/**
 * Language server pool manager.
 * Spawns multiple LS instances — one per unique outbound proxy (plus a default
 * no-proxy instance). Accounts are routed to the LS instance matching their
 * configured proxy so that each upstream Codeium request goes out through the
 * right egress IP. Also avoids the LS state-pollution bug where switching
 * accounts within a single LS session causes workspace setup streams to be
 * canceled.
 */

import { spawn, execSync } from 'child_process';
import { mkdirSync } from 'fs';
import { existsSync } from 'fs';
import http2 from 'http2';
import net from 'net';
import { randomUUID } from 'crypto';
import { resolve } from 'path';
import { log } from './config.js';
import { closeSessionForPort } from './grpc.js';

const DEFAULT_BINARY = '/opt/windsurf/language_server_linux_x64';
const DEFAULT_PORT = 42100;
const DEFAULT_CSRF = 'windsurf-api-csrf-fixed-token';
const DEFAULT_API_URL = 'https://server.self-serve.windsurf.com';
const DEFAULT_LINUX_DATA_ROOT = '/opt/windsurf/data';

// v2.0.96: cap LS pool size to prevent memory blowup (#174).
// Each LS instance uses ~200-400MB. With sticky proxy detection enabling
// per-account LS, memory can grow unbounded. Default cap: 20 instances.
const MAX_LS_INSTANCES = (() => {
  const n = parseInt(process.env.LS_MAX_INSTANCES || '', 10);
  return Number.isFinite(n) && n > 0 ? n : 20;
})();

// Auto-restart configuration (env-overridable)
const AUTO_RESTART_ENABLED = process.env.LS_AUTO_RESTART !== '0'; // default: on
const AUTO_RESTART_MAX_RETRIES = (() => {
  const n = parseInt(process.env.LS_AUTO_RESTART_MAX_RETRIES || '', 10);
  return Number.isFinite(n) && n > 0 ? n : 3;
})();
const AUTO_RESTART_BASE_DELAY_MS = (() => {
  const n = parseInt(process.env.LS_AUTO_RESTART_BASE_DELAY_MS || '', 10);
  return Number.isFinite(n) && n > 0 ? n : 1000;
})();

// Pool: key -> { process, port, csrfToken, proxy, startedAt, ready }
const _pool = new Map();
// In-flight Promise map so two concurrent ensureLs(proxy) calls for the
// same key share one spawn + readiness wait. Without this, both callers
// would each spawn an LS process, race on the port, and leave an orphan.
const _pending = new Map();
// Track which LS keys are being shut down intentionally so the exit handler
// doesn't fire an auto-restart for them. Without this, stopLanguageServer()
// and restartLsForProxy() would trigger unwanted respawns.
const _intentionalShutdown = new Set();
let _nextPort = DEFAULT_PORT + 1;
let _binaryPath = DEFAULT_BINARY;
let _apiServerUrl = DEFAULT_API_URL;

