dcs-retribution/gen/armor.py

from __future__ import annotations

import logging
import random
from dataclasses import dataclass
from typing import TYPE_CHECKING, List, Optional, Tuple

from dcs import Mission
from dcs.action import AITaskPush
from dcs.condition import GroupLifeLess, Or, TimeAfter, UnitDamaged
from dcs.country import Country
from dcs.mapping import Point
from dcs.planes import MQ_9_Reaper
from dcs.point import PointAction
from dcs.task import (EPLRS, AttackGroup, ControlledTask, FireAtPoint,
                      GoToWaypoint, Hold, OrbitAction, SetImmortalCommand,
                      SetInvisibleCommand)
from dcs.triggers import Event, TriggerOnce
from dcs.unit import Vehicle
from dcs.unitgroup import VehicleGroup
from dcs.unittype import VehicleType
from game import db
from game.unitmap import UnitMap
from game.utils import heading_sum, opposite_heading
from game.theater.controlpoint import ControlPoint

from gen.ground_forces.ai_ground_planner import (DISTANCE_FROM_FRONTLINE,
                                                 CombatGroup, CombatGroupRole)

from .callsigns import callsign_for_support_unit
from .conflictgen import Conflict
from .ground_forces.combat_stance import CombatStance
from .naming import namegen

if TYPE_CHECKING:
    from game import Game

SPREAD_DISTANCE_FACTOR = 0.1, 0.3
SPREAD_DISTANCE_SIZE_FACTOR = 0.1

FRONTLINE_CAS_FIGHTS_COUNT = 16, 24
FRONTLINE_CAS_GROUP_MIN = 1, 2
FRONTLINE_CAS_PADDING = 12000

RETREAT_DISTANCE = 20000
BREAKTHROUGH_OFFENSIVE_DISTANCE = 35000
AGGRESIVE_MOVE_DISTANCE = 16000

FIGHT_DISTANCE = 3500

RANDOM_OFFSET_ATTACK = 250


@dataclass(frozen=True)
class JtacInfo:
    """JTAC information."""
    dcsGroupName: str
    unit_name: str
    callsign: str
    region: str
    code: str
    # TODO: Radio info? Type?


class GroundConflictGenerator:

    def __init__(
            self,
            mission: Mission,
            conflict: Conflict,
            game: Game,
            player_planned_combat_groups: List[CombatGroup],
            enemy_planned_combat_groups: List[CombatGroup],
            player_stance: CombatStance,
            unit_map: UnitMap) -> None:
        self.mission = mission
        self.conflict = conflict
        self.enemy_planned_combat_groups = enemy_planned_combat_groups
        self.player_planned_combat_groups = player_planned_combat_groups
        self.player_stance = CombatStance(player_stance)
        self.enemy_stance = self._enemy_stance()
        self.game = game
        self.unit_map = unit_map
        self.jtacs: List[JtacInfo] = []

    def _enemy_stance(self):
        """Picks the enemy stance according to the number of planned groups on the frontline for each side"""
        if len(self.enemy_planned_combat_groups) > len(self.player_planned_combat_groups):
            return random.choice(
                [
                    CombatStance.AGGRESSIVE,
                    CombatStance.AGGRESSIVE,
                    CombatStance.AGGRESSIVE,
                    CombatStance.ELIMINATION,
                    CombatStance.BREAKTHROUGH
                ]
            )
        else:
            return random.choice(
                [
                    CombatStance.DEFENSIVE,
                    CombatStance.DEFENSIVE,
                    CombatStance.DEFENSIVE,
                    CombatStance.AMBUSH,
                    CombatStance.AGGRESSIVE
                ]
            )

    @staticmethod
    def _group_point(point: Point, base_distance) -> Point:
        distance = random.randint(
                int(base_distance * SPREAD_DISTANCE_FACTOR[0]),
                int(base_distance * SPREAD_DISTANCE_FACTOR[1]),
                )
        return point.random_point_within(distance, base_distance * SPREAD_DISTANCE_SIZE_FACTOR)

    def generate(self):
        position = Conflict.frontline_position(self.conflict.from_cp, self.conflict.to_cp, self.game.theater)
        frontline_vector = Conflict.frontline_vector(
            self.conflict.from_cp,
            self.conflict.to_cp,
            self.game.theater
            )

        # Create player groups at random position
        player_groups = self._generate_groups(self.player_planned_combat_groups, frontline_vector, True)

        # Create enemy groups at random position
        enemy_groups = self._generate_groups(self.enemy_planned_combat_groups, frontline_vector, False)

