import { readFileSync } from "node:fs";
import { join } from "node:path";

/** Load `.env` into process.env without overriding existing vars. */
export function loadDotEnv(cwd = process.cwd()): void {
  try {
    const text = readFileSync(join(cwd, ".env"), "utf8");
    for (const line of text.split(/\r?\n/)) {
      const trimmed = line.trim();
      if (!trimmed || trimmed.startsWith("#")) continue;
      const i = trimmed.indexOf("=");
      if (i <= 0) continue;
      const key = trimmed.slice(0, i).trim();
      const value = trimmed.slice(i + 1).trim();
      process.env[key] ??= value;
    }
  } catch {
    // optional .env
  }
}