// v2.0.71 (#119 follow-up): heuristic to recognise sticky-IP proxy
// usernames. Common providers embed a session/IP token inside the
// username so the same host:port serves many distinct egress IPs:
//   ipwo:        username_sid_xxxxxxx
//   lunaproxy:   user-zone-residential-session-xxx
//   smartproxy:  spxxxxx-session-xxx-stickyXX
//   bright data: brd-customer-xxx-zone-xxx[-session-xxx]
//   oxylabs:     customer-xxxxx-cc-xxx[-sessid-xxx]
// Match any of these and segregate LS automatically. Falls back to
// host:port when the username doesn't fit the pattern (avoids
// LS-per-account memory blow up for static-IP proxies that intentionally
// share an egress).
//
// v2.0.79 (audit M-1) — original regex only caught usernames that
// contained an explicit session token (`_sid_`, `-session-`, `+ws_`).
// Bright Data and Oxylabs username schemas don't always include the
// session token (some plans use a stable username + rotating egress
// per-request, but the upstream still treats the username itself as
// the routing fingerprint). Those usernames look like:
//   brd-customer-hl_abc123-zone-residential
//   customer-myuser-cc-US-country-US
// They'd hash to the same proxyKey as a static-IP shared username
// (because there's no `session` token), so the LS pool would lump
// every account behind that proxy onto one shared LS instance, which
// is what wnfilm and 0a00 reported in #118 — "30 minute rate-limit
// even though I have 31 trial accounts behind it". Widen the regex
// to also catch `brd-customer-` prefix and `customer-...-cc-` /
// `customer-...-zone-` patterns. Static-IP proxies whose username is
// a bare login (no provider-specific markers) still skip
// segregation, so memory stays bounded.
// v2.0.93: expanded sticky detection. Any proxy username with a provider-
// specific token, session marker, or non-trivial structure gets its own LS.
// This catches more providers (iproyal, webshare, proxy-seller, etc) and
// reduces cross-account LS sharing which triggers upstream rate limits.
const STICKY_USER_RE = /(?:[_-](?:sid|session|sessid|sticky|sess|token|res|rotating|sticky|ip[_-]?[0-9])|[+]ws_|^brd-customer-|^customer-|^user-|^res-|^sticky-|-zone-[a-z]+|-cc-[a-z]{2}|-country-|-state-|-city-|-session-|-sess-|-sticky-|-res-|-rotating-)/i;
function isStickyUsername(u) {
  if (typeof u !== 'string' || u.length < 4) return false;
  return STICKY_USER_RE.test(u);
}

function proxyKey(proxy) {
  if (!proxy || !proxy.host) return 'default';
  // Sanitize to [A-Za-z0-9_] — the key flows into a filesystem path
  // (`${LS_DATA_DIR}/${key}`) and a shell-quoted mkdir, so strip any
  // special character that could slip past execSync's naive quoting.
  const safeHost = proxy.host.replace(/[^a-zA-Z0-9]/g, '_');
  const safePort = String(proxy.port || 8080).replace(/[^0-9]/g, '');
  let key = `px_${safeHost}_${safePort}`;
  // v2.0.68/v2.0.71 (#119 CharwinYAO): sticky-IP proxy services (ipwo,
  // lunaproxy, smartproxy, oxylabs, bright data) embed a per-IP session
  // id inside the username. Default behaviour pools all sticky sessions
  // onto one LS instance (host:port identical) so multiple accounts
  // share one LS sessionId / Windsurf fingerprint, tripping upstream's
  // 30-min rate limit even though egress IPs differ.
  //
  // Auto-on (v2.0.71): username matches a known sticky session pattern
  // (`_sid_`, `-session-`, `-sticky`, `-sessid-`, `+ws_`) → segregate.
  // Static-IP proxies don't carry these markers so memory stays bounded.
  // Operator can force-on (`WINDSURFAPI_LS_PER_PROXY_USER=1`) to
  // segregate every distinct username, or force-off (`=0`) to disable.
  let segregateByUser = false;
  if (process.env.WINDSURFAPI_LS_PER_PROXY_USER === '0') {
    segregateByUser = false;
  } else if (process.env.WINDSURFAPI_LS_PER_PROXY_USER === '1') {
    segregateByUser = !!proxy.username;
  } else if (proxy.username && isStickyUsername(proxy.username)) {
    segregateByUser = true;
  }
  if (segregateByUser) {
    // Cap user portion at 32 chars to keep filesystem paths sane on
    // Windows where MAX_PATH still bites; sticky session ids are
    // typically <16 chars anyway.
    const safeUser = String(proxy.username).replace(/[^a-zA-Z0-9]/g, '_').slice(0, 32);
    if (safeUser) key += `_u${safeUser}`;
  }
  return key;
}

export function defaultLsDataRoot(platform = process.platform, home = process.env.HOME) {
  return platform === 'darwin'
    ? resolve(home || '.', '.windsurf', 'data')
    : DEFAULT_LINUX_DATA_ROOT;
}

function dataDirForKey(key) {
  const root = process.env.LS_DATA_DIR
    ? resolve(process.cwd(), process.env.LS_DATA_DIR)
    : defaultLsDataRoot();
  return `${root}/${key}`;
}

function proxyUrl(proxy) {
  if (!proxy || !proxy.host) return null;
  const auth = proxy.username
    ? `${encodeURIComponent(proxy.username)}:${encodeURIComponent(proxy.password || '')}@`
    : '';
  return `http://${auth}${proxy.host}:${proxy.port || 8080}`;
}

