// Regenerates src/lib/countries-data.ts from the local runtime's ICU (CLDR) region names.
// Usage: node scripts/generate-countries.mjs
import { writeFileSync } from "node:fs";

const dn = new Intl.DisplayNames(["en"], { type: "region" });
// CLDR also knows reserved, retired and pseudo codes that aren't current ISO 3166-1 countries.
// Keep only current ISO 3166-1 alpha-2 codes plus XK (Kosovo, the de-facto user-assigned code).
const EXCLUDE = new Set([
  "AC",
  "CP",
  "DG",
  "EA",
  "EU",
  "EZ",
  "IC",
  "TA",
  "UN", // exceptionally reserved
  "AN",
  "BU",
  "CQ",
  "CS",
  "DD",
  "DY",
  "FX",
  "HV",
  "NH",
  "RH",
  "SU",
  "TP",
  "VD",
  "YD",
  "YU",
  "ZR", // retired
  "UK", // reserved for GB; WHOIS "UK" is handled as an alias in countries.ts
  "QO",
  "XA",
  "XB", // CLDR-only pseudo territories
]);

const entries = [];
for (let a = 65; a <= 90; a++) {
  for (let b = 65; b <= 90; b++) {
    const code = String.fromCharCode(a, b);
    if (EXCLUDE.has(code)) continue;
    let name;
    try {
      name = dn.of(code);
    } catch {
      continue;
    }
    if (!name || name === code || name === "Unknown Region") continue;
    entries.push([code, name]);
  }
}

const body = entries.map(([c, n]) => `  ${c}: ${JSON.stringify(n)},`).join("\n");
writeFileSync(
  new URL("../src/lib/countries-data.ts", import.meta.url),
  `// Generated by scripts/generate-countries.mjs from CLDR (Unicode license). Do not edit by hand.\n` +
    `export const COUNTRY_NAMES: Record<string, string> = {\n${body}\n};\n`,
);
console.log(
  `Wrote ${entries.length} countries (Node ${process.version}, ICU ${process.versions.icu}, CLDR ${process.versions.cldr})`,
);