import { existsSync, readFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

function isDrizzlePkgRoot(dir: string): boolean {
  const pkg = path.join(dir, "package.json");
  if (!existsSync(pkg)) {
    return false;
  }
  try {
    const { name } = JSON.parse(readFileSync(pkg, "utf8")) as { name?: string };
    return name === "drizzle-pkg";
  } catch {
    return false;
  }
}

/**
 * `drizzle-pkg` 包根目录（与 `package.json`、`db.sqlite` 同级）。
 * - 开发：用 `import.meta` 锚定，避免 cwd 变化把 `file:db.sqlite` 指到错误文件（只读 / DBMOVED）。
 * - 生产：打包后 chunk 路径不可靠，回退到 `cwd/packages/drizzle-pkg`；再不行则回退 `process.cwd()`（与 `.output` 下 migrate/seed 的相对 `DATABASE_URL` 一致）。
 */
export function getDrizzlePkgRoot(): string {
  const fromMeta = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
  if (isDrizzlePkgRoot(fromMeta)) {
    return fromMeta;
  }
  const fromCwd = path.resolve(process.cwd(), "packages/drizzle-pkg");
  if (isDrizzlePkgRoot(fromCwd)) {
    return fromCwd;
  }
  return process.cwd();
}