#!/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_vpc_interface
extends_documentation_fragment:
- cisco.nxos.nxos
short_description: Manages interface VPC configuration
description:
- Manages interface VPC configuration
version_added: 1.0.0
author:
- Jason Edelman (@jedelman8)
- Gabriele Gerbino (@GGabriele)
notes:
- Tested against NXOSv 7.3.(0)D1(1) on VIRL
- Unsupported for Cisco MDS
- Either vpc or peer_link param is required, but not both.
- C(state=absent) removes whatever VPC config is on a port-channel if one exists.
- Re-assigning a vpc or peerlink from one portchannel to another is not supported.  The
  module will force the user to unconfigure an existing vpc/pl before configuring
  the same value on a new portchannel
options:
  portchannel:
    description:
    - Group number of the portchannel that will be configured.
    required: true
    type: str
  vpc:
    description:
    - VPC group/id that will be configured on associated portchannel.
    type: str
  peer_link:
    description:
    - Set to true/false for peer link config on associated portchannel.
    type: bool
  state:
    description:
    - Manages desired state of the resource.
    choices:
    - present
    - absent
    default: present
    type: str
"""

EXAMPLES = """
- cisco.nxos.nxos_vpc_interface:
    portchannel: 10
    vpc: 100
"""

RETURN = """
commands:
    description: commands sent to the device
    returned: always
    type: list
    sample: ["interface port-channel100", "vpc 10"]
"""

from ansible.module_utils.basic import AnsibleModule

from ansible_collections.cisco.nxos.plugins.module_utils.network.nxos.nxos import (
    get_config,
    load_config,
    run_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 get_portchannel_list(module):
    portchannels = []
    pc_list = []

    try:
        body = run_commands(module, ["show port-channel summary | json"])[0]
        pc_list = body["TABLE_channel"]["ROW_channel"]
    except (KeyError, AttributeError, TypeError):
        return portchannels

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

        for pc in pc_list:
            portchannels.append(pc["group"])

    return portchannels


def get_existing_portchannel_to_vpc_mappings(module):
    pc_vpc_mapping = {}

    try:
        body = run_commands(module, ["show vpc brief | json"])[0]
        vpc_table = body["TABLE_vpc"]["ROW_vpc"]
    except (KeyError, AttributeError, TypeError):
        vpc_table = None

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

        for vpc in vpc_table:
            pc_vpc_mapping[str(vpc["vpc-id"])] = str(vpc["vpc-ifindex"])

    return pc_vpc_mapping


def peer_link_exists(module):
    found = False
    run = get_config(module, flags=["vpc"])

    vpc_list = run.split("\n")
    for each in vpc_list:
        if "peer-link" in each:
            found = True
    return found


def get_active_vpc_peer_link(module):
    peer_link = None

    try:
        body = run_commands(module, ["show vpc brief | json"])[0]
        peer_link = body["TABLE_peerlink"]["ROW_peerlink"]["peerlink-ifindex"]
    except (KeyError, AttributeError, TypeError):
        return peer_link

    return peer_link


def get_portchannel_vpc_config(module, portchannel):
    peer_link_pc = None
    peer_link = False
    vpc = ""
    pc = ""
    config = {}

    try:
        body = run_commands(module, ["show vpc brief | json"])[0]
        table = body["TABLE_peerlink"]["ROW_peerlink"]
    except (KeyError, AttributeError, TypeError):
        table = {}

    if table:
        peer_link_pc = table.get("peerlink-ifindex", None)

    if peer_link_pc:
        plpc = str(peer_link_pc[2:])
        if portchannel == plpc:
            config["portchannel"] = portchannel
            config["peer-link"] = True
            config["vpc"] = vpc

    mapping = get_existing_portchannel_to_vpc_mappings(module)

    for existing_vpc, port_channel in mapping.items():
        port_ch = str(port_channel[2:])
        if port_ch == portchannel:
            pc = port_ch
            vpc = str(existing_vpc)

            config["portchannel"] = pc
            config["peer-link"] = peer_link
            config["vpc"] = vpc

    return config


def get_commands_to_config_vpc_interface(portchannel, delta, config_value, existing):
    commands = []

