#!/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/>.
#
from __future__ import absolute_import, division, print_function


__metaclass__ = type


DOCUMENTATION = """
module: nxos_evpn_vni
extends_documentation_fragment:
- cisco.nxos.nxos
short_description: Manages Cisco EVPN VXLAN Network Identifier (VNI).
description:
- Manages Cisco Ethernet Virtual Private Network (EVPN) VXLAN Network Identifier (VNI)
  configurations of a Nexus device.
version_added: 1.0.0
author: Gabriele Gerbino (@GGabriele)
notes:
- Tested against NXOSv 7.3.(0)D1(1) on VIRL
- Unsupported for Cisco MDS
- default, where supported, restores params default value.
- RD override is not permitted. You should set it to the default values first and
  then reconfigure it.
- C(route_target_both), C(route_target_import) and C(route_target_export valid) values
  are a list of extended communities, (i.e. ['1.2.3.4:5', '33:55']) or the keywords
  'auto' or 'default'.
- The C(route_target_both) property is discouraged due to the inconsistent behavior
  of the property across Nexus platforms and image versions. For this reason it is
  recommended to use explicit C(route_target_export) and C(route_target_import) properties
  instead of C(route_target_both).
- RD valid values are a string in one of the route-distinguisher formats, the keyword
  'auto', or the keyword 'default'.
options:
  vni:
    description:
    - The EVPN VXLAN Network Identifier.
    required: true
    type: str
  route_distinguisher:
    description:
    - The VPN Route Distinguisher (RD). The RD is combined with the IPv4 or IPv6 prefix
      learned by the PE router to create a globally unique address.
    type: str
  route_target_both:
    description:
    - Enables/Disables route-target settings for both import and export target communities
      using a single property.
    type: list
    elements: str
  route_target_import:
    description:
    - Sets the route-target 'import' extended communities.
    type: list
    elements: str
  route_target_export:
    description:
    - Sets the route-target 'export' extended communities.
    type: list
    elements: str
  state:
    description:
    - Determines whether the config should be present or not on the device.
    default: present
    choices:
    - present
    - absent
    type: str
"""

EXAMPLES = """
- name: vni configuration
  cisco.nxos.nxos_evpn_vni:
    vni: 6000
    route_distinguisher: 60:10
    route_target_import:
    - 5000:10
    - 4100:100
    route_target_export: auto
    route_target_both: default
"""

RETURN = """
commands:
    description: commands sent to the device
    returned: always
    type: list
    sample: ["evpn", "vni 6000 l2", "route-target import 5001:10"]
"""

import re

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.config import (
    CustomNetworkConfig,
)

from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    get_config,
    load_config,
)


PARAM_TO_COMMAND_KEYMAP = {
    "vni": "vni",
    "route_distinguisher": "rd",
    "route_target_both": "route-target both",
    "route_target_import": "route-target import",
    "route_target_export": "route-target export",
}


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


def get_route_target_value(arg, config, module):
    splitted_config = config.splitlines()
    value_list = []
    command = PARAM_TO_COMMAND_KEYMAP.get(arg)
    command_re = re.compile(r"(?:{0}\s)(?P<value>.*)$".format(command), re.M)

    for line in splitted_config:
        value = ""
        if command in line.strip():
            value = command_re.search(line).group("value")
            value_list.append(value)
    return value_list


def get_existing(module, args):
    existing = {}
    netcfg = CustomNetworkConfig(indent=2, contents=get_config(module))
    parents = ["evpn", "vni {0} l2".format(module.params["vni"])]
    config = netcfg.get_section(parents)

    if config:
        for arg in args:
            if arg != "vni":
                if arg == "route_distinguisher":
                    existing[arg] = get_value(arg, config, module)
                else:
                    existing[arg] = get_route_target_value(arg, config, module)

        existing_fix = dict((k, v) for k, v in existing.items() if v)
        if not existing_fix:
            existing = existing_fix

        existing["vni"] = module.params["vni"]

    return existing


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


def fix_proposed(proposed_commands):
    new_proposed = {}
    for key, value in proposed_commands.items():
        if key == "route-target both":
            new_proposed["route-target export"] = value
            new_proposed["route-target import"] = value
        else:
            new_proposed[key] = value
    return new_proposed


def state_present(module, existing, proposed):
    commands = list()
    parents = list()
    proposed_commands = apply_key_map(PARAM_TO_COMMAND_KEYMAP, proposed)
    existing_commands = apply_key_map(PARAM_TO_COMMAND_KEYMAP, existing)

    if proposed_commands.get("route-target both"):
        proposed_commands = fix_proposed(proposed_commands)

    for key, value in proposed_commands.items():
        if key.startswith("route-target"):
            if value == ["default"]:
                existing_value = existing_commands.get(key)

                if existing_value:
                    for target in existing_value:
                        commands.append("no {0} {1}".format(key, target))
            elif not isinstance(value, list):
                value = [value]

            for target in value:
                if target == "default":
                    continue
                if existing:
                    if target not in existing.get(key.replace("-", "_").replace(" ", "_")):
                        commands.append("{0} {1}".format(key, target))
                else:
                    commands.append("{0} {1}".format(key, target))

            if existing.get(key.replace("-", "_").replace(" ", "_")):
                for exi in existing.get(key.replace("-", "_").replace(" ", "_")):
                    if exi not in value:
                        commands.append("no {0} {1}".format(key, exi))

        elif value == "default":
            existing_value = existing_commands.get(key)
            if existing_value:
                commands.append("no {0} {1}".format(key, existing_value))
        else:
            command = "{0} {1}".format(key, value)
            commands.append(command)

    if commands:
        parents = ["evpn", "vni {0} l2".format(module.params["vni"])]

    return commands, parents


def state_absent(module, existing, proposed):
    commands = ["no vni {0} l2".format(module.params["vni"])]
    parents = ["evpn"]
    return commands, parents


def main():
    argument_spec = dict(
        vni=dict(required=True, type="str"),
        route_distinguisher=dict(required=False, type="str"),
        route_target_both=dict(required=False, type="list", elements="str"),
        route_target_import=dict(required=False, type="list", elements="str"),
        route_target_export=dict(required=False, type="list", elements="str"),
        state=dict(choices=["present", "absent"], default="present", required=False),
    )

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

    warnings = list()
    results = dict(changed=False, warnings=warnings)

    state = module.params["state"]
    args = PARAM_TO_COMMAND_KEYMAP.keys()
    existing = get_existing(module, args)
    proposed_args = dict((k, v) for k, v in module.params.items() if v is not None and k in args)
    commands = []
    parents = []

    proposed = {}
    for key, value in proposed_args.items():
        if key != "vni":
            if value == "true":
                value = True
            elif value == "false":
                value = False
            if existing.get(key) != value:
                proposed[key] = value

    if state == "present":
        commands, parents = state_present(module, existing, proposed)
    elif state == "absent" and existing:
        commands, parents = state_absent(module, existing, proposed)

    if commands:
        candidate = CustomNetworkConfig(indent=3)
        candidate.add(commands, parents=parents)
        candidate = candidate.items_text()
        if not module.check_mode:
            load_config(module, candidate)
            results["changed"] = True
        results["commands"] = candidate
    else:
        results["commands"] = []
    module.exit_json(**results)


if __name__ == "__main__":
    main()