// Pass only what the LS binary actually needs to its child env. Forwarding
// the full process.env exposed unrelated proxy secrets / build env / CI
// tokens to a binary we don't fully control. Allowlist covers HOME (asset
// paths), PATH (subprocess discovery), LANG/locale, TMPDIR, and the proxy
// vars that the LS reads to dial out.
const LS_ENV_ALLOWLIST = [
  'HOME', 'PATH', 'LANG', 'LC_ALL', 'TMPDIR', 'TMP', 'TEMP',
  'HTTP_PROXY', 'HTTPS_PROXY', 'NO_PROXY',
  'http_proxy', 'https_proxy', 'no_proxy',
  // SSL trust roots — without these LS can fail to verify the upstream
  // Codeium endpoint on hardened hosts.
  'SSL_CERT_FILE', 'SSL_CERT_DIR', 'NODE_EXTRA_CA_CERTS',
];

export function buildLanguageServerEnv(source = process.env, options = {}) {
  const env = {};
  for (const key of LS_ENV_ALLOWLIST) {
    if (source[key] != null && source[key] !== '') env[key] = source[key];
  }
  // Fall back to /root only when HOME isn't already set (e.g. a systemd
  // unit without User=). VPS deployments already have HOME in env; forcing
  // /root broke macOS/Windows dev runs where LS expects the real $HOME.
  if (!env.HOME) env.HOME = source.HOME || '/root';
  const pUrl = options.proxyUrl || null;
  if (pUrl) {
    env.HTTPS_PROXY = pUrl;
    env.HTTP_PROXY = pUrl;
    env.https_proxy = pUrl;
    env.http_proxy = pUrl;
  }
  return env;
}

export function redactProxyUrl(urlOrProxy) {
  if (!urlOrProxy) return 'none';
  if (typeof urlOrProxy === 'object') {
    const host = urlOrProxy.host || '';
    const port = urlOrProxy.port || 8080;
    return `${host}:${port}${urlOrProxy.username ? ' (auth=true)' : ''}`;
  }
  try {
    const u = new URL(String(urlOrProxy));
    return `${u.hostname}:${u.port || (u.protocol === 'https:' ? '443' : '80')}${u.username || u.password ? ' (auth=true)' : ''}`;
  } catch {
    return String(urlOrProxy).replace(/\/\/([^:@/\s]+):([^@/\s]*)@/g, '//***:***@');
  }
}

function isPortInUse(port) {
  return new Promise((resolve) => {
    const sock = net.createConnection({ port, host: '127.0.0.1' }, () => {
      sock.destroy(); resolve(true);
    });
    sock.on('error', () => resolve(false));
    sock.setTimeout(1000, () => { sock.destroy(); resolve(false); });
  });
}

export function probeLanguageServerPort(port, timeoutMs = 1500) {
  return new Promise((resolve) => {
    const client = http2.connect(`http://localhost:${port}`);
    let settled = false;
    let req = null;
    const finish = (ok) => {
      if (settled) return;
      settled = true;
      clearTimeout(timer);
      try { req?.close(); } catch {}
      try { client.close(); } catch {}
      resolve(ok);
    };
    const timer = setTimeout(() => finish(false), timeoutMs);
    client.on('error', () => finish(false));
    client.on('connect', () => {
      try {
        req = client.request({
          ':method': 'GET',
          ':path': '/exa.language_server_pb.LanguageServerService/GetUserStatus',
          'x-codeium-csrf-token': DEFAULT_CSRF,
        });
        req.on('response', (headers) => {
          const contentType = String(headers['content-type'] || '').toLowerCase();
          const server = String(headers.server || '').toLowerCase();
          const hasGrpcStatus = headers['grpc-status'] != null || headers['grpc-message'] != null;
          const looksLikeLs = hasGrpcStatus
            || contentType.includes('grpc')
            || contentType.includes('connect')
            || /grpc|connect/.test(server);
          finish(looksLikeLs);
        });
        req.on('error', () => finish(false));
        req.on('end', () => finish(false));
        req.end();
      } catch {
        finish(false);
      }
    });
  });
}

