// scripts/generate-locales.js
const fs = require("fs");
const path = require("path");

const localesDir = path.join(__dirname, "../public/locales");
const outputFile = path.join(__dirname, "../src/i18n/generatedLocales.ts");

// Discover locale folders
const rawLocales = fs
  .readdirSync(localesDir)
  .filter((name) => fs.statSync(path.join(localesDir, name)).isDirectory());

// Normalise folder names (e.g., en_GB → en-GB)
const locales = rawLocales.map((l) => l.replace("_", "-"));

// Sort by locale code
locales.sort((a, b) => a.localeCompare(b));

// Base locales (no hyphen)
const baseLocales = locales.filter((l) => !l.includes("-"));

// Only region-specific locales (those with a hyphen)
const availableLocales = locales.filter((l) => l.includes("-"));

// Fallback map: region -> base (and default to en)
const fallbackLng = locales.reduce((acc, locale) => {
  if (locale.includes("-")) {
    const base = locale.split("-")[0];
    if (baseLocales.includes(base)) {
      acc[locale] = base === "en" ? ["en"] : [base, "en"];
    } else {
      acc[locale] = ["en"];
    }
  }
  return acc;
}, {});

// Generate TS file
const ts = `
// AUTO-GENERATED FILE — DO NOT EDIT MANUALLY

export const availableLocales = ${JSON.stringify(availableLocales, null, 2)} as const;

export const baseLocales = ${JSON.stringify(baseLocales, null, 2)} as const;

export const fallbackLng = ${JSON.stringify(fallbackLng, null, 2)} as const;

export type Locale = typeof availableLocales[number];
`;

fs.writeFileSync(outputFile, ts);
console.log("Generated generatedLocales.ts");