import { spawn } from "child_process";
import { promises as fs } from "fs";
import process from "process";

import pty from "node-pty";
import { quote } from "shell-quote";

import { readLangConfig } from "../lib/yaml.js";
import {
  bash,
  getUUID,
  privilegedExec,
  privilegedPty,
  privilegedSession,
  privilegedWait,
  run,
} from "./util.js";

function die(msg) {
  console.error(msg);
  process.exit(1);
}

function log(msg) {
  console.log(msg);
}

async function main() {
  const sandboxScript = await fs.readFile("backend/sandbox.bash", "utf-8");
  const lang = process.env.L;
  if (!lang) {
    die("environment variable unset: $L");
  }
  const langConfig = await readLangConfig(lang);
  const uuid = getUUID();
  console.log(`Starting session with UUID ${uuid}`);
  const sessionArgs = privilegedSession({ uuid, lang });
  const session = pty.spawn(sessionArgs[0], sessionArgs.slice(1), {
    name: "xterm-color",
  });
  await run(privilegedWait({ uuid }), log);
  console.log(
    bash(
      `env L='${lang}' LANG_CONFIG=${quote([
        JSON.stringify(langConfig),
      ])} bash --rcfile <(cat <<< ${quote([sandboxScript])})`
    )[2]
  );
  const args = privilegedPty(
    { uuid },
    bash(
      `env L='${lang}' LANG_CONFIG=${quote([
        JSON.stringify(langConfig),
      ])} bash --rcfile <(cat <<< ${quote([sandboxScript])})`
    )
  );
  const proc = spawn(args[0], args.slice(1), {
    stdio: "inherit",
  });
  try {
    await new Promise((resolve, reject) => {
      proc.on("error", reject);
      proc.on("close", resolve);
    });
  } finally {
    session.kill();
  }
}

main().catch(die);