async function waitPortReady(port, timeoutMs = 20000) {
  const start = Date.now();
  while (Date.now() - start < timeoutMs) {
    try {
      await new Promise((resolve, reject) => {
        const client = http2.connect(`http://localhost:${port}`);
        const timer = setTimeout(() => { try { client.close(); } catch {} reject(new Error('timeout')); }, 2000);
        client.on('connect', () => { clearTimeout(timer); client.close(); resolve(); });
        client.on('error', (e) => { clearTimeout(timer); try { client.close(); } catch {} reject(e); });
      });
      return true;
    } catch {
      await new Promise(r => setTimeout(r, 500));
    }
  }
  throw new Error(`LS port ${port} not ready after ${timeoutMs}ms`);
}

/**
 * Spawn an LS instance for the given proxy (or no-proxy default).
 * Idempotent — returns the existing entry if one is already running.
 */
export async function ensureLs(proxy = null) {
  const key = proxyKey(proxy);
  const existing = _pool.get(key);
  if (existing && existing.ready) return existing;

  // Coalesce concurrent callers onto a single spawn. The chat handlers
  // call ensureLs(acct.proxy) on every request; before this guard, a burst
  // of requests for a never-seen proxy would spawn N LS processes that
  // all tried to bind the same _nextPort.
  const pending = _pending.get(key);
  if (pending) return pending;

  // Evict LRU non-default LS when at the pool cap (#174).
  if (key !== 'default' && _pool.size >= MAX_LS_INSTANCES) {
    let lruKey = null;
    let lruTime = Infinity;
    for (const [k, e] of _pool) {
      if (k === 'default') continue; // never evict default LS
      const at = e._evictAt || e.startedAt || 0;
      if (at < lruTime) { lruTime = at; lruKey = k; }
    }
    if (lruKey) {
      const evicted = _pool.get(lruKey);
      _intentionalShutdown.add(lruKey);
      try { evicted?.process?.kill('SIGTERM'); } catch {}
      _pool.delete(lruKey);
      log.warn(`LS pool at cap (${MAX_LS_INSTANCES}), evicted LRU instance ${lruKey} (started ${evicted?.startedAt ? new Date(evicted.startedAt).toISOString() : '?'})`);
    }
  }

  const promise = (async () => {
    const isDefault = key === 'default';
    let port = isDefault ? DEFAULT_PORT : _nextPort++;

    // If something is already listening on the default port, NEVER adopt
    // blindly — even a probe-based gRPC signature is spoofable by any local
    // process serving HTTP/2 with a `server: *grpc*` header (verified). The
    // adoption flow used to send account API keys to whatever was listening,
    // which is unacceptable for a public-facing proxy. Instead, walk to the
    // next free port and spawn a fresh LS there. Operator gives up the
    // post-crash "adopt the orphan" convenience; in exchange, a malicious or
    // accidental local process can no longer receive credentials.
    if (isDefault && await isPortInUse(port)) {
      log.warn(`LS default port ${port} already in use; starting LS on next free port instead of adopting (security)`);
      do {
        port = _nextPort++;
      } while (await isPortInUse(port));
    }

    // Non-default ports: skip anything already bound. A PM2 restart can
    // race the old LS's TCP teardown — if we spawn while the dying
    // process still owns 42101, waitPortReady would succeed by connecting
    // to the corpse and every request would hang. Advance _nextPort until
    // we find a free slot.
    if (!isDefault) {
      let tries = 0;
      while (await isPortInUse(port)) {
        if (++tries > 50) throw new Error(`No free port for LS in range starting ${DEFAULT_PORT + 1}`);
        log.debug(`LS port ${port} busy, advancing`);
        port = _nextPort++;
      }
    }

