import fc from "fast-check";
import { describe, expect, it } from "vitest";

import {
  conversionRows,
  formatColour,
  parseColour,
  parseColourList,
  toSrgbPreview,
  tryParseColour,
} from "../../src/colour";

describe("colour parsing and conversion", () => {
  it("converts the RapidTables reference colour", () => {
    const colour = parseColour("#f8f5ee");
    expect(colour.space).toBe("srgb");
    expect(colour.coords).toEqual([248 / 255, 245 / 255, 238 / 255]);
    expect(formatColour(colour, "hex")).toBe("#f8f5ee");
    expect(formatColour(colour, "rgb")).toBe("rgb(248, 245, 238)");
    expect(formatColour(colour, "hsl")).toBe("hsl(42 41.6667% 95.2941%)");
  });

  it("accepts CSS Color 4, named, bare hex and numeric RGB input", () => {
    expect(formatColour("rebeccapurple", "hex")).toBe("#663399");
    expect(formatColour("f8f5ee", "hex")).toBe("#f8f5ee");
    expect(formatColour("0xff000080", "hex8")).toBe("#ff000080");
    expect(formatColour("248, 245, 238", "hex")).toBe("#f8f5ee");
    const p3 = parseColour("color(display-p3 1 0.2 0.1 / 75%)");
    expect(p3.space).toBe("p3");
    expect(p3.alpha).toBeCloseTo(0.75);
  });

  it("parses custom HSV/HSB with angles and alpha", () => {
    expect(formatColour("hsv(120 50% 60% / 25%)", "rgba")).toBe(
      "rgba(77, 153, 77, 0.25)",
    );
    expect(formatColour("hsb(.333333turn, .5, .6)", "hex")).toBe("#4d994d");
    expect(parseColour("hsv(-30deg 100% 100%)").coords[0]).toBe(330);
  });

  it("parses custom CMYK and converts it deterministically", () => {
    expect(formatColour("cmyk(0% 100% 100% 0% / .5)", "hex8")).toBe(
      "#ff000080",
    );
    expect(formatColour("cmyk(100%, 0%, 100%, 25%)", "rgb")).toBe(
      "rgb(0, 191, 0)",
    );
    expect(formatColour("#000", "cmyk")).toBe("cmyk(0% 0% 0% 100%)");
  });

  it("returns structured failures without throwing", () => {
    expect(tryParseColour("")).toMatchObject({
      ok: false,
      error: { code: "empty" },
    });
    expect(tryParseColour("hsv(20 200% 20%)")).toMatchObject({
      ok: false,
      error: { code: "out-of-range" },
    });
    expect(tryParseColour("definitely-not-a-colour").ok).toBe(false);
  });

  it("splits lists only at top-level delimiters", () => {
    const colours = parseColourList("rgb(1, 2, 3), hsl(20 30% 40%);\n#fff");
    expect(colours).toHaveLength(3);
    expect(formatColour(colours[0]!, "rgb")).toBe("rgb(1, 2, 3)");
    expect(parseColourList('["#f00", "#0f0"]')).toHaveLength(2);
  });

  it("offers copy-ready conversion rows and a safe preview", () => {
    const rows = conversionRows("#f8f5ee", ["hex", "rgb", "oklch"]);
    expect(rows.map((row) => row.label)).toEqual(["HEX", "RGB", "OKLCH"]);
    expect(rows[0]?.copyValue).toBe("#f8f5ee");
    const preview = toSrgbPreview("color(display-p3 1 0 0)");
    expect(preview.wasMapped).toBe(true);
    expect(preview.css).toMatch(/^rgb\(/);
    expect(preview.rgb.every((channel) => channel >= 0 && channel <= 1)).toBe(
      true,
    );
  });

  it("round-trips arbitrary 8-bit RGB colours through HEX", () => {
    fc.assert(
      fc.property(
        fc.integer({ min: 0, max: 255 }),
        fc.integer({ min: 0, max: 255 }),
        fc.integer({ min: 0, max: 255 }),
        (red, green, blue) => {
          const value = {
            space: "srgb",
            coords: [red / 255, green / 255, blue / 255] as [
              number,
              number,
              number,
            ],
            alpha: 1,
          };
          expect(parseColour(formatColour(value, "hex")).coords).toEqual(
            value.coords,
          );
        },
      ),
      { numRuns: 200 },
    );
  });
});