from __future__ import annotations

import logging
from typing import List, TYPE_CHECKING, Tuple, Type

from dcs.mission import Mission, StartType
from dcs.planes import IL_78M, KC130, KC135MPRS, KC_135, PlaneType
from dcs.task import (
    AWACS,
    ActivateBeaconCommand,
    MainTask,
    Refueling,
    SetImmortalCommand,
    SetInvisibleCommand,
)
from dcs.unittype import UnitType

from game.callsigns import callsign_for_support_unit
from game.naming import namegen
from game.radio.radios import RadioRegistry
from game.radio.tacan import TacanBand, TacanRegistry, TacanUsage
from game.utils import Heading
from game.ato.ai_flight_planner_db import AEWC_CAPABLE
from .airsupport import AirSupport, AwacsInfo, TankerInfo
from .frontlineconflictdescription import FrontLineConflictDescription

if TYPE_CHECKING:
    from game import Game

TANKER_DISTANCE = 15000
TANKER_ALT = 4572
TANKER_HEADING_OFFSET = 45

AWACS_DISTANCE = 150000
AWACS_ALT = 13000


class AirSupportGenerator:
    def __init__(
        self,
        mission: Mission,
        conflict: FrontLineConflictDescription,
        game: Game,
        radio_registry: RadioRegistry,
        tacan_registry: TacanRegistry,
        air_support: AirSupport,
    ) -> None:
        self.mission = mission
        self.conflict = conflict
        self.game = game
        self.radio_registry = radio_registry
        self.tacan_registry = tacan_registry
        self.air_support = air_support

    @classmethod
    def support_tasks(cls) -> List[Type[MainTask]]:
        return [Refueling, AWACS]

    @staticmethod
    def _get_tanker_params(unit_type: Type[UnitType]) -> Tuple[int, int]:
        if unit_type is KC130:
            return TANKER_ALT - 500, 596
        elif unit_type is KC_135:
            return TANKER_ALT, 770
        elif unit_type is KC135MPRS:
            return TANKER_ALT + 500, 596
        return TANKER_ALT, 574

    def generate(self) -> None:
        player_cp = (
            self.conflict.blue_cp
            if self.conflict.blue_cp.captured
            else self.conflict.red_cp
        )

        country = self.mission.country(self.game.blue.country_name)

        if not self.game.settings.disable_legacy_tanker:
            fallback_tanker_number = 0

            for i, tanker_unit_type in enumerate(
                self.game.faction_for(player=True).tankers
            ):
                unit_type = tanker_unit_type.dcs_unit_type
                if not issubclass(unit_type, PlaneType):
                    logging.warning(f"Refueling aircraft {unit_type} must be a plane")
                    continue

                # TODO: Make loiter altitude a property of the unit type.
                alt, airspeed = self._get_tanker_params(tanker_unit_type.dcs_unit_type)
                freq = self.radio_registry.alloc_uhf()
                tacan = self.tacan_registry.alloc_for_band(
                    TacanBand.Y, TacanUsage.AirToAir
                )
                tanker_heading = Heading.from_degrees(
                    self.conflict.red_cp.position.heading_between_point(
                        self.conflict.blue_cp.position
                    )
                    + TANKER_HEADING_OFFSET * i
                )
                tanker_position = player_cp.position.point_from_heading(
                    tanker_heading.degrees, TANKER_DISTANCE
                )
                tanker_group = self.mission.refuel_flight(
                    country=country,
                    name=namegen.next_tanker_name(country, tanker_unit_type),
                    airport=None,
                    plane_type=unit_type,
                    position=tanker_position,
                    altitude=alt,
                    race_distance=58000,
                    frequency=freq.mhz,
                    start_type=StartType.Warm,
                    speed=airspeed,
                    tacanchannel=str(tacan),
                )
                tanker_group.set_frequency(freq.mhz)

                callsign = callsign_for_support_unit(tanker_group)
                tacan_callsign = {
                    "Texaco": "TEX",
                    "Arco": "ARC",
                    "Shell": "SHL",
                }.get(callsign)
                if tacan_callsign is None:
                    # The dict above is all the callsigns currently in the game, but
                    # non-Western countries don't use the callsigns and instead just
                    # use numbers. It's possible that none of those nations have
                    # TACAN compatible refueling aircraft, but fallback just in
                    # case.
                    tacan_callsign = f"TK{fallback_tanker_number}"
                    fallback_tanker_number += 1

                if tanker_unit_type != IL_78M:
                    # Override PyDCS tacan channel.
                    tanker_group.points[0].tasks.pop()
                    tanker_group.points[0].tasks.append(
                        ActivateBeaconCommand(
                            tacan.number,
                            tacan.band.value,
                            tacan_callsign,
                            True,
                            tanker_group.units[0].id,
                            True,
                        )
                    )

                tanker_group.points[0].tasks.append(SetInvisibleCommand(True))
                tanker_group.points[0].tasks.append(SetImmortalCommand(True))

                self.air_support.tankers.append(
                    TankerInfo(
                        str(tanker_group.name),
                        callsign,
                        tanker_unit_type.name,
                        freq,
                        tacan,
                        start_time=None,
                        end_time=None,
                        blue=True,
                    )
                )

        if not self.game.settings.disable_legacy_aewc:
            possible_awacs = [
                a
                for a in self.game.faction_for(player=True).aircrafts
                if a in AEWC_CAPABLE
            ]

            if not possible_awacs:
                logging.warning("No AWACS for faction")
                return

            awacs_unit = possible_awacs[0]
            freq = self.radio_registry.alloc_uhf()

            unit_type = awacs_unit.dcs_unit_type
            if not issubclass(unit_type, PlaneType):
                logging.warning(f"AWACS aircraft {unit_type} must be a plane")
                return

            awacs_flight = self.mission.awacs_flight(
                country=country,
                name=namegen.next_awacs_name(country),
                plane_type=unit_type,
                altitude=AWACS_ALT,
                airport=None,
                position=self.conflict.position.random_point_within(
                    AWACS_DISTANCE, AWACS_DISTANCE
                ),
                frequency=freq.mhz,
                start_type=StartType.Warm,
            )
            awacs_flight.set_frequency(freq.mhz)

            awacs_flight.points[0].tasks.append(SetInvisibleCommand(True))
            awacs_flight.points[0].tasks.append(SetImmortalCommand(True))

            self.air_support.awacs.append(
                AwacsInfo(
                    group_name=str(awacs_flight.name),
                    callsign=callsign_for_support_unit(awacs_flight),
                    freq=freq,
                    depature_location=None,
                    start_time=None,
                    end_time=None,
                    blue=True,
                )
            )