import { describe, expect, it } from "vitest";
import { dust, ringTicks, seedOf, seeded, starPath, starPoints, ticks } from "../src/lib/ornaments.ts";

describe("ornament geometry", () => {
  it("is the same on every build for the same seed", () => {
    expect(starPath({ x1: 0, x2: 600, y: 18, steps: 12, seed: 7 })).toEqual(starPath({ x1: 0, x2: 600, y: 18, steps: 12, seed: 7 }));
    expect(dust(10, 3)).toBe(dust(10, 3));
    expect(seeded(1)()).toBe(seeded(1)());
    expect(seedOf("Library")).not.toBe(seedOf("Store"));
  });

  it("keeps the ends of a star path on the line and nudges within its strength", () => {
    const p = starPath({ x1: 0, x2: 600, y: 20, steps: 12, seed: 42, strength: "standard" });
    expect(p.marks[0]!.y).toBe(20);
    expect(p.marks.at(-1)!.y).toBe(20);
    for (const m of p.marks) expect(Math.abs(m.y - 20)).toBeLessThanOrEqual(0.22 * 50 + 0.05);
    expect(p.links).toHaveLength(12);
  });

  it("makes about a third of the points small violet stars and one gold center star", () => {
    const p = starPath({ x1: 0, x2: 1200, y: 20, steps: 24, seed: 5, centerStar: true });
    const stars = p.marks.filter((m) => m.kind === "star");
    expect(stars.filter((s) => s.kind === "star" && s.gold)).toHaveLength(1);
    expect(stars.length).toBeGreaterThanOrEqual(8);
    expect(stars.length).toBeLessThanOrEqual(10);
  });

  it("stops each dotted link short of the marks it joins", () => {
    const p = starPath({ x1: 0, x2: 100, y: 10, steps: 2, seed: 0, strength: "calm" });
    expect(p.links[0]!.x1).toBeGreaterThan(0);
    expect(p.links[0]!.x2).toBeLessThan(50);
  });

  it("draws a long tick every fifth tick", () => {
    const t = ticks(200, 30);
    expect(t).toHaveLength(31);
    expect(t.filter((x) => x.long)).toHaveLength(7);
    expect(ringTicks(76)).toHaveLength(48);
  });

  it("draws a thin four-point star", () => {
    expect(starPoints(10, 10, 10)).toBe("10,0 11.6,8.4 20,10 11.6,11.6 10,20 8.4,11.6 0,10 8.4,8.4");
  });
});