    const dataDir = dataDirForKey(key);
    try { mkdirSync(`${dataDir}/db`, { recursive: true }); } catch (e) { log.warn(`mkdirSync ${dataDir}/db: ${e.message}`); }

    const args = [
      `--api_server_url=${_apiServerUrl}`,
      `--server_port=${port}`,
      `--csrf_token=${DEFAULT_CSRF}`,
      `--register_user_url=https://api.codeium.com/register_user/`,
      `--codeium_dir=${dataDir}`,
      `--database_dir=${dataDir}/db`,
      '--detect_proxy=false',
    ];

    const pUrl = proxyUrl(proxy);
    const env = buildLanguageServerEnv(process.env, { proxyUrl: pUrl });

    // One-shot readable warning when the LS binary is missing — the generic
    // ENOENT from spawn leaves users guessing which file is expected.
    if (!existsSync(_binaryPath)) {
      log.error(
        `Language server binary not found at ${_binaryPath}. ` +
        `Install it with:  bash install-ls.sh  (or set LS_BINARY_PATH env var)`
      );
    }

    log.info(`Starting LS instance key=${key} port=${port} proxy=${redactProxyUrl(pUrl)}`);

    const proc = spawn(_binaryPath, args, {
      stdio: ['pipe', 'pipe', 'pipe'],
      env,
    });

    proc.stdout.on('data', (data) => {
      const lines = data.toString().trim().split('\n');
      for (const line of lines) {
        if (!line) continue;
        if (/ERROR|error/.test(line)) log.error(`[LS:${key}] ${line}`);
        else log.debug(`[LS:${key}] ${line}`);
      }
    });
    proc.stderr.on('data', (data) => {
      const line = data.toString().trim();
      if (line) log.warn(`[LS:${key}:err] ${line}`);
    });
    proc.on('exit', (code, signal) => {
      log.warn(`LS instance ${key} exited: code=${code} signal=${signal}`);
      if (code === 1) {
        log.error('LS crashed on startup. Common causes:');
        log.error('  1. Binary incompatible with this OS/arch — re-download with: bash install-ls.sh');
        log.error('  2. Missing glibc/libstdc++ — run: ldd ' + _binaryPath + ' | grep "not found"');
        log.error('  3. Binary corrupted — delete and re-download: rm ' + _binaryPath + ' && bash install-ls.sh');
        log.error('  4. Port already in use — check: lsof -i :' + port);
      }
      const gone = _pool.get(key);
      const goneGen = gone?.generation;
      const gonePort = gone?.port;
      _pool.delete(key);
      if (gonePort) {
        closeSessionForPort(gonePort);
        import('./conversation-pool.js').then(m => m.invalidateFor({ lsPort: gonePort, lsGeneration: goneGen })).catch(() => {});
      }

      // Auto-restart: respawn the LS after a brief backoff so pending
      // requests don't fail with ECONNRESET. Respects the retry cap and
      // tracks per-key restart attempts to avoid infinite loops on
      // permanent errors (e.g. missing binary, incompatible arch).
      // Skip when the exit was intentional (stopLanguageServer / restartLsForProxy).
      if (AUTO_RESTART_ENABLED && gone && !_intentionalShutdown.has(key)) {
        scheduleLsRestart(key, gone.proxy, gonePort);
      }
      _intentionalShutdown.delete(key);
    });
    proc.on('error', (err) => {
      if (err.code === 'ENOEXEC') {
        const os = process.platform;
        log.error(
          `LS binary is not executable on this platform (${os}). ` +
          `The binary at ${_binaryPath} is likely built for a different OS/arch. ` +
          (os === 'darwin'
            ? 'You need the macOS build: copy language_server_macos_arm (Apple Silicon) or language_server_macos_x64 (Intel) from your Windsurf desktop app.'
            : os === 'win32'
              ? 'LS binary only runs on Linux. Use WSL2 or a Linux VM.'
              : `Ensure the binary matches your arch: ${process.arch}`)
        );
      } else {
        log.error(`LS instance ${key} spawn error: ${err.message}`);
      }
      _pool.delete(key);
    });

