import { describe, expect, it } from "vitest";
import { hueMatrix, levelTone, resolveTone, TONES, toneFilters, toneWash } from "./tone.js";

describe("toneFilters", () => {
  it("writes each layer's filter as literal values", () => {
    const filters = toneFilters(TONES.regular.dark);
    expect(filters.body.full).toBe("blur(1px) saturate(1.325) contrast(0.781) brightness(0.7915)");
    expect(filters.shade.full).toBe("brightness(1.33)");
    expect(filters.glow.full).toBe("saturate(1.1) brightness(1.3)");
    expect(filters.edge.full).toBe("brightness(0.66)");
    expect(filters.highlight.full).toBe("contrast(1.1) brightness(2.4)");
  });

  it("diffuses floating glass more", () => {
    expect(toneFilters(TONES.regular.dark, true).body.full).toBe("blur(6px) saturate(1.45) contrast(0.724) brightness(0.7445)");
    expect(toneFilters(TONES.regular.light, true).body.full).toBe("blur(4.5px) saturate(1.35) contrast(0.5) brightness(1.355)");
  });

  it("drops identity functions and clears the same list", () => {
    expect(toneFilters(TONES.regular.light).body).toEqual({ full: "blur(1px) saturate(1.3)", clear: "blur(0px) saturate(1)" });
    expect(toneFilters(TONES.clear.dark).body).toEqual({
      full: "saturate(1.05) contrast(0.97) brightness(0.96)",
      clear: "saturate(1) contrast(1) brightness(1)",
    });
    expect(toneFilters(TONES.clear.light).glow).toEqual({ full: "brightness(1.02)", clear: "brightness(1)" });
  });

  it("leaves a layer unfiltered when every value is identity", () => {
    expect(toneFilters(TONES.lens.light).body).toEqual({ full: "none", clear: "none" });
  });
});

describe("levelTone", () => {
  it("runs from More Clear through the default to More Tinted", () => {
    expect(levelTone("light", 0)).toMatchObject({ blur: 0, tint: 0.04 });
    expect(levelTone("light", 0.5)).toMatchObject({ blur: 1, saturate: 1.3, tint: 0.175 });
    expect(levelTone("light", 1)).toMatchObject({ blur: 5, contrast: 0.744, brightness: 1.173, tint: 0.4 });
    expect(levelTone("dark", 1).brightness).toBeLessThan(levelTone("dark", 0).brightness);
  });

  it("keeps floating glass frosted at every level", () => {
    expect(levelTone("dark", 0).floatingBlur).toBeGreaterThan(0);
    expect(levelTone("light", 0).floatingBlur).toBeGreaterThan(0);
  });

  it("clamps levels outside 0–1", () => {
    expect(levelTone("dark", -1)).toEqual(levelTone("dark", 0));
    expect(levelTone("dark", 3)).toEqual(levelTone("dark", 1));
  });
});

describe("resolveTone", () => {
  it("overrides only the given appearance", () => {
    const overrides = { dark: { tint: 0.5 } };
    expect(resolveTone("regular", "dark", overrides).tint).toBe(0.5);
    expect(resolveTone("regular", "light", overrides).tint).toBe(TONES.regular.light.tint);
  });

  it("takes regular glass's level, and leaves the other variants as they are", () => {
    expect(resolveTone("regular", "light", undefined, 1).tint).toBe(0.4);
    expect(resolveTone("clear", "light", undefined, 1)).toEqual(TONES.clear.light);
  });
});

describe("toneWash", () => {
  it("mixes the tint by the tone's share", () => {
    expect(toneWash(TONES.regular.light, "var(--surface)")).toBe("color-mix(in srgb, var(--surface) 17.5%, transparent)");
    expect(toneWash(TONES.regular.dark, "black")).toBe("color-mix(in srgb, black 23.5%, transparent)");
    expect(toneWash(TONES.regular.dark, "black", true)).toBe("color-mix(in srgb, black 31%, transparent)");
    expect(toneWash(TONES.lens.dark, "black")).toBe("transparent");
  });
});

describe("hueMatrix", () => {
  it("leaves neutral colours untinted", () => {
    expect(hueMatrix([128, 128, 128], 1)).toBeNull();
    expect(hueMatrix([255, 255, 255], 1)).toBeNull();
  });

  it("keeps alpha and shifts channels toward the hue", () => {
    const rows = hueMatrix([20, 30, 60], 1)?.split(" ").map(Number) ?? [];
    expect(rows).toHaveLength(20);
    expect(rows.slice(15)).toEqual([0, 0, 0, 1, 0]);
    // Blue gains, red loses: the blue row's own weight rises above red's.
    expect(rows[12]).toBeGreaterThan(rows[0] ?? 0);
  });

  it("scales with strength", () => {
    const full = hueMatrix([20, 30, 60], 1)?.split(" ").map(Number) ?? [];
    const half = hueMatrix([20, 30, 60], 0.5)?.split(" ").map(Number) ?? [];
    expect(Math.abs((half[12] ?? 0) - 1)).toBeCloseTo(Math.abs((full[12] ?? 0) - 1) / 2, 3);
  });
});