        # Plan combat actions for groups
        self.plan_action_for_groups(
            self.player_stance,
            player_groups,
            enemy_groups,
            self.conflict.heading + 90,
            self.conflict.from_cp,
            self.conflict.to_cp
        )
        self.plan_action_for_groups(
            self.enemy_stance,
            enemy_groups,
            player_groups,
            self.conflict.heading - 90,
            self.conflict.to_cp,
            self.conflict.from_cp
        )

        # Add JTAC
        if self.game.player_faction.has_jtac:
            n = "JTAC" + str(self.conflict.from_cp.id) + str(self.conflict.to_cp.id)
            code = 1688 - len(self.jtacs)

            utype = MQ_9_Reaper
            if self.game.player_faction.jtac_unit is not None:
                utype = self.game.player_faction.jtac_unit

            jtac = self.mission.flight_group(country=self.mission.country(self.game.player_country),
                                             name=n,
                                             aircraft_type=utype,
                                             position=position[0],
                                             airport=None,
                                             altitude=5000)
            jtac.points[0].tasks.append(SetInvisibleCommand(True))
            jtac.points[0].tasks.append(SetImmortalCommand(True))
            jtac.points[0].tasks.append(OrbitAction(5000, 300, OrbitAction.OrbitPattern.Circle))
            frontline = f"Frontline {self.conflict.from_cp.name}/{self.conflict.to_cp.name}"
            # Note: Will need to change if we ever add ground based JTAC.
            callsign = callsign_for_support_unit(jtac)
            self.jtacs.append(JtacInfo(str(jtac.name), n, callsign, frontline, str(code)))

    def gen_infantry_group_for_group(
        self,
        group: VehicleGroup,
        is_player: bool,
        side: Country,
        forward_heading: int
    ) -> None:

        infantry_position = self.conflict.find_ground_position(
            group.points[0].position.random_point_within(250, 50),
            500,
            forward_heading,
            self.conflict.theater
            )
        if not infantry_position:
            logging.warning("Could not find infantry position")
            return
        if side == self.conflict.attackers_country:
            cp = self.conflict.from_cp
        else:
            cp = self.conflict.to_cp

        if is_player:
            faction = self.game.player_name
        else:
            faction = self.game.enemy_name

        # Disable infantry unit gen if disabled
        if not self.game.settings.perf_infantry:
            if self.game.settings.manpads:
                # 50% of armored units protected by manpad
                if random.choice([True, False]):
                    manpads = db.find_manpad(faction)
                    if len(manpads) > 0:
                        u = random.choice(manpads)
                        self.mission.vehicle_group(
                            side,
                            namegen.next_infantry_name(side, cp.id, u), u,
                            position=infantry_position,
                            group_size=1,
                            heading=forward_heading,
                            move_formation=PointAction.OffRoad)
            return

        possible_infantry_units = db.find_infantry(faction, allow_manpad=self.game.settings.manpads)
        if len(possible_infantry_units) == 0:
            return

        u = random.choice(possible_infantry_units)
        self.mission.vehicle_group(
                side,
                namegen.next_infantry_name(side, cp.id, u), u,
                position=infantry_position,
                group_size=1,
                heading=forward_heading,
                move_formation=PointAction.OffRoad)

        for i in range(random.randint(3, 10)):
            u = random.choice(possible_infantry_units)
            position = infantry_position.random_point_within(55, 5)
            self.mission.vehicle_group(
                side,
                namegen.next_infantry_name(side, cp.id, u), u,
                position=position,
                group_size=1,
                heading=forward_heading,
                move_formation=PointAction.OffRoad)

    def _set_reform_waypoint(
        self,
        dcs_group: VehicleGroup,
        forward_heading: int
    ) -> None:
        """Setting a waypoint close to the spawn position allows the group to reform gracefully
        rather than spin        
        """
        reform_point = dcs_group.position.point_from_heading(forward_heading, 50)
        dcs_group.add_waypoint(reform_point)

    def _plan_artillery_action(
        self,
        stance: CombatStance,
        gen_group: CombatGroup,
        dcs_group: VehicleGroup,
        forward_heading: int,
        target: Point
    ) -> bool:
        """
        Handles adding the DCS tasks for artillery groups for all combat stances.
        Returns True if tasking was added, returns False if the stance was not a combat stance.
        """
        self._set_reform_waypoint(dcs_group, forward_heading)
        if stance != CombatStance.RETREAT:
            hold_task = Hold()
            hold_task.number = 1
            dcs_group.add_trigger_action(hold_task)

