"""Helper methods that are used across :term:`GSO`."""

import ipaddress
import re
from ipaddress import IPv4Address
from uuid import UUID

import pycountry
from orchestrator import step
from orchestrator.types import State, UUIDstr
from pydantic import BaseModel
from pydantic_forms.validators import Choice

from gso.products.product_blocks.iptrunk import IptrunkInterfaceBlock
from gso.products.product_blocks.router import RouterVendor
from gso.products.product_types.iptrunk import Iptrunk
from gso.products.product_types.router import Router
from gso.services import provisioning_proxy
from gso.services.netbox_client import NetboxClient
from gso.services.subscriptions import get_active_subscriptions_by_field_and_value


class LAGMember(BaseModel):
    """A :term:`LAG` member interface that consists of a name and description.

    TODO: validate interface name
    """

    interface_name: str
    interface_description: str

    def __hash__(self) -> int:
        """Calculate the hash based on the interface name and description, so that uniqueness can be determined.

        TODO: Check if this is still needed
        """
        return hash((self.interface_name, self.interface_description))


@step("[COMMIT] Set ISIS metric to 90.000")
def set_isis_to_90000(subscription: Iptrunk, process_id: UUIDstr, callback_route: str, tt_number: str) -> State:
    """Workflow step for setting the :term:`ISIS` metric to 90k as an arbitrarily high value to drain a link."""
    old_isis_metric = subscription.iptrunk.iptrunk_isis_metric
    subscription.iptrunk.iptrunk_isis_metric = 90000
    provisioning_proxy.provision_ip_trunk(
        subscription,
        process_id,
        callback_route,
        tt_number,
        "isis_interface",
        dry_run=False,
    )

    return {
        "subscription": subscription,
        "old_isis_metric": old_isis_metric,
    }


def available_interfaces_choices(router_id: UUID, speed: str) -> Choice | None:
    """Return a list of available interfaces for a given router and speed.

    For Nokia routers, return a list of available interfaces.
    For Juniper routers, return a string.
    """
    if get_router_vendor(router_id) != RouterVendor.NOKIA:
        return None
    interfaces = {
        interface["name"]: f"{interface['name']} - {interface['module']['display']} - {interface['description']}"
        for interface in NetboxClient().get_available_interfaces(router_id, speed)
    }
    return Choice("ae member", zip(interfaces.keys(), interfaces.items(), strict=True))  # type: ignore[arg-type]


def available_interfaces_choices_including_current_members(
    router_id: UUID,
    speed: str,
    interfaces: list[IptrunkInterfaceBlock],
) -> Choice | None:
    """Return a list of available interfaces for a given router and speed including the current members.

    For Nokia routers, return a list of available interfaces.
    For Juniper routers, return a string.
    """
    if get_router_vendor(router_id) != RouterVendor.NOKIA:
        return None

    available_interfaces = list(NetboxClient().get_available_interfaces(router_id, speed))
    available_interfaces.extend(
        [
            NetboxClient().get_interface_by_name_and_device(
                interface.interface_name,
                Router.from_subscription(router_id).router.router_fqdn,
            )
            for interface in interfaces
        ],
    )
    options = {
        interface["name"]: f"{interface['name']} - {interface['module']['display']} - {interface['description']}"
        for interface in available_interfaces
    }
    return Choice("ae member", zip(options.keys(), options.items(), strict=True))  # type: ignore[arg-type]


def available_lags_choices(router_id: UUID) -> Choice | None:
    """Return a list of available lags for a given router.

    For Nokia routers, return a list of available lags.
    For Juniper routers, return ``None``.
    """
    if get_router_vendor(router_id) != RouterVendor.NOKIA:
        return None
    side_a_ae_iface_list = NetboxClient().get_available_lags(router_id)
    return Choice("ae iface", zip(side_a_ae_iface_list, side_a_ae_iface_list, strict=True))  # type: ignore[arg-type]


def get_router_vendor(router_id: UUID) -> RouterVendor:
    """Retrieve the vendor of a router.

    :param router_id: The :term:`UUID` of the router.
    :type router_id: :class:`uuid.UUID`

    :return: The vendor of the router.
    :rtype: RouterVendor:
    """
    return Router.from_subscription(router_id).router.vendor


def iso_from_ipv4(ipv4_address: IPv4Address) -> str:
    """Calculate an :term:`ISO` address, based on an IPv4 address.

    :param IPv4Address ipv4_address: The address that's to be converted
    :returns: An :term:`ISO`-formatted address.
    """
    padded_octets = [f"{x:>03}" for x in str(ipv4_address).split(".")]
    joined_octets = "".join(padded_octets)
    re_split = ".".join(re.findall("....", joined_octets))
    return f"49.51e5.0001.{re_split}.00"


def validate_router_in_netbox(subscription_id: UUIDstr) -> UUIDstr:
    """Verify if a device exists in Netbox.

    Raises a :class:`ValueError` if the device is not found.

    :param subscription_id: The :term:`UUID` of the router subscription.
    :type subscription_id: :class:`UUIDstr`

    :return: The :term:`UUID` of the router subscription.
    :rtype: :class:`UUIDstr`
    """
    router_type = Router.from_subscription(subscription_id)
    if router_type.router.vendor == RouterVendor.NOKIA:
        device = NetboxClient().get_device_by_name(router_type.router.router_fqdn)
        if not device:
            msg = "The selected router does not exist in Netbox."
            raise ValueError(msg)
    return subscription_id


def validate_iptrunk_unique_interface(interfaces: list[LAGMember]) -> list[LAGMember]:
    """Verify if the interfaces are unique.

    Raises a :class:`ValueError` if the interfaces are not unique.

    :param interfaces: The list of interfaces.
    :type interfaces: list[:class:`LAGMember`]

    :return: The list of interfaces
    :rtype: list[:class:`LAGMember`]
    """
    interface_names = [member.interface_name for member in interfaces]
    if len(interface_names) != len(set(interface_names)):
        msg = "Interfaces must be unique."
        raise ValueError(msg)
    return interfaces


def validate_site_fields_is_unique(field_name: str, value: str | int) -> str | int:
    """Validate that a site field is unique."""
    if len(get_active_subscriptions_by_field_and_value(field_name, str(value))) > 0:
        msg = f"{field_name} must be unique"
        raise ValueError(msg)
    return value


def validate_ipv4_or_ipv6(value: str) -> str:
    """Validate that a value is a valid IPv4 or IPv6 address."""
    try:
        ipaddress.ip_address(value)
    except ValueError as e:
        msg = "Enter a valid IPv4 or IPv6 address."
        raise ValueError(msg) from e
    else:
        return value


def validate_country_code(country_code: str) -> str:
    """Validate that a country code is valid."""
    try:
        pycountry.countries.lookup(country_code)
    except LookupError as e:
        msg = "Invalid or non-existent country code, it must be in ISO 3166-1 alpha-2 format."
        raise ValueError(msg) from e
    else:
        return country_code


def validate_site_name(site_name: str) -> str:
    """Validate the site name.

    The site name must consist of three uppercase letters, optionally followed by a single digit.
    """
    pattern = re.compile(r"^[A-Z]{3}[0-9]?$")
    if not pattern.match(site_name):
        msg = (
            "Enter a valid site name. It must consist of three uppercase letters (A-Z), followed by an optional single "
            f"digit (0-9). Received: {site_name}"
        )
        raise ValueError(msg)
    return site_name