"""Battlefield front lines."""
from typing import Tuple

from dcs.mapping import Point
from . import ControlPoint, MissionTarget


# TODO: Dedup by moving everything to using this class.
FRONTLINE_MIN_CP_DISTANCE = 5000


class FrontLine(MissionTarget):
    """Defines a front line location between two control points.

    Front lines are the area where ground combat happens.
    """

    def __init__(self, control_point_a: ControlPoint,
                 control_point_b: ControlPoint) -> None:
        self.control_point_a = control_point_a
        self.control_point_b = control_point_b

    @property
    def control_points(self) -> Tuple[ControlPoint, ControlPoint]:
        """Returns a tuple of the two control points."""
        return self.control_point_a, self.control_point_b

    @property
    def name(self) -> str:
        a = self.control_point_a.name
        b = self.control_point_b.name
        return f"Front line {a}/{b}"

    @property
    def position(self) -> Point:
        a = self.control_point_a.position
        b = self.control_point_b.position
        attack_heading = a.heading_between_point(b)
        attack_distance = a.distance_to_point(b)
        middle_point = a.point_from_heading(attack_heading, attack_distance / 2)

        strength_delta = (self.control_point_a.base.strength - self.control_point_b.base.strength) / 1.0
        position = middle_point.point_from_heading(attack_heading,
                                                   strength_delta * attack_distance / 2 - FRONTLINE_MIN_CP_DISTANCE)
        return position