlans or trunk_allowed_vlans:
        if trunk_vlans:
            trunk_vlans_list = vlan_range_to_list(trunk_vlans)
        elif trunk_allowed_vlans:
            trunk_vlans_list = vlan_range_to_list(trunk_allowed_vlans)
            proposed['allowed'] = True

        existing_trunks_list = vlan_range_to_list(
            (existing['trunk_vlans'])
            )

        existing['trunk_vlans_list'] = existing_trunks_list
        proposed['trunk_vlans_list'] = trunk_vlans_list

    changed = False

    commands = []
    if state == 'present':
        command = get_switchport_config_commands(interface, existing, proposed, module)
        commands.append(command)
    elif state == 'unconfigured':
        is_default = is_switchport_default(existing)
        if not is_default:
            command = default_switchport_config(interface)
            commands.append(command)
    elif state == 'absent':
        command = remove_switchport_config_commands(interface, existing,
                                                    proposed, module)
        commands.append(command)

    if trunk_vlans or trunk_allowed_vlans:
        existing.pop('trunk_vlans_list')
        proposed.pop('trunk_vlans_list')

    end_state = existing

    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_switchport(interface, module)

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

    module.exit_json(**results)

if __name__ == '__main__':
    main()
