from src.vec import Vec


class Camera:
    UNIT_RATIO = 150

    def __init__(self) -> None:
        self.pos: Vec = Vec()
        self.up: Vec = Vec(0, -1)
        self.size: Vec = Vec(600, 600)
        self.zoom: float = 1

    def set_pos(self, pos: Vec):
        self.pos = pos

    def set_direction(self, up: Vec):
        self.up = up.normalized

    def set_size(self, size: Vec):
        self.size = size

    @property
    def center(self) -> Vec:
        return self.size / 2

    @property
    def car_screen_pos(self) -> Vec:
        return Vec(self.size.x / 2, 3 * self.size.y / 4)

    def screen2world(self, screen_pos: Vec) -> Vec:
        delta: Vec = screen_pos - self.car_screen_pos
        delta /= self.zoom * self.UNIT_RATIO
        dx: float = delta.x
        dy: float = delta.y

        v1: Vec = self.up.perp * dx
        v2: Vec = self.up * dy

        return self.pos + v1 + v2

    def world2screen(self, world_pos: Vec) -> Vec:
        delta: Vec = world_pos - self.pos
        dy: float = -delta.dot(self.up)
        dx: float = delta.dot(self.up.perp)
        screen_delta: Vec = Vec(dx, dy) * self.zoom * self.UNIT_RATIO
        screen_pos: Vec = self.car_screen_pos + screen_delta
        return screen_pos