    if not delta.get("peer-link") and existing.get("peer-link"):
        commands.append("no vpc peer-link")
        commands.insert(0, "interface port-channel{0}".format(portchannel))

    elif delta.get("peer-link") and not existing.get("peer-link"):
        commands.append("vpc peer-link")
        commands.insert(0, "interface port-channel{0}".format(portchannel))

    elif delta.get("vpc") and not existing.get("vpc"):
        command = "vpc {0}".format(config_value)
        commands.append(command)
        commands.insert(0, "interface port-channel{0}".format(portchannel))

    return commands


def state_present(portchannel, delta, config_value, existing):
    commands = []

    command = get_commands_to_config_vpc_interface(portchannel, delta, config_value, existing)
    commands.append(command)

    return commands


def state_absent(portchannel, existing):
    commands = []
    if existing.get("vpc"):
        command = "no vpc"
        commands.append(command)
    elif existing.get("peer-link"):
        command = "no vpc peer-link"
        commands.append(command)
    if commands:
        commands.insert(0, "interface port-channel{0}".format(portchannel))

    return commands


def main():
    argument_spec = dict(
        portchannel=dict(required=True, type="str"),
        vpc=dict(required=False, type="str"),
        peer_link=dict(required=False, type="bool"),
        state=dict(choices=["absent", "present"], default="present"),
    )

    module = AnsibleModule(
        argument_spec=argument_spec,
        mutually_exclusive=[["vpc", "peer_link"]],
        supports_check_mode=True,
    )

    warnings = list()
    commands = []
    results = {"changed": False, "warnings": warnings}

    portchannel = module.params["portchannel"]
    vpc = module.params["vpc"]
    peer_link = module.params["peer_link"]
    state = module.params["state"]

    args = {"portchannel": portchannel, "vpc": vpc, "peer-link": peer_link}
    active_peer_link = None

    if portchannel not in get_portchannel_list(module):
        if not portchannel.isdigit() or int(portchannel) not in get_portchannel_list(module):
            module.fail_json(
                msg="The portchannel you are trying to make a"
                " VPC or PL is not created yet. "
                "Create it first!",
            )
    if vpc:
        mapping = get_existing_portchannel_to_vpc_mappings(module)

        if vpc in mapping and portchannel != mapping[vpc].strip("Po"):
            module.fail_json(
                msg="This vpc is already configured on "
                "another portchannel. Remove it first "
                "before trying to assign it here. ",
                existing_portchannel=mapping[vpc],
            )

        for vpcid, existing_pc in mapping.items():
            if portchannel == existing_pc.strip("Po") and vpcid != vpc:
                module.fail_json(
                    msg="This portchannel already has another"
                    " VPC configured. Remove it first "
                    "before assigning this one",
                    existing_vpc=vpcid,
                )

        if peer_link_exists(module):
            active_peer_link = get_active_vpc_peer_link(module)
            if active_peer_link[-2:] == portchannel:
                module.fail_json(
                    msg="That port channel is the current "
                    "PEER LINK. Remove it if you want it"
                    " to be a VPC",
                )
        config_value = vpc

    elif peer_link is not None:
        if peer_link_exists(module):
            active_peer_link = get_active_vpc_peer_link(module)[2::]
            if active_peer_link != portchannel:
                if peer_link:
                    module.fail_json(
                        msg="A peer link already exists on" " the device. Remove it first",
                        current_peer_link="Po{0}".format(active_peer_link),
                    )
        config_value = "peer-link"

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

    if state == "present":
        delta = dict(set(proposed.items()).difference(existing.items()))
        if delta:
            commands = state_present(portchannel, delta, config_value, existing)

    elif state == "absent" and existing:
        commands = state_absent(portchannel, existing)

    cmds = flatten_list(commands)
    if cmds:
        if module.check_mode:
            module.exit_json(changed=True, commands=cmds)
        else:
            load_config(module, cmds)
            results["changed"] = True
            if "configure" in cmds:
                cmds.pop(0)

    results["commands"] = cmds
    module.exit_json(**results)


if __name__ == "__main__":
    main()