import { lstatSync, mkdirSync, chmodSync, unlinkSync, renameSync } from 'node:fs';
import { isAbsolute, join, dirname } from 'node:path';
import { randomBytes } from 'node:crypto';

export const TESTER_ORIGIN = 'http://mosaic-tester.invalid';
export function testerSocketPath(dataRoot) {
  if (typeof dataRoot !== 'string' || !isAbsolute(dataRoot)) throw Error('tester-socket-path');
  const path = join(dataRoot, 'console', 'tester.sock');
  if (Buffer.byteLength(path) > 107) throw Error('tester-socket-path');
  return path;
}
export async function bindTesterSocket(server, path) {
  if (typeof path !== 'string' || !isAbsolute(path) || Buffer.byteLength(path) > 107) throw Error('tester-socket-path');
  const parent = dirname(path);
  try { mkdirSync(parent, { mode: 0o700 }); } catch (e) { if (e.code !== 'EEXIST') throw Error('tester-socket-unsafe'); }
  const dir = lstatSync(parent);
  if (!dir.isDirectory() || dir.isSymbolicLink() || dir.uid !== process.getuid() || (dir.mode & 0o077)) throw Error('tester-socket-unsafe');
  try { lstatSync(path); throw Error('tester-socket-exists'); } catch (e) { if (e.code !== 'ENOENT') throw e; }
  // Same length as tester.sock, so the final-path capacity check covers the temporary name.
  const temporary = join(parent, '.' + randomBytes(4).toString('hex') + '.s');
  try { lstatSync(temporary); throw Error('tester-socket-exists'); } catch (e) { if (e.code !== 'ENOENT') throw e; }
  await new Promise((resolve, reject) => {
    server.once('error', reject);
    server.listen(temporary, () => { server.off('error', reject); resolve(); });
  });
  try {
    chmodSync(temporary, 0o600);
    const owned = lstatSync(temporary);
    if (!owned.isSocket() || owned.uid !== process.getuid() || (owned.mode & 0o777) !== 0o600) throw Error('tester-socket-unsafe');
    // Recheck before publishing. Same-uid swaps between lstat and rename/unlink remain
    // outside the boundary, as Sage's option-1 ruling and the build receipt state.
    try { lstatSync(path); throw Error('tester-socket-exists'); } catch (e) { if (e.code !== 'ENOENT') throw e; }
    renameSync(temporary, path);
    // libuv remembers only the now-absent temporary name. Publish the actual client path.
    server.address = () => server.listening ? path : null;
    server.once('close', () => {
      try { const s = lstatSync(path); if (s.dev === owned.dev && s.ino === owned.ino) unlinkSync(path); }
      catch (e) { if (e.code !== 'ENOENT') server.emit('error', e); }
    });
    return server;
  } catch (error) { await new Promise(r => server.close(r)); throw error; }
}
export async function startTesterSocket({ dataRoot, ...options }) {
  const { startServer } = await import('./serve.mjs');
  return startServer({ ...options, tester: true, testerSocket: testerSocketPath(dataRoot) });
}