        # Artillery strike random start
        artillery_trigger = TriggerOnce(Event.NoEvent, "ArtilleryFireTask #" + str(dcs_group.id))
        artillery_trigger.add_condition(TimeAfter(seconds=random.randint(1, 45) * 60))
        # TODO: Update to fire at group instead of point
        fire_task = FireAtPoint(target, len(gen_group.units) * 10, 100)
        fire_task.number = 2 if stance != CombatStance.RETREAT else 1
        dcs_group.add_trigger_action(fire_task)
        artillery_trigger.add_action(AITaskPush(dcs_group.id, len(dcs_group.tasks)))
        self.mission.triggerrules.triggers.append(artillery_trigger)

        # Artillery will fall back when under attack
        if stance != CombatStance.RETREAT:

            # Hold position
            dcs_group.points[1].tasks.append(Hold())
            retreat = self.find_retreat_point(dcs_group, heading_sum(forward_heading, 180), (int)(RETREAT_DISTANCE/3))
            dcs_group.add_waypoint(dcs_group.position.point_from_heading(forward_heading, 1), PointAction.OffRoad)
            dcs_group.points[2].tasks.append(Hold())
            dcs_group.add_waypoint(retreat, PointAction.OffRoad)

            artillery_fallback = TriggerOnce(Event.NoEvent, "ArtilleryRetreat #" + str(dcs_group.id))
            for i, u in enumerate(dcs_group.units):
                artillery_fallback.add_condition(UnitDamaged(u.id))
                if i < len(dcs_group.units) - 1:
                    artillery_fallback.add_condition(Or())

            hold_2 = Hold()
            hold_2.number = 3
            dcs_group.add_trigger_action(hold_2)

            retreat_task = GoToWaypoint(to_index=3)
            retreat_task.number = 4
            dcs_group.add_trigger_action(retreat_task)

            artillery_fallback.add_action(AITaskPush(dcs_group.id, len(dcs_group.tasks)))
            self.mission.triggerrules.triggers.append(artillery_fallback)

            for u in dcs_group.units:
                u.initial = True
                u.heading = forward_heading + random.randint(-5, 5)
            return True
        return False

    def _plan_tank_ifv_action(
        self,
        stance: CombatStance,
        enemy_groups: List[Tuple[VehicleGroup, CombatGroup]],
        dcs_group: VehicleGroup,
        forward_heading: int,
        to_cp: ControlPoint,
    ) -> bool:
        """
        Handles adding the DCS tasks for tank and IFV groups for all combat stances.
        Returns True if tasking was added, returns False if the stance was not a combat stance.
        """
        self._set_reform_waypoint(dcs_group, forward_heading)
        if stance == CombatStance.AGGRESSIVE:
            # Attack nearest enemy if any
            # Then move forward OR Attack enemy base if it is not too far away
            target = self.find_nearest_enemy_group(dcs_group, enemy_groups)
            if target is not None:
                rand_offset = Point(
                    random.randint(
                        -RANDOM_OFFSET_ATTACK, RANDOM_OFFSET_ATTACK
                    ),
                    random.randint(
                        -RANDOM_OFFSET_ATTACK, RANDOM_OFFSET_ATTACK
                    )
                )
                target_point = self.conflict.theater.nearest_land_pos(
                    target.points[0].position + rand_offset
                )
                dcs_group.add_waypoint(target_point)
                dcs_group.points[2].tasks.append(AttackGroup(target.id))