    const entry = {
      process: proc, port, csrfToken: DEFAULT_CSRF,
      proxy, startedAt: Date.now(), ready: false,
      // v2.0.25 LOW-1: per-spawn UUID so the conversation pool can tell a
      // new LS that landed on the same port apart from the dead one. Used
      // by checkout(expected={lsGeneration}) and invalidateFor({lsGeneration}).
      generation: randomUUID(),
      // One-shot Cascade workspace init promise. cascadeChat() awaits this so
      // the heavy InitializePanelState / AddTrackedWorkspace / UpdateWorkspaceTrust
      // trio only runs once per LS lifetime instead of once per request.
      workspaceInit: null,
      sessionId: null,
    };
    _pool.set(key, entry);

    try {
      await waitPortReady(port, 25000);
      entry.ready = true;
      log.info(`LS instance ${key} ready on port ${port}`);
    } catch (err) {
      log.error(`LS instance ${key} failed to become ready: ${err.message}`);
      try { proc.kill('SIGKILL'); } catch {}
      _pool.delete(key);
      throw err;
    }
    return entry;
  })();

  _pending.set(key, promise);
  try {
    return await promise;
  } finally {
    _pending.delete(key);
  }
}

/**
 * Stop and remove the LS instance associated with a given proxy.
 * Used when a proxy is reassigned so the old egress no longer exists.
 */
export async function restartLsForProxy(proxy) {
  const key = proxyKey(proxy);
  const entry = _pool.get(key);
  _intentionalShutdown.add(key);  // prevent auto-restart
  if (entry?.process) {
    try { entry.process.kill('SIGTERM'); } catch {}
  }
  if (entry?.port) {
    // v2.0.25 LOW-1: same-port LS replacement opens a window where stale
    // pool entries from the old LS could resume against the new LS's
    // session. Close the cached HTTP/2 session and invalidate this LS's
    // generation in the conversation pool synchronously, then spawn fresh.
    closeSessionForPort(entry.port);
    try {
      const m = await import('./conversation-pool.js');
      m.invalidateFor({ lsPort: entry.port, lsGeneration: entry.generation });
    } catch {}
  }
  _pool.delete(key);
  return ensureLs(proxy);
}

/**
 * Get the LS entry matching a proxy, or null if it hasn't been spawned.
 * Callers should `await ensureLs(proxy)` first — don't silently fall back
 * to the default LS, because that sends the request through the wrong
 * egress IP (Codeium will see the wrong source, invalidate the session,
 * and falsely mark the account expired).
 */
export function getLsFor(proxy) {
  const entry = _pool.get(proxyKey(proxy));
  if (entry) entry._evictAt = Date.now(); // touch LRU timestamp
  return entry || null;
}

// ─── Auto-restart ─────────────────────────────────────────────

const _restartAttempts = new Map();

function scheduleLsRestart(key, proxy, oldPort) {
  const attempts = (_restartAttempts.get(key) || 0) + 1;
  if (attempts > AUTO_RESTART_MAX_RETRIES) {
    log.error(`LS auto-restart: ${key} exceeded max retries (${AUTO_RESTART_MAX_RETRIES}), giving up`);
    _restartAttempts.delete(key);
    return;
  }

  const delay = AUTO_RESTART_BASE_DELAY_MS * Math.pow(2, attempts - 1);
  _restartAttempts.set(key, attempts);

  log.info(`LS auto-restart: scheduling ${key} restart #${attempts} in ${delay}ms`);

  setTimeout(async () => {
    try {
      await ensureLs(proxy);
      _restartAttempts.delete(key);
      log.info(`LS auto-restart: ${key} restarted successfully (attempt #${attempts})`);
    } catch (err) {
      log.error(`LS auto-restart: ${key} restart #${attempts} failed: ${err.message}`);
      if (attempts < AUTO_RESTART_MAX_RETRIES) {
        scheduleLsRestart(key, proxy, oldPort);
      }
    }
  }, delay).unref();
}

export function getRestartStats() {
  const stats = {};
  for (const [key, attempts] of _restartAttempts) {
    stats[key] = attempts;
  }
  return stats;
}

