/**
 * Ensures `.env.local` (and mode-specific `.env.desktop.local` / `.env.saas.local`)
 * files exist so developers have a place to put overrides (API keys, machine-specific
 * settings) without touching the committed `.env` / `.env.desktop` / `.env.saas` files.
 *
 * Vite automatically layers these `.local` files on top of the committed ones.
 *
 * Usage:
 *   tsx scripts/setup-env.mts              # ensures .env.local
 *   tsx scripts/setup-env.mts --desktop    # also ensures .env.desktop.local
 *   tsx scripts/setup-env.mts --saas       # also ensures .env.saas.local
 *
 * Why .mts (and not .ts)?
 *   This script needs `import.meta.url` to resolve paths relative to itself,
 *   because Task invokes it from the workspace root (frontend/) but the .env
 *   files live one level deeper at frontend/editor/. `import.meta` is only
 *   valid in ESM output; `editor/scripts/tsconfig.json` extends the editor
 *   tsconfig which uses `module: node16`, treating plain .ts as CommonJS
 *   (TS1470 error on `import.meta`). The .mts extension explicitly marks
 *   the file as ESM, which tsx already runs at runtime anyway.
 */

import { existsSync, writeFileSync } from "fs";
import { dirname, join, resolve } from "path";
import { fileURLToPath } from "url";

// .env files live next to the editor's vite.config.ts (frontend/editor/).
// Resolve relative to this script regardless of where the build was invoked.
const scriptDir = dirname(fileURLToPath(import.meta.url));
const root = resolve(scriptDir, "..");
const args = process.argv.slice(2);
const isDesktop = args.includes("--desktop");
const isSaas = args.includes("--saas");

function template(parent: string): string {
  return [
    "###############################################################################",
    `# Local overrides for \`frontend/editor/${parent}\``,
    "# Put API keys and machine-specific settings here. Any variable defined here",
    `# takes precedence over the committed \`${parent}\``,
    "###############################################################################",
    "",
  ].join("\n");
}

function ensureLocalFile(localFile: string, parentFile: string): void {
  const localPath = join(root, localFile);
  if (!existsSync(localPath)) {
    writeFileSync(localPath, template(parentFile));
    console.log(`setup-env: created empty ${localFile} for local overrides`);
  }
}

ensureLocalFile(".env.local", ".env");
if (isDesktop) ensureLocalFile(".env.desktop.local", ".env.desktop");
if (isSaas) ensureLocalFile(".env.saas.local", ".env.saas");