/**
* @license
* Copyright 2026 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import fs from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import process from 'node:process';
import {logger} from '../logger.js';
export const DAEMON_SCRIPT_PATH = path.join(import.meta.dirname, 'daemon.js');
export const INDEX_SCRIPT_PATH = path.join(
import.meta.dirname,
'..',
'index.js',
);
const APP_NAME = 'chrome-devtools-mcp';
// Using these paths due to strict limits on the POSIX socket path length.
export function getSocketPath(): string {
const uid = os.userInfo().uid;
if (IS_WINDOWS) {
// Windows uses Named Pipes, not file paths.
// This format is required for server.listen()
return path.join('\\\\.\\pipe', APP_NAME, 'server.sock');
}
// 1. Try XDG_RUNTIME_DIR (Linux standard, sometimes macOS)
if (process.env.XDG_RUNTIME_DIR) {
return path.join(process.env.XDG_RUNTIME_DIR, APP_NAME, 'server.sock');
}
// 2. macOS/Unix Fallback: Use /tmp/
// We use /tmp/ because it is much shorter than ~/Library/Application Support/
// and keeps us well under the 104-character limit.
return path.join('/tmp', `${APP_NAME}-${uid}.sock`);
}
export function getRuntimeHome(): string {
const platform = os.platform();
const uid = os.userInfo().uid;
// 1. Check for the modern Unix standard
if (process.env.XDG_RUNTIME_DIR) {
return path.join(process.env.XDG_RUNTIME_DIR, APP_NAME);
}
// 2. Fallback for macOS and older Linux
if (platform === 'darwin' || platform === 'linux') {
// /tmp is cleared on boot, making it perfect for PIDs
return path.join('/tmp', `${APP_NAME}-${uid}`);
}
// 3. Windows Fallback
return path.join(os.tmpdir(), APP_NAME);
}
export const IS_WINDOWS = os.platform() === 'win32';
export function getPidFilePath() {
const runtimeDir = getRuntimeHome();
return path.join(runtimeDir, 'daemon.pid');
}
export function getDaemonPid() {
try {
const pidFile = getPidFilePath();
logger(`Daemon pid file ${pidFile}`);
if (!fs.existsSync(pidFile)) {
return null;
}
const pidContent = fs.readFileSync(pidFile, 'utf-8');
const pid = parseInt(pidContent.trim(), 10);
logger(`Daemon pid: ${pid}`);
if (isNaN(pid)) {
return null;
}
return pid;
} catch {
return null;
}
}
export function isDaemonRunning(pid = getDaemonPid()): pid is number {
if (pid) {
try {
process.kill(pid, 0); // Throws if process doesn't exist
return true;
} catch {
// Process is dead, stale PID file. Proceed with startup.
}
}
return false;
}