/**
 * Look up an LS pool entry by its gRPC port. Used by WindsurfClient so it
 * can attach per-LS state (one-shot cascade workspace init, persistent
 * sessionId) without plumbing the entry through every call site.
 */
export function getLsEntryByPort(port) {
  for (const entry of _pool.values()) {
    if (entry.port === port) return entry;
  }
  return null;
}

/**
 * Iterate over live LS pool keys. Used by the dashboard binary-update
 * endpoint to restart every spawned instance after install-ls.sh
 * replaces the binary on disk.
 */
export function _poolKeys() {
  return [..._pool.keys()];
}

/**
 * Recover the proxy descriptor for a given pool key. Returns null for
 * the default no-proxy entry.
 */
export function getProxyByKey(key) {
  const entry = _pool.get(key);
  return entry?.proxy || null;
}

// ─── Backward-compat API ───────────────────────────────────

export function getLsPort() {
  return _pool.get('default')?.port || DEFAULT_PORT;
}
export function getCsrfToken() {
  return _pool.get('default')?.csrfToken || DEFAULT_CSRF;
}

/**
 * Legacy entry point used by index.js — starts the default (no-proxy) LS.
 */
export async function startLanguageServer(opts = {}) {
  _binaryPath = opts.binaryPath || process.env.LS_BINARY_PATH || _binaryPath;
  _apiServerUrl = opts.apiServerUrl || process.env.CODEIUM_API_URL || _apiServerUrl;
  const def = await ensureLs(null);
  return { port: def.port, csrfToken: def.csrfToken };
}

/**
 * v2.0.85 (#127 123cek): scan host process table for orphan
 * `language_server_linux_x64` instances left over from previous runs
 * (e.g. self-update via `process.exit(0)` skipped the SIGTERM hook,
 * or PM2 SIGKILL killed us before stopLanguageServer could run) and
 * kill them. Keeps long-running PM2 deployments from accumulating
 * dead LS processes that hold their pool ports.
 *
 * Limited to processes whose argv[0] matches our `_binaryPath` (or
 * the legacy DEFAULT_BINARY) so unrelated `language_server_linux_x64`
 * binaries on the same host (rare) are not touched. No-op on Windows
 * since the LS binary is Linux-only there.
 *
 * Skips itself: PIDs we currently track in `_pool` (none yet at
 * startup, but called also from /self-update before exit).
 *
 * Best-effort: any error is logged but doesn't block startup.
 */
export function cleanupOrphanLanguageServers() {
  if (process.platform === 'win32') return { scanned: 0, killed: 0 };
  let scanned = 0;
  let killed = 0;
  const ourPids = new Set();
  for (const entry of _pool.values()) {
    if (entry?.process?.pid) ourPids.add(entry.process.pid);
  }
  const targetBinaries = new Set([_binaryPath, DEFAULT_BINARY]);
  try {
    // -e: every process; -o pid,args: pid + full argv (so we can match
    // the binary path). Cap output at a few hundred lines via head; LS
    // pids are typically small clusters, not thousands.
    const out = execSync('ps -e -o pid=,args=', { timeout: 3000, encoding: 'utf-8' });
    for (const line of out.split('\n')) {
      const trimmed = line.trim();
      if (!trimmed) continue;
      const m = trimmed.match(/^(\d+)\s+(.*)$/);
      if (!m) continue;
      const pid = parseInt(m[1], 10);
      const argv = m[2];
      // Match either the configured binary path OR the default path.
      // v2.0.88 (audit L-1): anchor the match to argv[0] so we don't
      // SIGTERM a `grep language_server_linux_x64` or a monitoring
      // agent whose argv mentions our binary path elsewhere.
      const argv0 = argv.split(/\s+/, 1)[0];
      let isOurs = false;
      for (const bin of targetBinaries) {
        if (bin && argv0 === bin) { isOurs = true; break; }
      }
      if (!isOurs) continue;
      scanned++;
      if (ourPids.has(pid)) continue;
      if (pid === process.pid) continue;
      try {
        process.kill(pid, 'SIGTERM');
        killed++;
        log.info(`Killed orphan LS pid=${pid} (${argv.slice(0, 80)}...)`);
      } catch (e) {
        if (e.code !== 'ESRCH') log.warn(`Could not kill orphan LS pid=${pid}: ${e.message}`);
      }
    }
  } catch (e) {
    log.warn(`cleanupOrphanLanguageServers: ${e.message}`);
  }
  return { scanned, killed };
}

