from __future__ import annotations

from dataclasses import dataclass
from datetime import timedelta
from typing import Iterator, TYPE_CHECKING, Type

from ._common_ctld import generate_random_ctld_point
from game.ato.flightplans.standard import StandardFlightPlan, StandardLayout
from game.theater.controlpoint import ControlPointType
from game.theater.missiontarget import MissionTarget
from game.utils import Distance, feet, meters
from .ibuilder import IBuilder
from .planningerror import PlanningError
from .uizonedisplay import UiZone, UiZoneDisplay
from .waypointbuilder import WaypointBuilder
from ..flightwaypoint import FlightWaypointType
from ...theater.interfaces.CTLD import CTLD

if TYPE_CHECKING:
    from dcs import Point
    from ..flightwaypoint import FlightWaypoint


@dataclass(frozen=True)
class AirAssaultLayout(StandardLayout):
    # The pickup point is optional because we don't always need to load the cargo. When
    # departing from a carrier, LHA, or off-map spawn, the cargo is pre-loaded.
    pickup: FlightWaypoint | None
    nav_to_ingress: list[FlightWaypoint]
    ingress: FlightWaypoint
    drop_off: FlightWaypoint | None
    # This is an implementation detail used by CTLD. The aircraft will not go to this
    # waypoint. It is used by CTLD as the destination for unloaded troops.
    target: FlightWaypoint
    nav_to_home: list[FlightWaypoint]

    def iter_waypoints(self) -> Iterator[FlightWaypoint]:
        yield self.departure
        if self.pickup is not None:
            yield self.pickup
        yield from self.nav_to_ingress
        yield self.ingress
        if self.drop_off is not None:
            yield self.drop_off
        yield self.target
        yield from self.nav_to_home
        yield self.arrival
        if self.divert is not None:
            yield self.divert
        yield self.bullseye


class AirAssaultFlightPlan(StandardFlightPlan[AirAssaultLayout], UiZoneDisplay):
    @staticmethod
    def builder_type() -> Type[Builder]:
        return Builder

    @property
    def tot_waypoint(self) -> FlightWaypoint:
        if self.flight.is_helo and self.layout.drop_off is not None:
            return self.layout.drop_off
        return self.layout.target

    def tot_for_waypoint(self, waypoint: FlightWaypoint) -> timedelta | None:
        if waypoint == self.tot_waypoint:
            return self.tot
        return None

    def depart_time_for_waypoint(self, waypoint: FlightWaypoint) -> timedelta | None:
        return None

    @property
    def ctld_target_zone_radius(self) -> Distance:
        return meters(2500)

    @property
    def mission_departure_time(self) -> timedelta:
        return self.package.time_over_target

    def ui_zone(self) -> UiZone:
        return UiZone(
            [self.layout.target.position],
            self.ctld_target_zone_radius,
        )


class Builder(IBuilder[AirAssaultFlightPlan, AirAssaultLayout]):
    def layout(self) -> AirAssaultLayout:
        if not self.flight.is_helo and not self.flight.is_hercules:
            raise PlanningError(
                "Air assault is only usable by helicopters and Anubis' C-130 mod"
            )
        assert self.package.waypoints is not None

        altitude = feet(1500) if self.flight.is_helo else self.doctrine.ingress_altitude
        altitude_is_agl = self.flight.is_helo

        builder = WaypointBuilder(self.flight, self.coalition)

        if self.flight.is_hercules or self.flight.departure.cptype in [
            ControlPointType.AIRCRAFT_CARRIER_GROUP,
            ControlPointType.LHA_GROUP,
            ControlPointType.OFF_MAP,
        ]:
            # Off_Map spawns will be preloaded
            # Carrier operations load the logistics directly from the carrier
            pickup = None
            pickup_position = self.flight.departure.position
        else:
            pickup = builder.pickup_zone(
                MissionTarget(
                    "Pickup Zone",
                    self._generate_ctld_pickup(),
                )
            )
            pickup_position = pickup.position
        assault_area = builder.assault_area(self.package.target)
        heading = self.package.target.position.heading_between_point(pickup_position)
        if self.flight.is_hercules:
            assault_area.only_for_player = False
            assault_area.alt = feet(1000)

        # TODO: define CTLD dropoff zones in campaign miz?
        drop_off_zone = MissionTarget(
            "Dropoff zone",
            self.package.target.position.point_from_heading(heading, 1200),
        )
        dz = builder.dropoff_zone(drop_off_zone) if self.flight.is_helo else None

        return AirAssaultLayout(
            departure=builder.takeoff(self.flight.departure),
            pickup=pickup,
            nav_to_ingress=builder.nav_path(
                pickup_position,
                self.package.waypoints.ingress,
                altitude,
                altitude_is_agl,
            ),
            ingress=builder.ingress(
                FlightWaypointType.INGRESS_AIR_ASSAULT,
                self.package.waypoints.ingress,
                self.package.target,
            ),
            drop_off=dz,
            target=assault_area,
            nav_to_home=builder.nav_path(
                drop_off_zone.position,
                self.flight.arrival.position,
                altitude,
                altitude_is_agl,
            ),
            arrival=builder.land(self.flight.arrival),
            divert=builder.divert(self.flight.divert),
            bullseye=builder.bullseye(),
        )

    def build(self) -> AirAssaultFlightPlan:
        return AirAssaultFlightPlan(self.flight, self.layout())

    def _generate_ctld_pickup(self) -> Point:
        assert isinstance(self.flight.departure, CTLD)
        return generate_random_ctld_point(self.flight.departure)