import { describe, it, expect } from "vitest";
import { shouldApplyTimeUpdate } from "./timeTracking";

/**
 * TRACES: UT-245 | DR-265
 */
describe("shouldApplyTimeUpdate", () => {
  const base = { isPlaying: false, isSeeking: false, isDraggingSeekBar: false, readyState: 4 };

  it("applies the update while the video is PLAYING", () => {
    // THE REPORTED BUG. `timeupdate` was the only position source that still
    // fires once requestAnimationFrame stops -- which is exactly what happens
    // when the activity is paused behind a picture-in-picture window. Gating it
    // on `!isPlaying` disabled it precisely when it was the only thing left,
    // so the component's `currentTime` froze at the moment PiP was entered
    // while the element played on. The background-audio handoff then resumed
    // the audio-only stream at that frozen position.
    expect(shouldApplyTimeUpdate({ ...base, isPlaying: true })).toBe(true);
  });

  it("still applies the update while paused", () => {
    // The case it always handled: RAF is stopped, timeupdate carries the seek.
    expect(shouldApplyTimeUpdate(base)).toBe(true);
  });

  it("yields to an in-flight seek", () => {
    // A seek owns the position until it settles; a stale element read landing
    // mid-seek is what makes a scrubbed video snap back.
    expect(shouldApplyTimeUpdate({ ...base, isSeeking: true })).toBe(false);
    expect(shouldApplyTimeUpdate({ ...base, isPlaying: true, isSeeking: true })).toBe(false);
  });

  it("yields while the user is dragging the seek bar", () => {
    expect(shouldApplyTimeUpdate({ ...base, isDraggingSeekBar: true })).toBe(false);
    expect(shouldApplyTimeUpdate({ ...base, isPlaying: true, isDraggingSeekBar: true })).toBe(
      false,
    );
  });

  it("ignores an element with no usable data yet", () => {
    // readyState < HAVE_CURRENT_DATA reads 0, which would rewind the position.
    expect(shouldApplyTimeUpdate({ ...base, readyState: 1 })).toBe(false);
    expect(shouldApplyTimeUpdate({ ...base, isPlaying: true, readyState: 0 })).toBe(false);
  });
});