#!/usr/bin/python
# -*- coding: utf-8 -*-
from __future__ import absolute_import, division, print_function


__metaclass__ = type

# (c) 2017, Ansible by Red Hat, inc
#
# This file is part of Ansible by Red Hat
#
# 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: eos_vrf
author: Ricardo Carrillo Cruz (@rcarrillocruz)
short_description: Manage VRFs on Arista EOS network devices
description:
- This module provides declarative management of VRFs on Arista EOS network devices.
version_added: 1.0.0
notes:
- Tested against Arista EOS 4.24.6F
options:
  name:
    description:
    - Name of the VRF.
    type: str
  rd:
    description:
    - Route distinguisher of the VRF
    type: str
  interfaces:
    description:
    - Identifies the set of interfaces that should be configured in the VRF. Interfaces
      must be routed interfaces in order to be placed into a VRF. The name of interface
      should be in expanded format and not abbreviated.
    type: list
    elements: str
  associated_interfaces:
    description:
    - This is a intent option and checks the operational state of the for given vrf
      C(name) for associated interfaces. If the value in the C(associated_interfaces)
      does not match with the operational state of vrf interfaces on device it will
      result in failure.
    type: list
    elements: str
  aggregate:
    description: List of VRFs instances
    type: list
    elements: dict
    suboptions:
      name:
        description:
        - Name of the VRF.
        required: true
        type: str
      rd:
        description:
        - Route distinguisher of the VRF
        type: str
      interfaces:
        description:
        - Identifies the set of interfaces that should be configured in the VRF. Interfaces
          must be routed interfaces in order to be placed into a VRF. The name of interface
          should be in expanded format and not abbreviated.
        type: list
        elements: str
      associated_interfaces:
        description:
        - This is a intent option and checks the operational state of the for given vrf
          C(name) for associated interfaces. If the value in the C(associated_interfaces)
          does not match with the operational state of vrf interfaces on device it will
          result in failure.
        type: list
        elements: str
      delay:
        description:
        - Time in seconds to wait before checking for the operational state on remote
          device. This wait is applicable for operational state arguments.
        default: 10
        type: int
      state:
        description:
        - State of the VRF configuration.
        default: present
        type: str
        choices:
        - present
        - absent
  purge:
    description:
    - Purge VRFs not defined in the I(aggregate) parameter.
    default: false
    type: bool
  delay:
    description:
    - Time in seconds to wait before checking for the operational state on remote
      device. This wait is applicable for operational state arguments.
    default: 10
    type: int
  state:
    description:
    - State of the VRF configuration.
    default: present
    type: str
    choices:
    - present
    - absent
"""

EXAMPLES = """
- name: Create vrf
  arista.eos.eos_vrf:
    name: test
    rd: 1:200
    interfaces:
    - Ethernet2
    state: present

- name: Delete VRFs
  arista.eos.eos_vrf:
    name: test
    state: absent

- name: Create aggregate of VRFs with purge
  arista.eos.eos_vrf:
    aggregate:
    - name: test4
      rd: 1:204
    - name: test5
      rd: 1:205
    state: present
    purge: yes

- name: Delete aggregate of VRFs
  arista.eos.eos_vrf:
    aggregate:
    - name: test2
    - name: test3
    - name: test4
    - name: test5
    state: absent
"""

RETURN = """
commands:
  description: The list of configuration mode commands to send to the device
  returned: always
  type: list
  sample:
    - vrf instance test
    - rd 1:100
    - interface Ethernet1
    - vrf test
"""
import re
import time

from copy import deepcopy

from ansible.module_utils.basic import AnsibleModule
from ansible_collections.ansible.netcommon.plugins.module_utils.network.common.utils import (
    remove_default_spec,
)

from ansible_collections.arista.eos.plugins.module_utils.network.eos.eos import (
    load_config,
    run_commands,
)


def search_obj_in_list(name, lst):
    for o in lst:
        if o["name"] == name:
            return o


def map_obj_to_commands(updates, module):
    commands = list()
    want, have = updates
    state = module.params["state"]
    purge = module.params["purge"]

    for w in want:
        name = w["name"]
        rd = w["rd"]

        obj_in_have = search_obj_in_list(name, have)

        if state == "absent":
            if obj_in_have:
                commands.append("no vrf instance %s" % name)
        elif state == "present":
            if not obj_in_have:
                commands.append("vrf instance %s" % name)

                if rd is not None:
                    commands.append("rd %s" % rd)

                if w["interfaces"]:
                    for i in w["interfaces"]:
                        commands.append("interface %s" % i)
                        commands.append("vrf %s" % w["name"])
            else:
                if w["rd"] is not None and w["rd"] != obj_in_have["rd"]:
                    commands.append("vrf instance %s" % w["name"])
                    commands.append("rd %s" % w["rd"])

                if w["interfaces"]:
                    if not obj_in_have["interfaces"]:
                        for i in w["interfaces"]:
                            commands.append("interface %s" % i)
                            commands.append("vrf %s" % w["name"])
                    elif set(w["interfaces"]) != obj_in_have["interfaces"]:
                        missing_interfaces = list(
                            set(w["interfaces"])
                            - set(obj_in_have["interfaces"]),
                        )