            if (
                to_cp.position.distance_to_point(dcs_group.points[0].position)
                <=
                AGGRESIVE_MOVE_DISTANCE
            ):
                attack_point = self.conflict.theater.nearest_land_pos(
                    to_cp.position.random_point_within(500, 0)
                )
            else:
                attack_point = self.find_offensive_point(
                    dcs_group,
                    forward_heading,
                    AGGRESIVE_MOVE_DISTANCE
                )
            dcs_group.add_waypoint(attack_point, PointAction.OffRoad)
        elif stance == CombatStance.BREAKTHROUGH:
            # In breakthrough mode, the units will move forward
            # If the enemy base is close enough, the units will attack the base
            if to_cp.position.distance_to_point(
                    dcs_group.points[0].position) <= BREAKTHROUGH_OFFENSIVE_DISTANCE:
                attack_point = self.conflict.theater.nearest_land_pos(
                    to_cp.position.random_point_within(500, 0)
                )
            else:
                attack_point = self.find_offensive_point(dcs_group, forward_heading, BREAKTHROUGH_OFFENSIVE_DISTANCE)
            dcs_group.add_waypoint(attack_point, PointAction.OffRoad)
        elif stance == CombatStance.ELIMINATION:
            # In elimination mode, the units focus on destroying as much enemy groups as possible
            targets = self.find_n_nearest_enemy_groups(dcs_group, enemy_groups, 3)
            for i, target in enumerate(targets, start=1):
                rand_offset = Point(
                    random.randint(
                        -RANDOM_OFFSET_ATTACK, RANDOM_OFFSET_ATTACK
                    ),
                    random.randint(
                        -RANDOM_OFFSET_ATTACK,
                        RANDOM_OFFSET_ATTACK
                    )
                )
                target_point = self.conflict.theater.nearest_land_pos(
                    target.points[0].position+rand_offset
                )
                dcs_group.add_waypoint(target_point, PointAction.OffRoad)
                dcs_group.points[i + 1].tasks.append(AttackGroup(target.id))
            if to_cp.position.distance_to_point(dcs_group.points[0].position) <= AGGRESIVE_MOVE_DISTANCE:
                attack_point = self.conflict.theater.nearest_land_pos(
                    to_cp.position.random_point_within(500, 0)
                )
                dcs_group.add_waypoint(attack_point)

        if stance != CombatStance.RETREAT:
            self.add_morale_trigger(dcs_group, forward_heading)
            return True
        return False

    def _plan_apc_atgm_action(
        self,
        stance: CombatStance,
        dcs_group: VehicleGroup,
        forward_heading: int,
        to_cp: ControlPoint,
    ) -> bool:
        """
        Handles adding the DCS tasks for APC and ATGM groups for all combat stances.
        Returns True if tasking was added, returns False if the stance was not a combat stance.
        """
        self._set_reform_waypoint(dcs_group, forward_heading)
        if stance in [CombatStance.AGGRESSIVE, CombatStance.BREAKTHROUGH, CombatStance.ELIMINATION]:
            # APC & ATGM will never move too much forward, but will follow along any offensive
            if to_cp.position.distance_to_point(dcs_group.points[0].position) <= AGGRESIVE_MOVE_DISTANCE:
                attack_point = self.conflict.theater.nearest_land_pos(to_cp.position.random_point_within(500, 0))
            else:
                attack_point = self.find_offensive_point(dcs_group, forward_heading, AGGRESIVE_MOVE_DISTANCE)
            dcs_group.add_waypoint(attack_point, PointAction.OffRoad)

        if stance != CombatStance.RETREAT:
            self.add_morale_trigger(dcs_group, forward_heading)
            return True
        return False

    def plan_action_for_groups(
        self, stance: CombatStance,
        ally_groups: List[Tuple[VehicleGroup, CombatGroup]],
        enemy_groups: List[Tuple[VehicleGroup, CombatGroup]],
        forward_heading: int,
        from_cp: ControlPoint,
        to_cp: ControlPoint
    ) -> None:

        if not self.game.settings.perf_moving_units:
            return

        for dcs_group, group in ally_groups:
            if hasattr(group.units[0], 'eplrs') and group.units[0].eplrs:
                dcs_group.points[0].tasks.append(EPLRS(dcs_group.id))

            if group.role == CombatGroupRole.ARTILLERY:
                if self.game.settings.perf_artillery:
                    target = self.get_artillery_target_in_range(dcs_group, group, enemy_groups)
                    if target is not None:
                        self._plan_artillery_action(stance, group, dcs_group, forward_heading, target)

            elif group.role in [CombatGroupRole.TANK, CombatGroupRole.IFV]:
                self._plan_tank_ifv_action(stance, enemy_groups, dcs_group, forward_heading, to_cp)

            elif group.role in [CombatGroupRole.APC, CombatGroupRole.ATGM]:
                self._plan_apc_atgm_action(stance, dcs_group, forward_heading, to_cp)

            if stance == CombatStance.RETREAT:
                # In retreat mode, the units will fall back
                # If the ally base is close enough, the units will even regroup there
                if from_cp.position.distance_to_point(dcs_group.points[0].position) <= RETREAT_DISTANCE:
                    retreat_point = from_cp.position.random_point_within(500, 250)
                else:
                    retreat_point = self.find_retreat_point(dcs_group, forward_heading)
                reposition_point = retreat_point.point_from_heading(forward_heading, 10)  # Another point to make the unit face the enemy
                dcs_group.add_waypoint(retreat_point, PointAction.OffRoad)
                dcs_group.add_waypoint(reposition_point, PointAction.OffRoad)

    def add_morale_trigger(self, dcs_group: VehicleGroup, forward_heading: int) -> None:
        """
        This add a trigger to manage units fleeing whenever their group is hit hard, or being engaged by CAS
        """

        if len(dcs_group.units) == 1:
            return

        # Units should hold position on last waypoint
        dcs_group.points[len(dcs_group.points) - 1].tasks.append(Hold())

        # Force unit heading
        for unit in dcs_group.units:
            unit.heading = forward_heading
        dcs_group.manualHeading = True

