import { expect, test } from "bun:test";
import { moveVector } from "../static/steer.js";

test("W walks the way you are looking, whichever way that is", () => {
  const east = moveVector(0, -1, 0);
  expect(east.x).toBeCloseTo(1, 6);
  expect(east.y).toBeCloseTo(0, 6);
  const south = moveVector(0, -1, Math.PI / 2);
  expect(south.x).toBeCloseTo(0, 6);
  expect(south.y).toBeCloseTo(1, 6);
});

test("D strafes across the facing, not along it", () => {
  const right = moveVector(1, 0, 0);
  expect(right.x).toBeCloseTo(0, 6);
  expect(right.y).toBeCloseTo(1, 6);
  const other = moveVector(-1, 0, 0);
  expect(other.y).toBeCloseTo(-1, 6);
});

test("forward and strafe together keep their length", () => {
  const both = moveVector(1, -1, 0.7);
  expect(Math.hypot(both.x, both.y)).toBeCloseTo(Math.SQRT2, 6);
});

test("standing still stays still", () => {
  const still = moveVector(0, 0, 2.2);
  expect(still.x).toBeCloseTo(0, 6);
  expect(still.y).toBeCloseTo(0, 6);
});

test("it fills the object it was given, so the input loop allocates nothing", () => {
  const out = { x: 0, y: 0 };
  expect(moveVector(0, -1, 0, out)).toBe(out);
});