                        for i in missing_interfaces:
                            commands.append("interface %s" % i)
                            commands.append("vrf %s" % w["name"])

    if purge:
        for h in have:
            obj_in_want = search_obj_in_list(h["name"], want)
            if not obj_in_want:
                commands.append("no vrf instance %s" % h["name"])

    return commands


def map_config_to_obj(module):
    objs = []
    output = run_commands(module, {"command": "show vrf", "output": "text"})

    lines = output[0].strip().splitlines()[3:]

    out_len = len(lines)
    index = 0
    while out_len > index:
        line = lines[index]
        if not line:
            continue

        splitted_line = re.split(r"\s{2,}", line.strip())

        if len(splitted_line) == 1:
            index += 1
            continue
        obj = dict()
        obj["name"] = splitted_line[0]
        obj["rd"] = splitted_line[1]
        obj["interfaces"] = []

        if len(splitted_line) > 4:
            obj["interfaces"] = []
            interfaces = splitted_line[4]
            if interfaces.endswith(","):
                while interfaces.endswith(","):
                    # gather all comma separated interfaces
                    if out_len <= index:
                        break
                    index += 1
                    line = lines[index]
                    vrf_line = re.split(r"\s{2,}", line.strip())
                    interfaces += vrf_line[-1]

            for i in interfaces.split(","):
                obj["interfaces"].append(i.strip().lower())
        index += 1
        objs.append(obj)

    return objs


def map_params_to_obj(module):
    obj = []
    aggregate = module.params.get("aggregate")
    if aggregate:
        for item in aggregate:
            for key in item:
                if item.get(key) is None:
                    item[key] = module.params[key]

            if item.get("interfaces"):
                item["interfaces"] = [
                    intf.replace(" ", "").lower()
                    for intf in item.get("interfaces")
                    if intf
                ]

            if item.get("associated_interfaces"):
                item["associated_interfaces"] = [
                    intf.replace(" ", "").lower()
                    for intf in item.get("associated_interfaces")
                    if intf
                ]

            obj.append(item.copy())
    else:
        obj.append(
            {
                "name": module.params["name"],
                "state": module.params["state"],
                "rd": module.params["rd"],
                "interfaces": [
                    intf.replace(" ", "").lower()
                    for intf in module.params["interfaces"]
                ]
                if module.params["interfaces"]
                else [],
                "associated_interfaces": [
                    intf.replace(" ", "").lower()
                    for intf in module.params["associated_interfaces"]
                ]
                if module.params["associated_interfaces"]
                else [],
            },
        )

    return obj


def check_declarative_intent_params(want, module, result):
    have = None
    is_delay = False

    for w in want:
        if w.get("associated_interfaces") is None:
            continue

        if result["changed"] and not is_delay:
            time.sleep(module.params["delay"])
            is_delay = True

        if have is None:
            have = map_config_to_obj(module)

        for i in w["associated_interfaces"]:
            obj_in_have = search_obj_in_list(w["name"], have)

            if obj_in_have:
                interfaces = obj_in_have.get("interfaces")
                if interfaces is not None and i not in interfaces:
                    module.fail_json(
                        msg="Interface %s not configured on vrf %s"
                        % (i, w["name"]),
                    )


def main():
    """main entry point for module execution"""
    element_spec = dict(
        name=dict(),
        interfaces=dict(type="list", elements="str"),
        associated_interfaces=dict(type="list", elements="str"),
        delay=dict(default=10, type="int"),
        rd=dict(),
        state=dict(default="present", choices=["present", "absent"]),
    )

    aggregate_spec = deepcopy(element_spec)
    aggregate_spec["name"] = dict(required=True)

    # remove default in aggregate spec, to handle common arguments
    remove_default_spec(aggregate_spec)
    aggregate_spec["state"].update(default="present")
    aggregate_spec["delay"].update(default=10)

    argument_spec = dict(
        aggregate=dict(type="list", elements="dict", options=aggregate_spec),
        purge=dict(default=False, type="bool"),
    )

    argument_spec.update(element_spec)

    required_one_of = [["name", "aggregate"]]
    mutually_exclusive = [["name", "aggregate"]]
    module = AnsibleModule(
        argument_spec=argument_spec,
        required_one_of=required_one_of,
        mutually_exclusive=mutually_exclusive,
        supports_check_mode=True,
    )

    warnings = list()

    result = {"changed": False}

    if warnings:
        result["warnings"] = warnings

    want = map_params_to_obj(module)
    have = map_config_to_obj(module)

    commands = map_obj_to_commands((want, have), module)
    result["commands"] = commands

    if commands:
        commit = not module.check_mode
        response = load_config(module, commands, commit=commit)
        if response.get("diff") and module._diff:
            result["diff"] = {"prepared": response.get("diff")}
        result["session_name"] = response.get("session")
        result["changed"] = True

    check_declarative_intent_params(want, module, result)

    module.exit_json(**result)


if __name__ == "__main__":
    main()
