import { describe, expect, it } from "vitest";
import { frameToTime, timeToFrame } from "./frame-utils";

describe("timeToFrame", () => {
  it("round-trips every frame through frameToTime", () => {
    for (const fps of [23.976, 24, 25, 29.97, 30]) {
      for (let f = 0; f < 5000; f++) {
        expect(timeToFrame(frameToTime(f, fps), fps)).toBe(f);
      }
    }
  });

  it("reads a seek target rounded to microseconds as that frame", () => {
    // Browsers can report currentTime rounded, e.g. 4/24 as 0.166666
    expect(timeToFrame(0.166666, 24)).toBe(4);
  });

  it("still floors positions inside a frame", () => {
    expect(timeToFrame(4.5 / 24, 24)).toBe(4);
    expect(timeToFrame(4.99 / 24, 24)).toBe(4);
  });
});