// Read-only connector discovery. Never load binding policy or token resources.
import { lstatSync, readdirSync, openSync, closeSync, fstatSync, readFileSync, constants } from 'node:fs';
import { join, resolve, parse } from 'node:path';
import { readPid, ownerState } from '../../discord/src/journal.mjs';

const NAME = /^[a-z0-9][a-z0-9._-]{0,63}$/;
// Check every existing ancestor, not just the final component.
export function noLinks(path) {
  const absolute = resolve(path);
  let current = parse(absolute).root;
  for (const part of absolute.slice(current.length).split('/').filter(Boolean)) {
    current = join(current, part);
    try { if (lstatSync(current).isSymbolicLink()) return false; }
    catch (e) { if (e.code === 'ENOENT') return true; return false; }
  }
  return true;
}
function stat(path) { try { return lstatSync(path); } catch { return null; } }
export function discoverDiscordAgents(dataRoot) {
  const specs = [], errors = [];
  const dir = join(dataRoot, 'discord');
  if (!noLinks(dir)) return { specs, errors: ['discord discovery: unsafe directory'] };
  const ds = stat(dir);
  if (!ds) return { specs, errors };
  if (!ds.isDirectory()) return { specs, errors: ['discord discovery: invalid directory'] };
  let names;
  try { names = readdirSync(dir).sort(); } catch { return { specs, errors: ['discord discovery: unreadable directory'] }; }
  for (const file of names.filter(n => n.endsWith('.json'))) {
    let fd;
    try {
      const name = file.slice(0, -5);
      if (!NAME.test(name)) throw new Error();
      fd = openSync(join(dir, file), constants.O_RDONLY | constants.O_NOFOLLOW | constants.O_NONBLOCK);
      const s = fstatSync(fd);
      if (!s.isFile() || (s.mode & 0o7777) !== 0o600 || s.size > 1024 * 1024) throw new Error();
      const raw = JSON.parse(readFileSync(fd, 'utf8'));
      if (!raw || raw.name !== name || typeof raw.seat !== 'string' || !NAME.test(raw.seat)) throw new Error();
      // Do not retain the binding object, even in internal scan specs.
      specs.push({ agent: `${raw.seat} (discord: ${name})`, project: 'fleet', sessionsDir: join(dataRoot, 'sessions', `discord-${name}`), tmux: null, connector: { binding: name, journalDir: join(dir, name) } });
    } catch { errors.push('discord discovery: skipped invalid binding'); }
    finally { if (fd !== undefined) closeSync(fd); }
  }
  return { specs, errors };
}
export function inspectDiscord(connector, { identity } = {}) {
  const dir = connector.journalDir, owner = join(dir, 'run.lock', 'owner.json');
  let braked = null;
  if (noLinks(dir)) {
    try { lstatSync(join(dir, 'STOP')); braked = true; }
    catch (e) { if (e.code === 'ENOENT') braked = false; }
  }
  let ownerStatus = 'invalid';
  if (noLinks(owner)) {
    const s = stat(owner);
    if (!s || s.isFile()) {
      try { ownerStatus = ownerState(readPid(dir), identity ? { identity } : {}); } catch { ownerStatus = 'invalid'; }
    }
  }
  return { binding: connector.binding, braked, ownerState: ownerStatus, alive: ownerStatus === 'live' };
}
// Connector session trees must not follow links, including ancestor links.
export function newestDiscordSession(dir) {
  if (!noLinks(dir)) return null;
  let best = null;
  const walk = path => {
    const s = stat(path);
    if (!s || s.isSymbolicLink()) return;
    if (s.isDirectory()) { for (const name of readdirSync(path)) walk(join(path, name)); }
    else if (s.isFile() && path.endsWith('.jsonl') && (!best || s.mtimeMs > best.time)) best = { path, time: s.mtimeMs };
  };
  walk(dir);
  return best?.path ?? null;
}