        # We add a new retreat waypoint
        dcs_group.add_waypoint(
            self.find_retreat_point(dcs_group, forward_heading, (int)(RETREAT_DISTANCE / 8)),
            PointAction.OffRoad
        )

        # Fallback task
        fallback = ControlledTask(GoToWaypoint(to_index=len(dcs_group.points)))
        fallback.enabled = False
        dcs_group.add_trigger_action(Hold())
        dcs_group.add_trigger_action(fallback)

        # Create trigger
        fallback = TriggerOnce(Event.NoEvent, "Morale manager #" + str(dcs_group.id))

        # Usually more than 50% casualties = RETREAT
        fallback.add_condition(GroupLifeLess(dcs_group.id, random.randint(51, 76)))

        # Do retreat to the configured retreat waypoint
        fallback.add_action(AITaskPush(dcs_group.id, len(dcs_group.tasks)))

        self.mission.triggerrules.triggers.append(fallback)

    def find_retreat_point(
        self,
        dcs_group: VehicleGroup,
        frontline_heading: int,
        distance: int = RETREAT_DISTANCE
    ) -> Point:
        """
        Find a point to retreat to
        :param dcs_group: DCS mission group we are searching a retreat point for
        :param frontline_heading: Heading of the frontline
        :return: dcs.mapping.Point object with the desired position
        """
        desired_point = dcs_group.points[0].position.point_from_heading(heading_sum(frontline_heading, +180), distance)
        if self.conflict.theater.is_on_land(desired_point):
            return desired_point
        return self.conflict.theater.nearest_land_pos(desired_point)


    def find_offensive_point(
        self,
        dcs_group: VehicleGroup,
        frontline_heading: int,
        distance: int
    ) -> Point:
        """
        Find a point to attack
        :param dcs_group:  DCS mission group we are searching an attack point for
        :param frontline_heading: Heading of the frontline
        :param distance: Distance of the offensive (how far unit should move)
        :return: dcs.mapping.Point object with the desired position
        """
        desired_point = dcs_group.points[0].position.point_from_heading(frontline_heading, distance)
        if self.conflict.theater.is_on_land(desired_point):
            return desired_point
        return self.conflict.theater.nearest_land_pos(desired_point)

    @staticmethod
    def find_n_nearest_enemy_groups(
        player_group: VehicleGroup,
        enemy_groups: List[Tuple[VehicleGroup, CombatGroup]],
        n: int
    ) -> List[VehicleGroup]:
        """
        Return the nearest enemy group for the player group
        @param group Group for which we should find the nearest ennemies
        @param enemy_groups Potential enemy groups
        @param n number of nearby groups to take
        """
        targets = []  # type: List[Optional[VehicleGroup]]
        sorted_list = sorted(
            enemy_groups,
            key=lambda group: player_group.points[0].position.distance_to_point(group[0].points[0].position)
        )
        for i in range(n):
            # TODO: Is this supposed to return no groups if enemy_groups is less than n?
            if len(sorted_list) <= i:
                break
            else:
                targets.append(sorted_list[i][0])
        return targets

    @staticmethod
    def find_nearest_enemy_group(
        player_group: VehicleGroup,
        enemy_groups: List[Tuple[VehicleGroup, CombatGroup]]
    ) -> Optional[VehicleGroup]:
        """
        Search the enemy groups for a potential target suitable to armored assault
        @param group Group for which we should find the nearest ennemy
        @param enemy_groups Potential enemy groups
        """
        min_distance = 99999999
        target = None
        for dcs_group, _ in enemy_groups:
            dist = player_group.points[0].position.distance_to_point(dcs_group.points[0].position)
            if dist < min_distance:
                min_distance = dist
                target = dcs_group
        return target

