from __future__ import annotations

from collections import defaultdict
from datetime import timedelta
from enum import Enum
from typing import Dict, List, Optional, TYPE_CHECKING, Type

from dcs.mapping import Point
from dcs.point import MovingPoint, PointAction
from dcs.unittype import FlyingType

from game import db
from game.data.weapons import Weapon
from game.theater.controlpoint import ControlPoint, MissionTarget
from game.utils import Distance, meters

if TYPE_CHECKING:
    from gen.ato import Package
    from gen.flights.flightplan import FlightPlan


class FlightType(Enum):
    TARCAP = "TARCAP"
    BARCAP = "BARCAP"
    CAS = "CAS"
    INTERCEPTION = "Intercept"
    STRIKE = "Strike"
    ANTISHIP = "Anti-ship"
    SEAD = "SEAD"
    DEAD = "DEAD"
    ESCORT = "Escort"
    BAI = "BAI"
    SWEEP = "Fighter sweep"
    OCA_RUNWAY = "OCA/Runway"
    OCA_AIRCRAFT = "OCA/Aircraft"

    def __str__(self) -> str:
        return self.value


class FlightWaypointType(Enum):
    TAKEOFF = 0             # Take off point
    ASCEND_POINT = 1        # Ascension point after take off
    PATROL = 2              # Patrol point
    PATROL_TRACK = 3        # Patrol race track
    NAV = 4                 # Nav point
    INGRESS_STRIKE = 5      # Ingress strike (For generator, means that this should have bombing on next TARGET_POINT points)
    INGRESS_SEAD = 6        # Ingress sead (For generator, means that this should attack groups on TARGET_GROUP_LOC points)
    INGRESS_CAS = 7         # Ingress cas (should start CAS task)
    CAS = 8                 # Should do CAS there
    EGRESS = 9              # Should stop attack
    DESCENT_POINT = 10       # Should start descending to pattern alt
    LANDING_POINT = 11      # Should land there
    TARGET_POINT = 12       # A target building or static object, position
    TARGET_GROUP_LOC = 13   # A target group approximate location
    TARGET_SHIP = 14        # A target ship known location
    CUSTOM = 15             # User waypoint (no specific behaviour)
    JOIN = 16
    SPLIT = 17
    LOITER = 18
    INGRESS_ESCORT = 19
    INGRESS_DEAD = 20
    INGRESS_SWEEP = 21
    INGRESS_BAI = 22
    DIVERT = 23
    INGRESS_OCA_RUNWAY = 24
    INGRESS_OCA_AIRCRAFT = 25


class FlightWaypoint:

    def __init__(self, waypoint_type: FlightWaypointType, x: float, y: float,
                 alt: Distance = meters(0)) -> None:
        """Creates a flight waypoint.

        Args:
            waypoint_type: The waypoint type.
            x: X cooidinate of the waypoint.
            y: Y coordinate of the waypoint.
            alt: Altitude of the waypoint. By default this is AGL, but it can be
            changed to MSL by setting alt_type to "RADIO".
        """
        self.waypoint_type = waypoint_type
        self.x = x
        self.y = y
        self.alt = alt
        self.alt_type = "BARO"
        self.name = ""
        # TODO: Merge with pretty_name.
        # Only used in the waypoint list in the flight edit page. No sense
        # having three names. A short and long form is enough.
        self.description = ""
        self.targets: List[MissionTarget] = []
        self.obj_name = ""
        self.pretty_name = ""
        self.only_for_player = False
        self.flyover = False

        # These are set very late by the air conflict generator (part of mission
        # generation). We do it late so that we don't need to propagate changes
        # to waypoint times whenever the player alters the package TOT or the
        # flight's offset in the UI.
        self.tot: Optional[timedelta] = None
        self.departure_time: Optional[timedelta] = None

    @property
    def position(self) -> Point:
        return Point(self.x, self.y)

    @classmethod
    def from_pydcs(cls, point: MovingPoint,
                   from_cp: ControlPoint) -> "FlightWaypoint":
        waypoint = FlightWaypoint(FlightWaypointType.NAV, point.position.x,
                                  point.position.y, meters(point.alt))
        waypoint.alt_type = point.alt_type
        # Other actions exist... but none of them *should* be the first
        # waypoint for a flight.
        waypoint.waypoint_type = {
            PointAction.TurningPoint: FlightWaypointType.NAV,
            PointAction.FlyOverPoint: FlightWaypointType.NAV,
            PointAction.FromParkingArea: FlightWaypointType.TAKEOFF,
            PointAction.FromParkingAreaHot: FlightWaypointType.TAKEOFF,
            PointAction.FromRunway: FlightWaypointType.TAKEOFF,
        }[point.action]
        if waypoint.waypoint_type == FlightWaypointType.NAV:
            waypoint.name = "NAV"
            waypoint.pretty_name = "Nav"
            waypoint.description = "Nav"
        else:
            waypoint.name = "TAKEOFF"
            waypoint.pretty_name = "Takeoff"
            waypoint.description = "Takeoff"
            waypoint.description = f"Takeoff from {from_cp.name}"
        return waypoint


class Flight:

    def __init__(self, package: Package, country: str, unit_type: Type[FlyingType],
                 count: int, flight_type: FlightType, start_type: str,
                 departure: ControlPoint, arrival: ControlPoint,
                 divert: Optional[ControlPoint],
                 custom_name: Optional[str] = None) -> None:
        self.package = package
        self.country = country
        self.unit_type = unit_type
        self.count = count
        self.departure = departure
        self.arrival = arrival
        self.divert = divert
        self.flight_type = flight_type
        # TODO: Replace with FlightPlan.
        self.targets: List[MissionTarget] = []
        self.loadout: Dict[int, Optional[Weapon]] = {}
        self.start_type = start_type
        self.use_custom_loadout = False
        self.client_count = 0
        self.custom_name = custom_name

        # Will be replaced with a more appropriate FlightPlan by
        # FlightPlanBuilder, but an empty flight plan the flight begins with an
        # empty flight plan.
        from gen.flights.flightplan import CustomFlightPlan
        self.flight_plan: FlightPlan = CustomFlightPlan(
            package=package,
            flight=self,
            custom_waypoints=[]
        )

    @property
    def from_cp(self) -> ControlPoint:
        return self.departure

    @property
    def points(self) -> List[FlightWaypoint]:
        return self.flight_plan.waypoints[1:]

    def __repr__(self):
        name = db.unit_type_name(self.unit_type)
        if self.custom_name:
            return f"{self.custom_name} {self.count} x {name}"
        return f"[{self.flight_type}] {self.count} x {name}"

    def __str__(self):
        name = db.unit_pretty_name(self.country, self.unit_type)
        if self.custom_name:
            return f"{self.custom_name} {self.count} x {name}"
        return f"[{self.flight_type}] {self.count} x {name}"