export function stopLanguageServer() {
  // v2.0.25 LOW-1: tear down ALL conversation pool entries pinned to LSes
  // we're about to kill, so the dashboard restart path doesn't leak dead
  // cascade ids into the next LS's session window.
  const portsToClose = [];
  for (const [key, entry] of _pool) {
    _intentionalShutdown.add(key);  // prevent auto-restart
    try { entry.process?.kill('SIGTERM'); } catch {}
    if (entry?.port) portsToClose.push({ port: entry.port, generation: entry.generation });
    log.info(`LS instance ${key} stopped`);
  }
  _pool.clear();
  if (portsToClose.length) {
    import('./conversation-pool.js').then(m => {
      for (const p of portsToClose) {
        closeSessionForPort(p.port);
        m.invalidateFor({ lsPort: p.port, lsGeneration: p.generation });
      }
    }).catch(() => {});
  }
}

/**
 * v2.0.88 (audit H-4): like `stopLanguageServer` but waits for each
 * spawned LS process to actually exit (capped per-process timeout)
 * before returning. Used by `dashboard /self-update` so `process.exit`
 * doesn't fire while children still hold their ports — preventing
 * orphan LS processes that would otherwise win a port-conflict race
 * against the freshly-restarted parent.
 *
 * Per-process wait cap defaults to 1.5s; total wait for many LSes is
 * bounded by Promise.allSettled. SIGKILL fallback if SIGTERM doesn't
 * land within the cap.
 */
export async function stopLanguageServerAndWait({ perProcessTimeoutMs = 1500 } = {}) {
  const procs = [];
  const portsToClose = [];
  for (const [key, entry] of _pool) {
    if (entry?.process) procs.push({ key, proc: entry.process });
    if (entry?.port) portsToClose.push({ port: entry.port, generation: entry.generation });
  }
  _pool.clear();
  await Promise.allSettled(procs.map(({ key, proc }) => new Promise((resolve) => {
    let settled = false;
    const finish = (how) => {
      if (settled) return;
      settled = true;
      log.info(`LS instance ${key} stopped (${how})`);
      resolve();
    };
    try { proc.once('exit', () => finish('exited')); } catch {}
    try { proc.kill('SIGTERM'); } catch (e) { finish(`kill failed: ${e.message}`); return; }
    setTimeout(() => {
      if (settled) return;
      try { proc.kill('SIGKILL'); } catch {}
      finish(`SIGKILL after ${perProcessTimeoutMs}ms`);
    }, perProcessTimeoutMs).unref();
  })));
  if (portsToClose.length) {
    try {
      const m = await import('./conversation-pool.js');
      for (const p of portsToClose) {
        closeSessionForPort(p.port);
        m.invalidateFor({ lsPort: p.port, lsGeneration: p.generation });
      }
    } catch {}
  }
}

export function isLanguageServerRunning() {
  return _pool.size > 0;
}

export async function waitForReady(/* timeoutMs */) {
  const def = _pool.get('default');
  if (!def) throw new Error('default LS not initialized');
  if (def.ready) return true;
  await waitPortReady(def.port, 20000);
  def.ready = true;
  return true;
}

export function getLsStatus() {
  const def = _pool.get('default');
  return {
    running: _pool.size > 0,
    pid: def?.process?.pid || null,
    port: def?.port || DEFAULT_PORT,
    startedAt: def?.startedAt || null,
    restartCount: 0,
    instances: Array.from(_pool.entries()).map(([key, e]) => ({
      key, port: e.port,
      pid: e.process?.pid || null,
      proxy: e.proxy ? `${e.proxy.host}:${e.proxy.port}` : null,
      startedAt: e.startedAt,
      ready: e.ready,
    })),
  };
}