    @staticmethod
    def get_artillery_target_in_range(
        dcs_group: VehicleGroup,
        group: CombatGroup,
        enemy_groups: List[Tuple[VehicleGroup, CombatGroup]]
    ) -> Optional[Point]:
        """
        Search the enemy groups for a potential target suitable to an artillery unit
        """
        # TODO: Update to return a list of groups instead of a single point
        rng = group.units[0].threat_range
        if not enemy_groups:
            return None
        for _ in range(10):
            potential_target = random.choice(enemy_groups)[0]
            distance_to_target = dcs_group.points[0].position.distance_to_point(potential_target.points[0].position)
            if distance_to_target < rng:
                return potential_target.points[0].position
        return None

    @staticmethod
    def get_artilery_group_distance_from_frontline(group: CombatGroup) -> int:
        """
        For artilery group, decide the distance from frontline with the range of the unit
        """
        rg = group.units[0].threat_range - 7500
        if rg > DISTANCE_FROM_FRONTLINE[CombatGroupRole.ARTILLERY][1]:
            rg = random.randint(
                DISTANCE_FROM_FRONTLINE[CombatGroupRole.ARTILLERY][0],
                DISTANCE_FROM_FRONTLINE[CombatGroupRole.ARTILLERY][1]
            )
        elif rg < DISTANCE_FROM_FRONTLINE[CombatGroupRole.ARTILLERY][1]:
            rg = random.randint(
                DISTANCE_FROM_FRONTLINE[CombatGroupRole.TANK][0],
                DISTANCE_FROM_FRONTLINE[CombatGroupRole.TANK][1]
            )
        return rg

    def get_valid_position_for_group(
        self,
        conflict_position: Point,
        combat_width: int,
        distance_from_frontline: int,
        heading: int,
        spawn_heading: int
    ):
        shifted = conflict_position.point_from_heading(heading, random.randint(0, combat_width))
        desired_point = shifted.point_from_heading(
            spawn_heading,
            distance_from_frontline
        )
        return Conflict.find_ground_position(desired_point, combat_width, heading, self.conflict.theater)


    def _generate_groups(
        self,
        groups: List[CombatGroup],
        frontline_vector: Tuple[Point, int, int],
        is_player: bool
    ) -> List[Tuple[VehicleGroup, CombatGroup]]:
        """Finds valid positions for planned groups and generates a pydcs group for them"""
        positioned_groups = []
        position, heading, combat_width = frontline_vector
        spawn_heading = int(heading_sum(heading, -90)) if is_player else int(heading_sum(heading, 90))
        country = self.game.player_country if is_player else self.game.enemy_country
        for group in groups:
            if group.role == CombatGroupRole.ARTILLERY:
                distance_from_frontline = self.get_artilery_group_distance_from_frontline(group)
            else:
                distance_from_frontline = random.randint(
                    DISTANCE_FROM_FRONTLINE[group.role][0], 
                    DISTANCE_FROM_FRONTLINE[group.role][1]
                )

            final_position = self.get_valid_position_for_group(
                position,
                combat_width,
                distance_from_frontline,
                heading,
                spawn_heading
            )

            if final_position is not None:
                g = self._generate_group(
                    self.mission.country(country),
                    group.units[0],
                    len(group.units),
                    final_position,
                    distance_from_frontline,
                    heading=opposite_heading(spawn_heading),
                )
                if is_player:
                    g.set_skill(self.game.settings.player_skill)
                else:
                    g.set_skill(self.game.settings.enemy_vehicle_skill)
                positioned_groups.append((g, group))

                if group.role in [CombatGroupRole.APC, CombatGroupRole.IFV]:
                    self.gen_infantry_group_for_group(
                        g,
                        is_player,
                        self.mission.country(country),
                        opposite_heading(spawn_heading)
                    )
            else:
                logging.warning(f"Unable to get valid position for {group}")

        return positioned_groups

    def _generate_group(
        self,
        side: Country,
        unit: VehicleType,
        count: int,
        at: Point,
        distance_from_frontline,
        move_formation: PointAction = PointAction.OffRoad,
        heading=0,
    ) -> VehicleGroup:

        if side == self.conflict.attackers_country:
            cp = self.conflict.from_cp
        else:
            cp = self.conflict.to_cp

        logging.info("armorgen: {} for {}".format(unit, side.id))
        group = self.mission.vehicle_group(
                side,
                namegen.next_unit_name(side, cp.id, unit), unit,
                position=at,
                group_size=count,
                heading=heading,
                move_formation=move_formation)

        self.unit_map.add_front_line_units(group, cp)

        for c in range(count):
            vehicle: Vehicle = group.units[c]
            vehicle.player_can_drive = True

        return group