import type { ThemeAppearance } from "./themePalettes.js"; export type ThemePreviewColors = Readonly<{  canvas: string;  accent: string;  messageAction: string;}>; /** The standard T3 Code artwork is not a built-in theme, so its preview colors live here. */export const STANDARD_THEME_PREVIEW_COLORS: Readonly<Record<ThemeAppearance, ThemePreviewColors>> =  {    light: {      canvas: "#fcfcfc",      accent: "#f4f4f5",      messageAction: "#4f46e5",    },    dark: {      canvas: "#0a0a0a",      accent: "#1c1c1f",      messageAction: "#8b9cff",    },  }; export type ThemePreviewRenderSpec = Readonly<{  baseTarget: string;  baseWeight: number;  accent: Readonly<{    center: readonly [x: number, y: number];    middleOffset: number;    middleOpacity: number;    endOffset: number;  }>;  action: Readonly<{    center: readonly [x: number, y: number];    startOpacity: number;    endOffset: number;  }>;  scale: number;  blurAt56Px: number;}>; /** Shared geometry and falloff for the web and native theme preview orbs. */export const THEME_PREVIEW_RENDER_SPECS: Readonly<Record<ThemeAppearance, ThemePreviewRenderSpec>> =  {    light: {      baseTarget: "#ffffff",      baseWeight: 0.8,      accent: {        center: [0.72, 0.22],        middleOffset: 0.28,        middleOpacity: 0.72,        endOffset: 0.58,      },      action: {        center: [0.18, 0.82],        startOpacity: 0.45,        endOffset: 0.55,      },      scale: 1.1,      blurAt56Px: 3,    },    dark: {      baseTarget: "#09090b",      baseWeight: 0.8,      accent: {        center: [0.28, 0.78],        middleOffset: 0.28,        middleOpacity: 0.62,        endOffset: 0.58,      },      action: {        center: [0.82, 0.18],        startOpacity: 0.45,        endOffset: 0.55,      },      scale: 1.1,      blurAt56Px: 3,    },  }; type Oklab = Readonly<{ l: number; a: number; b: number }>; const OKLCH_PATTERN = /^oklch\(\s*([\d.]+)\s+([\d.]+)\s+(-?[\d.]+)/;const HEX_PATTERN = /^#([\da-f]{2})([\da-f]{2})([\da-f]{2})$/i; function srgbToLinear(value: number): number {  return value <= 0.04045 ? value / 12.92 : ((value + 0.055) / 1.055) ** 2.4;} function linearToSrgb(value: number): number {  const converted = value <= 0.0031308 ? 12.92 * value : 1.055 * value ** (1 / 2.4) - 0.055;  return Math.round(Math.min(1, Math.max(0, converted)) * 255);} function parseOklab(value: string): Oklab | null {  const oklch = OKLCH_PATTERN.exec(value);  if (oklch) {    const lightness = Number(oklch[1]);    const chroma = Number(oklch[2]);    const hue = (Number(oklch[3]) * Math.PI) / 180;    return { l: lightness, a: chroma * Math.cos(hue), b: chroma * Math.sin(hue) };  }   const hex = HEX_PATTERN.exec(value);  if (!hex) return null;  const red = srgbToLinear(Number.parseInt(hex[1]!, 16) / 255);  const green = srgbToLinear(Number.parseInt(hex[2]!, 16) / 255);  const blue = srgbToLinear(Number.parseInt(hex[3]!, 16) / 255);  const lRoot = Math.cbrt(0.4122214708 * red + 0.5363325363 * green + 0.0514459929 * blue);  const mRoot = Math.cbrt(0.2119034982 * red + 0.6806995451 * green + 0.1073969566 * blue);  const sRoot = Math.cbrt(0.0883024619 * red + 0.2817188376 * green + 0.6299787005 * blue);  return {    l: 0.2104542553 * lRoot + 0.793617785 * mRoot - 0.0040720468 * sRoot,    a: 1.9779984951 * lRoot - 2.428592205 * mRoot + 0.4505937099 * sRoot,    b: 0.0259040371 * lRoot + 0.7827717662 * mRoot - 0.808675766 * sRoot,  };} function oklabToHex(color: Oklab): string {  const lPrime = color.l + 0.3963377774 * color.a + 0.2158037573 * color.b;  const mPrime = color.l - 0.1055613458 * color.a - 0.0638541728 * color.b;  const sPrime = color.l - 0.0894841775 * color.a - 1.291485548 * color.b;  const l = lPrime ** 3;  const m = mPrime ** 3;  const s = sPrime ** 3;  const channels = [    linearToSrgb(4.0767416621 * l - 3.3077115913 * m + 0.2309699292 * s),    linearToSrgb(-1.2684380046 * l + 2.6097574011 * m - 0.3413193965 * s),    linearToSrgb(-0.0041960863 * l - 0.7034186147 * m + 1.707614701 * s),  ];  return `#${channels.map((channel) => channel.toString(16).padStart(2, "0")).join("")}`;} export function mixThemePreviewBase(colors: ThemePreviewColors, mode: ThemeAppearance): string {  const spec = THEME_PREVIEW_RENDER_SPECS[mode]!;  const canvas = parseOklab(colors.canvas);  const target = parseOklab(spec.baseTarget);  if (!canvas || !target) return colors.canvas;  const targetWeight = 1 - spec.baseWeight;  return oklabToHex({    l: canvas.l * spec.baseWeight + target.l * targetWeight,    a: canvas.a * spec.baseWeight + target.a * targetWeight,    b: canvas.b * spec.baseWeight + target.b * targetWeight,  });}