import { mkdir, readFile, writeFile } from "node:fs/promises";
import { dirname, join } from "node:path";

const root = process.cwd();
const packageJson = JSON.parse(await readFile(join(root, "package.json"), "utf8")) as { version: string };
const giteaVersion = packageJson.version;
const localeNames = ["locale_zh-CN.json"];
const localLocaleBaseDir = join(root, "options", "locale");
const remoteLocaleBaseUrl =
  process.env.GITEA_LOCALE_BASE_URL ??
  `https://raw.githubusercontent.com/go-gitea/gitea/v${giteaVersion}/options/locale`;
const refreshRemote = process.env.GITEA_LOCALE_REFRESH === "1" || process.argv.includes("--remote");

async function readJsonFile(path: string): Promise<Record<string, string>> {
  return JSON.parse(await readFile(path, "utf8")) as Record<string, string>;
}

async function writeJsonFile(path: string, data: Record<string, string>) {
  await mkdir(dirname(path), { recursive: true });
  await writeFile(path, `${JSON.stringify(data, null, 2)}\n`);
}

async function fetchOfficialLocale(name: string): Promise<Record<string, string>> {
  const response = await fetch(`${remoteLocaleBaseUrl}/${name}`);

  if (!response.ok) {
    throw new Error(`failed to fetch official locale ${name}: ${response.status} ${response.statusText}`);
  }

  return (await response.json()) as Record<string, string>;
}

async function readOfficialLocale(name: string): Promise<Record<string, string>> {
  if (!refreshRemote) {
    try {
      return await readJsonFile(join(localLocaleBaseDir, name));
    } catch (error) {
      const code = error instanceof Error && "code" in error ? error.code : undefined;

      if (code !== "ENOENT") {
        throw error;
      }
    }
  }

  const official = await fetchOfficialLocale(name);
  await writeJsonFile(join(localLocaleBaseDir, name), official);

  return official;
}

export async function syncLocales() {
  await Promise.all(
    localeNames.map(async (name) => {
      const official = await readOfficialLocale(name);
      const overrides = await readJsonFile(join(root, "options", "locale-overrides", name));
      const merged = { ...official, ...overrides };

      await writeJsonFile(join(root, ".gitea", "custom", "options", "locale", name), merged);
    }),
  );
}

if (import.meta.main) {
  await syncLocales();
  console.log(
    refreshRemote
      ? `synced ${localeNames.length} locale file from ${remoteLocaleBaseUrl}`
      : `synced ${localeNames.length} locale file from ${localLocaleBaseDir}`,
  );
}