from __future__ import annotations

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

from dcs import Point

from game.utils import Heading
from .ibuilder import IBuilder
from .loiter import LoiterFlightPlan, LoiterLayout
from .waypointbuilder import WaypointBuilder
from ...flightplan import HoldZoneGeometry

if TYPE_CHECKING:
    from ..flightwaypoint import FlightWaypoint


@dataclass
class SweepLayout(LoiterLayout):
    nav_to: list[FlightWaypoint]
    sweep_start: FlightWaypoint
    sweep_end: FlightWaypoint
    nav_from: list[FlightWaypoint]

    def iter_waypoints(self) -> Iterator[FlightWaypoint]:
        yield self.departure
        if self.hold:
            yield self.hold
        yield from self.nav_to
        yield self.sweep_start
        yield self.sweep_end
        yield from self.nav_from
        yield self.arrival
        if self.divert is not None:
            yield self.divert
        yield self.bullseye


class SweepFlightPlan(LoiterFlightPlan):
    @staticmethod
    def builder_type() -> Type[Builder]:
        return Builder

    @property
    def combat_speed_waypoints(self) -> set[FlightWaypoint]:
        return {self.layout.sweep_end}

    @property
    def tot_waypoint(self) -> FlightWaypoint:
        return self.layout.sweep_end

    def default_tot_offset(self) -> timedelta:
        return -timedelta(minutes=5)

    @property
    def sweep_start_time(self) -> datetime:
        travel_time = self.total_time_between_waypoints(
            self.layout.sweep_start, self.layout.sweep_end
        )
        return self.sweep_end_time - travel_time

    @property
    def sweep_end_time(self) -> datetime:
        return self.tot

    def tot_for_waypoint(self, waypoint: FlightWaypoint) -> datetime | None:
        if waypoint == self.layout.sweep_start:
            return self.sweep_start_time
        if waypoint == self.layout.sweep_end:
            return self.sweep_end_time
        return None

    def depart_time_for_waypoint(self, waypoint: FlightWaypoint) -> datetime | None:
        if waypoint == self.layout.hold:
            return self.push_time
        return None

    @property
    def push_time(self) -> datetime:
        return self.sweep_end_time - self.travel_time_between_waypoints(
            self.layout.hold,
            self.layout.sweep_end,
        )

    @property
    def mission_begin_on_station_time(self) -> datetime | None:
        return None

    @property
    def mission_departure_time(self) -> datetime:
        return self.sweep_end_time


class Builder(IBuilder[SweepFlightPlan, SweepLayout]):
    def layout(self) -> SweepLayout:
        assert self.package.waypoints is not None
        target = self.package.target.position
        heading = Heading.from_degrees(
            self.package.waypoints.join.heading_between_point(target)
        )
        start_pos = target.point_from_heading(
            heading.degrees, -self.doctrine.sweep_distance.meters
        )

        builder = WaypointBuilder(self.flight)
        start, end = builder.sweep(start_pos, target, self.doctrine.ingress_altitude)

        hold = builder.hold(self._hold_point())

        return SweepLayout(
            departure=builder.takeoff(self.flight.departure),
            hold=hold,
            nav_to=builder.nav_path(
                hold.position, start.position, self.doctrine.ingress_altitude
            ),
            nav_from=builder.nav_path(
                end.position,
                self.flight.arrival.position,
                self.doctrine.ingress_altitude,
            ),
            sweep_start=start,
            sweep_end=end,
            arrival=builder.land(self.flight.arrival),
            divert=builder.divert(self.flight.divert),
            bullseye=builder.bullseye(),
        )

    def _hold_point(self) -> Point:
        assert self.package.waypoints is not None
        origin = self.flight.departure.position
        target = self.package.target.position
        join = self.package.waypoints.join
        ip = self.package.waypoints.ingress
        return HoldZoneGeometry(
            target, origin, ip, join, self.coalition, self.theater
        ).find_best_hold_point()

    def build(self, dump_debug_info: bool = False) -> SweepFlightPlan:
        return SweepFlightPlan(self.flight, self.layout())