import { describe, expect, it } from "vitest";
import { getActiveMotionClipAtTime, resolveMotionClipEnd } from "./motion";
import type { MotionClip } from "../../schema/directorProject";

function clip(partial: Partial<MotionClip> & Pick<MotionClip, "id" | "start" | "end">): MotionClip {
  return {
    kind: "walk",
    speed: 1,
    amplitude: 1,
    enabled: true,
    ...partial,
  };
}

describe("getActiveMotionClipAtTime", () => {
  it("returns null when there are no clips", () => {
    expect(getActiveMotionClipAtTime(undefined, 1, 10)).toBeNull();
    expect(getActiveMotionClipAtTime([], 1, 10)).toBeNull();
  });

  it("returns the clip covering the current time", () => {
    const a = clip({ id: "a", start: 0, end: 2 });
    const b = clip({ id: "b", kind: "run", start: 2, end: 5 });
    expect(getActiveMotionClipAtTime([a, b], 1, 5)?.id).toBe("a");
    expect(getActiveMotionClipAtTime([a, b], 3, 5)?.id).toBe("b");
  });

  it("later clips win on overlap (last covering segment wins)", () => {
    const a = clip({ id: "a", start: 0, end: 5 });
    const b = clip({ id: "b", start: 2, end: 6 });
    expect(getActiveMotionClipAtTime([a, b], 3, 6)?.id).toBe("b");
  });

  it("treats an open-ended clip (Infinity) as lasting to the timeline end", () => {
    const a = clip({ id: "a", start: 0, end: Number.POSITIVE_INFINITY });
    expect(getActiveMotionClipAtTime([a], 999, 10)?.id).toBe("a");
  });

  it("returns null for disabled / none clips (character stays static)", () => {
    const disabled = clip({ id: "a", start: 0, end: 5, enabled: false });
    const none = clip({ id: "b", start: 0, end: 5, kind: "none" });
    expect(getActiveMotionClipAtTime([disabled], 1, 5)).toBeNull();
    expect(getActiveMotionClipAtTime([none], 1, 5)).toBeNull();
  });

  it("returns null outside any clip", () => {
    const a = clip({ id: "a", start: 1, end: 4 });
    expect(getActiveMotionClipAtTime([a], 0, 5)).toBeNull();
    expect(getActiveMotionClipAtTime([a], 5, 5)).toBeNull();
  });
});

describe("resolveMotionClipEnd", () => {
  it("keeps a finite end within bounds", () => {
    const a = clip({ id: "a", start: 1, end: 4 });
    expect(resolveMotionClipEnd(a, 10)).toBe(4);
  });

  it("resolves an open-ended end to the timeline duration", () => {
    const a = clip({ id: "a", start: 1, end: Number.POSITIVE_INFINITY });
    expect(resolveMotionClipEnd(a, 10)).toBe(10);
  });
});