/**
 * Writes the light and foil versions of the motif SVGs from the dark originals
 * in src/assets/motifs, using the inks Greg picked on the light motif board
 * (2026-10-18), and the light GK monogram in src/assets/brand/light. Run after
 * a motif or the monogram changes: node packages/ui/scripts/light-motifs.mjs
 *
 *   light/       deep gold line: the dark inks swapped for Starlight-page inks, glow removed
 *   foil/        the dark seal with its gold as foil, glow kept
 *   foil-light/  the light seal with its gold as foil
 */
import { mkdirSync, readdirSync, readFileSync, writeFileSync } from "node:fs";
import { join } from "node:path";

const dir = join(import.meta.dirname, "../src/assets/motifs");

// Dark colors as they appear in the motif files, and their light inks.
const LIGHT = {
  "#C9A24A": "#8A6516",
  "#14A39A": "#0F8C84",
  "#0E1522": "#F4F2ED",
  "#101A2A": "#ECE8DF",
  "#F4F2ED": "#131C2B",
  "#F2D58A": "#A57C1F",
  "#F6E7B8": "#8A6516",
  "#2BC2B7": "#0F8C84",
  "#9A70F5": "#6A2FE0",
  "#FFF": "#F4F2ED",
};
const GOLD = ["#C9A24A", "#F2D58A"];

const stops = (s) => s.map(([o, c]) => `<stop offset="${o}" stop-color="${c}"/>`).join("");
const DARK_FOIL = stops([[0, "#8A6516"], [0.3, "#C9A24A"], [0.5, "#F6E7B8"], [0.68, "#C9A24A"], [1, "#8A6516"]]);
const LIGHT_FOIL = stops([[0, "#6F5112"], [0.35, "#A57C1F"], [0.5, "#C9A24A"], [0.65, "#8A6516"], [1, "#6F5112"]]);

const hex = (c) => new RegExp(c.replace("#", "#") + "(?![0-9A-Fa-f])", "gi");

function recolor(svg, map) {
  // One pass, so a swapped color is never swapped again.
  const keys = Object.keys(map).sort((a, b) => b.length - a.length);
  const any = new RegExp(`(${keys.join("|")})(?![0-9A-Fa-f])`, "gi");
  return svg.replace(any, (m) => map[keys.find((k) => k.toLowerCase() === m.toLowerCase())]);
}

function foil(svg, gradStops, golds) {
  const [, , , w, h] = svg.match(/viewBox="([-\d.]+) ([-\d.]+) ([\d.]+) ([\d.]+)"/) ?? [0, 0, 0, 400, 400];
  const grad = `<linearGradient id="gkfoil" gradientUnits="userSpaceOnUse" x1="0" y1="0" x2="${w}" y2="${h}">${gradStops}</linearGradient>`;
  for (const g of golds) svg = svg.replace(hex(g), "url(#gkfoil)");
  return svg.includes("<defs>") ? svg.replace("<defs>", `<defs>${grad}`) : svg.replace(/(<svg[^>]*>)/, `$1<defs>${grad}</defs>`);
}

// Glow filters are for the night sky only.
const unglow = (svg) => svg.replace(/\sfilter="url\(#[^)]*\)"/g, "");

for (const sub of ["light", "foil", "foil-light"]) mkdirSync(join(dir, sub), { recursive: true });
const files = readdirSync(dir).filter((f) => f.endsWith(".svg"));
for (const f of files) {
  const dark = readFileSync(join(dir, f), "utf8");
  const light = recolor(unglow(dark), LIGHT);
  writeFileSync(join(dir, "light", f), light);
  // Only the seals stand alone large enough for foil.
  if (/seal|astrolabe|transmutation/.test(f) && !f.startsWith("mini-") && !f.startsWith("filament-banner")) {
    writeFileSync(join(dir, "foil", f), foil(dark, DARK_FOIL, ["#C9A24A"]));
    writeFileSync(join(dir, "foil-light", f), foil(light, LIGHT_FOIL, ["#8A6516", "#A57C1F"]));
  }
}
console.log(`${files.length} motifs written`);

// The GK monogram on Starlight: a pale disc, deep gold rings and ink letters.
const MONOGRAM = {
  ...LIGHT,
  "#131C2B": "#FFFFFF",
  "#1F3B49": "#ECE6D8",
  "#15232F": "#FBF9F4",
};
const brand = join(dir, "../brand");
mkdirSync(join(brand, "light"), { recursive: true });
writeFileSync(join(brand, "light", "gk-monogram.svg"), recolor(readFileSync(join(brand, "gk-monogram.svg"), "utf8"), MONOGRAM));
console.log("monogram written");