from __future__ import annotations

from datetime import timedelta
from typing import Type

from dcs import Point

from game.utils import Distance, Heading, feet, meters
from .patrolling import PatrollingLayout
from .theaterrefueling import (
    Builder as TheaterRefuelingBuilder,
    TheaterRefuelingFlightPlan,
)
from .waypointbuilder import WaypointBuilder
from ..flightwaypoint import FlightWaypoint
from ..flightwaypointtype import FlightWaypointType


class Builder(TheaterRefuelingBuilder):
    def build(self) -> PatrollingLayout:
        package_waypoints = self.package.waypoints
        assert package_waypoints is not None

        racetrack_half_distance = Distance.from_nautical_miles(20).meters

        racetrack_center = package_waypoints.refuel

        split_heading = Heading.from_degrees(
            racetrack_center.heading_between_point(package_waypoints.split)
        )
        home_heading = split_heading.opposite

        racetrack_start = racetrack_center.point_from_heading(
            split_heading.degrees, racetrack_half_distance
        )

        racetrack_end = racetrack_center.point_from_heading(
            home_heading.degrees, racetrack_half_distance
        )

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

        tanker_type = self.flight.unit_type
        if tanker_type.patrol_altitude is not None:
            altitude = tanker_type.patrol_altitude
        else:
            altitude = feet(21000)

        racetrack = builder.race_track(racetrack_start, racetrack_end, altitude)

        return PatrollingLayout(
            departure=builder.takeoff(self.flight.departure),
            nav_to=builder.nav_path(
                self.flight.departure.position, racetrack_start, altitude
            ),
            nav_from=builder.nav_path(
                racetrack_end, self.flight.arrival.position, altitude
            ),
            patrol_start=racetrack[0],
            patrol_end=racetrack[1],
            arrival=builder.land(self.flight.arrival),
            divert=builder.divert(self.flight.divert),
            bullseye=builder.bullseye(),
        )


class PackageRefuelingFlightPlan(TheaterRefuelingFlightPlan):
    @staticmethod
    def builder_type() -> Type[Builder]:
        return Builder

    @property
    def patrol_duration(self) -> timedelta:
        # TODO: Only consider aircraft that can refuel with this tanker type.
        refuel_time_minutes = 5
        for self.flight in self.package.flights:
            flight_size = self.flight.roster.max_size
            refuel_time_minutes = refuel_time_minutes + 4 * flight_size + 1

        return timedelta(minutes=refuel_time_minutes)

    def target_area_waypoint(self) -> FlightWaypoint:
        return FlightWaypoint(
            "TARGET AREA",
            FlightWaypointType.TARGET_GROUP_LOC,
            self.package.target.position,
            meters(0),
            "RADIO",
        )

    @property
    def patrol_start_time(self) -> timedelta:
        altitude = self.flight.unit_type.patrol_altitude

        if altitude is None:
            altitude = Distance.from_feet(20000)

        assert self.package.waypoints is not None

        # Cheat in a FlightWaypoint for the split point.
        split: Point = self.package.waypoints.split
        split_waypoint: FlightWaypoint = FlightWaypoint(
            "SPLIT", FlightWaypointType.SPLIT, split, altitude
        )

        # Cheat in a FlightWaypoint for the refuel point.
        refuel: Point = self.package.waypoints.refuel
        refuel_waypoint: FlightWaypoint = FlightWaypoint(
            "REFUEL", FlightWaypointType.REFUEL, refuel, altitude
        )

        delay_target_to_split: timedelta = self.travel_time_between_waypoints(
            self.target_area_waypoint(), split_waypoint
        )
        delay_split_to_refuel: timedelta = self.travel_time_between_waypoints(
            split_waypoint, refuel_waypoint
        )

        return (
            self.package.time_over_target
            + delay_target_to_split
            + delay_split_to_refuel
            - timedelta(minutes=1.5)
        )