import { describe, expect, it, beforeEach } from "vitest";
import { defaultKnobs, type Knobs } from "./knobs";
import type { Preset } from "./preset.types";
import {
  registerPreset,
  getPreset,
  getPresetNames,
  clearPresets,
  resolveThemeFromPreset,
} from "./shared";

const testPreset: Preset = {
  theme: "blue" as any,
  knobs: { ...defaultKnobs, fillStyle: "outlined" },
  intents: {},
  tints: [],
};

describe("preset registry", () => {
  beforeEach(() => {
    clearPresets();
  });

  it("registers and retrieves a preset", () => {
    registerPreset("test", testPreset);
    expect(getPreset("test")).toBe(testPreset);
  });

  it("returns undefined for unregistered preset", () => {
    expect(getPreset("nonexistent")).toBeUndefined();
  });

  it("lists registered preset names", () => {
    registerPreset("alpha", testPreset);
    registerPreset("beta", testPreset);
    expect(getPresetNames()).toEqual(["alpha", "beta"]);
  });

  it("clears all presets", () => {
    registerPreset("first", testPreset);
    clearPresets();
    expect(getPresetNames()).toEqual([]);
    expect(getPreset("first")).toBeUndefined();
  });

  it("overwrites a preset with the same name", () => {
    const updated = { ...testPreset, theme: "green" as any };
    registerPreset("test", testPreset);
    registerPreset("test", updated);
    expect(getPreset("test")?.theme).toBe("green");
  });
});

describe("resolveThemeFromPreset", () => {
  beforeEach(() => {
    clearPresets();
  });

  it("resolves a registered preset with no overrides", () => {
    registerPreset("myPreset", testPreset);
    const resolved = resolveThemeFromPreset("myPreset", {});
    expect(resolved.knobs.fillStyle).toBe("outlined");
    expect(resolved.theme).toBe("blue");
  });

  it("merges overrides on top of preset knobs", () => {
    registerPreset("myPreset", testPreset);
    const resolved = resolveThemeFromPreset("myPreset", { size: "large" });
    expect(resolved.knobs.size).toBe("large");
    expect(resolved.knobs.fillStyle).toBe("outlined");
  });

  it("falls back to defaultKnobs for unknown preset", () => {
    const resolved = resolveThemeFromPreset("unknown", { size: "small" });
    expect(resolved.knobs.size).toBe("small");
    expect(resolved.knobs.fillStyle).toBe(defaultKnobs.fillStyle);
  });

  it("does not mutate the original preset", () => {
    registerPreset("immutable", testPreset);
    resolveThemeFromPreset("immutable", { size: "large" });
    expect(testPreset.knobs.size).toBe("medium");
  });
});